// SPDX-License-Identifier: GPL-3.0-or-later

// enodia-sentinel-go is the experimental Phase 1 sidecar. Python remains the
// production implementation and behavioral oracle until parity is complete.
package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"

	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/agent"
	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/system"
)

func main() {
	if err := run(); err != nil {
		fmt.Fprintln(os.Stderr, "enodia-sentinel-go:", err)
		os.Exit(1)
	}
}

func run() error {
	once := flag.Bool("once", false, "emit one sweep and exit")
	configPath := flag.String("config", "", "Sentinel TOML path (default: ENODIA_CONFIG or /etc/enodia-sentinel.toml)")
	procRoot := flag.String("proc-root", "/proc", "procfs root")
	fixture := flag.String("fixture", "", "JSON SystemState fixture (parity/testing only)")
	host := flag.String("host", "", "override hostname (parity/testing only)")
	timestamp := flag.String("timestamp", "", "override RFC3339 timestamp (parity/testing only)")
	flag.Parse()

	cfg, err := config.Load(*configPath)
	if err != nil {
		return err
	}
	capture := func() (model.State, error) { return system.Capture(*procRoot) }
	if *fixture != "" {
		capture = func() (model.State, error) {
			var state model.State
			raw, err := os.ReadFile(*fixture)
			if err != nil {
				return state, err
			}
			err = json.Unmarshal(raw, &state)
			return state, err
		}
	}

	runner := agent.New(cfg, capture)
	if *host != "" {
		runner.Host = func() (string, error) { return *host, nil }
	}
	if *timestamp != "" {
		fixed, err := time.Parse(time.RFC3339Nano, *timestamp)
		if err != nil {
			return fmt.Errorf("timestamp: %w", err)
		}
		runner.Now = func() time.Time { return fixed }
	}

	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	encoder := json.NewEncoder(os.Stdout)
	encoder.SetEscapeHTML(false)
	return runner.Run(ctx, *once, func(event map[string]any) error {
		return encoder.Encode(event)
	})
}