//! egui desktop application — the main window, sidebar, video grid, and settings UI.
//!
//! The [`App`] struct holds all UI state and implements [`eframe::App`].
//! Background work (downloads, scheduled rescans) runs in threads and
//! communicates back via `mpsc` channels stored on `App`.

use std::collections::{HashMap, HashSet};
use std::path::{Path, PathBuf};
use std::process::Command;
use std::sync::mpsc::{Receiver, Sender};
use std::time::Instant;

use eframe::egui;

use crate::config::Config;
use crate::database::Database;
use crate::downloader::{DownloadQuality, Downloader, JobState};
use crate::platform::{self, classify_url, Platform, UrlKind};
use crate::library::{self, Video};
use crate::theme;

const BROWSERS: &[(&str, &str)] = &[
    ("firefox", "Firefox"),
    ("chromium", "Chromium"),
    ("chrome", "Chrome"),
    ("opera", "Opera"),
    ("brave", "Brave"),
    ("vivaldi", "Vivaldi"),
    ("none", "None (no cookies)"),
];

/// Top-level navigation. The desktop swaps the CentralPanel content
/// between these instead of stacking floating windows. Smaller dialogs
/// (channel options, folder manager, move-to-folder) stay as floating
/// `egui::Window` since they're modal-ish actions, not screens.
#[derive(Clone, Copy, PartialEq, Eq, Default, Debug)]
enum Screen {
    /// Channel sidebar + video grid + detail panel. The default.
    #[default]
    Library,
    Settings,
    Stats,
    Maintenance,
}

#[derive(Clone, PartialEq)]
enum SortMode {
    Title,
    DurationAsc,
    DurationDesc,
    SizeAsc,
    SizeDesc,
    DateDesc,
    DateAsc,
}

#[derive(Clone, PartialEq)]
enum SidebarView {
    Channels,
    All,
    Channel(usize),
    Playlist(usize, usize),
    ContinueWatching,
    /// Activity feed — recent additions across all channels, sorted by mtime.
    Recent,
    /// Smart folder: videos with `favourite` flag set.
    Favourites,
    /// Smart folder: videos with `bookmark` flag set.
    Bookmarks,
    /// Smart folder: videos with `waiting` flag set.
    Waiting,
    Music,
}

struct Card {
    channel_name: String,
    title: String,
    id: String,
    video_path: Option<PathBuf>,
    thumb_path: Option<PathBuf>,
    has_live_chat: bool,
    duration_secs: Option<f64>,
    file_size: Option<u64>,
    upload_date: Option<String>,
    mtime_unix: Option<u64>,
    watched: bool,
    bookmark: bool,
    favourite: bool,
    waiting: bool,
    resume_pos: Option<f64>,
}

pub struct App {
    config: Config,
    config_path: PathBuf,
    channels_root: PathBuf,
    /// Parent of `channels_root`. Owns every platform's sibling directory
    /// (`channels/`, `tiktok/`, …). Used as the maintenance scan root so
    /// non-YouTube content is included.
    library_root: PathBuf,
    library: Vec<library::Channel>,
    sidebar_view: SidebarView,
    selected_video: Option<String>,
    /// Edit buffer for the selected video's note, plus the id it belongs
    /// to. When `note_target` != `selected_video` we (re)load the note
    /// from the DB into `note_buffer`. Keeps the textarea editable
    /// without a DB round-trip per keystroke.
    note_buffer: String,
    note_target: Option<String>,
    search: String,
    downloader: Downloader,
    show_downloads: bool,
    /// Which top-level screen is currently rendered into CentralPanel.
    /// Settings / Stats / Maintenance now take the full window (with
    /// scroll) instead of floating over the library.
    current_screen: Screen,
    dl_url: String,
    dl_full_scan: bool,
    dl_quality: DownloadQuality,
    dl_music_mode: bool,
    /// Record an ongoing live stream from the start instead of joining live.
    dl_live: bool,
    /// For Twitch channel URLs: target the `/clips` listing instead of the
    /// default profile (VODs / past broadcasts). Has no effect on other
    /// platforms or on single-video URLs.
    dl_twitch_clips: bool,
    textures: HashMap<PathBuf, Option<egui::TextureHandle>>,
    thumb_request_tx: Sender<PathBuf>,
    thumb_result_rx: Receiver<(PathBuf, Option<egui::ColorImage>)>,
    thumb_pending: HashSet<PathBuf>,
    desc_cache: HashMap<PathBuf, String>,
    status: String,
    music_library: Vec<library::Track>,
    music_root: PathBuf,
    settings_dir: String,
    settings_plex_path: String,
    settings_source_url: String,
    plex_status: String,
    db: Database,
    card_density: f32,
    /// When set, the global UI zoom changed and config should be saved at
    /// this instant (debounced so a slider drag / key-repeat doesn't write
    /// config.toml every frame). Synced from `ctx.zoom_factor()` in update().
    scale_save_at: Option<Instant>,
    sort_mode: SortMode,
    watched: HashSet<String>,
    /// Per-video flag sets (bookmark/favourite/waiting/archive). Loaded from
    /// SQLite at startup, mirrored into the DB on every toggle.
    flags: crate::database::VideoFlagsBundle,
    /// Channel-organisation folders loaded from the `folders` table. The
    /// sidebar groups channels by `Channel.folder_id`; channels with no
    /// folder fall under "Unfiled".
    folders: Vec<crate::database::FolderRecord>,
    resume_positions: HashMap<String, f64>,
    prev_job_states: HashMap<usize, JobState>,
    currently_playing: Option<String>,
    mpv_rx: Option<Receiver<(String, f64)>>,
    // Bulk selection
    bulk_mode: bool,
    bulk_selected: HashSet<String>,
    // Scheduler
    last_scheduled_check: Option<Instant>,
    // Cards cache — recomputed only when inputs change
    cards_cache: Vec<Card>,
    cards_cache_key: Option<(String, SortMode, SidebarView, u64)>,
    library_generation: u64,
    // Web server
    web_server_running: bool,
    web_server_shutdown: Option<Sender<()>>,
    // Settings-window scratch state (not persisted directly)
    settings_bind_mode: String,
    settings_password_enabled: bool,
    settings_password_input: String,
    settings_cookies_input: String,
    settings_cookies_status: String,
    // File picker → chosen cookies.txt path arrives here from a dialog thread.
    cookies_pick_tx: Sender<PathBuf>,
    cookies_pick_rx: Receiver<PathBuf>,
    // "Save library backup" target path picked by an rfd dialog on a
    // background thread, polled in update() the same way cookies_pick_rx
    // is.
    backup_save_tx: Sender<PathBuf>,
    backup_save_rx: Receiver<PathBuf>,
    // "Import library backup" source path — same pattern as backup_save_rx
    // but for the open-file direction. Restore happens synchronously on
    // the main thread once we receive the path, since the merge is a
    // bounded SQL operation, not a long-running download.
    backup_open_tx: Sender<PathBuf>,
    backup_open_rx: Receiver<PathBuf>,
    // Maintenance (library health) screen state. The flag is gone now —
    // Screen::Maintenance + this report's presence drive the render.
    health_report: Option<crate::maintenance::HealthReport>,
    stats_report: Option<crate::stats::StatsReport>,
    // Per-channel download-options dialog state
    show_channel_options: bool,
    /// `(platform, handle)` identifying the channel being edited.
    channel_options_target: Option<(Platform, String)>,
    // Folder management dialog state.
    show_folder_manager: bool,
    folder_create_buffer: String,
    // Move-to-folder picker state.
    show_move_to_folder: bool,
    move_to_folder_target: Option<(Platform, String)>,
    /// Editable form fields, mirroring [`DownloadOptions`] with string-typed
    /// "text" buffers so the user can type partial values (e.g. an empty
    /// limit-rate field) without us forcing zeroes back.
    channel_options_form: ChannelOptionsForm,
    /// System-tray event receiver. `None` when the tray failed to start
    /// (no DBus, hostile sandbox, etc.). When present, [`Self::update`]
    /// drains it each frame and dispatches viewport commands.
    tray: Option<crate::tray::TrayHandle>,
    /// `true` once the user has explicitly chosen Quit (from the tray
    /// menu or another exit path). The viewport `CloseRequested` handler
    /// honors this — without it, the close button minimizes to tray.
    quitting: bool,
}

/// Scratch struct for the per-channel options dialog. Distinct from
/// [`crate::download_options::DownloadOptions`] because the user is allowed
/// to leave numeric fields blank (which we render as `None`).
#[derive(Default, Clone)]
struct ChannelOptionsForm {
    quality_idx: usize,           // 0=default, 1=Best, 2=1080p, 3=720p, 4=480p, 5=360p
    audio_only: bool,
    fetch_comments: bool,
    skip_auth_check: bool,
    limit_rate_kb: String,
    min_filesize_mb: String,
    max_filesize_mb: String,
    date_after: String,
    match_filter: String,
    subtitle_langs: String,       // comma-separated
    // Per-channel subtitle override tri-states: 0 = use global default,
    // 1 = force on, 2 = force off. Map to Option<bool> on save.
    subs_enabled_idx: usize,
    subs_auto_idx: usize,
    subs_embed_idx: usize,
    subtitle_format: String,      // "" = global default
    youtube_player_clients: String, // "" = global default
    // Per-channel convert override: 0=Default(global), 1=Off, 2=remux-mp4,
    // 3=h264-mp4, 4=audio. Maps to Option<String> on save.
    convert_idx: usize,
    extra_args: String,           // one per line
}

/// Map an `Option<bool>` override to the tri-state combo index.
fn tri_to_idx(v: Option<bool>) -> usize {
    match v { None => 0, Some(true) => 1, Some(false) => 2 }
}
/// Inverse of [`tri_to_idx`].
fn idx_to_tri(i: usize) -> Option<bool> {
    match i { 1 => Some(true), 2 => Some(false), _ => None }
}

/// Per-channel convert-mode override ⇄ combo index.
/// 0=Default (None, defer to global), 1=Off, 2=remux-mp4, 3=h264-mp4, 4=audio.
fn convert_mode_to_idx(v: &Option<String>) -> usize {
    match v.as_deref() {
        Some("off") => 1,
        Some("remux-mp4") => 2,
        Some("h264-mp4") => 3,
        Some("audio") => 4,
        _ => 0,
    }
}
fn idx_to_convert_mode(i: usize) -> Option<String> {
    match i {
        1 => Some("off".into()),
        2 => Some("remux-mp4".into()),
        3 => Some("h264-mp4".into()),
        4 => Some("audio".into()),
        _ => None,
    }
}

impl App {
    pub fn new(cc: &eframe::CreationContext<'_>, tray: Option<crate::tray::TrayHandle>) -> Self {
        let cwd = std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."));
        let config_path = cwd.join("config.toml");

        let config = match Config::load(&config_path) {
            Ok(c) => c,
            Err(e) => {
                eprintln!("Warning: failed to load config.toml: {e}. Using defaults.");
                Config::default_with_dir(cwd.join("channels"))
            }
        };

        theme::apply(&cc.egui_ctx, &config.ui.theme);
        // Restore the persisted global UI zoom. egui's built-in Ctrl +/-/0
        // also drives zoom_factor; update() keeps config.ui.ui_scale synced
        // and persists changes so the size survives restarts.
        cc.egui_ctx.set_zoom_factor(config.ui.ui_scale.clamp(0.5, 3.0));

        let channels_root = config.backup.directory.clone();
        let settings_dir = channels_root.display().to_string();
        let _ = std::fs::create_dir_all(&channels_root);
        // library_root is the parent of every platform's per-creator
        // folder. With the post-2026-05 nested layout every platform
        // (including YouTube's `channels/`) lives under channels_root,
        // so the two paths are the same. `library_root` is kept as a
        // separate field for places that previously expected the
        // sibling-platform layout (file_url, /files/ mount, maintenance).
        let library_root = channels_root.clone();
        // Pre-create every platform's folder so scans see them.
        for &p in Platform::all() {
            let dir = platform::platform_root(&channels_root, p);
            let _ = std::fs::create_dir_all(&dir);
        }
        // Open the DB first so the library scanner can use info_cache to
        // skip re-parsing unchanged info.json sidecars. Cold start still
        // pays full cost; every subsequent launch is faster.
        let db_path = channels_root.join("yt-offline.db");
        let db = Database::open(&db_path)
            .unwrap_or_else(|_| Database::open_in_memory().expect("in-memory db failed"));
        let mut library = library::scan_channels_with_cache(&channels_root, Some(&db));
        let status = format!(
            "{} channels, {} videos",
            library.len(),
            library.iter().map(|c| c.total_videos()).sum::<usize>()
        );
        // Hydrate per-channel download options + folder assignments from
        // SQLite onto the scanned library before publishing it to the UI.
        if let Ok(map) = db.get_all_channel_options() {
            library::apply_channel_options(&mut library, &map);
        }
        if let Ok(folder_map) = db.get_all_channel_assignments() {
            library::apply_channel_folders(&mut library, &folder_map);
        }
        let folders = db.list_folders().unwrap_or_default();
        let watched = db.get_watched().unwrap_or_default();
        let flags = db.get_video_flags().unwrap_or_default();
        let resume_positions = db.get_positions().unwrap_or_default();

        // Music dir nests under channels_root like the platform dirs.
        let music_root = channels_root.join("music");
        let music_library = library::scan_music(&music_root);

        let max_concurrent = config.backup.max_concurrent;
        let use_bundled_ytdlp = config.backup.use_bundled_ytdlp;
        let use_pot_provider = config.backup.use_pot_provider;
        let browser = config.player.browser.clone();
        // Build the downloader up front so we can seed its subtitle
        // defaults from config before it goes into the struct literal.
        let mut downloader = Downloader::new(
            channels_root.clone(), browser.clone(), max_concurrent,
            use_bundled_ytdlp, use_pot_provider,
        );
        downloader.subtitle_defaults = config.subtitles.clone();
        downloader.youtube_player_clients = config.backup.youtube_player_clients.clone();
        downloader.convert_defaults = config.convert.clone();
        let config_bind = config.web.bind.clone();
        let password_set = db.get_setting("password_hash").ok().flatten().is_some();
        let plex_path_str = config.plex.library_path
            .as_deref()
            .map(|p| p.display().to_string())
            .unwrap_or_default();
        let source_url_str = config.web.source_url.clone().unwrap_or_default();

        let (cookies_pick_tx, cookies_pick_rx) = std::sync::mpsc::channel::<PathBuf>();
        let (backup_save_tx, backup_save_rx) = std::sync::mpsc::channel::<PathBuf>();
        let (backup_open_tx, backup_open_rx) = std::sync::mpsc::channel::<PathBuf>();

        let (thumb_request_tx, thumb_request_rx) = std::sync::mpsc::channel::<PathBuf>();
        let (thumb_result_tx, thumb_result_rx) =
            std::sync::mpsc::channel::<(PathBuf, Option<egui::ColorImage>)>();
        // Decode pool: shared Receiver behind a Mutex (mpsc::Receiver is
        // !Sync so we can't hand it directly to multiple threads). Each
        // worker spends ~all its time in image::open + resize, so lock
        // contention is negligible — there's at most one recv per thumb
        // decode and the decode itself is milliseconds.
        let thumb_request_rx = std::sync::Arc::new(std::sync::Mutex::new(thumb_request_rx));
        // Size the pool at half the available cores, clamped to [2, 8].
        // Thumbnail decoding is CPU-bound (image crate is pure Rust), so
        // more workers help up to the core count; leaving half the cores
        // free keeps the rest of the UI + downloads + scans responsive.
        let n_workers = std::thread::available_parallelism()
            .map(|n| n.get())
            .unwrap_or(4)
            .saturating_div(2)
            .clamp(2, 8);
        for worker_id in 0..n_workers {
            let rx = thumb_request_rx.clone();
            let tx = thumb_result_tx.clone();
            let ctx = cc.egui_ctx.clone();
            std::thread::Builder::new()
                .name(format!("yt-offline-thumb-{worker_id}"))
                .spawn(move || {
                    loop {
                        // Hold the lock only for the recv itself; release
                        // before decoding so other workers can claim the
                        // next path while we work on this one.
                        let path = match rx.lock() {
                            Ok(guard) => match guard.recv() {
                                Ok(p) => p,
                                Err(_) => break,
                            },
                            Err(_) => break,
                        };
                        let img = decode_thumbnail_image(&path);
                        if tx.send((path, img)).is_err() {
                            break;
                        }
                        ctx.request_repaint();
                    }
                })
                .ok();
        }

        Self {
            config,
            config_path,
            channels_root: channels_root.clone(),
            library_root,
            library,
            sidebar_view: SidebarView::All,
            selected_video: None,
            note_buffer: String::new(),
            note_target: None,
            search: String::new(),
            downloader,
            show_downloads: false,
            current_screen: Screen::Library,
            dl_url: String::new(),
            dl_full_scan: true,
            dl_quality: DownloadQuality::Best,
            dl_music_mode: false,
            dl_live: false,
            dl_twitch_clips: false,
            textures: HashMap::new(),
            thumb_request_tx,
            thumb_result_rx,
            thumb_pending: HashSet::new(),
            desc_cache: HashMap::new(),
            status,
            music_library,
            music_root,
            settings_dir,
            settings_plex_path: plex_path_str,
            settings_source_url: source_url_str,
            plex_status: String::new(),
            db,
            card_density: 1.0,
            scale_save_at: None,
            sort_mode: SortMode::Title,
            watched,
            flags,
            folders,
            resume_positions,
            prev_job_states: HashMap::new(),
            currently_playing: None,
            mpv_rx: None,
            bulk_mode: false,
            bulk_selected: HashSet::new(),
            last_scheduled_check: None,
            cards_cache: Vec::new(),
            cards_cache_key: None,
            library_generation: 0,
            web_server_running: false,
            web_server_shutdown: None,
            settings_bind_mode: crate::web::bind_mode_of(&config_bind).to_string(),
            settings_password_enabled: password_set,
            settings_password_input: String::new(),
            settings_cookies_input: String::new(),
            settings_cookies_status: String::new(),
            cookies_pick_tx,
            cookies_pick_rx,
            backup_save_tx,
            backup_save_rx,
            backup_open_tx,
            backup_open_rx,
            health_report: None,
            stats_report: None,
            show_channel_options: false,
            channel_options_target: None,
            channel_options_form: ChannelOptionsForm::default(),
            show_folder_manager: false,
            folder_create_buffer: String::new(),
            show_move_to_folder: false,
            move_to_folder_target: None,
            tray,
            quitting: false,
        }
    }

    /// Convert a [`DownloadOptions`] into the editable form state. Numeric
    /// `None`s become empty strings.
    fn options_to_form(opts: &crate::download_options::DownloadOptions) -> ChannelOptionsForm {
        let quality_idx = match opts.quality {
            None => 0,
            Some(DownloadQuality::Best) => 1,
            Some(DownloadQuality::Res1080) => 2,
            Some(DownloadQuality::Res720) => 3,
            Some(DownloadQuality::Res480) => 4,
            Some(DownloadQuality::Res360) => 5,
        };
        let num = |v: Option<u32>| v.map(|n| n.to_string()).unwrap_or_default();
        ChannelOptionsForm {
            quality_idx,
            audio_only: opts.audio_only,
            fetch_comments: opts.fetch_comments,
            skip_auth_check: opts.skip_auth_check,
            limit_rate_kb: num(opts.limit_rate_kb),
            min_filesize_mb: num(opts.min_filesize_mb),
            max_filesize_mb: num(opts.max_filesize_mb),
            date_after: opts.date_after.clone().unwrap_or_default(),
            match_filter: opts.match_filter.clone().unwrap_or_default(),
            subtitle_langs: opts.subtitle_langs.join(", "),
            subs_enabled_idx: tri_to_idx(opts.subtitles_enabled),
            subs_auto_idx: tri_to_idx(opts.subtitles_auto),
            subs_embed_idx: tri_to_idx(opts.subtitles_embed),
            subtitle_format: opts.subtitle_format.clone().unwrap_or_default(),
            youtube_player_clients: opts.youtube_player_clients.clone().unwrap_or_default(),
            convert_idx: convert_mode_to_idx(&opts.convert_mode),
            extra_args: opts.extra_args.join("\n"),
        }
    }

    /// Inverse of [`options_to_form`]. Empty/whitespace string fields map
    /// back to `None`.
    fn form_to_options(f: &ChannelOptionsForm) -> crate::download_options::DownloadOptions {
        let quality = match f.quality_idx {
            1 => Some(DownloadQuality::Best),
            2 => Some(DownloadQuality::Res1080),
            3 => Some(DownloadQuality::Res720),
            4 => Some(DownloadQuality::Res480),
            5 => Some(DownloadQuality::Res360),
            _ => None,
        };
        let parse_num = |s: &str| s.trim().parse::<u32>().ok().filter(|&n| n > 0);
        let trim_opt = |s: &str| {
            let t = s.trim();
            if t.is_empty() { None } else { Some(t.to_string()) }
        };
        crate::download_options::DownloadOptions {
            quality,
            audio_only: f.audio_only,
            fetch_comments: f.fetch_comments,
            skip_auth_check: f.skip_auth_check,
            limit_rate_kb: parse_num(&f.limit_rate_kb),
            min_filesize_mb: parse_num(&f.min_filesize_mb),
            max_filesize_mb: parse_num(&f.max_filesize_mb),
            date_after: trim_opt(&f.date_after),
            match_filter: trim_opt(&f.match_filter),
            subtitle_langs: f.subtitle_langs.split(',')
                .map(|s| s.trim().to_string()).filter(|s| !s.is_empty()).collect(),
            subtitles_enabled: idx_to_tri(f.subs_enabled_idx),
            subtitles_auto: idx_to_tri(f.subs_auto_idx),
            subtitles_embed: idx_to_tri(f.subs_embed_idx),
            subtitle_format: trim_opt(&f.subtitle_format),
            youtube_player_clients: trim_opt(&f.youtube_player_clients),
            convert_mode: idx_to_convert_mode(f.convert_idx),
            extra_args: f.extra_args.lines()
                .map(|s| s.trim().to_string()).filter(|s| !s.is_empty()).collect(),
        }
    }

    fn rescan(&mut self) {
        let mut new_lib = library::scan_channels_with_cache(&self.channels_root, Some(&self.db));
        if let Ok(map) = self.db.get_all_channel_options() {
            library::apply_channel_options(&mut new_lib, &map);
        }
        if let Ok(folder_map) = self.db.get_all_channel_assignments() {
            library::apply_channel_folders(&mut new_lib, &folder_map);
        }
        self.folders = self.db.list_folders().unwrap_or_default();
        self.library = new_lib;
        self.music_library = library::scan_music(&self.music_root);
        self.sidebar_view = SidebarView::All;
        self.selected_video = None;
        self.desc_cache.clear();
        // Keep already-decoded thumbnail textures across rescans — they're keyed
        // by file path and don't change. Drop only entries whose thumbnail is no
        // longer in the library so removed videos don't leak GPU textures. This
        // avoids the full thumbnail reload flicker on every rescan.
        let valid: HashSet<PathBuf> = self
            .library
            .iter()
            .flat_map(|c| c.videos.iter().chain(c.playlists.iter().flat_map(|p| p.videos.iter())))
            .filter_map(|v| v.thumb_path.clone())
            .collect();
        self.textures.retain(|p, _| valid.contains(p));
        self.thumb_pending.retain(|p| valid.contains(p));
        // Bump the generation so the card cache recomputes against the new library.
        self.library_generation += 1;
        self.status = format!(
            "Rescanned: {} channels, {} videos",
            self.library.len(),
            self.library.iter().map(|c| c.total_videos()).sum::<usize>()
        );
    }

    fn cards_take(&mut self) -> Vec<Card> {
        let key = (
            self.search.clone(),
            self.sort_mode.clone(),
            self.sidebar_view.clone(),
            self.library_generation,
        );
        if self.cards_cache_key.as_ref() != Some(&key) {
            self.cards_cache = self.compute_cards();
            self.cards_cache_key = Some(key);
        }
        std::mem::take(&mut self.cards_cache)
    }

    fn compute_cards(&self) -> Vec<Card> {
        let query = self.search.trim().to_lowercase();

        let mut cards = Vec::new();

        let add_video = |cards: &mut Vec<Card>, ch_name: &str, v: &library::Video| {
            // Search matches title / id / channel name. Description matching
            // would require reading the .description sidecar per-video on every
            // keystroke — punted to a future "load descriptions into the
            // search index on rescan" pass if users ask for it.
            if !query.is_empty()
                && !v.title.to_lowercase().contains(&query)
                && !v.id.to_lowercase().contains(&query)
                && !ch_name.to_lowercase().contains(&query)
            {
                return;
            }
            let resume_pos = self.resume_positions.get(&v.id).copied();
            cards.push(Card {
                channel_name: ch_name.to_string(),
                title: v.title.clone(),
                id: v.id.clone(),
                video_path: v.video_path.clone(),
                thumb_path: v.thumb_path.clone(),
                has_live_chat: v.has_live_chat,
                duration_secs: v.duration_secs,
                file_size: v.file_size,
                upload_date: v.upload_date.clone(),
                mtime_unix: v.mtime_unix,
                watched: self.watched.contains(&v.id),
                bookmark: self.flags.bookmark.contains(&v.id),
                favourite: self.flags.favourite.contains(&v.id),
                waiting: self.flags.waiting.contains(&v.id),
                resume_pos,
            });
        };

        match &self.sidebar_view {
            SidebarView::Channels | SidebarView::Music => { return cards; } // rendered separately
            SidebarView::ContinueWatching => {
                for ch in &self.library {
                    for v in ch.videos.iter().chain(ch.playlists.iter().flat_map(|p| p.videos.iter())) {
                        if self.resume_positions.contains_key(&v.id) {
                            add_video(&mut cards, &ch.name, v);
                        }
                    }
                }
                cards.sort_by(|a, b| {
                    b.resume_pos.unwrap_or(0.0)
                        .partial_cmp(&a.resume_pos.unwrap_or(0.0))
                        .unwrap_or(std::cmp::Ordering::Equal)
                });
                return cards;
            }
            SidebarView::Recent => {
                // Most-recently-modified videos across the whole library.
                // Cap at 100 entries so the grid stays responsive for users
                // with thousands of files.
                for ch in &self.library {
                    for v in ch.videos.iter().chain(ch.playlists.iter().flat_map(|p| p.videos.iter())) {
                        if v.mtime_unix.is_some() {
                            add_video(&mut cards, &ch.name, v);
                        }
                    }
                }
                cards.sort_by(|a, b| b.mtime_unix.unwrap_or(0).cmp(&a.mtime_unix.unwrap_or(0)));
                cards.truncate(100);
                return cards;
            }
            SidebarView::Favourites | SidebarView::Bookmarks | SidebarView::Waiting => {
                // Smart folders. Filter the whole library by the matching
                // flag bundle set.
                let set = match self.sidebar_view {
                    SidebarView::Favourites => &self.flags.favourite,
                    SidebarView::Bookmarks => &self.flags.bookmark,
                    SidebarView::Waiting => &self.flags.waiting,
                    _ => unreachable!("outer match guarantees the variant"),
                };
                for ch in &self.library {
                    for v in ch.videos.iter().chain(ch.playlists.iter().flat_map(|p| p.videos.iter())) {
                        if set.contains(&v.id) {
                            add_video(&mut cards, &ch.name, v);
                        }
                    }
                }
                return cards;
            }
            SidebarView::All => {
                for ch in &self.library {
                    for v in ch.videos.iter().chain(ch.playlists.iter().flat_map(|p| p.videos.iter())) {
                        add_video(&mut cards, &ch.name, v);
                    }
                }
            }
            SidebarView::Channel(ci) => {
                if let Some(ch) = self.library.get(*ci) {
                    for v in ch.videos.iter().chain(ch.playlists.iter().flat_map(|p| p.videos.iter())) {
                        add_video(&mut cards, &ch.name, v);
                    }
                }
            }
            SidebarView::Playlist(ci, pi) => {
                if let Some(ch) = self.library.get(*ci) {
                    if let Some(pl) = ch.playlists.get(*pi) {
                        for v in &pl.videos {
                            add_video(&mut cards, &ch.name, v);
                        }
                    }
                }
            }
        }

        match self.sort_mode {
            SortMode::Title => cards.sort_by(|a, b| a.title.to_lowercase().cmp(&b.title.to_lowercase())),
            SortMode::DurationAsc => cards.sort_by(|a, b| {
                a.duration_secs.unwrap_or(0.0)
                    .partial_cmp(&b.duration_secs.unwrap_or(0.0))
                    .unwrap_or(std::cmp::Ordering::Equal)
            }),
            SortMode::DurationDesc => cards.sort_by(|a, b| {
                b.duration_secs.unwrap_or(0.0)
                    .partial_cmp(&a.duration_secs.unwrap_or(0.0))
                    .unwrap_or(std::cmp::Ordering::Equal)
            }),
            SortMode::SizeAsc => cards.sort_by_key(|c| c.file_size.unwrap_or(0)),
            SortMode::SizeDesc => {
                cards.sort_by_key(|c| c.file_size.unwrap_or(0));
                cards.reverse();
            }
            SortMode::DateDesc => {
                // Empty/missing dates sort to the end of "newest first".
                cards.sort_by(|a, b| b.upload_date.as_deref().unwrap_or("").cmp(a.upload_date.as_deref().unwrap_or("")));
            }
            SortMode::DateAsc => {
                // Empty/missing dates sort to the end of "oldest first" too.
                cards.sort_by(|a, b| {
                    match (a.upload_date.as_deref(), b.upload_date.as_deref()) {
                        (Some(x), Some(y)) => x.cmp(y),
                        (Some(_), None) => std::cmp::Ordering::Less,
                        (None, Some(_)) => std::cmp::Ordering::Greater,
                        (None, None) => std::cmp::Ordering::Equal,
                    }
                });
            }
        }

        cards
    }

    fn find_video_by_id(&self, id: &str) -> Option<(Video, String)> {
        library::find_video(&self.library, id)
            .map(|(v, ch)| (v.clone(), ch.name.clone()))
    }

    fn texture(&mut self, _ctx: &egui::Context, path: &Path) -> Option<egui::TextureHandle> {
        if let Some(slot) = self.textures.get(path) {
            return slot.clone();
        }
        let pb = path.to_path_buf();
        if self.thumb_pending.insert(pb.clone()) {
            let _ = self.thumb_request_tx.send(pb);
        }
        None
    }

    fn description(&mut self, video: &Video) -> String {
        let Some(path) = &video.description_path else {
            return "(no description file)".to_string();
        };
        if let Some(text) = self.desc_cache.get(path) {
            return text.clone();
        }
        let text = std::fs::read_to_string(path)
            .unwrap_or_else(|e| format!("(could not read description: {e})"));
        self.desc_cache.insert(path.clone(), text.clone());
        text
    }

    /// Pick a random unwatched, downloaded video and open it in the
    /// configured player. Mirrors the web 🎲 shuffle. Falls back to
    /// "any downloaded video" when everything's already been watched.
    fn shuffle_play(&mut self) {
        use rand::seq::SliceRandom;
        // Collect (video_path, id) of every downloaded video, partitioned by
        // watched status. We borrow library briefly, then drop before calling
        // play_with_tracking (which takes &mut self).
        let (unwatched, all): (Vec<(PathBuf, String)>, Vec<(PathBuf, String)>) = {
            let mut unwatched = Vec::new();
            let mut all = Vec::new();
            for ch in &self.library {
                for v in ch.all_videos() {
                    if let Some(p) = &v.video_path {
                        all.push((p.clone(), v.id.clone()));
                        if !self.watched.contains(&v.id) {
                            unwatched.push((p.clone(), v.id.clone()));
                        }
                    }
                }
            }
            (unwatched, all)
        };
        let mut rng = rand::thread_rng();
        let pick = if !unwatched.is_empty() {
            unwatched.choose(&mut rng).cloned()
        } else if !all.is_empty() {
            self.status = "Everything is watched — playing a random one anyway".to_string();
            all.choose(&mut rng).cloned()
        } else {
            None
        };
        if let Some((path, id)) = pick {
            self.selected_video = Some(id.clone());
            self.play_with_tracking(&path, id);
        } else {
            self.status = "No downloaded videos to shuffle from".to_string();
        }
    }

    fn play_with_tracking(&mut self, path: &Path, video_id: String) {
        let cmd = self.config.player.command.clone();
        // Only enable IPC for genuine mpv invocations — substring matching
        // would also fire for things like `mympv-wrapper`, `gnomempv`, etc.,
        // which don't implement the JSON-IPC protocol.
        let exe = std::path::Path::new(&cmd)
            .file_name()
            .and_then(|s| s.to_str())
            .unwrap_or(cmd.as_str());
        let use_mpv_ipc = exe == "mpv" || exe == "mpv.exe";

        #[cfg(unix)]
        let sock_path = format!("/tmp/yt-offline-{video_id}.sock");

        let mut child_cmd = Command::new(&cmd);

        #[cfg(unix)]
        if use_mpv_ipc {
            child_cmd.arg(format!("--input-ipc-server={sock_path}"));
        }

        if let Some(&pos) = self.resume_positions.get(&video_id) {
            if pos > 5.0 && use_mpv_ipc {
                child_cmd.arg(format!("--start={}", pos as u64));
            }
        }

        child_cmd.arg(path);

        match child_cmd.spawn() {
            Ok(_) => {
                self.status = format!("Playing {}", file_label(path));
                self.currently_playing = Some(video_id.clone());

                #[cfg(unix)]
                if use_mpv_ipc {
                    let (tx, rx) = std::sync::mpsc::channel();
                    self.mpv_rx = Some(rx);
                    let id = video_id.clone();
                    std::thread::spawn(move || {
                        spawn_mpv_tracker(sock_path, id, tx);
                    });
                }
            }
            Err(_) => {
                #[cfg(target_os = "macos")]
                let fallback = "open";
                #[cfg(not(target_os = "macos"))]
                let fallback = "xdg-open";

                match Command::new(fallback).arg(path).spawn() {
                    Ok(_) => self.status = format!("Opened {} in default player", file_label(path)),
                    Err(e) => self.status = format!("Couldn't open {}: {e}", file_label(path)),
                }
            }
        }
    }

    fn open_in_file_manager(&mut self, path: &Path) {
        let target = if path.is_dir() { path } else { path.parent().unwrap_or(path) };
        #[cfg(target_os = "macos")]
        let cmd = "open";
        #[cfg(not(target_os = "macos"))]
        let cmd = "xdg-open";
        if let Err(e) = Command::new(cmd).arg(target).spawn() {
            self.status = format!("Couldn't open folder: {e}");
        }
    }

    fn toggle_watched(&mut self, video_id: &str) {
        let now_watched = !self.watched.contains(video_id);
        if let Ok(()) = self.db.set_watched(video_id, now_watched) {
            if now_watched {
                self.watched.insert(video_id.to_string());
            } else {
                self.watched.remove(video_id);
            }
        }
    }

    /// Flip a per-video flag (`"bookmark"`, `"favourite"`, `"waiting"`, or
    /// `"archive"`) and persist the change. Unknown flag names are ignored
    /// rather than panic so a typo surfaces in the UI as a no-op.
    fn toggle_video_flag(&mut self, video_id: &str, flag: &'static str) {
        let set = match flag {
            "bookmark" => &mut self.flags.bookmark,
            "favourite" => &mut self.flags.favourite,
            "waiting" => &mut self.flags.waiting,
            "archive" => &mut self.flags.archive,
            _ => return,
        };
        let now_set = !set.contains(video_id);
        if let Err(e) = self.db.set_video_flag(video_id, flag, now_set) {
            self.status = format!("Flag {flag}: {e}");
            return;
        }
        if now_set { set.insert(video_id.to_string()); } else { set.remove(video_id); }
        // Bust the cards cache so the action icons + smart-folder counts
        // refresh on the next paint.
        self.cards_cache_key = None;
    }

    fn start_web_server(&mut self) {
        if self.web_server_running {
            return;
        }
        let shutdown = crate::web::run_with_shutdown(self.config.clone());
        self.web_server_shutdown = Some(shutdown);
        self.web_server_running = true;
        let port = self.config.web.port;
        self.status = format!("Web server started on port {port}. Access at http://localhost:{port}");
    }

    fn stop_web_server(&mut self) {
        if !self.web_server_running {
            return;
        }
        if let Some(shutdown) = self.web_server_shutdown.take() {
            let _ = shutdown.send(());
        }
        self.web_server_running = false;
        self.status = "Web server stopped.".to_string();
    }

    fn bulk_mark_watched(&mut self, watched: bool) {
        let ids: Vec<String> = self.bulk_selected.iter().cloned().collect();
        for id in &ids {
            if let Ok(()) = self.db.set_watched(id, watched) {
                if watched {
                    self.watched.insert(id.clone());
                } else {
                    self.watched.remove(id);
                }
            }
        }
        self.bulk_selected.clear();
        self.status = format!(
            "{} {} as {}watched",
            ids.len(),
            if ids.len() == 1 { "video" } else { "videos" },
            if watched { "" } else { "un" }
        );
    }

    /// Bulk-apply a single per-video flag (`"bookmark"` / `"favourite"` /
    /// `"waiting"` / `"archive"`) across the current selection. Same shape
    /// as [`bulk_mark_watched`], extended for the smart-folder flag set.
    fn bulk_set_flag(&mut self, flag: &'static str, value: bool) {
        let ids: Vec<String> = self.bulk_selected.iter().cloned().collect();
        let count = ids.len();
        for id in &ids {
            if self.db.set_video_flag(id, flag, value).is_err() { continue; }
            let set = match flag {
                "bookmark" => &mut self.flags.bookmark,
                "favourite" => &mut self.flags.favourite,
                "waiting" => &mut self.flags.waiting,
                "archive" => &mut self.flags.archive,
                _ => return,
            };
            if value { set.insert(id.clone()); } else { set.remove(id); }
        }
        self.bulk_selected.clear();
        self.cards_cache_key = None;
        self.status = format!(
            "{count} {} {}{flag}",
            if count == 1 { "video" } else { "videos" },
            if value { "→ " } else { "un" },
        );
    }

    fn run_scheduled_check(&mut self) {
        // Snapshot each channel's URL + options first so we don't hold an
        // immutable borrow of `self.library` while calling
        // `self.downloader.start` (which takes &mut self).
        let scheduled: Vec<(String, crate::download_options::DownloadOptions)> = self.library.iter()
            .map(|ch| (crate::downloader::recheck_url(ch), ch.download_options.clone()))
            .collect();
        let count = scheduled.len();
        for (url, opts) in scheduled {
            let info = classify_url(&url);
            // Channel options' quality override (if any) wins over the
            // hard-coded Best for scheduled re-checks.
            let quality = opts.quality.unwrap_or(DownloadQuality::Best);
            self.downloader.start(url, &info, true, quality, false, Some(&opts));
        }
        self.status = format!("Scheduled check: started {} channel downloads", count);
    }

    fn check_notifications(&mut self) {
        let jobs = &self.downloader.jobs;
        let mut finished: Vec<(String, bool)> = Vec::new();

        for (i, job) in jobs.iter().enumerate() {
            let prev = self.prev_job_states.get(&i).copied();
            if prev == Some(JobState::Running) && job.state != JobState::Running {
                finished.push((job.label.clone(), job.state == JobState::Done));
            }
        }

        // Rebuild snapshot
        self.prev_job_states = jobs.iter().enumerate()
            .map(|(i, j)| (i, j.state))
            .collect();

        for (label, ok) in finished {
            let summary = if ok {
                format!("Download complete: {label}")
            } else {
                format!("Download failed: {label}")
            };
            let _ = notify_rust::Notification::new()
                .summary("yt-offline")
                .body(&summary)
                .timeout(notify_rust::Timeout::Milliseconds(4000))
                .show();
        }
    }

    fn channel_total_size(ch: &library::Channel) -> u64 {
        ch.total_size_cached
    }

    fn top_bar(&mut self, ctx: &egui::Context) {
        egui::TopBottomPanel::top("top_bar").show(ctx, |ui| {
            ui.add_space(2.0);
            ui.horizontal(|ui| {
                ui.heading("yt-offline");
                ui.separator();
                ui.label("🔍");
                ui.add(
                    egui::TextEdit::singleline(&mut self.search)
                        .hint_text("filter by title or id")
                        .desired_width(200.0),
                );
                if !self.search.is_empty() && ui.button("✖").on_hover_text("clear").clicked() {
                    self.search.clear();
                }
                ui.separator();
                ui.label("Size:");
                ui.add(
                    egui::Slider::new(&mut self.card_density, 0.5_f32..=2.0_f32)
                        .show_value(false)
                        .step_by(0.1),
                );
                ui.separator();
                if ui.button("⟳ Rescan").clicked() {
                    self.rescan();
                }
                if ui.button("🎲 Shuffle")
                    .on_hover_text("Play a random unwatched downloaded video")
                    .clicked()
                {
                    self.shuffle_play();
                }
                let dl_label = if self.show_downloads { "⬇ Downloads ▸" } else { "⬇ Downloads" };
                if ui.selectable_label(self.show_downloads, dl_label).clicked() {
                    self.show_downloads = !self.show_downloads;
                }
                // Top-level screen nav. Clicking the active screen returns
                // to Library (which is the canonical "home" view).
                if ui.selectable_label(self.current_screen == Screen::Library, "📚 Library").clicked() {
                    self.current_screen = Screen::Library;
                }
                if ui.selectable_label(self.current_screen == Screen::Stats, "📊 Stats").clicked() {
                    if self.current_screen == Screen::Stats {
                        self.current_screen = Screen::Library;
                    } else {
                        self.stats_report = Some(crate::stats::build(
                            &self.library,
                            &self.watched,
                            &self.resume_positions,
                            crate::stats::now_unix(),
                        ));
                        self.current_screen = Screen::Stats;
                    }
                }
                if ui.selectable_label(self.current_screen == Screen::Maintenance, "🩺 Maintenance").clicked() {
                    if self.current_screen == Screen::Maintenance {
                        self.current_screen = Screen::Library;
                    } else {
                        self.health_report =
                            Some(crate::maintenance::scan(&self.library_root, &self.library));
                        self.current_screen = Screen::Maintenance;
                    }
                }
                if ui.selectable_label(self.current_screen == Screen::Settings, "⚙ Settings").clicked() {
                    if self.current_screen == Screen::Settings {
                        self.current_screen = Screen::Library;
                    } else {
                        self.settings_dir = self.channels_root.display().to_string();
                        self.settings_plex_path = self.config.plex.library_path
                            .as_deref().map(|p| p.display().to_string()).unwrap_or_default();
                        self.settings_source_url = self.config.web.source_url.clone().unwrap_or_default();
                        self.plex_status.clear();
                        self.settings_bind_mode =
                            crate::web::bind_mode_of(&self.config.web.bind).to_string();
                        self.settings_password_enabled =
                            self.db.get_setting("password_hash").ok().flatten().is_some();
                        self.settings_password_input.clear();
                        self.settings_cookies_input.clear();
                        let (exists, n) = crate::web::cookies_status();
                        self.settings_cookies_status = if exists {
                            let fresh = crate::web::cookies_freshness();
                            if fresh.no_auth_cookies {
                                format!("{n} cookie(s) — ⚠ ANONYMOUS (no YouTube login session); export a fresh cookies.txt while signed in — anonymous requests get captcha'd most")
                            } else if fresh.expired {
                                let ago = fresh.days_left.map(|d| d.abs()).unwrap_or(0);
                                format!("{n} cookie(s) — ⚠ login cookies EXPIRED ({ago}d ago); refresh them (stale cookies worsen bot-detection)")
                            } else if fresh.days_left.is_some_and(|d| d <= 3) {
                                let d = fresh.days_left.unwrap_or(0);
                                format!("{n} cookie(s) — ⚠ login cookies expire in {d}d; refresh soon")
                            } else {
                                format!("{n} cookie(s) loaded")
                            }
                        } else {
                            "no cookies.txt".to_string()
                        };
                        self.current_screen = Screen::Settings;
                    }
                }
                ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                    ui.label(egui::RichText::new(&self.status).weak());
                });
            });
            ui.add_space(2.0);
        });
    }

    fn channel_panel(&mut self, ctx: &egui::Context) {
        egui::SidePanel::left("channels")
            .resizable(true)
            .default_width(230.0)
            .show(ctx, |ui| {
                ui.add_space(4.0);
                ui.heading("Channels");
                ui.separator();
                egui::ScrollArea::vertical().show(ui, |ui| {
                    let total: usize = self.library.iter().map(|c| c.total_videos()).sum();
                    let resume_count = self.resume_positions.len();

                    if ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Channels,
                            format!("⊟ Channels  ({})", self.library.len()),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Channels;
                        self.selected_video = None;
                    }

                    if ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::All,
                            format!("⊞ All  ({total})"),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::All;
                        self.selected_video = None;
                    }

                    if resume_count > 0 {
                        if ui
                            .selectable_label(
                                self.sidebar_view == SidebarView::ContinueWatching,
                                format!("▶ Continue Watching  ({resume_count})"),
                            )
                            .clicked()
                        {
                            self.sidebar_view = SidebarView::ContinueWatching;
                            self.selected_video = None;
                        }
                    }

                    // Recent additions across the whole library — capped at 100
                    // in `compute_cards`. Only shown when the library has
                    // anything dated; on a brand-new install this stays hidden.
                    let has_dated = self.library.iter()
                        .flat_map(|c| c.all_videos())
                        .any(|v| v.mtime_unix.is_some());
                    if has_dated && ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Recent,
                            "🕒 Recent additions",
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Recent;
                        self.selected_video = None;
                    }

                    // Smart-folder sidebar entries — each shown only when at
                    // least one video carries the matching flag. Keeps a
                    // brand-new install free of empty rows.
                    let fav_count = self.flags.favourite.len();
                    if fav_count > 0 && ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Favourites,
                            format!("★ Favourites  ({fav_count})"),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Favourites;
                        self.selected_video = None;
                    }
                    let bmk_count = self.flags.bookmark.len();
                    if bmk_count > 0 && ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Bookmarks,
                            format!("🔖 Bookmarks  ({bmk_count})"),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Bookmarks;
                        self.selected_video = None;
                    }
                    let wait_count = self.flags.waiting.len();
                    if wait_count > 0 && ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Waiting,
                            format!("⏳ Waiting  ({wait_count})"),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Waiting;
                        self.selected_video = None;
                    }

                    let music_count = self.music_library.len();
                    if ui
                        .selectable_label(
                            self.sidebar_view == SidebarView::Music,
                            format!("♫ Music  ({music_count})"),
                        )
                        .clicked()
                    {
                        self.sidebar_view = SidebarView::Music;
                        self.selected_video = None;
                    }

                    ui.separator();

                    // Collect any right-click download action outside the loop
                    let mut pending_ch_download: Option<(String, String)> = None; // (url, channel_name)
                    // Same trick for the "Channel options…" menu item — capture
                    // the channel index, open the dialog after the loop so we
                    // don't recursively borrow `self` from inside the closure.
                    let mut pending_open_options: Option<usize> = None;
                    let mut pending_move_to_folder: Option<usize> = None;
                    let mut pending_open_folder_manager = false;

                    // Build an ordered list of (header-or-channel-index) items
                    // so folders render above platform sections. Channels with
                    // a folder_id appear only in their folder; unfiled channels
                    // still get the per-platform grouping.
                    // FolderHeader carries a `depth` for indentation so the
                    // N-level nesting reads as a tree.
                    enum SidebarItem { FolderHeader(String, usize, usize), FolderManageBtn, PlatformHeader(Platform), Channel(usize, usize) }
                    let mut items: Vec<SidebarItem> = Vec::new();
                    let has_any_folder_or_assignment = !self.folders.is_empty()
                        || self.library.iter().any(|c| c.folder_id.is_some());
                    if has_any_folder_or_assignment {
                        items.push(SidebarItem::FolderManageBtn);
                        // Recursively emit a folder, its member channels, then
                        // its children. Count includes the whole subtree.
                        let folders = self.folders.clone();
                        let library = &self.library;
                        let subtree_count = |fid: i64| -> usize {
                            // Iterative DFS counting members of fid + descendants.
                            let mut seen = std::collections::HashSet::new();
                            let mut stack = vec![fid];
                            let mut n = 0usize;
                            while let Some(cur) = stack.pop() {
                                if !seen.insert(cur) { continue; }
                                n += library.iter().filter(|c| c.folder_id == Some(cur)).count();
                                for f in &folders {
                                    if f.parent_id == Some(cur) { stack.push(f.id); }
                                }
                            }
                            n
                        };
                        // Walk the tree depth-first. `emit` is iterative to avoid
                        // borrow-checker gymnastics with a recursive closure.
                        let mut seen = std::collections::HashSet::new();
                        // Stack holds (folder_index_into_folders, depth).
                        let roots: Vec<usize> = folders.iter().enumerate()
                            .filter(|(_, f)| f.parent_id.is_none())
                            .map(|(i, _)| i)
                            .collect();
                        // Push roots in reverse so the first root pops first.
                        let mut stack: Vec<(usize, usize)> =
                            roots.into_iter().rev().map(|i| (i, 0usize)).collect();
                        while let Some((fi, depth)) = stack.pop() {
                            let f = &folders[fi];
                            if !seen.insert(f.id) { continue; }
                            items.push(SidebarItem::FolderHeader(f.name.clone(), subtree_count(f.id), depth));
                            for (i, c) in library.iter().enumerate() {
                                if c.folder_id == Some(f.id) {
                                    items.push(SidebarItem::Channel(i, depth + 1));
                                }
                            }
                            // Push children (reverse for stable order).
                            let mut kids: Vec<usize> = folders.iter().enumerate()
                                .filter(|(_, c)| c.parent_id == Some(f.id))
                                .map(|(i, _)| i)
                                .collect();
                            kids.reverse();
                            for ki in kids { stack.push((ki, depth + 1)); }
                        }
                        // Orphans whose parent was deleted: render at root.
                        for (fi, f) in folders.iter().enumerate() {
                            if !seen.contains(&f.id) {
                                items.push(SidebarItem::FolderHeader(f.name.clone(), subtree_count(f.id), 0));
                                for (i, c) in library.iter().enumerate() {
                                    if c.folder_id == Some(f.id) {
                                        items.push(SidebarItem::Channel(i, 1));
                                    }
                                }
                                let _ = fi;
                            }
                        }
                    } else {
                        items.push(SidebarItem::FolderManageBtn);
                    }
                    let mut last_platform_marker: Option<Platform> = None;
                    for (i, ch) in self.library.iter().enumerate() {
                        if ch.folder_id.is_some() { continue; }
                        if Some(ch.platform) != last_platform_marker {
                            items.push(SidebarItem::PlatformHeader(ch.platform));
                            last_platform_marker = Some(ch.platform);
                        }
                        // Unfiled channels render at the flat (depth 0) indent.
                        items.push(SidebarItem::Channel(i, 0));
                    }

                    for item in items {
                        match item {
                            SidebarItem::FolderManageBtn => {
                                ui.horizontal(|ui| {
                                    ui.label(egui::RichText::new("📁 Folders").small().weak());
                                    if ui.small_button("manage").clicked() {
                                        pending_open_folder_manager = true;
                                    }
                                });
                            }
                            SidebarItem::FolderHeader(name, count, depth) => {
                                // Two spaces of base indent + 2 per nesting level.
                                let indent = "  ".repeat(depth + 1);
                                ui.label(
                                    egui::RichText::new(format!("{indent}📁 {name} ({count})"))
                                        .small()
                                        .weak(),
                                );
                            }
                            SidebarItem::PlatformHeader(p) => {
                                ui.label(
                                    egui::RichText::new(format!("{} {}", p.icon(), p.display_name()))
                                        .small()
                                        .weak(),
                                );
                            }
                            SidebarItem::Channel(i, _depth) => {
                        let (name, total, has_playlists, size_bytes, channel_url, platform) = {
                            let ch = &self.library[i];
                            // Prefer the stored `.source-url` over folder-name guessing so
                            // re-checks work across platforms (and across legacy YouTube
                            // libraries where the URL was never recorded).
                            let url = crate::downloader::recheck_url(ch);
                            (
                                ch.name.clone(),
                                ch.total_videos(),
                                !ch.playlists.is_empty(),
                                Self::channel_total_size(ch),
                                url,
                                ch.platform,
                            )
                        };

                        let is_ch_selected = matches!(self.sidebar_view, SidebarView::Channel(ci) if ci == i)
                            || matches!(self.sidebar_view, SidebarView::Playlist(ci, _) if ci == i);

                        let size_str = if size_bytes > 0 {
                            format!(" · {}", format_size(size_bytes))
                        } else {
                            String::new()
                        };
                        // Show platform icon for non-YouTube channels so the sidebar
                        // reads as a unified library while still making the source
                        // obvious at a glance.
                        let prefix = if platform == Platform::YouTube {
                            String::new()
                        } else {
                            format!("{} ", platform.icon())
                        };
                        let label = format!("{prefix}{}  ({}{})", name, total, size_str);

                        let ch_selected_no_pl = matches!(self.sidebar_view, SidebarView::Channel(ci) if ci == i);
                        let resp = ui
                            .selectable_label(ch_selected_no_pl, label)
                            .on_hover_text(format!(
                                "{}\n{}",
                                self.library[i].path.display(),
                                platform.display_name(),
                            ));
                        if resp.clicked() {
                            self.sidebar_view = SidebarView::Channel(i);
                            self.selected_video = None;
                        }
                        // Right-click context menu
                        let url_for_menu = channel_url.clone();
                        let name_for_menu = name.clone();
                        let channel_idx = i;
                        resp.context_menu(|ui| {
                            {
                                let url = &url_for_menu;
                                if ui.button("⬇ Check for new videos").clicked() {
                                    pending_ch_download = Some((url.clone(), name_for_menu.clone()));
                                    ui.close_menu();
                                }
                            }
                            if ui.button("⚙ Channel options…").clicked() {
                                pending_open_options = Some(channel_idx);
                                ui.close_menu();
                            }
                            if ui.button("📁 Move to folder…").clicked() {
                                pending_move_to_folder = Some(channel_idx);
                                ui.close_menu();
                            }
                            if ui.button("📁 Open folder").clicked() {
                                let path = self.library[i].path.clone();
                                if let Err(e) = std::process::Command::new("xdg-open").arg(&path).spawn() {
                                    eprintln!("xdg-open: {e}");
                                }
                                ui.close_menu();
                            }
                        });

                        if is_ch_selected && has_playlists {
                            let playlist_count = self.library[i].playlists.len();
                            for pi in 0..playlist_count {
                                let (pl_name, pl_len) = {
                                    let pl = &self.library[i].playlists[pi];
                                    (pl.name.clone(), pl.videos.len())
                                };
                                let is_pl = matches!(self.sidebar_view, SidebarView::Playlist(ci, pli) if ci == i && pli == pi);
                                let pl_label = format!("    └ {}  ({})", pl_name, pl_len);
                                if ui.selectable_label(is_pl, pl_label).clicked() {
                                    self.sidebar_view = SidebarView::Playlist(i, pi);
                                    self.selected_video = None;
                                }
                            }
                        }
                            } // close SidebarItem::Channel arm
                        }     // close match item
                    }         // close for item in items

                    if let Some(ci) = pending_open_options {
                        if let Some(ch) = self.library.get(ci) {
                            self.channel_options_target = Some((ch.platform, ch.name.clone()));
                            self.channel_options_form = Self::options_to_form(&ch.download_options);
                            self.show_channel_options = true;
                        }
                    }
                    if let Some(ci) = pending_move_to_folder {
                        if let Some(ch) = self.library.get(ci) {
                            self.move_to_folder_target = Some((ch.platform, ch.name.clone()));
                            self.show_move_to_folder = true;
                        }
                    }
                    if pending_open_folder_manager {
                        self.show_folder_manager = true;
                        self.folder_create_buffer.clear();
                    }

                    // Process deferred right-click download action. The
                    // channel's own options + quality override apply for
                    // user-triggered re-checks just like for scheduled ones.
                    if let Some((url, ch_name)) = pending_ch_download {
                        let info = classify_url(&url);
                        let opts = self.library.iter()
                            .find(|c| c.name == ch_name)
                            .map(|c| c.download_options.clone())
                            .unwrap_or_default();
                        let quality = opts.quality.unwrap_or(DownloadQuality::Best);
                        self.downloader.start(url, &info, !self.dl_full_scan, quality, false, Some(&opts));
                        self.status = format!("Checking {} for new videos…", ch_name);
                    }
                });
            });
    }

    fn downloads_panel(&mut self, ctx: &egui::Context) {
        egui::SidePanel::right("downloads")
            .resizable(true)
            .default_width(380.0)
            .show(ctx, |ui| {
                ui.add_space(4.0);
                ui.heading("New download");
                ui.label("Video, playlist, or channel URL:");
                ui.add(
                    egui::TextEdit::singleline(&mut self.dl_url)
                        .hint_text("https://www.youtube.com/…")
                        .desired_width(f32::INFINITY),
                );

                let info = classify_url(self.dl_url.trim());
                let plat_dir = info.platform.dir_name();
                let (type_label, dest_preview) = match &info.kind {
                    UrlKind::Channel { handle } => {
                        ("Channel", format!("→ {plat_dir}/{handle}/"))
                    }
                    UrlKind::Playlist => ("Playlist", format!("→ {plat_dir}/<creator>/<playlist>/")),
                    UrlKind::Video => ("Video", format!("→ {plat_dir}/<creator>/")),
                    UrlKind::Unknown => ("—", String::new()),
                };

                if !self.dl_url.trim().is_empty() {
                    ui.horizontal(|ui| {
                        ui.label("Source:");
                        ui.strong(format!("{} {}", info.platform.icon(), info.platform.display_name()));
                        ui.separator();
                        ui.label("Type:");
                        ui.strong(type_label);
                    });
                    if !dest_preview.is_empty() {
                        ui.label(egui::RichText::new(&dest_preview).small().weak());
                    }
                }

                ui.horizontal(|ui| {
                    ui.selectable_value(&mut self.dl_music_mode, false, "🎬 Video");
                    ui.selectable_value(&mut self.dl_music_mode, true, "🎵 Music");
                });

                if self.dl_music_mode {
                    ui.label(egui::RichText::new("Audio-only — saves to music/ directory").small().weak());
                } else {
                    ui.horizontal(|ui| {
                        ui.label("Quality:");
                        egui::ComboBox::from_id_salt("dl_quality")
                            .selected_text(self.dl_quality.label())
                            .show_ui(ui, |ui| {
                                for &q in DownloadQuality::all() {
                                    ui.selectable_value(&mut self.dl_quality, q, q.label());
                                }
                            });
                    });
                    ui.checkbox(&mut self.dl_full_scan, "Fast mode (stop at first already-downloaded video)")
                        .on_hover_text("Faster for large channels but may miss new videos if gaps exist in the archive. Leave off to check every video.");
                    ui.checkbox(&mut self.dl_live, "🔴 Live stream (record from start)")
                        .on_hover_text(
                            "Use for Twitch/YouTube Live broadcasts. Adds --live-from-start \
                             so yt-dlp records from the beginning instead of joining mid-stream. \
                             Also waits if the stream hasn't begun yet.",
                        );
                    if info.platform == Platform::Twitch
                        && matches!(info.kind, UrlKind::Channel { .. })
                    {
                        ui.checkbox(&mut self.dl_twitch_clips, "Clips only (Twitch)")
                            .on_hover_text(
                                "Pull only the channel's Clips section instead of the \
                                 default VOD/highlights mix. Rewrites the URL to \
                                 twitch.tv/<channel>/clips before submitting.",
                            );
                    }
                }

                let ready = !self.dl_url.trim().is_empty();
                if ui.add_enabled(ready, egui::Button::new("⬇  Start download")).clicked() {
                    let mut url = self.dl_url.trim().to_string();
                    // Twitch clips-only: rewrite `twitch.tv/<user>` to
                    // `twitch.tv/<user>/clips`. yt-dlp's TwitchClips extractor
                    // handles the rest and we still classify it as Channel so
                    // the output folder is unchanged.
                    if self.dl_twitch_clips
                        && info.platform == Platform::Twitch
                        && matches!(info.kind, UrlKind::Channel { .. })
                        && !url.contains("/clips")
                    {
                        url = format!("{}/clips", url.trim_end_matches('/'));
                    }
                    let dest = dest_preview.clone();
                    if self.dl_music_mode {
                        self.downloader.start_music(url);
                        self.status = "Downloading music…".to_string();
                    } else {
                        // Explicit submit: user already chose quality/live in
                        // the dialog. We don't know which channel the URL
                        // belongs to yet (yt-dlp resolves it), so no
                        // channel-options lookup — caller-side overrides
                        // win.
                        self.downloader.start(url, &info, !self.dl_full_scan, self.dl_quality, self.dl_live, None);
                        self.status = format!("Downloading: {dest}");
                    }
                }

                ui.separator();
                ui.horizontal(|ui| {
                    ui.heading("Jobs");
                    if !self.downloader.jobs.is_empty()
                        && !self.downloader.any_running()
                        && ui.button("Clear finished").clicked()
                    {
                        self.downloader.jobs.retain(|j| j.state == JobState::Running);
                        self.prev_job_states.clear();
                    }
                });
                if self.downloader.jobs.is_empty() && self.downloader.pending_count() == 0 {
                    ui.label(egui::RichText::new("Nothing queued yet.").weak());
                }
                let pending_count = self.downloader.pending_count();
                if pending_count > 0 {
                    let max = self.downloader.max_concurrent;
                    ui.label(
                        egui::RichText::new(format!(
                            "⏳ {pending_count} queued (max {max} concurrent)"
                        ))
                        .small()
                        .weak(),
                    );
                    let snapshots = self.downloader.pending_snapshots();
                    for (label, _url) in &snapshots {
                        ui.label(egui::RichText::new(format!("  · {label}")).small().weak());
                    }
                }
                let mut remove_job: Option<usize> = None;
                egui::ScrollArea::vertical().show(ui, |ui| {
                    let n = self.downloader.jobs.len();
                    for i in (0..n).rev() {
                        let job = &self.downloader.jobs[i];
                        let (text, color) = match job.state {
                            JobState::Running => ("running", egui::Color32::from_rgb(230, 200, 60)),
                            JobState::Done => ("done", egui::Color32::from_rgb(110, 200, 110)),
                            JobState::Failed => ("failed", egui::Color32::from_rgb(220, 110, 110)),
                        };
                        let finished = job.state != JobState::Running;
                        ui.push_id(i, |ui| {
                            ui.group(|ui| {
                                ui.horizontal(|ui| {
                                    ui.colored_label(color, text);
                                    ui.label(&job.label);
                                    if finished {
                                        ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                                            if ui.small_button("✕").clicked() {
                                                remove_job = Some(i);
                                            }
                                        });
                                    }
                                });
                                ui.label(egui::RichText::new(&job.url).small().weak());
                                if job.state == JobState::Running {
                                    ui.add(egui::ProgressBar::new(job.progress).show_percentage());
                                }
                                let last = job.log.back().map(String::as_str).unwrap_or("");
                                if !last.is_empty() {
                                    ui.label(egui::RichText::new(last).small().monospace());
                                }
                                // Failure classification hint. Drawn as a
                                // colored block so it visually separates
                                // from the raw stderr last-line above.
                                if let Some(cls) = job.failure_class {
                                    if cls != crate::error_class::ErrorClass::Other {
                                        ui.horizontal(|ui| {
                                            ui.colored_label(
                                                egui::Color32::from_rgb(220, 110, 110),
                                                format!("⚠ {}", cls.label()),
                                            );
                                            ui.label(
                                                egui::RichText::new(cls.hint())
                                                    .small()
                                                    .color(egui::Color32::from_rgb(240, 180, 180)),
                                            );
                                        });
                                    }
                                }
                                ui.collapsing("output log", |ui| {
                                    egui::ScrollArea::vertical()
                                        .max_height(180.0)
                                        .auto_shrink([false, true])
                                        .stick_to_bottom(true)
                                        .show(ui, |ui| {
                                            for line in &self.downloader.jobs[i].log {
                                                ui.label(egui::RichText::new(line).small().monospace());
                                            }
                                        });
                                });
                            });
                        });
                    }
                });
                if let Some(i) = remove_job {
                    self.downloader.remove_job(i);
                }
            });
    }

    fn maintenance_screen(&mut self, ctx: &egui::Context) {
        let report = self.health_report.clone().unwrap_or_default();

        // Actions are collected during rendering and applied after the closure
        // to avoid borrowing `self` while the report is borrowed immutably.
        let mut to_remove: Vec<PathBuf> = Vec::new();
        let mut to_repair: Vec<String> = Vec::new();
        let mut rescan_health = false;

        egui::CentralPanel::default().show(ctx, |ui| {
            ui.horizontal(|ui| {
                if ui.button("← Library").clicked() {
                    self.current_screen = Screen::Library;
                }
                ui.heading("🩺 Library health");
                ui.separator();
                if ui.button("⟳ Rescan health").clicked() {
                    rescan_health = true;
                }
            });
            ui.separator();
            egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| {
                    ui.heading(format!("Duplicates ({})", report.duplicates.len()));
                    if report.duplicates.is_empty() {
                        ui.label(egui::RichText::new("No duplicate video IDs found.").weak());
                    }
                    for g in &report.duplicates {
                        ui.group(|ui| {
                            ui.label(
                                egui::RichText::new(format!("{} [{}]", g.title, g.id)).strong(),
                            );
                            for c in &g.copies {
                                let size = c
                                    .file_size
                                    .map(format_size)
                                    .unwrap_or_else(|| "no video".to_string());
                                let tag = if c.recommended_keep { "✓ keep" } else { "✗ remove" };
                                ui.label(format!(
                                    "  {} · {} · {} files — {}",
                                    c.location, size, c.files.len(), tag
                                ));
                            }
                            if ui.button("🗑 Remove non-recommended copies").clicked() {
                                for c in &g.copies {
                                    if !c.recommended_keep {
                                        to_remove.extend(c.files.iter().cloned());
                                    }
                                }
                            }
                        });
                    }

                    ui.add_space(10.0);
                    ui.heading(format!("Missing assets ({})", report.missing.len()));
                    if report.missing.is_empty() {
                        ui.label(
                            egui::RichText::new(
                                "Every video has its thumbnail, metadata, and description.",
                            )
                            .weak(),
                        );
                    }
                    if report.missing.len() > 1
                        && ui
                            .button(format!("⬇ Fetch all missing ({})", report.missing.len()))
                            .clicked()
                    {
                        for m in &report.missing {
                            to_repair.push(m.id.clone());
                        }
                    }
                    for m in &report.missing {
                        ui.horizontal(|ui| {
                            let need: Vec<&str> = [
                                m.missing_thumbnail.then_some("thumbnail"),
                                m.missing_info.then_some("metadata"),
                                m.missing_description.then_some("description"),
                            ]
                            .into_iter()
                            .flatten()
                            .collect();
                            ui.label(format!("{} — missing {}", m.title, need.join(", ")));
                            if ui.button("⬇ Fetch").clicked() {
                                to_repair.push(m.id.clone());
                            }
                        });
                    }
            });
        });

        // ── Apply collected actions ────────────────────────────────────────
        let mut changed = false;
        if !to_remove.is_empty() {
            let (removed, errors) =
                crate::maintenance::remove_files(&self.library_root, &to_remove);
            self.status = if errors.is_empty() {
                format!("Removed {removed} file(s)")
            } else {
                format!("Removed {removed} file(s), {} error(s)", errors.len())
            };
            changed = true;
        }
        if !to_repair.is_empty() {
            for id in &to_repair {
                if let Some((dir, stem)) = crate::maintenance::locate(&self.library, id) {
                    self.downloader.repair(id, &dir, &stem);
                }
            }
            self.status = format!("Queued {} repair(s) — see Downloads", to_repair.len());
            self.show_downloads = true;
        }
        if changed || rescan_health {
            self.rescan();
            self.health_report =
                Some(crate::maintenance::scan(&self.library_root, &self.library));
        }
    }

    fn stats_screen(&mut self, ctx: &egui::Context) {
        let report = match &self.stats_report {
            Some(r) => r.clone(),
            None => {
                egui::CentralPanel::default().show(ctx, |ui| {
                    ui.horizontal(|ui| {
                        if ui.button("← Library").clicked() {
                            self.current_screen = Screen::Library;
                        }
                        ui.heading("📊 Library statistics");
                    });
                    ui.separator();
                    ui.label(egui::RichText::new("No stats yet — try Recompute.").weak());
                });
                return;
            }
        };
        let mut rescan = false;
        egui::CentralPanel::default().show(ctx, |ui| {
            ui.horizontal(|ui| {
                if ui.button("← Library").clicked() {
                    self.current_screen = Screen::Library;
                }
                ui.heading("📊 Library statistics");
                ui.separator();
                if ui.button("⟳ Recompute").clicked() { rescan = true; }
            });
            ui.separator();
            egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| {
                    ui.heading("Totals");
                    egui::Grid::new("stats_totals").num_columns(2).striped(true).show(ui, |ui| {
                        ui.label("Channels");      ui.label(report.total_channels.to_string()); ui.end_row();
                        ui.label("Videos");        ui.label(report.total_videos.to_string()); ui.end_row();
                        ui.label("Playlists");     ui.label(report.total_playlists.to_string()); ui.end_row();
                        ui.label("Disk used");     ui.label(format_size(report.total_size_bytes)); ui.end_row();
                        ui.label("Total runtime"); ui.label(format_hours(report.total_duration_secs)); ui.end_row();
                        ui.label("Watched");
                        ui.label(format!("{} · {}", report.watched_count, format_hours(report.watched_duration_secs)));
                        ui.end_row();
                        ui.label("Continue watching"); ui.label(report.continue_watching_count.to_string()); ui.end_row();
                    });

                    ui.add_space(8.0);
                    ui.heading(format!("Downloads — last {} weeks", report.downloads_per_week.len()));
                    draw_bars(ui, report.downloads_per_week.iter().map(|w| (
                        format!("{}", week_label(w.week_start_unix)),
                        w.count as f32,
                        format!("{} videos · {}", w.count, format_size(w.size_bytes)),
                    )));

                    if !report.videos_per_year.is_empty() {
                        ui.add_space(8.0);
                        ui.heading("Videos by upload year");
                        draw_bars(ui, report.videos_per_year.iter().map(|y| (
                            y.year.to_string(),
                            y.count as f32,
                            format!("{}: {}", y.year, y.count),
                        )));
                    }

                    ui.add_space(8.0);
                    ui.heading("Top channels by size");
                    for row in &report.top_channels_by_size {
                        ui.label(format!(
                            "  {} — {} videos · {} · {}",
                            row.name, row.count, format_size(row.size_bytes),
                            format_hours(row.duration_secs),
                        ));
                    }

                    ui.add_space(8.0);
                    ui.heading("Top channels by count");
                    for row in &report.top_channels_by_count {
                        ui.label(format!(
                            "  {} — {} videos · {} · {}",
                            row.name, row.count, format_size(row.size_bytes),
                            format_hours(row.duration_secs),
                        ));
                    }
                });
            });
        if rescan {
            self.stats_report = Some(crate::stats::build(
                &self.library, &self.watched, &self.resume_positions, crate::stats::now_unix(),
            ));
        }
    }

    /// Per-channel download-options editor. Lives as a separate `egui::Window`
    /// rather than a modal because egui doesn't really do modals.
    fn channel_options_window(&mut self, ctx: &egui::Context) {
        if !self.show_channel_options { return; }
        let Some((platform, handle)) = self.channel_options_target.clone() else {
            self.show_channel_options = false;
            return;
        };
        let mut open = self.show_channel_options;
        let mut save = false;
        let mut clear = false;
        let mut cancel = false;
        egui::Window::new(format!("⚙ {} · {}", platform.display_name(), handle))
            .open(&mut open)
            .collapsible(false)
            .resizable(true)
            .default_width(440.0)
            .show(ctx, |ui| {
                ui.label(
                    egui::RichText::new(
                        "Overrides apply to scheduled re-checks and the right-click \
                         \"Check for new videos\" action. Explicit downloads from the \
                         URL bar still use the dialog's own picker.",
                    )
                    .small()
                    .weak(),
                );
                ui.separator();
                let form = &mut self.channel_options_form;
                egui::Grid::new("ch_opts_grid").num_columns(2).spacing([12.0, 6.0]).striped(true).show(ui, |ui| {
                    ui.label("Quality cap");
                    egui::ComboBox::from_id_salt("ch_opts_quality")
                        .selected_text(match form.quality_idx {
                            1 => "Best",
                            2 => "1080p",
                            3 => "720p",
                            4 => "480p",
                            5 => "360p",
                            _ => "— Global default —",
                        })
                        .show_ui(ui, |ui| {
                            for (idx, label) in [
                                (0, "— Global default —"),
                                (1, "Best"),
                                (2, "1080p"),
                                (3, "720p"),
                                (4, "480p"),
                                (5, "360p"),
                            ] {
                                ui.selectable_value(&mut form.quality_idx, idx, label);
                            }
                        });
                    ui.end_row();

                    ui.label("Audio-only");
                    ui.checkbox(&mut form.audio_only, "Extract audio (best format)");
                    ui.end_row();

                    ui.label("Fetch comments");
                    ui.checkbox(&mut form.fetch_comments, "Embed --write-comments into info.json")
                        .on_hover_text("Slow on popular videos. Once captured, comments are browsable from the player modal in the web UI.");
                    ui.end_row();

                    ui.label("Skip auth check");
                    ui.checkbox(&mut form.skip_auth_check, "Suppress the channel-tab authentication warning")
                        .on_hover_text("Passes --extractor-args youtubetab:skip=authcheck. Safe for PUBLIC channels — it silences yt-dlp's \"playlists that require authentication may not extract correctly\" warning without changing which videos are found. Leave OFF for members-only/private channels, where that warning signals your cookies may not be working.");
                    ui.end_row();

                    ui.label("Bandwidth cap (KB/s)");
                    ui.add(egui::TextEdit::singleline(&mut form.limit_rate_kb).desired_width(100.0).hint_text("off"));
                    ui.end_row();

                    ui.label("Min size (MB)");
                    ui.add(egui::TextEdit::singleline(&mut form.min_filesize_mb).desired_width(100.0).hint_text("off"));
                    ui.end_row();

                    ui.label("Max size (MB)");
                    ui.add(egui::TextEdit::singleline(&mut form.max_filesize_mb).desired_width(100.0).hint_text("off"));
                    ui.end_row();

                    ui.label("Date after (YYYYMMDD)");
                    ui.add(egui::TextEdit::singleline(&mut form.date_after).desired_width(120.0).hint_text("e.g. 20240101"));
                    ui.end_row();
                });

                ui.add_space(6.0);
                ui.label("Match filter (yt-dlp --match-filter):");
                ui.add(
                    egui::TextEdit::singleline(&mut self.channel_options_form.match_filter)
                        .desired_width(f32::INFINITY)
                        .hint_text("e.g. duration > 60 & view_count > 100")
                        .font(egui::TextStyle::Monospace),
                );

                ui.add_space(6.0);
                ui.label("Subtitle languages (comma separated, blank = all):");
                ui.add(
                    egui::TextEdit::singleline(&mut self.channel_options_form.subtitle_langs)
                        .desired_width(f32::INFINITY)
                        .hint_text("en, ja"),
                );

                // Per-channel subtitle overrides. "Default" defers to the
                // global [subtitles] config; the other choices force the
                // behavior for this channel only.
                ui.add_space(6.0);
                ui.label(egui::RichText::new("Subtitle overrides (Default = use global setting):").small().weak());
                let form = &mut self.channel_options_form;
                let tri_combo = |ui: &mut egui::Ui, id: &str, label: &str, idx: &mut usize| {
                    ui.horizontal(|ui| {
                        ui.label(label);
                        egui::ComboBox::from_id_salt(id)
                            .selected_text(match *idx { 1 => "On", 2 => "Off", _ => "Default" })
                            .show_ui(ui, |ui| {
                                ui.selectable_value(idx, 0, "Default");
                                ui.selectable_value(idx, 1, "On");
                                ui.selectable_value(idx, 2, "Off");
                            });
                    });
                };
                tri_combo(ui, "subs_enabled", "Download subtitles", &mut form.subs_enabled_idx);
                tri_combo(ui, "subs_auto", "Auto-generated captions", &mut form.subs_auto_idx);
                tri_combo(ui, "subs_embed", "Embed into video", &mut form.subs_embed_idx);
                ui.horizontal(|ui| {
                    ui.label("Convert format");
                    ui.add(
                        egui::TextEdit::singleline(&mut form.subtitle_format)
                            .desired_width(120.0)
                            .hint_text("global (srt/vtt/ass)"),
                    ).on_hover_text("Blank = use the global setting. e.g. srt for Plex.");
                });

                ui.add_space(6.0);
                ui.horizontal(|ui| {
                    ui.label("YouTube player clients");
                    ui.add(
                        egui::TextEdit::singleline(&mut form.youtube_player_clients)
                            .desired_width(160.0)
                            .hint_text("global (e.g. tv,mweb)"),
                    ).on_hover_text(
                        "Per-channel --extractor-args youtube:player_client override. \
                         Blank = use the global setting. If this channel keeps hitting \
                         captchas, try 'tv,mweb' — those clients are currently the least \
                         bot-checked.");
                });

                ui.add_space(6.0);
                ui.horizontal(|ui| {
                    ui.label("Convert");
                    let label = match form.convert_idx {
                        1 => "Off", 2 => "Remux → mp4", 3 => "H.264 mp4", 4 => "Audio",
                        _ => "Default (global)",
                    };
                    egui::ComboBox::from_id_salt("ch_convert")
                        .selected_text(label)
                        .show_ui(ui, |ui| {
                            ui.selectable_value(&mut form.convert_idx, 0, "Default (global)");
                            ui.selectable_value(&mut form.convert_idx, 1, "Off");
                            ui.selectable_value(&mut form.convert_idx, 2, "Remux → mp4");
                            ui.selectable_value(&mut form.convert_idx, 3, "H.264 mp4");
                            ui.selectable_value(&mut form.convert_idx, 4, "Audio");
                        });
                }).response.on_hover_text(
                    "Post-download ffmpeg conversion for this channel. Default = use the \
                     global Format-conversion setting. CRF / preset / audio-format come \
                     from the global config.");

                ui.add_space(6.0);
                ui.label("Extra yt-dlp args (one per line):");
                ui.add(
                    egui::TextEdit::multiline(&mut self.channel_options_form.extra_args)
                        .desired_rows(3)
                        .desired_width(f32::INFINITY)
                        .hint_text("--no-mtime\n--ignore-config")
                        .font(egui::TextStyle::Monospace),
                );

                ui.add_space(8.0);
                ui.separator();
                ui.horizontal(|ui| {
                    if ui.button("🗑 Clear all").clicked() { clear = true; }
                    ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                        if ui.button("Save").clicked() { save = true; }
                        if ui.button("Cancel").clicked() { cancel = true; }
                    });
                });
            });

        // Apply the decisions outside the closure so we can mutate self.
        if save {
            let opts = Self::form_to_options(&self.channel_options_form);
            let platform_dir = platform.dir_name();
            let result = if opts.is_empty() {
                self.db.delete_channel_options(platform_dir, &handle)
            } else {
                match serde_json::to_string(&opts) {
                    Ok(json) => self.db.set_channel_options(platform_dir, &handle, &json),
                    Err(e) => {
                        self.status = format!("Channel options: encode error: {e}");
                        Ok(())
                    }
                }
            };
            match result {
                Ok(()) => {
                    // Reflect immediately on the in-memory library so the next
                    // re-check sees the change without waiting for a rescan.
                    for ch in self.library.iter_mut() {
                        if ch.platform == platform && ch.name == handle {
                            ch.download_options = opts.clone();
                            break;
                        }
                    }
                    self.status = format!("Channel options saved for {handle}");
                    self.show_channel_options = false;
                }
                Err(e) => self.status = format!("Channel options: {e}"),
            }
        } else if clear {
            let platform_dir = platform.dir_name();
            if let Err(e) = self.db.delete_channel_options(platform_dir, &handle) {
                self.status = format!("Channel options: {e}");
            } else {
                for ch in self.library.iter_mut() {
                    if ch.platform == platform && ch.name == handle {
                        ch.download_options = Default::default();
                        break;
                    }
                }
                self.status = format!("Channel options cleared for {handle}");
                self.show_channel_options = false;
            }
        } else if cancel || !open {
            self.show_channel_options = false;
        }
    }

    /// Folder management dialog — create / rename / delete folders.
    fn folder_manager_window(&mut self, ctx: &egui::Context) {
        if !self.show_folder_manager { return; }
        let mut open = self.show_folder_manager;
        let mut create_clicked = false;
        let mut to_rename: Option<(i64, String)> = None;
        let mut to_delete: Option<(i64, String, usize)> = None;
        let mut to_check: Option<i64> = None;
        // (folder id, new parent or None) collected during render, applied after.
        let mut to_reparent: Option<(i64, Option<i64>)> = None;
        egui::Window::new("📁 Manage folders")
            .open(&mut open)
            .collapsible(false)
            .resizable(true)
            .default_width(400.0)
            .show(ctx, |ui| {
                if self.folders.is_empty() {
                    ui.label(egui::RichText::new("No folders yet — create one below.").weak());
                }
                let folders = self.folders.clone();
                // Precompute each folder's descendant set so the parent
                // picker can exclude choices that would create a cycle.
                let descendants = |fid: i64| -> std::collections::HashSet<i64> {
                    let mut out = std::collections::HashSet::new();
                    let mut stack = vec![fid];
                    while let Some(cur) = stack.pop() {
                        for f in &folders {
                            if f.parent_id == Some(cur) && out.insert(f.id) {
                                stack.push(f.id);
                            }
                        }
                    }
                    out
                };
                for f in &folders {
                    let member_count = self.library.iter()
                        .filter(|c| c.folder_id == Some(f.id))
                        .count();
                    ui.horizontal(|ui| {
                        ui.label(format!("📁 {} ({} channel{})", f.name, member_count, if member_count == 1 { "" } else { "s" }));
                        ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                            if ui.small_button("🗑").on_hover_text("Delete folder").clicked() {
                                to_delete = Some((f.id, f.name.clone(), member_count));
                            }
                            if ui.small_button("✏").on_hover_text("Rename (type new name in field below first)").clicked() {
                                to_rename = Some((f.id, f.name.clone()));
                            }
                            if member_count > 0
                                && ui.small_button("⬇").on_hover_text("Check every channel in this folder for new videos").clicked()
                            {
                                to_check = Some(f.id);
                            }
                        });
                    });
                    // Parent picker for nesting. Banned = self + descendants.
                    let banned = {
                        let mut b = descendants(f.id);
                        b.insert(f.id);
                        b
                    };
                    let current_parent_name = f.parent_id
                        .and_then(|pid| folders.iter().find(|o| o.id == pid))
                        .map(|o| o.name.as_str())
                        .unwrap_or("— top level —");
                    ui.horizontal(|ui| {
                        ui.label(egui::RichText::new("    ↳ parent:").small().weak());
                        egui::ComboBox::from_id_salt(("folder_parent", f.id))
                            .selected_text(current_parent_name)
                            .show_ui(ui, |ui| {
                                if ui.selectable_label(f.parent_id.is_none(), "— top level —").clicked() {
                                    to_reparent = Some((f.id, None));
                                }
                                for o in &folders {
                                    if banned.contains(&o.id) { continue; }
                                    if ui.selectable_label(f.parent_id == Some(o.id), &o.name).clicked() {
                                        to_reparent = Some((f.id, Some(o.id)));
                                    }
                                }
                            });
                    });
                    ui.separator();
                }
                ui.add_space(6.0);
                ui.horizontal(|ui| {
                    ui.add(
                        egui::TextEdit::singleline(&mut self.folder_create_buffer)
                            .hint_text("New folder name")
                            .desired_width(220.0),
                    );
                    if ui.button("Create").clicked() { create_clicked = true; }
                });
            });
        if create_clicked {
            let name = self.folder_create_buffer.trim();
            if !name.is_empty() {
                if let Err(e) = self.db.create_folder(name) {
                    self.status = format!("Create folder: {e}");
                } else {
                    self.folders = self.db.list_folders().unwrap_or_default();
                    self.folder_create_buffer.clear();
                    self.status = "Folder created".to_string();
                }
            }
        }
        if let Some((id, new_parent)) = to_reparent {
            match self.db.set_folder_parent(id, new_parent) {
                Ok(()) => {
                    self.folders = self.db.list_folders().unwrap_or_default();
                    self.status = "Folder moved".to_string();
                }
                Err(e) => self.status = format!("Move folder: {e}"),
            }
        }
        if let Some((id, old_name)) = to_rename {
            // Inline rename: stash the id in a small confirm-style flow.
            // For brevity in v1 the rename is handled via a system prompt-free
            // approach — replace the existing folder name with the create
            // buffer if set, otherwise leave it as-is. (Future iteration:
            // proper per-folder edit row.)
            let new_name = self.folder_create_buffer.trim().to_string();
            if !new_name.is_empty() {
                if let Err(e) = self.db.rename_folder(id, &new_name) {
                    self.status = format!("Rename folder: {e}");
                } else {
                    self.folders = self.db.list_folders().unwrap_or_default();
                    self.status = format!("Renamed '{old_name}' → '{new_name}'");
                    self.folder_create_buffer.clear();
                }
            } else {
                self.status = format!("Type new name into the field below, then click ✏ on '{old_name}' again");
            }
        }
        if let Some(folder_id) = to_check {
            // Check every member channel for new videos, applying that
            // channel's own DownloadOptions / quality override just like
            // a scheduled re-check would.
            let scheduled: Vec<(String, crate::download_options::DownloadOptions)> =
                self.library.iter()
                    .filter(|ch| ch.folder_id == Some(folder_id))
                    .map(|ch| (crate::downloader::recheck_url(ch), ch.download_options.clone()))
                    .collect();
            let count = scheduled.len();
            for (url, opts) in scheduled {
                let info = classify_url(&url);
                let quality = opts.quality.unwrap_or(DownloadQuality::Best);
                self.downloader.start(url, &info, true, quality, false, Some(&opts));
            }
            self.status = format!("Folder check: started {count} channel download{}", if count == 1 { "" } else { "s" });
        }
        if let Some((id, name, count)) = to_delete {
            // Hard delete — member channels revert to Unfiled.
            if let Err(e) = self.db.delete_folder(id) {
                self.status = format!("Delete folder: {e}");
            } else {
                for ch in self.library.iter_mut() {
                    if ch.folder_id == Some(id) { ch.folder_id = None; }
                }
                self.folders = self.db.list_folders().unwrap_or_default();
                self.status = format!("Deleted '{name}' ({count} channel{} unfiled)", if count == 1 { "" } else { "s" });
            }
        }
        self.show_folder_manager = open;
    }

    /// Move-to-folder picker — small list of all folders + an "Unfiled"
    /// row for clearing the assignment.
    fn move_to_folder_window(&mut self, ctx: &egui::Context) {
        if !self.show_move_to_folder { return; }
        let Some((platform, handle)) = self.move_to_folder_target.clone() else {
            self.show_move_to_folder = false;
            return;
        };
        let mut open = self.show_move_to_folder;
        let mut pick: Option<Option<i64>> = None;
        let current = self.library.iter()
            .find(|c| c.platform == platform && c.name == handle)
            .and_then(|c| c.folder_id);
        let folders = self.folders.clone();
        egui::Window::new(format!("📁 Move \"{handle}\""))
            .open(&mut open)
            .collapsible(false)
            .resizable(false)
            .default_width(300.0)
            .show(ctx, |ui| {
                if ui.selectable_label(current.is_none(), "— Unfiled —").clicked() {
                    pick = Some(None);
                }
                for f in &folders {
                    if ui.selectable_label(current == Some(f.id), format!("📁 {}", f.name)).clicked() {
                        pick = Some(Some(f.id));
                    }
                }
                if folders.is_empty() {
                    ui.label(egui::RichText::new("No folders yet — open Manage folders to create one.").small().weak());
                }
            });
        if let Some(folder_id) = pick {
            let platform_dir = platform.dir_name();
            match self.db.set_channel_folder(platform_dir, &handle, folder_id) {
                Ok(()) => {
                    for ch in self.library.iter_mut() {
                        if ch.platform == platform && ch.name == handle {
                            ch.folder_id = folder_id;
                            break;
                        }
                    }
                    self.status = match folder_id {
                        Some(id) => {
                            let n = self.folders.iter().find(|f| f.id == id).map(|f| f.name.as_str()).unwrap_or("(unknown)");
                            format!("Moved '{handle}' to '{n}'")
                        }
                        None => format!("Moved '{handle}' to Unfiled"),
                    };
                    self.show_move_to_folder = false;
                }
                Err(e) => self.status = format!("Move: {e}"),
            }
        } else {
            self.show_move_to_folder = open;
        }
    }

    fn settings_screen(&mut self, ctx: &egui::Context) {
        egui::CentralPanel::default().show(ctx, |ui| {
            ui.horizontal(|ui| {
                if ui.button("← Library").clicked() {
                    self.current_screen = Screen::Library;
                }
                ui.heading("⚙ Settings");
            });
            ui.separator();
            egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| {
                egui::Grid::new("settings_grid")
                    .num_columns(2)
                    .spacing([12.0, 8.0])
                    .striped(true)
                    .show(ui, |ui| {
                        ui.label("Backup directory:");
                        ui.add(
                            egui::TextEdit::singleline(&mut self.settings_dir)
                                .desired_width(300.0)
                                .hint_text("/path/to/channels"),
                        );
                        ui.end_row();

                        ui.label("Player command:");
                        ui.add(
                            egui::TextEdit::singleline(&mut self.config.player.command)
                                .desired_width(300.0)
                                .hint_text("mpv"),
                        );
                        ui.end_row();

                        ui.label("Cookie browser:");
                        let current_browser = self.config.player.browser.clone();
                        let display = BROWSERS
                            .iter()
                            .find(|(id, _)| *id == current_browser)
                            .map(|(_, label)| *label)
                            .unwrap_or(current_browser.as_str());
                        egui::ComboBox::from_id_salt("browser_combo")
                            .selected_text(display)
                            .show_ui(ui, |ui| {
                                for (id, label) in BROWSERS {
                                    if ui
                                        .selectable_label(self.config.player.browser == *id, *label)
                                        .clicked()
                                    {
                                        self.config.player.browser = id.to_string();
                                        self.downloader.browser = id.to_string();
                                    }
                                }
                            });
                        ui.end_row();

                        ui.label("Theme:");
                        egui::ComboBox::from_id_salt("theme_combo")
                            .selected_text(
                                theme::THEMES
                                    .iter()
                                    .find(|(id, _)| *id == self.config.ui.theme)
                                    .map(|(_, label)| *label)
                                    .unwrap_or("Dark"),
                            )
                            .show_ui(ui, |ui| {
                                for (id, label) in theme::THEMES {
                                    if ui
                                        .selectable_label(self.config.ui.theme == *id, *label)
                                        .clicked()
                                    {
                                        self.config.ui.theme = id.to_string();
                                        theme::apply(ctx, id);
                                    }
                                }
                            });
                        ui.end_row();

                        ui.label("UI scale:");
                        ui.horizontal(|ui| {
                            // Drive zoom_factor directly; update() mirrors it
                            // back into config.ui.ui_scale and persists it.
                            let mut scale = ctx.zoom_factor();
                            let resp = ui.add(
                                egui::Slider::new(&mut scale, 0.5_f32..=3.0_f32)
                                    .step_by(0.1)
                                    .suffix("×"),
                            );
                            if resp.changed() {
                                ctx.set_zoom_factor(scale);
                            }
                            if ui.button("Reset").on_hover_text("Back to 1.0× (Ctrl+0)").clicked() {
                                ctx.set_zoom_factor(1.0);
                            }
                            ui.label(
                                egui::RichText::new("scales the whole UI · also Ctrl + / Ctrl - / Ctrl 0")
                                    .small().weak(),
                            );
                        });
                        ui.end_row();

                        ui.label("Minimize to tray:");
                        ui.checkbox(&mut self.config.ui.minimize_to_tray, "hide window on close instead of quitting")
                            .on_hover_text("Requires a working StatusNotifier host (KDE native, GNOME with AppIndicator extension). Ctrl+Q always quits.");
                        ui.end_row();

                        ui.label("Auto-check channels:");
                        ui.checkbox(&mut self.config.scheduler.enabled, "enabled");
                        ui.end_row();

                        ui.label("Check interval (hours):");
                        ui.add(
                            egui::DragValue::new(&mut self.config.scheduler.interval_hours)
                                .range(1..=168)
                                .suffix("h"),
                        );
                        ui.end_row();

                        ui.label("Max concurrent downloads:");
                        ui.add(
                            egui::DragValue::new(&mut self.config.backup.max_concurrent)
                                .range(1..=10),
                        )
                        .on_hover_text("Maximum simultaneous yt-dlp processes. Extra downloads queue automatically.");
                        ui.end_row();

                        ui.label("yt-dlp binary:");
                        ui.horizontal(|ui| {
                            ui.radio_value(&mut self.config.backup.use_bundled_ytdlp, false, "System")
                                .on_hover_text("Use whatever yt-dlp is on PATH.");
                            ui.radio_value(&mut self.config.backup.use_bundled_ytdlp, true, "Bundled")
                                .on_hover_text("Use the yt-dlp + deno installed under ~/.local/share/yt-offline/bin/.");
                            let installed = crate::ytdlp_bin::bundled_installed();
                            let btn_label = if installed { "Update" } else { "Install" };
                            if ui.button(btn_label)
                                .on_hover_text("Download (or update) the bundled yt-dlp + deno from GitHub. Streams output as a job.")
                                .clicked()
                            {
                                self.downloader.start_ytdlp_update();
                            }
                            if installed {
                                ui.label(egui::RichText::new("✓ installed").weak().small());
                            } else {
                                ui.label(egui::RichText::new("not installed").weak().small());
                            }
                        });
                        ui.end_row();

                        ui.label("POT token provider:");
                        ui.horizontal(|ui| {
                            // Disabled when the bundled yt-dlp isn't in use — the
                            // Python plugin lives in that venv. System-yt-dlp users
                            // who want POT install the plugin themselves.
                            let pot_available = self.config.backup.use_bundled_ytdlp;
                            ui.add_enabled_ui(pot_available, |ui| {
                                ui.checkbox(&mut self.config.backup.use_pot_provider, "enable")
                                    .on_hover_text(
                                        "Spawn the bgutil-pot HTTP server and pass its \
                                         extractor-args to yt-dlp. YouTube increasingly \
                                         requires a Proof-of-Origin token for each video — \
                                         without one, format URLs come back empty.\n\n\
                                         Requires the bundled yt-dlp (Python plugin lives \
                                         in that venv).",
                                    );
                            });
                            let pot_installed = crate::pot_provider::installed();
                            let pot_btn = if pot_installed { "Update" } else { "Install" };
                            if ui.add_enabled(pot_available, egui::Button::new(pot_btn))
                                .on_hover_text(
                                    "Download (or update) the bgutil-pot binary from GitHub \
                                     and pip-install the matching Python plugin into the \
                                     bundled venv. Streams output as a job.",
                                )
                                .clicked()
                            {
                                self.downloader.start_pot_provider_update();
                            }
                            if pot_installed {
                                ui.label(egui::RichText::new("✓ installed").weak().small());
                            } else {
                                ui.label(egui::RichText::new("not installed").weak().small());
                            }
                        });
                        ui.end_row();

                        ui.label("YouTube player clients:");
                        ui.add(
                            egui::TextEdit::singleline(&mut self.config.backup.youtube_player_clients)
                                .desired_width(180.0)
                                .hint_text("default (e.g. tv,mweb)"),
                        ).on_hover_text(
                            "Comma-separated --extractor-args youtube:player_client list. \
                             Blank = let yt-dlp pick (recommended). YouTube's bot-detection \
                             targets different clients over time; if you keep hitting \
                             captchas, 'tv,mweb' are currently the least-checked. \
                             Per-channel overrides live in each channel's options.");
                        ui.end_row();

                        ui.label("Web UI port:");
                        ui.add(
                            egui::DragValue::new(&mut self.config.web.port)
                                .range(1024..=65535),
                        );
                        ui.end_row();

                        ui.label("Bind interface:");
                        let binds = crate::web::get_available_binds(self.config.web.port);
                        let selected_label = binds
                            .iter()
                            .find(|b| b.id == self.settings_bind_mode)
                            .map(|b| b.label.clone())
                            .unwrap_or_else(|| "Localhost only".to_string());
                        egui::ComboBox::from_id_salt("bind_combo")
                            .selected_text(selected_label)
                            .show_ui(ui, |ui| {
                                for b in &binds {
                                    if ui
                                        .selectable_label(self.settings_bind_mode == b.id, &b.label)
                                        .clicked()
                                    {
                                        self.settings_bind_mode = b.id.clone();
                                    }
                                }
                            });
                        ui.end_row();

                        ui.label("Download password:");
                        ui.vertical(|ui| {
                            ui.checkbox(&mut self.settings_password_enabled, "require for web downloads");
                            if self.settings_password_enabled {
                                let hint = if self.settings_password_input.is_empty() {
                                    "leave blank to keep current"
                                } else {
                                    "set a password"
                                };
                                ui.add(
                                    egui::TextEdit::singleline(&mut self.settings_password_input)
                                        .password(true)
                                        .desired_width(220.0)
                                        .hint_text(hint),
                                );
                            }
                        });
                        ui.end_row();

                        ui.label("Web server:");
                        ui.horizontal(|ui| {
                            if self.web_server_running {
                                if ui.button("🛑 Stop").clicked() {
                                    self.stop_web_server();
                                }
                                ui.label(egui::RichText::new("Running").small().weak());
                            } else {
                                if ui.button("▶ Start").clicked() {
                                    self.start_web_server();
                                }
                                ui.label(egui::RichText::new("Stopped").small().weak());
                            }
                        });
                        ui.end_row();

                        ui.label("Cookies:");
                        ui.vertical(|ui| {
                            ui.label(egui::RichText::new(&self.settings_cookies_status).small().weak());
                            if ui.button("📁 Choose cookies.txt…").clicked() {
                                // Run the file dialog off the UI thread; the chosen
                                // path comes back via cookies_pick_rx (polled in update()).
                                let tx = self.cookies_pick_tx.clone();
                                std::thread::spawn(move || {
                                    if let Ok(rt) = tokio::runtime::Builder::new_current_thread()
                                        .enable_all()
                                        .build()
                                    {
                                        let picked = rt.block_on(async {
                                            rfd::AsyncFileDialog::new()
                                                .set_title("Select cookies.txt")
                                                .add_filter("cookies", &["txt"])
                                                .pick_file()
                                                .await
                                        });
                                        if let Some(f) = picked {
                                            let _ = tx.send(f.path().to_path_buf());
                                        }
                                    }
                                });
                            }
                            ui.label(egui::RichText::new("…or paste below").small().weak());
                            ui.add(
                                egui::TextEdit::multiline(&mut self.settings_cookies_input)
                                    .desired_rows(3)
                                    .desired_width(300.0)
                                    .hint_text("paste Netscape cookies.txt…"),
                            );
                            ui.horizontal(|ui| {
                                if ui.button("Update cookies").clicked() {
                                    match crate::web::write_cookies(&self.settings_cookies_input) {
                                        Ok(n) => {
                                            self.settings_cookies_status = format!("{n} cookie(s) loaded");
                                            self.settings_cookies_input.clear();
                                            self.status = format!("Cookies updated ({n} entries)");
                                        }
                                        Err(e) => self.status = format!("Cookies error: {e}"),
                                    }
                                }
                                if ui.button("Clear cookies").clicked() {
                                    match crate::web::clear_cookies() {
                                        Ok(()) => {
                                            self.settings_cookies_status = "no cookies.txt".to_string();
                                            self.status = "Cookies cleared".to_string();
                                        }
                                        Err(e) => self.status = format!("Error clearing cookies: {e}"),
                                    }
                                }
                            });
                            ui.label(
                                egui::RichText::new("Export via a browser extension, then paste.")
                                    .small()
                                    .weak(),
                            );
                        });
                        ui.end_row();
                    });

                ui.add_space(8.0);
                ui.separator();
                ui.heading("Subtitles (global defaults)");
                ui.add_space(4.0);
                ui.label(
                    egui::RichText::new(
                        "Applied to every download. Individual channels can override these \
                         in their Channel options dialog.",
                    ).small().weak(),
                );
                let subs = &mut self.config.subtitles;
                ui.checkbox(&mut subs.enabled, "Download subtitles");
                ui.add_enabled_ui(subs.enabled, |ui| {
                    ui.checkbox(&mut subs.auto_generated, "Include auto-generated (machine) captions");
                    ui.checkbox(&mut subs.embed, "Embed subtitles into the video file")
                        .on_hover_text("--embed-subs: soft subs toggleable in the player, in addition to sidecar files.");
                    ui.horizontal(|ui| {
                        ui.label("Languages (comma sep, blank = all):");
                        ui.add(egui::TextEdit::singleline(&mut subs.langs).desired_width(160.0).hint_text("en, ja"));
                    });
                    ui.horizontal(|ui| {
                        ui.label("Convert to format (blank = native):");
                        ui.add(egui::TextEdit::singleline(&mut subs.format).desired_width(100.0).hint_text("srt"))
                            .on_hover_text("--convert-subs. srt is the most player/Plex-compatible.");
                    });
                });

                ui.add_space(8.0);
                ui.separator();
                ui.heading("Format conversion (global defaults)");
                ui.add_space(4.0);
                ui.label(
                    egui::RichText::new(
                        "Runs ffmpeg after each download. Individual channels can override \
                         the mode in their Channel options. Requires ffmpeg on PATH.",
                    ).small().weak(),
                );
                let cv = &mut self.config.convert;
                ui.horizontal(|ui| {
                    ui.label("Mode:");
                    let mode_label = match cv.mode.as_str() {
                        "remux-mp4" => "Remux → mp4 (no re-encode)",
                        "h264-mp4" => "Re-encode → H.264 mp4",
                        "audio" => "Extract audio",
                        _ => "Off",
                    };
                    egui::ComboBox::from_id_salt("convert_mode")
                        .selected_text(mode_label)
                        .show_ui(ui, |ui| {
                            ui.selectable_value(&mut cv.mode, String::new(), "Off");
                            ui.selectable_value(&mut cv.mode, "remux-mp4".into(), "Remux → mp4 (no re-encode)");
                            ui.selectable_value(&mut cv.mode, "h264-mp4".into(), "Re-encode → H.264 mp4");
                            ui.selectable_value(&mut cv.mode, "audio".into(), "Extract audio");
                        });
                });
                if cv.mode == "h264-mp4" {
                    ui.horizontal(|ui| {
                        ui.label("CRF (quality):");
                        ui.add(egui::DragValue::new(&mut cv.crf).range(0..=51))
                            .on_hover_text("0–51, lower = bigger/better. 23 is a good default.");
                        if cv.crf == 0 { cv.crf = 23; }
                        ui.label("Preset:");
                        let preset_disp = if cv.preset.is_empty() { "medium" } else { cv.preset.as_str() };
                        egui::ComboBox::from_id_salt("convert_preset")
                            .selected_text(preset_disp)
                            .show_ui(ui, |ui| {
                                for p in ["ultrafast","superfast","veryfast","faster","fast","medium","slow","slower","veryslow"] {
                                    ui.selectable_value(&mut cv.preset, p.to_string(), p);
                                }
                            });
                    });
                }
                if cv.mode == "audio" {
                    ui.horizontal(|ui| {
                        ui.label("Audio format:");
                        let af = if cv.audio_format.is_empty() { "mp3" } else { cv.audio_format.as_str() };
                        egui::ComboBox::from_id_salt("convert_audio_fmt")
                            .selected_text(af)
                            .show_ui(ui, |ui| {
                                for f in ["mp3","m4a","opus","flac"] {
                                    ui.selectable_value(&mut cv.audio_format, f.to_string(), f);
                                }
                            });
                    });
                }
                if !cv.mode.is_empty() {
                    ui.checkbox(&mut cv.keep_original, "Keep original file alongside the converted one")
                        .on_hover_text("Renames the source to <name>.original.<ext>. When off, the original is deleted after a successful convert.");
                }

                ui.add_space(8.0);
                ui.separator();
                ui.heading("Backup");
                ui.add_space(4.0);
                ui.label(
                    egui::RichText::new(
                        "Saves a copy of yt-offline.db (watched / favourites / bookmarks / \
                         waiting / channel-options / folders). Restore by copying it back \
                         into your channels directory before launch.",
                    )
                    .small()
                    .weak(),
                );
                ui.horizontal(|ui| {
                    if ui.button("💾 Save library backup…").clicked() {
                        // Open the save dialog off the UI thread, mirroring the
                        // cookies file-picker pattern.
                        let tx = self.backup_save_tx.clone();
                        let default_name = format!(
                            "yt-offline-{}.db",
                            std::time::SystemTime::now()
                                .duration_since(std::time::UNIX_EPOCH)
                                .map(|d| d.as_secs()).unwrap_or(0),
                        );
                        std::thread::spawn(move || {
                            if let Ok(rt) = tokio::runtime::Builder::new_current_thread()
                                .enable_all()
                                .build()
                            {
                                let picked = rt.block_on(async {
                                    rfd::AsyncFileDialog::new()
                                        .set_title("Save library backup")
                                        .set_file_name(&default_name)
                                        .add_filter("SQLite database", &["db"])
                                        .save_file()
                                        .await
                                });
                                if let Some(f) = picked {
                                    let _ = tx.send(f.path().to_path_buf());
                                }
                            }
                        });
                    }
                    if ui.button("📂 Import library backup…")
                        .on_hover_text(
                            "Merge a previously-saved snapshot into the live DB. \
                             Watched / positions / flags / folders / channel options \
                             from the backup are merged in idempotently — running \
                             twice with the same file is safe.")
                        .clicked()
                    {
                        let tx = self.backup_open_tx.clone();
                        std::thread::spawn(move || {
                            if let Ok(rt) = tokio::runtime::Builder::new_current_thread()
                                .enable_all()
                                .build()
                            {
                                let picked = rt.block_on(async {
                                    rfd::AsyncFileDialog::new()
                                        .set_title("Choose library backup to import")
                                        .add_filter("SQLite database", &["db"])
                                        .pick_file()
                                        .await
                                });
                                if let Some(f) = picked {
                                    let _ = tx.send(f.path().to_path_buf());
                                }
                            }
                        });
                    }
                });

                ui.add_space(8.0);
                ui.separator();
                ui.heading("Source code (AGPL §13)");
                ui.add_space(4.0);
                ui.label("Repository URL (shown in web UI footer):");
                ui.add(
                    egui::TextEdit::singleline(&mut self.settings_source_url)
                        .hint_text("https://codeberg.org/you/your-fork")
                        .desired_width(400.0),
                );
                ui.label(
                    egui::RichText::new(
                        "Every network user must be offered a way to obtain the running source code. \
                         Leave empty to hide the link.",
                    )
                    .small()
                    .weak(),
                );

                ui.add_space(8.0);
                ui.separator();
                ui.heading("Plex");
                ui.add_space(4.0);
                ui.label("Plex library path:");
                ui.horizontal(|ui| {
                    ui.add(
                        egui::TextEdit::singleline(&mut self.settings_plex_path)
                            .hint_text("/media/plex/YouTube")
                            .desired_width(300.0),
                    );
                });
                ui.label(
                    egui::RichText::new(
                        "Creates a TV-show symlink tree here. Point a Plex TV library at this folder.",
                    )
                    .small()
                    .weak(),
                );
                ui.horizontal(|ui| {
                    let can_generate = !self.settings_plex_path.trim().is_empty();
                    if ui.add_enabled(can_generate, egui::Button::new("⟳ Generate Plex library")).clicked() {
                        let plex_path = PathBuf::from(self.settings_plex_path.trim());
                        let result = crate::plex::generate(&self.library, &plex_path);
                        self.plex_status = if result.errors.is_empty() {
                            format!("{} link(s) created/updated", result.links_created)
                        } else {
                            format!(
                                "{} link(s) created, {} error(s): {}",
                                result.links_created,
                                result.errors.len(),
                                result.errors.first().unwrap_or(&String::new())
                            )
                        };
                    }
                    if !self.plex_status.is_empty() {
                        ui.label(egui::RichText::new(&self.plex_status).small());
                    }
                });

                ui.add_space(8.0);
                ui.separator();
                ui.add_space(4.0);

                ui.horizontal(|ui| {
                    if ui.button("Apply & Save").clicked() {
                        let new_dir = PathBuf::from(&self.settings_dir);
                        let dir_changed = new_dir != self.config.backup.directory;
                        self.config.backup.directory = new_dir.clone();

                        // Plex library path
                        let plex_trimmed = self.settings_plex_path.trim();
                        self.config.plex.library_path = if plex_trimmed.is_empty() {
                            None
                        } else {
                            Some(PathBuf::from(plex_trimmed))
                        };

                        // Source URL (AGPL §13)
                        let src_trimmed = self.settings_source_url.trim();
                        self.config.web.source_url = if src_trimmed.is_empty() {
                            None
                        } else {
                            Some(src_trimmed.to_string())
                        };

                        // Resolve the chosen interface to a concrete bind address.
                        let new_bind = crate::web::resolve_bind_mode(&self.settings_bind_mode);
                        let bind_changed = new_bind != self.config.web.bind;
                        self.config.web.bind = new_bind;

                        // Apply the download-password setting to the database.
                        let pwd_result = if !self.settings_password_enabled {
                            self.db.set_setting("password_hash", None)
                        } else if !self.settings_password_input.is_empty() {
                            match crate::web::hash_password(&self.settings_password_input) {
                                Some(hash) => {
                                    let r = self.db.set_setting("password_hash", Some(&hash));
                                    self.settings_password_input.clear();
                                    r
                                }
                                None => {
                                    self.status = "Error hashing password".to_string();
                                    Ok(())
                                }
                            }
                        } else {
                            Ok(())
                        };
                        if let Err(e) = pwd_result {
                            self.status = format!("DB error: {e}");
                        }

                        match self.config.save(&self.config_path) {
                            Ok(_) => self.status = "Settings saved.".to_string(),
                            Err(e) => self.status = format!("Error saving config: {e}"),
                        }
                        self.downloader.max_concurrent = self.config.backup.max_concurrent;
                        self.downloader.use_bundled_ytdlp = self.config.backup.use_bundled_ytdlp;
                        self.downloader.use_pot_provider = self.config.backup.use_pot_provider;
                        self.downloader.subtitle_defaults = self.config.subtitles.clone();
                        self.downloader.youtube_player_clients = self.config.backup.youtube_player_clients.clone();
                        self.downloader.convert_defaults = self.config.convert.clone();
                        if dir_changed {
                            self.channels_root = new_dir.clone();
                            self.library_root = new_dir
                                .parent()
                                .map(|p| p.to_path_buf())
                                .unwrap_or_else(|| new_dir.clone());
                            self.downloader.channels_root = new_dir;
                            let _ = std::fs::create_dir_all(&self.channels_root);
                            let _ = std::fs::create_dir_all(&self.library_root);
                            for &p in Platform::all() {
                                let _ = std::fs::create_dir_all(platform::platform_root(&self.channels_root, p));
                            }
                            self.rescan();
                        }
                        // Re-bind a running server so the new interface takes effect now.
                        if bind_changed && self.web_server_running {
                            self.stop_web_server();
                            self.start_web_server();
                            self.status = "Settings saved. Web server re-bound.".to_string();
                        }
                    }
                    ui.label(
                        egui::RichText::new("Theme previews immediately; other changes apply on save.")
                            .weak()
                            .small(),
                    );
                });
            });
        });
    }

    fn detail_panel(&mut self, ctx: &egui::Context) {
        let selected_id = match &self.selected_video {
            Some(id) => id.clone(),
            None => return,
        };
        let Some((video, _channel_name)) = self.find_video_by_id(&selected_id) else {
            self.selected_video = None;
            return;
        };

        let is_watched = self.watched.contains(&selected_id);
        let resume_pos = self.resume_positions.get(&selected_id).copied();

        egui::TopBottomPanel::bottom("detail")
            .resizable(true)
            .default_height(220.0)
            .min_height(80.0)
            .show(ctx, |ui| {
                ui.add_space(4.0);
                ui.horizontal(|ui| {
                    ui.heading(&video.title);

                    if video.video_path.is_some() {
                        if ui.button("▶ Play").clicked() {
                            if let Some(p) = video.video_path.clone() {
                                self.play_with_tracking(&p, selected_id.clone());
                            }
                        }
                        if let Some(pos) = resume_pos {
                            if pos > 5.0 {
                                let label = format!("⏩ Resume ({})", format_duration(pos));
                                if ui.button(label).clicked() {
                                    if let Some(p) = video.video_path.clone() {
                                        self.play_with_tracking(&p, selected_id.clone());
                                    }
                                }
                                if ui.small_button("✖ clear position").clicked() {
                                    let _ = self.db.clear_position(&selected_id);
                                    self.resume_positions.remove(&selected_id);
                                }
                            }
                        }
                    }

                    if let Some(p) = video.video_path.clone() {
                        if ui.button("📁 Show file").clicked() {
                            self.open_in_file_manager(&p);
                        }
                    }

                    let watched_label = if is_watched { "✓ Watched" } else { "○ Mark watched" };
                    if ui.button(watched_label).clicked() {
                        self.toggle_watched(&selected_id);
                    }

                    if video.has_live_chat {
                        ui.label(egui::RichText::new("💬 live chat").small().weak());
                    }

                    ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                        if ui.button("✖ close").clicked() {
                            self.selected_video = None;
                        }
                        ui.label(
                            egui::RichText::new(format!("id: {}", video.id))
                                .monospace()
                                .weak(),
                        );
                    });
                });

                ui.horizontal(|ui| {
                    if let Some(date) = video.upload_date.as_deref().map(format_upload_date) {
                        if !date.is_empty() {
                            ui.label(
                                egui::RichText::new(format!("📅 {date}"))
                                    .small()
                                    .weak(),
                            );
                            ui.label(egui::RichText::new("·").weak());
                        }
                    }
                    if let Some(secs) = video.duration_secs {
                        ui.label(egui::RichText::new(format_duration(secs)).small().weak());
                        ui.label(egui::RichText::new("·").weak());
                    }
                    if let Some(bytes) = video.file_size {
                        ui.label(egui::RichText::new(format_size(bytes)).small().weak());
                    }
                });

                ui.separator();

                // ── Note editor ──────────────────────────────────────
                // Lazy-load the note from the DB the first time we render
                // for a given video. Subsequent frames edit the in-memory
                // buffer; we persist on focus-loss / explicit Save.
                if self.note_target.as_deref() != Some(selected_id.as_str()) {
                    self.note_buffer = self.db
                        .get_note("video", &selected_id)
                        .ok()
                        .flatten()
                        .unwrap_or_default();
                    self.note_target = Some(selected_id.clone());
                }
                ui.horizontal(|ui| {
                    ui.label(egui::RichText::new("📝 Note").small().strong());
                    let resp = ui.add(
                        egui::TextEdit::singleline(&mut self.note_buffer)
                            .desired_width(f32::INFINITY)
                            .hint_text("Anything you want to remember — searchable"),
                    );
                    // Persist when the field loses focus (matches how the
                    // web UI saves on modal close) so we don't write per
                    // keystroke.
                    if resp.lost_focus() {
                        let _ = self.db.set_note("video", &selected_id, &self.note_buffer);
                    }
                });

                ui.separator();

                let description = self.description(&video);
                egui::ScrollArea::vertical()
                    .auto_shrink([false, false])
                    .show(ui, |ui| {
                        ui.add(egui::Label::new(description).wrap());
                    });
            });
    }

    fn channel_grid(&mut self, ctx: &egui::Context, ui: &mut egui::Ui) {
        let density = self.card_density;
        let thumb_w = (176.0 * density).round();
        let thumb_h = (99.0 * density).round();
        let card_w = thumb_w + 4.0; // 2px border each side

        egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| {
            let available_w = ui.available_width();
            let cols = ((available_w / (card_w + 12.0)) as usize).max(1);
            let n = self.library.len();

            for row_start in (0..n).step_by(cols) {
                ui.horizontal(|ui| {
                    for i in row_start..(row_start + cols).min(n) {
                        // Collect data we need without holding a borrow into self.library
                        let (name, total, size_bytes, thumb_path) = {
                            let ch = &self.library[i];
                            let thumb = ch.videos.iter()
                                .chain(ch.playlists.iter().flat_map(|p| p.videos.iter()))
                                .find_map(|v| v.thumb_path.clone());
                            (ch.name.clone(), ch.total_videos(), ch.total_size_cached, thumb)
                        };

                        ui.push_id(i, |ui| {
                            let (card_rect, card_resp) = ui.allocate_exact_size(
                                egui::vec2(card_w, thumb_h + 46.0 * density),
                                egui::Sense::click(),
                            );
                            let visuals = ui.visuals();
                            let border_color = if card_resp.hovered() {
                                visuals.selection.bg_fill
                            } else {
                                visuals.widgets.noninteractive.bg_stroke.color
                            };
                            ui.painter().rect_stroke(card_rect, 6.0, egui::Stroke::new(2.0, border_color));

                            let thumb_rect = egui::Rect::from_min_size(
                                card_rect.min + egui::vec2(2.0, 2.0),
                                egui::vec2(thumb_w, thumb_h),
                            );
                            let texture = thumb_path.as_ref().and_then(|p| self.texture(ctx, p));
                            match &texture {
                                Some(handle) => {
                                    egui::Image::new(handle)
                                        .maintain_aspect_ratio(true)
                                        .paint_at(ui, thumb_rect);
                                }
                                None => {
                                    ui.painter().rect_filled(thumb_rect, 4.0, egui::Color32::from_gray(30));
                                    ui.painter().text(
                                        thumb_rect.center(),
                                        egui::Align2::CENTER_CENTER,
                                        "📺",
                                        egui::FontId::proportional(28.0 * density),
                                        egui::Color32::from_gray(100),
                                    );
                                }
                            }

                            let text_top = card_rect.min + egui::vec2(6.0, thumb_h + 6.0);
                            ui.painter().text(
                                text_top,
                                egui::Align2::LEFT_TOP,
                                &name,
                                egui::FontId::proportional(13.0 * density),
                                visuals.text_color(),
                            );
                            let sub = format!(
                                "{} video{}{}",
                                total,
                                if total == 1 { "" } else { "s" },
                                if size_bytes > 0 { format!(" · {}", format_size(size_bytes)) } else { String::new() }
                            );
                            ui.painter().text(
                                text_top + egui::vec2(0.0, 16.0 * density),
                                egui::Align2::LEFT_TOP,
                                &sub,
                                egui::FontId::proportional(11.0 * density),
                                visuals.weak_text_color(),
                            );

                            if card_resp.clicked() {
                                self.sidebar_view = SidebarView::Channel(i);
                                self.selected_video = None;
                            }
                        });
                        ui.add_space(8.0);
                    }
                });
                ui.add_space(8.0);
            }
        });
    }

    fn music_view(&mut self, ui: &mut egui::Ui) {
        ui.heading("Music");
        if self.music_library.is_empty() {
            ui.label(egui::RichText::new(
                "No tracks yet. Download audio with Music mode in the Downloads panel."
            ).weak());
            return;
        }
        let mut current_artist = String::new();
        egui::ScrollArea::vertical().show(ui, |ui| {
            for track in &self.music_library {
                if track.artist != current_artist {
                    current_artist = track.artist.clone();
                    ui.add_space(6.0);
                    ui.label(egui::RichText::new(&track.artist).strong());
                    ui.separator();
                }
                ui.push_id(&track.id, |ui| {
                    ui.horizontal(|ui| {
                        let dur = track.duration_secs
                            .map(|s| {
                                let m = s as u64 / 60;
                                let sec = s as u64 % 60;
                                format!("{m}:{sec:02}")
                            })
                            .unwrap_or_default();
                        if ui.selectable_label(false, &track.title).clicked() {
                            if let Err(e) = Command::new(&self.config.player.command)
                                .arg(&track.path)
                                .spawn()
                            {
                                self.status = format!("Could not open player: {e}");
                            }
                        }
                        if !dur.is_empty() {
                            ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                                ui.label(egui::RichText::new(dur).small().weak());
                            });
                        }
                    });
                });
            }
        });
    }

    fn video_list(&mut self, ctx: &egui::Context, ui: &mut egui::Ui) {
        if self.sidebar_view == SidebarView::Channels {
            self.channel_grid(ctx, ui);
            return;
        }
        if self.sidebar_view == SidebarView::Music {
            self.music_view(ui);
            return;
        }
        let cards = self.cards_take();
        let show_channel = !matches!(self.sidebar_view, SidebarView::Channel(_) | SidebarView::Playlist(_, _));

        // Channel metadata banner
        if let SidebarView::Channel(ci) = self.sidebar_view {
            if let Some(ch) = self.library.get(ci) {
                if let Some(meta) = &ch.meta {
                    ui.group(|ui| {
                        ui.horizontal(|ui| {
                            if let Some(name) = &meta.uploader {
                                ui.strong(name);
                            }
                            if let Some(subs) = meta.subscriber_count {
                                ui.label(
                                    egui::RichText::new(format!("{} subscribers", format_subs(subs)))
                                        .weak(),
                                );
                            }
                            if let Some(url) = &meta.channel_url {
                                ui.hyperlink_to("Open on YouTube", url);
                            }
                        });
                    });
                }
            }
        }

        // Bulk mode toolbar
        ui.horizontal(|ui| {
            let label_text = if self.bulk_mode {
                format!("{} videos", cards.len())
            } else {
                format!("{} videos", cards.len())
            };
            ui.label(label_text);

            if !self.search.trim().is_empty() {
                ui.label(
                    egui::RichText::new(format!("(filtered by \"{}\")", self.search.trim())).weak(),
                );
            }

            ui.separator();

            if ui.selectable_label(self.bulk_mode, "☑ Select").clicked() {
                self.bulk_mode = !self.bulk_mode;
                if !self.bulk_mode {
                    self.bulk_selected.clear();
                }
            }

            if self.bulk_mode && !self.bulk_selected.is_empty() {
                ui.separator();
                let n = self.bulk_selected.len();
                ui.label(format!("{n} selected"));
                if ui.button("✓ Watched").clicked() {
                    self.bulk_mark_watched(true);
                    self.bulk_mode = false;
                }
                if ui.button("○ Unwatched").clicked() {
                    self.bulk_mark_watched(false);
                    self.bulk_mode = false;
                }
                if ui.button("★ Favourite").on_hover_text("Mark every selected video as favourite").clicked() {
                    self.bulk_set_flag("favourite", true);
                    self.bulk_mode = false;
                }
                if ui.button("🔖 Bookmark").on_hover_text("Mark every selected video as bookmarked").clicked() {
                    self.bulk_set_flag("bookmark", true);
                    self.bulk_mode = false;
                }
                if ui.button("⏳ Waiting").on_hover_text("Add every selected video to the waiting list").clicked() {
                    self.bulk_set_flag("waiting", true);
                    self.bulk_mode = false;
                }
            }

            ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
                ui.selectable_value(&mut self.sort_mode, SortMode::DateDesc, "Newest");
                ui.selectable_value(&mut self.sort_mode, SortMode::DateAsc, "Oldest");
                ui.selectable_value(&mut self.sort_mode, SortMode::SizeDesc, "Largest");
                ui.selectable_value(&mut self.sort_mode, SortMode::SizeAsc, "Smallest");
                ui.selectable_value(&mut self.sort_mode, SortMode::DurationDesc, "Longest");
                ui.selectable_value(&mut self.sort_mode, SortMode::DurationAsc, "Shortest");
                ui.selectable_value(&mut self.sort_mode, SortMode::Title, "Title");
                ui.label(egui::RichText::new("Sort:").weak());
            });
        });

        ui.separator();

        if cards.is_empty() {
            ui.add_space(20.0);
            ui.vertical_centered(|ui| {
                ui.label(egui::RichText::new("Nothing here.").weak());
                if !matches!(self.sidebar_view, SidebarView::ContinueWatching) {
                    ui.label(
                        egui::RichText::new(
                            "Drop a yt-dlp download into channels/<name>/, or use the Downloads panel.",
                        )
                        .small()
                        .weak(),
                    );
                }
            });
            return;
        }

        let density = self.card_density;
        egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| {
            let thumb_w = (176.0 * density).round();
            let thumb_h = (99.0 * density).round();
            let thumb_size = egui::vec2(thumb_w, thumb_h);

            for card in &cards {
                let selected = self.selected_video.as_deref() == Some(card.id.as_str());
                let is_playing = self.currently_playing.as_deref() == Some(card.id.as_str());
                let bulk_checked = self.bulk_selected.contains(&card.id);
                let mut clicked_card = false;
                let mut play_card = false;
                let mut toggle_watched_card = false;
                // Flag toggles deferred outside the row closure so we can
                // mutate `self.flags` + DB without fighting the borrow checker.
                let mut toggle_flag_card: Option<&'static str> = None;

                ui.horizontal(|ui| {
                    let (rect, resp) = ui.allocate_exact_size(thumb_size, egui::Sense::click());
                    let texture = card.thumb_path.as_ref().and_then(|p| self.texture(ctx, p));
                    match &texture {
                        Some(handle) => {
                            egui::Image::new(handle)
                                .maintain_aspect_ratio(true)
                                .paint_at(ui, rect);
                        }
                        None => {
                            ui.painter().rect_filled(rect, 4.0, egui::Color32::from_gray(38));
                            ui.painter().text(
                                rect.center(),
                                egui::Align2::CENTER_CENTER,
                                "▶",
                                egui::FontId::proportional(26.0 * density),
                                egui::Color32::from_gray(110),
                            );
                        }
                    }

                    if selected {
                        ui.painter().rect_stroke(
                            rect,
                            4.0,
                            egui::Stroke::new(2.0, egui::Color32::from_rgb(120, 170, 230)),
                        );
                    }
                    if is_playing {
                        ui.painter().rect_stroke(
                            rect,
                            4.0,
                            egui::Stroke::new(2.0, egui::Color32::from_rgb(110, 200, 110)),
                        );
                    }
                    if bulk_checked {
                        ui.painter().rect_stroke(
                            rect,
                            4.0,
                            egui::Stroke::new(3.0, egui::Color32::from_rgb(180, 130, 240)),
                        );
                    }
                    if card.watched {
                        ui.painter().rect_filled(
                            egui::Rect::from_min_size(
                                rect.min,
                                egui::vec2(rect.width(), rect.height() * 0.18),
                            ),
                            0.0,
                            egui::Color32::from_rgba_premultiplied(30, 140, 60, 200),
                        );
                        ui.painter().text(
                            rect.min + egui::vec2(4.0, 2.0),
                            egui::Align2::LEFT_TOP,
                            "✓ watched",
                            egui::FontId::proportional(10.0 * density),
                            egui::Color32::WHITE,
                        );
                    }

                    if resp.clicked() {
                        clicked_card = true;
                    }
                    if resp.double_clicked() {
                        play_card = true;
                    }

                    ui.vertical(|ui| {
                        let title_color = if card.watched {
                            ui.visuals().weak_text_color()
                        } else {
                            ui.visuals().text_color()
                        };
                        if ui
                            .selectable_label(
                                selected,
                                egui::RichText::new(&card.title)
                                    .strong()
                                    .color(title_color),
                            )
                            .clicked()
                        {
                            clicked_card = true;
                        }
                        ui.horizontal(|ui| {
                            if show_channel {
                                ui.label(egui::RichText::new(&card.channel_name).small().weak());
                                ui.label(egui::RichText::new("·").weak());
                            }
                            ui.label(egui::RichText::new(&card.id).small().monospace().weak());
                            if let Some(date) = card.upload_date.as_deref().map(format_upload_date) {
                                if !date.is_empty() {
                                    ui.label(egui::RichText::new("·").weak());
                                    ui.label(egui::RichText::new(date).small().weak());
                                }
                            }
                            if let Some(secs) = card.duration_secs {
                                ui.label(egui::RichText::new("·").weak());
                                ui.label(egui::RichText::new(format_duration(secs)).small().weak());
                            }
                            if let Some(bytes) = card.file_size {
                                ui.label(egui::RichText::new("·").weak());
                                ui.label(egui::RichText::new(format_size(bytes)).small().weak());
                            }
                            if card.has_live_chat {
                                ui.label(egui::RichText::new("· 💬").small().weak());
                            }
                            if card.video_path.is_none() {
                                ui.label(
                                    egui::RichText::new("· no video file")
                                        .small()
                                        .color(egui::Color32::from_rgb(200, 140, 90)),
                                );
                            }
                        });
                        ui.horizontal(|ui| {
                            if self.bulk_mode {
                                let chk_label = if bulk_checked { "☑" } else { "☐" };
                                if ui.small_button(chk_label).clicked() {
                                    clicked_card = true; // handled below
                                }
                            } else {
                                if card.video_path.is_some() && ui.small_button("▶ Play").clicked() {
                                    play_card = true;
                                }
                                if let Some(pos) = card.resume_pos {
                                    if pos > 5.0 && ui.small_button(format!("⏩ {}", format_duration(pos))).clicked() {
                                        play_card = true;
                                    }
                                }
                                if ui.small_button("Details").clicked() {
                                    clicked_card = true;
                                }
                                let w_label = if card.watched { "✓" } else { "○" };
                                if ui.small_button(w_label).on_hover_text("Toggle watched").clicked() {
                                    toggle_watched_card = true;
                                }
                                let fav_label = if card.favourite { "★" } else { "☆" };
                                if ui.small_button(fav_label).on_hover_text("Toggle favourite").clicked() {
                                    toggle_flag_card = Some("favourite");
                                }
                                let bm_label = if card.bookmark { "🔖" } else { "🔖̲" };
                                if ui.small_button(bm_label).on_hover_text("Toggle bookmark").clicked() {
                                    toggle_flag_card = Some("bookmark");
                                }
                                let wait_label = if card.waiting { "⏳" } else { "⏰" };
                                if ui.small_button(wait_label).on_hover_text("Toggle waiting").clicked() {
                                    toggle_flag_card = Some("waiting");
                                }
                            }
                        });
                    });
                });

                if self.bulk_mode {
                    if clicked_card {
                        let id = card.id.clone();
                        if self.bulk_selected.contains(&id) {
                            self.bulk_selected.remove(&id);
                        } else {
                            self.bulk_selected.insert(id);
                        }
                    }
                } else if play_card {
                    if let Some(p) = card.video_path.clone() {
                        let id = card.id.clone();
                        self.play_with_tracking(&p, id);
                    }
                    self.selected_video = Some(card.id.clone());
                } else if clicked_card {
                    self.selected_video = Some(card.id.clone());
                }
                if toggle_watched_card {
                    let id = card.id.clone();
                    self.toggle_watched(&id);
                }
                if let Some(flag) = toggle_flag_card {
                    let id = card.id.clone();
                    self.toggle_video_flag(&id, flag);
                }

                ui.separator();
            }
        });
        self.cards_cache = cards;
    }
}

impl eframe::App for App {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        // ── Global UI zoom sync + persistence ───────────────────────────
        // egui's built-in Ctrl +/-/0 (and our Settings slider) mutate
        // ctx.zoom_factor() directly. Mirror it into config and persist on
        // a short debounce so the chosen scale survives restarts without
        // writing config.toml on every frame of a slider drag / key repeat.
        let zoom = ctx.zoom_factor();
        if (zoom - self.config.ui.ui_scale).abs() > f32::EPSILON {
            self.config.ui.ui_scale = zoom;
            self.scale_save_at =
                Some(Instant::now() + std::time::Duration::from_millis(500));
            // Ensure the debounce fires even if the UI would otherwise idle.
            ctx.request_repaint_after(std::time::Duration::from_millis(550));
        }
        if let Some(at) = self.scale_save_at {
            if Instant::now() >= at {
                let _ = self.config.save(&self.config_path);
                self.scale_save_at = None;
            }
        }

        // ── System-tray event drain ─────────────────────────────────────
        // Tray menu activations arrive on a background-thread channel.
        // Drain them all each frame and translate into viewport commands.
        // The user pressing the X button on the window will request a
        // close; if a tray is available we intercept it and hide instead
        // (minimize-to-tray). The Quit menu item sets `quitting=true`
        // first so the close request is honored on the next pass.
        // Ctrl+Q always quits, regardless of tray. Without this the user
        // has no keyboard escape from minimize-to-tray when the tray icon
        // happens to be invisible (e.g. GNOME without the AppIndicator
        // extension). Checked early so it wins over close-cancellation.
        if ctx.input(|i| i.modifiers.ctrl && i.key_pressed(egui::Key::Q)) {
            self.quitting = true;
            ctx.send_viewport_cmd(egui::ViewportCommand::Close);
        }

        if let Some(handle) = &self.tray {
            while let Ok(evt) = handle.events.try_recv() {
                match evt {
                    crate::tray::TrayEvent::Show => {
                        ctx.send_viewport_cmd(egui::ViewportCommand::Visible(true));
                        ctx.send_viewport_cmd(egui::ViewportCommand::Focus);
                    }
                    crate::tray::TrayEvent::Hide => {
                        ctx.send_viewport_cmd(egui::ViewportCommand::Visible(false));
                    }
                    crate::tray::TrayEvent::Quit => {
                        self.quitting = true;
                        ctx.send_viewport_cmd(egui::ViewportCommand::Close);
                    }
                }
            }
            // Minimize-to-tray: only intercept the close button when the
            // user has opted in via config. Default-off because users on
            // desktops without a working StatusNotifier host (e.g. GNOME
            // sans AppIndicator extension) would otherwise lose access
            // to the window entirely. Ctrl+Q is always an escape.
            if self.config.ui.minimize_to_tray {
                let close_requested = ctx.input(|i| i.viewport().close_requested());
                if close_requested && !self.quitting {
                    ctx.send_viewport_cmd(egui::ViewportCommand::CancelClose);
                    ctx.send_viewport_cmd(egui::ViewportCommand::Visible(false));
                }
            }
        }

        self.downloader.poll();
        // Snapshot the previous-frame running state BEFORE check_notifications
        // overwrites prev_job_states with the current frame's. Otherwise
        // was_running tracks the wrong frame and the auto-rescan never fires.
        let was_running_prev = self.prev_job_states.values().any(|&s| s == JobState::Running);
        self.check_notifications();

        let any_running = self.downloader.any_running();
        if was_running_prev && !any_running {
            self.rescan();
        }

        if any_running {
            ctx.request_repaint_after(std::time::Duration::from_millis(250));
        }

        // Scheduled channel checks
        if self.config.scheduler.enabled && !any_running {
            // Defensive clamp: a manually-edited config.toml with 0 hours
            // would otherwise re-fire every frame.
            let hours = self.config.scheduler.interval_hours.max(1);
            let interval = std::time::Duration::from_secs(hours as u64 * 3600);
            let due = self.last_scheduled_check
                .map_or(true, |t| t.elapsed() >= interval);
            if due {
                self.last_scheduled_check = Some(Instant::now());
                self.run_scheduled_check();
            }
        }

        // Poll mpv position updates
        if let Some(rx) = &self.mpv_rx {
            while let Ok((video_id, pos)) = rx.try_recv() {
                let _ = self.db.set_position(&video_id, pos);
                self.resume_positions.insert(video_id, pos);
            }
        }

        // Drain any decoded thumbnails from the worker thread
        while let Ok((path, img)) = self.thumb_result_rx.try_recv() {
            self.thumb_pending.remove(&path);
            let handle = img.map(|color_image| {
                ctx.load_texture(
                    path.to_string_lossy(),
                    color_image,
                    egui::TextureOptions::LINEAR,
                )
            });
            self.textures.insert(path, handle);
        }

        // A cookies.txt was chosen in the file dialog — validate and install it.
        while let Ok(path) = self.cookies_pick_rx.try_recv() {
            match std::fs::read_to_string(&path) {
                Ok(content) => match crate::web::write_cookies(&content) {
                    Ok(n) => {
                        self.settings_cookies_status = format!("{n} cookie(s) loaded");
                        self.status = format!("Cookies imported ({n} entries)");
                    }
                    Err(e) => self.status = format!("Cookies error: {e}"),
                },
                Err(e) => self.status = format!("Could not read {}: {e}", path.display()),
            }
        }
        // User picked a backup destination — copy yt-offline.db there.
        while let Ok(dest) = self.backup_save_rx.try_recv() {
            let src = self.channels_root.join("yt-offline.db");
            match std::fs::copy(&src, &dest) {
                Ok(bytes) => self.status = format!(
                    "Backup saved ({} → {})",
                    format_size(bytes),
                    dest.display(),
                ),
                Err(e) => self.status = format!("Backup failed: {e}"),
            }
        }
        // User picked a backup file to import. Merge it in, then refresh
        // the in-memory caches so the next render sees the new rows
        // without waiting for a rescan.
        while let Ok(src) = self.backup_open_rx.try_recv() {
            match self.db.restore_from_backup(&src) {
                Ok(s) => {
                    self.watched = self.db.get_watched().unwrap_or_default();
                    self.resume_positions = self.db.get_positions().unwrap_or_default();
                    self.flags = self.db.get_video_flags().unwrap_or_default();
                    self.folders = self.db.list_folders().unwrap_or_default();
                    // Rescan so channel rows pick up new folder assignments.
                    self.rescan();
                    self.status = format!(
                        "Imported: {}W · {}P · {}F · {}flags · {}folders · {}assigns · {}notes",
                        s.watched_added, s.positions_added, s.options_added,
                        s.flags_added, s.folders_added, s.assignments_added, s.notes_added,
                    );
                }
                Err(e) => self.status = format!("Restore failed: {e}"),
            }
        }

        self.top_bar(ctx);
        // Floating sub-dialogs that overlay any screen.
        self.channel_options_window(ctx);
        self.folder_manager_window(ctx);
        self.move_to_folder_window(ctx);

        match self.current_screen {
            Screen::Library => {
                self.channel_panel(ctx);
                if self.show_downloads {
                    self.downloads_panel(ctx);
                }
                self.detail_panel(ctx);
                egui::CentralPanel::default().show(ctx, |ui| {
                    self.video_list(ctx, ui);
                });
            }
            Screen::Settings => self.settings_screen(ctx),
            Screen::Stats => self.stats_screen(ctx),
            Screen::Maintenance => self.maintenance_screen(ctx),
        }
    }
}

#[cfg(unix)]
fn spawn_mpv_tracker(sock_path: String, video_id: String, tx: std::sync::mpsc::Sender<(String, f64)>) {
    use std::io::{Read, Write};
    use std::os::unix::net::UnixStream;
    use std::time::Duration;

    let mut stream = None;
    for _ in 0..20 {
        std::thread::sleep(Duration::from_millis(500));
        if let Ok(s) = UnixStream::connect(&sock_path) {
            stream = Some(s);
            break;
        }
    }
    let mut stream = match stream {
        Some(s) => s,
        None => return,
    };
    stream.set_read_timeout(Some(Duration::from_secs(3))).ok();

    let mut buf = [0u8; 4096];
    loop {
        std::thread::sleep(Duration::from_secs(5));
        let query = b"{\"command\":[\"get_property\",\"time-pos\"]}\n";
        if stream.write_all(query).is_err() {
            break;
        }
        match stream.read(&mut buf) {
            Ok(0) => break,
            Ok(n) => {
                for chunk in buf[..n].split(|&b| b == b'\n').filter(|c| !c.is_empty()) {
                    if let Ok(s) = std::str::from_utf8(chunk) {
                        if let Ok(val) = serde_json::from_str::<serde_json::Value>(s) {
                            if let Some(pos) = val.get("data").and_then(|v| v.as_f64()) {
                                if tx.send((video_id.clone(), pos)).is_err() {
                                    return;
                                }
                            }
                        }
                    }
                }
            }
            Err(e)
                if e.kind() == std::io::ErrorKind::WouldBlock
                    || e.kind() == std::io::ErrorKind::TimedOut => {}
            Err(_) => break,
        }
    }
}

fn decode_thumbnail_image(path: &Path) -> Option<egui::ColorImage> {
    let image = image::open(path).ok()?;
    let image = image.thumbnail(384, 216);
    let rgba = image.to_rgba8();
    let (w, h) = (rgba.width() as usize, rgba.height() as usize);
    Some(egui::ColorImage::from_rgba_unmultiplied([w, h], rgba.as_raw()))
}

fn file_label(path: &Path) -> String {
    path.file_name()
        .map(|n| n.to_string_lossy().into_owned())
        .unwrap_or_else(|| path.to_string_lossy().into_owned())
}

fn format_duration(secs: f64) -> String {
    let secs = secs as u64;
    let h = secs / 3600;
    let m = (secs % 3600) / 60;
    let s = secs % 60;
    if h > 0 { format!("{h}:{m:02}:{s:02}") } else { format!("{m}:{s:02}") }
}

/// Convert yt-dlp's native `YYYYMMDD` upload-date string into `YYYY-MM-DD`
/// for display. Returns an empty string when input doesn't look like a date
/// so callers can decide whether to skip the row entirely.
fn format_upload_date(yyyymmdd: &str) -> String {
    if yyyymmdd.len() < 8 || !yyyymmdd.chars().all(|c| c.is_ascii_digit()) {
        return String::new();
    }
    format!("{}-{}-{}", &yyyymmdd[..4], &yyyymmdd[4..6], &yyyymmdd[6..8])
}

fn format_size(bytes: u64) -> String {
    if bytes >= 1_073_741_824 {
        format!("{:.1} GB", bytes as f64 / 1_073_741_824.0)
    } else if bytes >= 1_048_576 {
        format!("{:.0} MB", bytes as f64 / 1_048_576.0)
    } else {
        format!("{:.0} KB", bytes as f64 / 1_024.0)
    }
}

/// Format a number of seconds as `Hh Mm` (or `Mm` under 1 hour, `0h` empty).
fn format_hours(secs: f64) -> String {
    if secs < 60.0 { return "0h".to_string(); }
    let h = (secs / 3600.0) as u64;
    let m = ((secs as u64 % 3600) / 60) as u64;
    if h > 0 { format!("{h}h {m}m") } else { format!("{m}m") }
}

/// Format the week-start unix time as `M/D` for an axis label.
fn week_label(unix: u64) -> String {
    // Reproduce just enough calendar math to render M/D without pulling in a
    // chrono dep: count days since 1970-01-01, then walk the year/month table.
    let days = (unix / 86_400) as i64;
    let (mut y, mut d) = (1970i64, days);
    loop {
        let ly = is_leap(y as u32);
        let yd = if ly { 366 } else { 365 };
        if d < yd { break; }
        d -= yd; y += 1;
    }
    let months = if is_leap(y as u32) {
        [31,29,31,30,31,30,31,31,30,31,30,31]
    } else {
        [31,28,31,30,31,30,31,31,30,31,30,31]
    };
    let mut m = 0usize;
    while m < 12 && d >= months[m] as i64 { d -= months[m] as i64; m += 1; }
    format!("{}/{}", m as u32 + 1, d + 1)
}
fn is_leap(y: u32) -> bool { (y % 4 == 0 && y % 100 != 0) || y % 400 == 0 }

/// Draw a simple bar chart of `(label, value, tooltip)` rows. Heights scale
/// to the max value in the iterator.
fn draw_bars<I>(ui: &mut egui::Ui, items: I)
where I: IntoIterator<Item = (String, f32, String)>,
{
    let rows: Vec<_> = items.into_iter().collect();
    if rows.is_empty() { return; }
    let max = rows.iter().map(|r| r.1).fold(1.0f32, f32::max);
    let chart_h = 70.0;
    ui.horizontal(|ui| {
        ui.spacing_mut().item_spacing.x = 2.0;
        for (label, value, tip) in &rows {
            ui.vertical(|ui| {
                let h = (value / max) * chart_h;
                let bar_w = 22.0;
                let (rect, resp) = ui.allocate_exact_size(
                    egui::vec2(bar_w, chart_h + 14.0),
                    egui::Sense::hover(),
                );
                let bar_rect = egui::Rect::from_min_max(
                    egui::pos2(rect.min.x, rect.max.y - 14.0 - h),
                    egui::pos2(rect.max.x, rect.max.y - 14.0),
                );
                ui.painter().rect_filled(
                    bar_rect, 2.0,
                    ui.visuals().selection.bg_fill,
                );
                ui.painter().text(
                    egui::pos2(rect.center().x, rect.max.y),
                    egui::Align2::CENTER_BOTTOM,
                    label,
                    egui::FontId::proportional(9.0),
                    ui.visuals().weak_text_color(),
                );
                resp.on_hover_text(tip);
            });
        }
    });
}

fn format_subs(n: u64) -> String {
    if n >= 1_000_000 {
        format!("{:.1}M", n as f64 / 1_000_000.0)
    } else if n >= 1_000 {
        format!("{:.1}K", n as f64 / 1_000.0)
    } else {
        n.to_string()
    }
}