package cmd

import (
	"context"
	"errors"
	"fmt"
	"log"
	"os"
	"os/signal"
	"path/filepath"
	"strings"
	"syscall"
	"time"

	"github.com/fatih/color"
	"github.com/spf13/cobra"
	"github.com/torrentclaw/unarr/internal/agent"
	"github.com/torrentclaw/unarr/internal/config"
	"github.com/torrentclaw/unarr/internal/engine"
	"github.com/torrentclaw/unarr/internal/funnel"
	"github.com/torrentclaw/unarr/internal/library"
	"github.com/torrentclaw/unarr/internal/library/mediainfo"
	"github.com/torrentclaw/unarr/internal/usenet/download"
	"github.com/torrentclaw/unarr/internal/vpn"
)

// newStartCmd creates the top-level `unarr start` command.
func newStartCmd() *cobra.Command {
	return &cobra.Command{
		Use:   "start",
		Short: "Start the download daemon (foreground)",
		Long: `Start the unarr daemon in the foreground.

Registers with the server, receives download tasks via periodic sync,
and executes them using the configured download method.
Supports torrent, debrid, and usenet downloads concurrently.

The daemon syncs state with the server every 3s when someone is viewing
the web dashboard, or every 60s when idle. Press Ctrl+C to stop
gracefully — active downloads get up to 30 seconds to finish.

Requires: API key, agent ID, and download directory (run 'unarr init' first).

To run as a background service, use 'unarr daemon install' instead.`,
		Example: `  unarr start
  unarr start --config /path/to/config.toml`,
		RunE: func(cmd *cobra.Command, args []string) error {
			return runDaemonStart()
		},
	}
}

// newStopCmd creates the top-level `unarr stop` command.
func newStopCmd() *cobra.Command {
	return &cobra.Command{
		Use:   "stop",
		Short: "Stop the running daemon",
		Long: `Stop the unarr daemon gracefully.

Reads the daemon PID from the state file and sends a graceful stop signal.
Works regardless of whether the daemon was started in the foreground or as a service.

To stop a service-managed daemon and prevent auto-restart, use 'unarr daemon stop' instead.`,
		Example: `  unarr stop`,
		RunE: func(cmd *cobra.Command, args []string) error {
			return stopDaemonByPID()
		},
	}
}

// newDaemonCmd creates `unarr daemon` for administrative subcommands.
func newDaemonCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "daemon <command>",
		Short: "Manage the daemon as a system service",
		Long: `Install, control and inspect the unarr daemon as a system service.

  Linux:   systemd user service (~/.config/systemd/user/unarr.service)
  macOS:   launchd agent (~/Library/LaunchAgents/com.torrentclaw.unarr.plist)
  Windows: Task Scheduler task (runs at logon)`,
		Example: `  unarr daemon install
  unarr daemon start
  unarr daemon status
  unarr daemon logs -f
  unarr daemon reload
  unarr daemon restart
  unarr daemon stop
  unarr daemon uninstall`,
	}

	cmd.AddCommand(
		newDaemonInstallCmdReal(),
		newDaemonUninstallCmdReal(),
		newDaemonStartCmd(),
		newDaemonStopCmd(),
		newDaemonRestartCmd(),
		newDaemonSvcStatusCmd(),
		newDaemonLogsCmd(),
		newDaemonReloadCmd(),
	)

	return cmd
}

func runDaemonStart() error {
	cfg := loadConfig()
	bold := color.New(color.Bold)

	// Validate config
	if cfg.Auth.APIKey == "" {
		return fmt.Errorf("no API key configured — run 'unarr init' first")
	}
	if cfg.Agent.ID == "" {
		return fmt.Errorf("no agent ID — run 'unarr init' first")
	}
	if cfg.Download.Dir == "" {
		return fmt.Errorf("no download directory — run 'unarr init' first")
	}

	// Validate configured paths are safe
	if err := cfg.ValidatePaths(); err != nil {
		return fmt.Errorf("unsafe configuration: %w", err)
	}

	// Ensure download dir exists
	if err := os.MkdirAll(cfg.Download.Dir, 0o755); err != nil {
		return fmt.Errorf("create download dir: %w", err)
	}

	// Clean up stale resume files (>7 days old)
	resumeDir := filepath.Join(config.DataDir(), "resume")
	if removed := download.CleanStaleFiles(resumeDir, 7*24*time.Hour); removed > 0 {
		log.Printf("Cleaned %d stale resume file(s)", removed)
	}

	fmt.Println()
	bold.Println("  unarr Daemon")
	fmt.Println()

	userAgent := "unarr/" + Version

	// Probe HW accel + derive a sensible transcode resolution cap. The cap
	// is what the web side uses to decide whether the user should pre-empt
	// transcoding by downloading a smaller version (4K source on a software
	// libx264-only host is the canonical case where pre-download wins).
	//
	// Use the full diagnostic (encoders + devices + ffmpeg version) instead
	// of just the picked backend — the extra fields ride along in the
	// register payload so the web "Diagnose transcoder" modal can show *why*
	// libx264 was selected on a host with a GPU (e.g. brew's ffmpeg without
	// --enable-nvenc). 10 s ceiling so a hung ffmpeg binary can't stall
	// startup forever.
	ffmpegResolved, _ := mediainfo.ResolveFFmpeg(cfg.Library.FFmpegPath)
	probeCtx, probeCancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer probeCancel() // guard against a panic inside DetectHWAccelDiagnostic
	hwDiag := engine.DetectHWAccelDiagnostic(probeCtx, ffmpegResolved)
	log.Println(hwDiag.LogLine())
	hwAccelPick := hwDiag.Pick
	maxTranscodeHeight := 1080
	if hwAccelPick != engine.HWAccelNone {
		maxTranscodeHeight = 2160
	}

	// Create daemon config
	daemonCfg := agent.DaemonConfig{
		AgentID:            cfg.Agent.ID,
		AgentName:          cfg.Agent.Name,
		Version:            Version,
		DownloadDir:        cfg.Download.Dir,
		StreamPort:         cfg.Download.StreamPort,
		LanIP:              engine.LanIP(),
		TailscaleIP:        engine.TailscaleIP(),
		CanDelete:          cfg.Library.AllowDelete,
		ScanPaths:          library.ResolveScanPaths(cfg.Download.Dir, cfg.Organize.MoviesDir, cfg.Organize.TVShowsDir, cfg.Library.ScanPath),
		HWAccel:            string(hwAccelPick),
		MaxTranscodeHeight: maxTranscodeHeight,
		FFmpegVersion:      hwDiag.FFmpegVersion,
		FFmpegPath:         hwDiag.FFmpegPath,
		HWEncoders:         hwDiag.Encoders,
		HWDevices:          hwDiag.Devices,
		AutoUpgrade:        cfg.Daemon.AutoUpgradeEnabled(),
	}

	// Create HTTP client with mirror failover so a `.com` block-out rolls
	// over to `.to` / .onion without restarting the daemon.
	agentClient := newAgentClientFromConfig(cfg, userAgent)
	log.Printf("Transport: HTTP sync → %s (mirrors: %d)", cfg.Auth.APIURL, len(cfg.Auth.Mirrors))

	// Create daemon
	d := agent.NewDaemon(daemonCfg, agentClient)

	// Start SIGUSR1 reload watcher (unix only, no-op on Windows)
	startReloadWatcher(&ReloadableConfig{Daemon: d})

	// Daemon-scoped context — cancelled on shutdown
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Parse speed limits
	maxDl, _ := config.ParseSpeed(cfg.Download.MaxDownloadSpeed)
	maxUl, _ := config.ParseSpeed(cfg.Download.MaxUploadSpeed)

	// Parse torrent timeouts
	metaTimeout, _ := time.ParseDuration(cfg.Download.MetadataTimeout)
	stallTimeout, _ := time.ParseDuration(cfg.Download.StallTimeout)

	// Create progress reporter — only used for stream tasks (handleStreamTask)
	// The sync goroutine handles all regular progress reporting.
	statusInterval, _ := time.ParseDuration(cfg.Daemon.StatusInterval)
	if statusInterval == 0 {
		statusInterval = 3 * time.Second
	}
	reporter := engine.NewProgressReporter(agentClient, statusInterval)
	reporter.SetWatchingFunc(func() bool { return d.Watching.Load() })

	// Managed-VPN add-on: bring up the in-process WireGuard split-tunnel before
	// the torrent client so peer + tracker traffic routes through it. Failure is
	// non-fatal — log and download in the clear (better than refusing to run).
	var vpnTunnel *vpn.Tunnel
	if cfg.Download.VPN.ConfigFile != "" {
		// Self-hosted / personal-VPN mode: read a local .conf directly.
		raw, rerr := os.ReadFile(cfg.Download.VPN.ConfigFile)
		if rerr != nil {
			log.Printf("[vpn] could not read config_file %q (%v) — downloading in the clear", cfg.Download.VPN.ConfigFile, rerr)
		} else if t, uerr := vpn.Up(string(raw)); uerr != nil {
			log.Printf("[vpn] tunnel failed to start from config_file (%v) — downloading in the clear", uerr)
		} else {
			vpnTunnel = t
			defer vpnTunnel.Close()
			log.Printf("[vpn] managed VPN active (local config_file) — torrent traffic split-tunnelled through WireGuard")
		}
	} else if cfg.Download.VPN.Enabled {
		apiURL := cfg.Auth.APIURL
		if apiURL == "" {
			apiURL = "https://torrentclaw.com"
		}
		fetchCtx, cancel := context.WithTimeout(context.Background(), 25*time.Second)
		conf, ferr := vpn.FetchConfig(fetchCtx, apiURL, cfg.Auth.APIKey, "unarr/"+Version, cfg.Agent.ID, false)
		cancel()
		var fe *vpn.FetchError
		switch {
		case ferr != nil && errors.As(ferr, &fe) && fe.Code == vpn.ErrSlotOnDevice:
			log.Printf("[vpn] the single WireGuard slot is already held by another unarr agent — this one downloads in the clear. To protect this machine too, set up OpenVPN on it (1 agent uses WireGuard, the rest use OpenVPN — up to 10). See https://torrentclaw.com/vpn")
		case ferr != nil:
			log.Printf("[vpn] could not enable VPN (%v) — downloading in the clear", ferr)
		default:
			if t, uerr := vpn.Up(conf); uerr != nil {
				log.Printf("[vpn] tunnel failed to start (%v) — downloading in the clear", uerr)
			} else {
				vpnTunnel = t
				defer vpnTunnel.Close()
				log.Printf("[vpn] managed VPN active — torrent traffic split-tunnelled through WireGuard")
			}
		}
	}

	// Record VPN split-tunnel state for `unarr vpn status`.
	if vpnTunnel != nil {
		mode := "managed"
		if cfg.Download.VPN.ConfigFile != "" {
			mode = "self-hosted"
		}
		d.SetVPNState(true, mode, vpnTunnel.Endpoint)
	}

	// Create torrent downloader
	torrentDl, err := engine.NewTorrentDownloader(engine.TorrentConfig{
		DataDir:         cfg.Download.Dir,
		MetadataTimeout: metaTimeout,
		StallTimeout:    stallTimeout,
		MaxTimeout:      0,
		MaxDownloadRate: maxDl,
		MaxUploadRate:   maxUl,
		ListenPort:      cfg.Download.ListenPort,
		SeedEnabled:     false,
		VPNTunnel:       vpnTunnel,
	})
	if err != nil {
		return fmt.Errorf("create torrent downloader: %w", err)
	}

	if maxDl > 0 || maxUl > 0 {
		dlStr, ulStr := "unlimited", "unlimited"
		if maxDl > 0 {
			dlStr = formatSpeedLog(maxDl)
		}
		if maxUl > 0 {
			ulStr = formatSpeedLog(maxUl)
		}
		log.Printf("Speed limits: download=%s upload=%s", dlStr, ulStr)
	}

	// Create debrid downloader
	debridDl := engine.NewDebridDownloader()

	// Create download manager
	manager := engine.NewManager(engine.ManagerConfig{
		MaxConcurrent: cfg.Download.MaxConcurrent,
		OutputDir:     cfg.Download.Dir,
		Notifications: cfg.Notifications.Enabled,
		Organize: engine.OrganizeConfig{
			Enabled:    cfg.Organize.Enabled,
			MoviesDir:  cfg.Organize.MoviesDir,
			TVShowsDir: cfg.Organize.TVShowsDir,
			OutputDir:  cfg.Download.Dir,
		},
	}, reporter, torrentDl, debridDl, engine.NewUsenetDownloader(agentClient))

	// Create persistent stream server
	streamSrv := engine.NewStreamServer(cfg.Download.StreamPort)
	streamSrv.SetUPnPEnabled(cfg.Download.EnableUPnP)
	// CORS extras = operator config + dynamic mirror list from /api/mirrors.
	// Without the mirror merge, a user playing from `torrentclaw.to` (or any
	// future mirror) hits the daemon, gets 200 + body, but no
	// `Access-Control-Allow-Origin` → browser drops the response → player
	// reports "404 todos los canales". Fetching /api/mirrors at startup
	// future-proofs against mirror additions without a CLI rebuild.
	corsExtras := append([]string(nil), cfg.Download.CORSExtraOrigins...)
	corsExtras = append(corsExtras, mirrorCORSOrigins(ctx, cfg, userAgent)...)
	streamSrv.SetCORSAllowedOrigins(corsExtras)
	// Reap HLS tmpdirs left over from a previous daemon run before we start
	// accepting new sessions. The in-memory registry doesn't survive a
	// restart, so without this disk usage grows unbounded across restarts.
	if err := engine.CleanupHLSOrphanDirs(); err != nil {
		log.Printf("[hls] orphan tmpdir cleanup: %v", err)
	}

	// Persistent HLS segment cache — survives across sessions so re-plays
	// of the same file at the same quality skip ffmpeg entirely. Off when
	// hls_cache.enabled = false; size cap from hls_cache.size_gb; path from
	// hls_cache.dir (defaults to ~/.cache/unarr/hls-cache).
	var hlsCache *engine.HLSCache
	if cfg.Download.HLSCache.Enabled {
		cacheDir := cfg.Download.HLSCache.Dir
		if cacheDir == "" {
			if base, err := os.UserCacheDir(); err == nil {
				cacheDir = filepath.Join(base, "unarr", "hls-cache")
			} else {
				cacheDir = filepath.Join(os.TempDir(), "unarr-hls-cache")
			}
		}
		c, err := engine.NewHLSCache(cacheDir, cfg.Download.HLSCache.SizeGB)
		if err != nil {
			log.Printf("[hls_cache] init failed (%v) — falling back to per-session tmpdirs", err)
		} else {
			hlsCache = c
			hlsCache.StartSweeper(ctx, time.Hour)
			log.Printf("[hls_cache] enabled: dir=%s budget=%dGB", cacheDir, cfg.Download.HLSCache.SizeGB)
		}
	} else {
		log.Printf("[hls_cache] disabled by config — every play re-encodes from scratch")
	}
	if err := streamSrv.Listen(ctx); err != nil {
		return fmt.Errorf("start stream server: %w", err)
	}
	d.UpdateStreamPort(streamSrv.Port())

	// CloudFlare Quick Tunnel — needs the ACTUAL listening port (the
	// configured port may have been busy and bumped). Spawning here ensures
	// cloudflared --url points at the right socket. Failures degrade to
	// Tailscale/LAN only; the supervisor keeps the tunnel up across CF's
	// periodic rotation + transient cloudflared crashes.
	if cfg.Download.Funnel.Enabled {
		go superviseFunnel(ctx, d, streamSrv.Port())
	}

	// Warn at startup if transcode is enabled but ffmpeg/ffprobe are missing.
	// HLS sessions get rejected at runtime (see daemon.go ~line 455), but
	// surfacing it here gives the operator a chance to install ffmpeg before
	// a user hits a confusing "rejected" line in the logs.
	if cfg.Download.Transcode.Enabled {
		if _, err := mediainfo.ResolveFFmpeg(cfg.Library.FFmpegPath); err != nil {
			log.Printf("[hls] transcode enabled but ffmpeg/ffprobe not found — install ffmpeg to use HLS")
		} else if _, err := mediainfo.ResolveFFprobe(cfg.Library.FFprobePath); err != nil {
			log.Printf("[hls] transcode enabled but ffmpeg/ffprobe not found — install ffmpeg to use HLS")
		}
	}

	// Wire sync client callbacks
	sc := d.SyncClient()
	sc.GetFreeSlots = manager.FreeSlots
	sc.GetTaskStates = manager.TaskStates
	d.GetActiveCount = manager.ActiveCount

	// Trigger immediate sync when a download slot frees up
	manager.OnTaskDone = func() { d.TriggerSync() }

	// Wire: sync receives new tasks → submit to manager or handle stream
	d.OnTasksClaimed = func(tasks []agent.Task) {
		for _, t := range tasks {
			if t.Mode == "stream" {
				if isStreamingTask(t.ID) {
					continue
				}
				cancelStreamContexts()
				streamSrv.ClearFile()
				streamCtx, streamCancel := context.WithCancel(ctx) //nolint:gosec // G118: cancel stored in registry
				streamRegistry.mu.Lock()
				streamRegistry.cancels[t.ID] = streamCancel
				streamRegistry.mu.Unlock()
				go handleStreamTask(streamCtx, t, reporter, cfg, agentClient, streamSrv)
			} else {
				manager.Submit(ctx, t)
			}
		}
	}

	// Wire: sync receives control signals → act on manager
	d.OnControlAction = func(action, taskID string, deleteFiles bool) {
		switch action {
		case "cancel":
			if deleteFiles {
				manager.CancelAndDeleteFiles(taskID)
			} else {
				manager.CancelTask(taskID)
			}
			cancelStreamTask(taskID)
			if streamSrv.CurrentTaskID() == taskID {
				streamSrv.ClearFile()
			}
		case "pause":
			manager.PauseTask(taskID)
			cancelStreamTask(taskID)
			if streamSrv.CurrentTaskID() == taskID {
				streamSrv.ClearFile()
			}
		case "resume":
			log.Printf("[%s] resume requested, triggering sync", agent.ShortID(taskID))
			d.TriggerSync()
		case "stream":
			if streamSrv.CurrentTaskID() == taskID {
				return
			}
			task := manager.GetTask(taskID)
			if task == nil || task.GetStreamURL() != "" {
				return
			}
			provider, err := torrentDl.GetStreamProvider(taskID)
			if err != nil {
				log.Printf("[%s] stream failed: %v", agent.ShortID(taskID), err)
				return
			}
			cancelStreamContexts()
			streamSrv.SetFile(provider, taskID)
			task.SetStreamURL(streamSrv.URLsJSON())
			log.Printf("[%s] streaming: %s", agent.ShortID(taskID), provider.FileName())

			watchCtx, watchCancel := context.WithCancel(ctx) //nolint:gosec // G118
			streamRegistry.mu.Lock()
			streamRegistry.cancels["watch:"+taskID] = watchCancel
			streamRegistry.mu.Unlock()
			go engine.NewWatchReporter(agentClient, streamSrv, taskID).Run(watchCtx)
		case "stop-stream":
			cancelStreamTask(taskID)
			if streamSrv.CurrentTaskID() == taskID {
				streamSrv.ClearFile()
			}
		}
	}

	// Wire: sync receives file deletion requests from the server
	if cfg.Library.AllowDelete && len(daemonCfg.ScanPaths) > 0 {
		sc.OnDeleteFiles = func(items []agent.LibraryDeleteRequest) []int {
			return library.DeleteFiles(items, daemonCfg.ScanPaths)
		}
	}

	// Wire: sync receives stream requests for completed downloads
	d.OnStreamRequested = func(sr agent.StreamRequest) {
		if streamSrv.CurrentTaskID() == sr.TaskID {
			// Already serving — notify server it's ready
			go func() {
				if _, err := agentClient.ReportStatus(ctx, agent.StatusUpdate{
					TaskID:      sr.TaskID,
					StreamReady: true,
				}); err != nil {
					log.Printf("[%s] stream ready re-notify failed: %v", agent.ShortID(sr.TaskID), err)
				}
			}()
			return
		}

		filePath := filepath.Clean(sr.FilePath)
		if !isAllowedStreamPath(filePath, cfg.Download.Dir, cfg.Library.ScanPath,
			cfg.Organize.MoviesDir, cfg.Organize.TVShowsDir) {
			log.Printf("[%s] stream request rejected: path outside allowed dirs: %s", agent.ShortID(sr.TaskID), filePath)
			go func() {
				if _, err := agentClient.ReportStatus(ctx, agent.StatusUpdate{
					TaskID:       sr.TaskID,
					Status:       "failed",
					ErrorMessage: fmt.Sprintf("path outside allowed dirs: %s", filePath),
				}); err != nil {
					log.Printf("[%s] stream error report failed: %v", agent.ShortID(sr.TaskID), err)
				}
			}()
			return
		}
		info, err := os.Stat(filePath)
		if err != nil {
			log.Printf("[%s] stream request: file not found: %s", agent.ShortID(sr.TaskID), filePath)
			go func() {
				if _, err := agentClient.ReportStatus(ctx, agent.StatusUpdate{
					TaskID:       sr.TaskID,
					Status:       "failed",
					ErrorMessage: fmt.Sprintf("file not found: %s", filePath),
				}); err != nil {
					log.Printf("[%s] stream error report failed: %v", agent.ShortID(sr.TaskID), err)
				}
			}()
			return
		}

		if info.IsDir() {
			found := engine.FindVideoFile(filePath)
			if found == "" {
				log.Printf("[%s] stream request: no video file in directory: %s", agent.ShortID(sr.TaskID), filePath)
				go func() {
					if _, err := agentClient.ReportStatus(ctx, agent.StatusUpdate{
						TaskID:       sr.TaskID,
						Status:       "failed",
						ErrorMessage: fmt.Sprintf("no video file in directory: %s", filePath),
					}); err != nil {
						log.Printf("[%s] stream error report failed: %v", agent.ShortID(sr.TaskID), err)
					}
				}()
				return
			}
			filePath = found
			log.Printf("[%s] resolved directory to video file: %s", agent.ShortID(sr.TaskID), filepath.Base(filePath))
		}

		cancelStreamContexts()
		streamSrv.SetFile(engine.NewDiskFileProvider(filePath), sr.TaskID)
		log.Printf("[%s] streaming from disk: %s → %s", agent.ShortID(sr.TaskID), filepath.Base(filePath), streamSrv.URL())

		watchCtx, watchCancel := context.WithCancel(ctx) //nolint:gosec // G118
		streamRegistry.mu.Lock()
		streamRegistry.cancels["watch:"+sr.TaskID] = watchCancel
		streamRegistry.mu.Unlock()
		go engine.NewWatchReporter(agentClient, streamSrv, sr.TaskID).Run(watchCtx)

		go func() {
			if _, err := agentClient.ReportStatus(ctx, agent.StatusUpdate{
				TaskID:      sr.TaskID,
				StreamReady: true,
			}); err != nil {
				log.Printf("[%s] stream ready report failed: %v", agent.ShortID(sr.TaskID), err)
			}
		}()
	}

	// Wire: sync receives HLS streaming session requests. Each session spawns
	// one ffmpeg process and registers its HLS playlist with the StreamServer.
	// Validate FilePath against allowed dirs to prevent path traversal abuse
	// from a compromised server.
	d.OnStreamSession = func(sess agent.StreamSession) {
		if playerSessionRegistry.has(sess.SessionID) {
			return // already running
		}
		filePath := sess.FilePath
		if filePath == "" {
			log.Printf("[hls %s] rejected: empty file path", agent.ShortID(sess.SessionID))
			return
		}
		filePath = filepath.Clean(filePath)
		if !isAllowedStreamPath(filePath, cfg.Download.Dir, cfg.Library.ScanPath,
			cfg.Organize.MoviesDir, cfg.Organize.TVShowsDir) {
			log.Printf("[hls %s] rejected: path outside allowed dirs: %s",
				agent.ShortID(sess.SessionID), filePath)
			return
		}
		// Resolve directory → first video file (matches StreamRequest behavior).
		if info, err := os.Stat(filePath); err == nil && info.IsDir() {
			found := engine.FindVideoFile(filePath)
			if found == "" {
				log.Printf("[hls %s] rejected: no video file in dir %s",
					agent.ShortID(sess.SessionID), filePath)
				return
			}
			filePath = found
		}

		tcRuntime := buildTranscodeRuntime(ctx, cfg)
		if tcRuntime.FFmpegPath == "" || tcRuntime.FFprobePath == "" {
			log.Printf("[hls %s] rejected: ffmpeg/ffprobe unavailable", agent.ShortID(sess.SessionID))
			return
		}
		hlsCtx, hlsCancel := context.WithCancel(ctx)
		playerSessionRegistry.add(sess.SessionID, hlsCancel)
		hlsCfg := engine.HLSSessionConfig{
			SessionID:  sess.SessionID,
			SourcePath: filePath,
			FileName:   sess.FileName,
			Quality:    sess.Quality,
			AudioIndex: sess.AudioIndex,
			Transcode:  tcRuntime,
			Cache:      hlsCache,
		}
		// StartHLSSession runs ffprobe (15 s cap, typical 0.3–1 s) before
		// returning. Doing this synchronously inside the sync handler holds
		// the next sync HTTP cycle until ffprobe is done, so any other
		// pending actions (new tasks, deletes) wait too. Hand it off so
		// the sync loop returns immediately — browser HEAD probes already
		// have a 30 s retry budget that absorbs the gap until
		// `streamSrv.HLS().Register` lands.
		go func() {
			hsess, err := engine.StartHLSSession(hlsCtx, hlsCfg)
			if err != nil {
				playerSessionRegistry.remove(sess.SessionID)
				hlsCancel()
				log.Printf("[hls %s] start failed: %v", agent.ShortID(sess.SessionID), err)
				return
			}
			streamSrv.HLS().Register(hsess)
		}()
	}

	// Periodic DHT node persistence (every 5 min)
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				torrentDl.SaveDhtNodes()
			case <-ctx.Done():
				return
			}
		}
	}()

	// Periodic HLS session sweeper (every 5 min). Closes sessions whose last
	// segment fetch was over 30 min ago — kills the orphan ffmpeg + removes
	// the per-session tmpdir, so a tab that died mid-stream doesn't leak
	// disk space until daemon shutdown.
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				if n := streamSrv.HLS().SweepIdle(); n > 0 {
					log.Printf("[hls] swept %d idle session(s)", n)
				}
			case <-ctx.Done():
				return
			}
		}
	}()

	// Start auto-scan goroutine
	scanPaths := daemonCfg.ScanPaths
	if len(scanPaths) > 0 && cfg.Library.AutoScan {
		scanInterval := 24 * time.Hour
		if cfg.Library.ScanInterval != "" {
			if parsed, err := time.ParseDuration(cfg.Library.ScanInterval); err == nil && parsed > 0 {
				scanInterval = parsed
			}
		}
		go runAutoScan(ctx, cfg, scanInterval, agentClient, d.ScanNow, scanPaths)
	}

	// Start reporter only for stream task handling
	go reporter.Run(ctx)

	// Start daemon (blocks — runs sync loop)
	errCh := make(chan error, 1)
	go func() {
		errCh <- d.Run(ctx)
	}()

	// Start idle guard for the persistent stream server
	go startIdleGuard(ctx, streamSrv)

	// Signal handling
	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)

	// Wait for signal or error
	select {
	case sig := <-sigCh:
		fmt.Printf("\n  Received %s, shutting down...\n", sig)
		cancelStreamContexts()
		cancelAllPlayerSessions()
		streamSrv.Shutdown(context.Background())
		cancel()

		// Give active downloads 30s to finish
		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 30*time.Second)
		defer shutdownCancel()
		manager.Shutdown(shutdownCtx)

		d.Deregister()
		fmt.Println("  Daemon stopped.")
		return nil

	case err := <-errCh:
		cancelStreamContexts()
		cancelAllPlayerSessions()
		streamSrv.Shutdown(context.Background())
		cancel()
		return err
	}
}

// isAllowedStreamPath checks that filePath is within one of the directories
// the daemon is configured to manage. This defends against a compromised API
// server sending a path traversal payload (e.g. /etc/passwd) in StreamRequest.
// isAllowedStreamPath reports whether filePath is contained within one of the
// allowedDirs. filePath must already be cleaned (filepath.Clean) by the caller.
// This defends against a compromised API server sending a path traversal payload.
func isAllowedStreamPath(filePath string, allowedDirs ...string) bool {
	for _, dir := range allowedDirs {
		if dir == "" {
			continue
		}
		rel, err := filepath.Rel(filepath.Clean(dir), filePath)
		if err == nil && !strings.HasPrefix(rel, "..") {
			return true
		}
	}
	return false
}

func formatSpeedLog(bps int64) string {
	switch {
	case bps >= 1024*1024*1024:
		return fmt.Sprintf("%.1f GB/s", float64(bps)/(1024*1024*1024))
	case bps >= 1024*1024:
		return fmt.Sprintf("%.1f MB/s", float64(bps)/(1024*1024))
	case bps >= 1024:
		return fmt.Sprintf("%.0f KB/s", float64(bps)/1024)
	default:
		return fmt.Sprintf("%d B/s", bps)
	}
}

// runAutoScan runs a library scan + sync on a timer or on-demand via scanNow channel.
// It scans all provided paths and syncs each independently so stale-item cleanup
// is scoped to the correct directory prefix on the server.
func runAutoScan(ctx context.Context, cfg config.Config, interval time.Duration, ac *agent.Client, scanNow <-chan struct{}, scanPaths []string) {
	log.Printf("[auto-scan] enabled: every %s, paths: %v", interval, scanPaths)

	select {
	case <-time.After(30 * time.Second):
	case <-scanNow:
	case <-ctx.Done():
		return
	}

	doScan := func() {
		defer func() {
			if r := recover(); r != nil {
				log.Printf("[auto-scan] panic recovered: %v", r)
			}
		}()
		log.Printf("[auto-scan] starting scan of %v", scanPaths)

		existing, _ := library.LoadCache()

		workers := cfg.Library.Workers
		if workers == 0 {
			workers = 8
		}

		scanOpts := library.ScanOptions{
			Workers:     workers,
			FFprobePath: cfg.Library.FFprobePath,
			Incremental: existing != nil,
		}

		// Scan each path independently and sync per path so the server can
		// scope stale-item deletion to the correct directory prefix.
		const batchSize = 100
		totalSynced := 0
		var mergedItems []library.LibraryItem

		for _, scanPath := range scanPaths {
			cache, err := library.Scan(ctx, scanPath, existing, scanOpts)
			if err != nil {
				log.Printf("[auto-scan] scan failed for %s: %v", scanPath, err)
				continue
			}
			mergedItems = append(mergedItems, cache.Items...)

			items := library.BuildSyncItems(cache)
			if len(items) == 0 {
				log.Printf("[auto-scan] no items under %s", scanPath)
				continue
			}

			syncStartedAt := time.Now().UTC().Format(time.RFC3339)
			for i := 0; i < len(items); i += batchSize {
				end := i + batchSize
				if end > len(items) {
					end = len(items)
				}
				isLast := end >= len(items)

				_, err := ac.SyncLibrary(ctx, agent.LibrarySyncRequest{
					Items:         items[i:end],
					ScanPath:      scanPath,
					IsLastBatch:   isLast,
					SyncStartedAt: syncStartedAt,
				})
				if err != nil {
					log.Printf("[auto-scan] sync failed for %s: %v", scanPath, err)
					break
				}
			}
			totalSynced += len(items)
		}

		// Save merged cache for incremental scanning next time.
		if len(mergedItems) > 0 {
			mergedCache := &library.LibraryCache{
				ScannedAt: time.Now().UTC().Format(time.RFC3339),
				Path:      scanPaths[0],
				Items:     mergedItems,
			}
			if err := library.SaveCache(mergedCache); err != nil {
				log.Printf("[auto-scan] save cache failed: %v", err)
			}
		}

		log.Printf("[auto-scan] synced %d items across %d path(s)", totalSynced, len(scanPaths))
	}

	doScan()

	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			doScan()
		case <-scanNow:
			log.Printf("[auto-scan] on-demand scan triggered")
			ticker.Reset(interval)
			doScan()
		case <-ctx.Done():
			return
		}
	}
}

// superviseFunnel keeps a CloudFlare Quick Tunnel up across cloudflared
// crashes and CF's ~6h tunnel rotation. On a clean exit (cancellation) it
// returns; on a crash it clears the reported URL and respawns with an
// exponential backoff so we don't hammer cloudflared into a tight loop when
// it can't reach the CF edge.
func superviseFunnel(ctx context.Context, d *agent.Daemon, port int) {
	backoff := 2 * time.Second
	const maxBackoff = 5 * time.Minute
	for ctx.Err() == nil {
		t, err := funnel.Start(ctx, funnel.Config{Port: port})
		if err != nil {
			log.Printf("[funnel] could not start CloudFlare tunnel (%v) — retrying in %s", err, backoff)
			select {
			case <-time.After(backoff):
			case <-ctx.Done():
				return
			}
			backoff = min(backoff*2, maxBackoff)
			continue
		}
		log.Printf("[funnel] cloudflared started, waiting for public URL...")
		go func() {
			url, werr := t.WaitURL(45 * time.Second)
			if werr != nil {
				log.Printf("[funnel] cloudflared did not emit a URL (%v)", werr)
				return
			}
			log.Printf("[funnel] public URL: %s", url)
			d.SetFunnelURL(url)
		}()
		// Block until cloudflared exits (CF rotation, crash, or shutdown).
		exitErr := <-t.Done()
		_ = t.Close()
		d.SetFunnelURL("")
		if ctx.Err() != nil {
			return
		}
		if exitErr != nil {
			log.Printf("[funnel] cloudflared exited: %v — restarting in %s", exitErr, backoff)
		} else {
			log.Printf("[funnel] cloudflared exited cleanly — restarting in %s", backoff)
		}
		select {
		case <-time.After(backoff):
		case <-ctx.Done():
			return
		}
		backoff = min(backoff*2, maxBackoff)
	}
}

// mirrorCORSOrigins fetches /api/mirrors from the configured primary (+ extra
// mirror candidates + static IPFS fallback) and returns the discovered URLs as
// Origin strings. Best-effort: any failure logs a warning and returns an empty
// slice; the static defaultCORSAllowedOrigins in validate.go covers the known
// mirrors (.com / .to / built-in onion) so the daemon still accepts the
// official surfaces when this call fails.
//
// Bounded to a short timeout so a slow /api/mirrors response can't delay
// daemon startup — every second here is a second the user can't play.
func mirrorCORSOrigins(parent context.Context, cfg config.Config, userAgent string) []string {
	ctx, cancel := context.WithTimeout(parent, 10*time.Second)
	defer cancel()

	candidates := append([]string{cfg.Auth.APIURL}, cfg.Auth.Mirrors...)
	resp, err := agent.FetchMirrorsWithFallback(ctx, candidates, userAgent)
	if err != nil {
		log.Printf("[cors] mirror discovery failed (%v) — using static allowlist only", err)
		return nil
	}

	seen := make(map[string]struct{})
	out := make([]string, 0, len(resp.Mirrors))
	add := func(rawURL string) {
		if rawURL == "" {
			return
		}
		origin := strings.TrimRight(rawURL, "/")
		if _, dup := seen[origin]; dup {
			return
		}
		seen[origin] = struct{}{}
		out = append(out, origin)
	}
	for _, m := range resp.Mirrors {
		add(m.URL)
	}
	if resp.Tor != nil {
		add(resp.Tor.URL)
	}
	if len(out) > 0 {
		log.Printf("[cors] merged %d mirror origins from /api/mirrors", len(out))
	}
	return out
}