// SPDX-License-Identifier: AGPL-3.0-or-later
//
// BirdWatch Relay — self-hosted, end-to-end encrypted push relay for Frigate NVR.
// Subscribes to Frigate's /ws WebSocket, encrypts each event payload with each
// registered device's X25519 public key (NaCl sealed box), and forwards the
// ciphertext via Firebase Cloud Messaging. Google FCM only ever sees ciphertext
// and a device token — never event content.

package main

import (
	"context"
	"errors"
	"log/slog"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/cyrilinait/birdwatch-relay/internal/config"
	"github.com/cyrilinait/birdwatch-relay/internal/fcm"
	"github.com/cyrilinait/birdwatch-relay/internal/frigate"
	"github.com/cyrilinait/birdwatch-relay/internal/handlers"
	"github.com/cyrilinait/birdwatch-relay/internal/notify"
	"github.com/cyrilinait/birdwatch-relay/internal/storage"
)

func main() {
	logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
	slog.SetDefault(logger)

	cfg, err := config.Load()
	if err != nil {
		logger.Error("config load failed", "err", err)
		os.Exit(1)
	}

	store, err := storage.Open(cfg.DBPath)
	if err != nil {
		logger.Error("storage open failed", "err", err, "path", cfg.DBPath)
		os.Exit(1)
	}
	defer store.Close()

	rootCtx, cancelRoot := context.WithCancel(context.Background())
	defer cancelRoot()

	sender, err := fcm.New(rootCtx, cfg.FirebaseKeyPath)
	if err != nil {
		logger.Error("fcm init failed", "err", err)
		os.Exit(1)
	}

	dispatcher := notify.NewDispatcher(store, sender)

	frigateClient, err := frigate.NewClient(
		cfg.FrigateURL,
		cfg.FrigateUser,
		cfg.FrigatePassword,
		func(payload []byte) {
			ctx, cancel := context.WithTimeout(rootCtx, 15*time.Second)
			defer cancel()
			dispatcher.Send(ctx, payload)
		},
	)
	if err != nil {
		logger.Error("frigate client init failed", "err", err)
		os.Exit(1)
	}
	go frigateClient.Run(rootCtx)
	logger.Info("frigate ws subscriber started", "url", cfg.FrigateURL)

	mux := http.NewServeMux()
	handlers.Register(mux, store, cfg)

	srv := &http.Server{
		Addr:              ":" + cfg.Port,
		Handler:           mux,
		ReadHeaderTimeout: 5 * time.Second,
		ReadTimeout:       30 * time.Second,
		WriteTimeout:      30 * time.Second,
		IdleTimeout:       120 * time.Second,
		MaxHeaderBytes:    8 * 1024,
	}

	go func() {
		logger.Info("birdwatch-relay listening", "port", cfg.Port)
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			logger.Error("http server failed", "err", err)
			os.Exit(1)
		}
	}()

	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
	<-stop
	logger.Info("shutdown signal received")

	cancelRoot()

	shutdownCtx, cancelShutdown := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancelShutdown()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		logger.Error("shutdown error", "err", err)
	}
}