# SPDX-License-Identifier: GPL-3.0-or-later
"""Phone-push backends. Each separates a pure ``build()`` (testable, no network)
from ``send()`` (does the request), so request construction is unit-tested
without ever hitting the wire."""
from __future__ import annotations

import json
import urllib.parse
import urllib.request

from ..alert import Severity
from ..config import Config

_TIMEOUT = 6

# Severity -> per-service priority/tags.
_NTFY_PRIORITY = {Severity.MEDIUM: "3", Severity.HIGH: "4", Severity.CRITICAL: "5"}
_NTFY_TAGS = {Severity.MEDIUM: "mag", Severity.HIGH: "warning",
              Severity.CRITICAL: "rotating_light"}
_PUSHOVER_PRIORITY = {Severity.MEDIUM: "-1", Severity.HIGH: "0", Severity.CRITICAL: "1"}


def _send(req: urllib.request.Request) -> bool:
    with urllib.request.urlopen(req, timeout=_TIMEOUT) as resp:
        return 200 <= resp.status < 300


class Ntfy:
    name = "ntfy"

    @staticmethod
    def enabled(cfg: Config) -> bool:
        return bool(cfg.notify_ntfy_url and cfg.notify_ntfy_topic)

    @staticmethod
    def build(cfg: Config, notif) -> urllib.request.Request:
        url = f"{cfg.notify_ntfy_url.rstrip('/')}/{cfg.notify_ntfy_topic}"
        headers = {
            "Title": notif.title(),
            "Priority": _NTFY_PRIORITY.get(notif.severity, "4"),
            "Tags": _NTFY_TAGS.get(notif.severity, "warning"),
        }
        if cfg.notify_ntfy_token:
            headers["Authorization"] = f"Bearer {cfg.notify_ntfy_token}"
        return urllib.request.Request(
            url, data=notif.message().encode("utf-8"),
            headers=headers, method="POST")

    @classmethod
    def send(cls, cfg: Config, notif) -> bool:
        return _send(cls.build(cfg, notif))


class Pushover:
    name = "pushover"

    @staticmethod
    def enabled(cfg: Config) -> bool:
        return bool(cfg.notify_pushover_token and cfg.notify_pushover_user)

    @staticmethod
    def build(cfg: Config, notif) -> urllib.request.Request:
        form = urllib.parse.urlencode({
            "token": cfg.notify_pushover_token,
            "user": cfg.notify_pushover_user,
            "title": notif.title(),
            "message": notif.message(),
            "priority": _PUSHOVER_PRIORITY.get(notif.severity, "0"),
        }).encode("utf-8")
        return urllib.request.Request(
            "https://api.pushover.net/1/messages.json", data=form,
            headers={"Content-Type": "application/x-www-form-urlencoded"},
            method="POST")

    @classmethod
    def send(cls, cfg: Config, notif) -> bool:
        return _send(cls.build(cfg, notif))


class Webhook:
    name = "webhook"

    @staticmethod
    def enabled(cfg: Config) -> bool:
        return bool(cfg.notify_webhook_url)

    @staticmethod
    def build(cfg: Config, notif) -> urllib.request.Request:
        body = json.dumps({
            "title": notif.title(),
            "message": notif.message(),
            **notif.to_dict(),
        }).encode("utf-8")
        return urllib.request.Request(
            cfg.notify_webhook_url, data=body,
            headers={"Content-Type": "application/json"}, method="POST")

    @classmethod
    def send(cls, cfg: Config, notif) -> bool:
        return _send(cls.build(cfg, notif))