// backend\main.go

package main

import (
	"bufio"
	"bytes"
	"context"
	"encoding/binary"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"math"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"time"

	"github.com/grafov/m3u8"
	gocpu "github.com/shirou/gopsutil/v3/cpu"
	godisk "github.com/shirou/gopsutil/v3/disk"
)

var roomDossierRegexp = regexp.MustCompile(`window\.initialRoomDossier = "(.*?)"`)

type JobStatus string

const (
	JobRunning  JobStatus = "running"
	JobPostwork JobStatus = "postwork" // ✅ NEU: Aufnahme vorbei, Nacharbeiten laufen noch
	JobFinished JobStatus = "finished"
	JobStopped  JobStatus = "stopped"
	JobFailed   JobStatus = "failed"
)

type RecordJob struct {
	ID              string     `json:"id"`
	SourceURL       string     `json:"sourceUrl"`
	Output          string     `json:"output"`
	Status          JobStatus  `json:"status"`
	StartedAt       time.Time  `json:"startedAt"`
	EndedAt         *time.Time `json:"endedAt,omitempty"`
	StartedAtMs     int64      `json:"startedAtMs,omitempty"`
	EndedAtMs       int64      `json:"endedAtMs,omitempty"`
	DurationSeconds float64    `json:"durationSeconds,omitempty"`
	SizeBytes       int64      `json:"sizeBytes,omitempty"`
	VideoWidth      int        `json:"videoWidth,omitempty"`
	VideoHeight     int        `json:"videoHeight,omitempty"`
	FPS             float64    `json:"fps,omitempty"`
	Meta            *videoMeta `json:"meta,omitempty"`

	Hidden bool `json:"-"`

	Error string `json:"error,omitempty"`

	PreviewDir       string    `json:"-"`
	previewCmd       *exec.Cmd `json:"-"`
	LiveThumbStarted bool      `json:"-"`

	// ✅ Preview-Status (z.B. private/offline anhand ffmpeg HTTP Fehler)
	PreviewState    string `json:"previewState,omitempty"`    // "", "private", "offline", "error"
	PreviewStateAt  string `json:"previewStateAt,omitempty"`  // RFC3339Nano
	PreviewStateMsg string `json:"previewStateMsg,omitempty"` // kurze Info

	// Thumbnail cache (verhindert, dass pro HTTP-Request ffmpeg läuft)
	previewMu     sync.Mutex `json:"-"`
	previewWebp   []byte     `json:"-"`
	previewWebpAt time.Time  `json:"-"`
	previewGen    bool       `json:"-"`

	PreviewM3U8   string `json:"-"` // HLS url, die ffmpeg inputt
	PreviewCookie string `json:"-"` // Cookie header (falls nötig)
	PreviewUA     string `json:"-"` // user-agent

	previewCancel  context.CancelFunc `json:"-"`
	previewLastHit time.Time          `json:"-"`
	previewStartMu sync.Mutex         `json:"-"`

	// ✅ Frontend Progress beim Stop/Finalize
	Phase    string `json:"phase,omitempty"`    // stopping | remuxing | moving
	Progress int    `json:"progress,omitempty"` // 0..100

	PostWorkKey string             `json:"postWorkKey,omitempty"`
	PostWork    *PostWorkKeyStatus `json:"postWork,omitempty"`

	cancel context.CancelFunc `json:"-"`
}

type dummyResponseWriter struct {
	h http.Header
}

type ffprobeStreamInfo struct {
	Width        int    `json:"width"`
	Height       int    `json:"height"`
	AvgFrameRate string `json:"avg_frame_rate"`
	RFrameRate   string `json:"r_frame_rate"`
}

type ffprobeInfo struct {
	Streams []ffprobeStreamInfo `json:"streams"`
}

func parseFFRate(s string) float64 {
	s = strings.TrimSpace(s)
	if s == "" || s == "0/0" {
		return 0
	}
	// "30000/1001"
	if a, b, ok := strings.Cut(s, "/"); ok {
		num, err1 := strconv.ParseFloat(strings.TrimSpace(a), 64)
		den, err2 := strconv.ParseFloat(strings.TrimSpace(b), 64)
		if err1 == nil && err2 == nil && den != 0 {
			return num / den
		}
		return 0
	}
	// "25"
	f, err := strconv.ParseFloat(s, 64)
	if err != nil {
		return 0
	}
	return f
}

func probeVideoProps(ctx context.Context, filePath string) (w int, h int, fps float64, err error) {
	filePath = strings.TrimSpace(filePath)
	if filePath == "" {
		return 0, 0, 0, fmt.Errorf("empty path")
	}

	cmd := exec.CommandContext(ctx, ffprobePath,
		"-v", "error",
		"-select_streams", "v:0",
		"-show_entries", "stream=width,height,avg_frame_rate,r_frame_rate",
		"-of", "json",
		filePath,
	)

	out, err := cmd.Output()
	if err != nil {
		return 0, 0, 0, err
	}

	var info ffprobeInfo
	if err := json.Unmarshal(out, &info); err != nil {
		return 0, 0, 0, err
	}
	if len(info.Streams) == 0 {
		return 0, 0, 0, fmt.Errorf("no video stream")
	}

	s := info.Streams[0]
	w, h = s.Width, s.Height

	// bevorzugt avg_frame_rate, fallback r_frame_rate
	fps = parseFFRate(s.AvgFrameRate)
	if fps <= 0 {
		fps = parseFFRate(s.RFrameRate)
	}

	return w, h, fps, nil
}

func metaJSONPathForAssetID(assetID string) (string, error) {
	root, err := generatedMetaRoot()
	if err != nil {
		return "", err
	}
	if strings.TrimSpace(root) == "" {
		return "", fmt.Errorf("generated/meta root leer")
	}
	return filepath.Join(root, assetID, "meta.json"), nil
}

func readVideoMetaIfValid(metaPath string, fi os.FileInfo) (*videoMeta, bool) {
	b, err := os.ReadFile(metaPath)
	if err != nil || len(b) == 0 {
		return nil, false
	}
	var m videoMeta
	if err := json.Unmarshal(b, &m); err != nil {
		return nil, false
	}

	// nur akzeptieren wenn Datei identisch (damit wir nicht stale Werte zeigen)
	if m.FileSize != fi.Size() || m.FileModUnix != fi.ModTime().Unix() {
		return nil, false
	}

	// Mindestvalidierung
	if m.DurationSeconds <= 0 {
		return nil, false
	}

	return &m, true
}

func ensureVideoMetaForFile(ctx context.Context, fullPath string, fi os.FileInfo, sourceURL string) (*videoMeta, bool) {
	// assetID aus Dateiname
	stem := strings.TrimSuffix(filepath.Base(fullPath), filepath.Ext(fullPath))
	assetID := stripHotPrefix(strings.TrimSpace(stem))
	if assetID == "" {
		return nil, false
	}

	// sanitize wie bei deinen generated Ordnern
	var err error
	assetID, err = sanitizeID(assetID)
	if err != nil || assetID == "" {
		return nil, false
	}

	metaPath, err := metaJSONPathForAssetID(assetID)
	if err != nil {
		return nil, false
	}

	// 1) valid meta vorhanden?
	if m, ok := readVideoMetaIfValid(metaPath, fi); ok {
		return m, true
	}

	// 2) sonst neu erzeugen (mit Concurrency-Limit)
	if ctx == nil {
		ctx = context.Background()
	}
	cctx, cancel := context.WithTimeout(ctx, 8*time.Second)
	defer cancel()

	if durSem != nil {
		if err := durSem.Acquire(cctx); err != nil {
			return nil, false
		}
		defer durSem.Release()
	}

	// Dauer
	dur, derr := durationSecondsCached(cctx, fullPath)
	if derr != nil || dur <= 0 {
		return nil, false
	}

	// Video props
	w, h, fps, perr := probeVideoProps(cctx, fullPath)
	if perr != nil {
		// width/height/fps dürfen 0 bleiben, duration ist aber trotzdem nützlich
		w, h, fps = 0, 0, 0
	}

	// meta dir anlegen
	_ = os.MkdirAll(filepath.Dir(metaPath), 0o755)

	m := &videoMeta{
		Version:         2,
		DurationSeconds: dur,
		FileSize:        fi.Size(),
		FileModUnix:     fi.ModTime().Unix(),
		VideoWidth:      w,
		VideoHeight:     h,
		FPS:             fps,
		Resolution:      formatResolution(w, h),
		SourceURL:       strings.TrimSpace(sourceURL),
		UpdatedAtUnix:   time.Now().Unix(),
	}

	b, _ := json.MarshalIndent(m, "", "  ")
	b = append(b, '\n')
	_ = atomicWriteFile(metaPath, b) // best effort

	return m, true
}

func attachMetaToJobBestEffort(ctx context.Context, job *RecordJob, fullPath string) {
	if job == nil {
		return
	}
	fullPath = strings.TrimSpace(fullPath)
	if fullPath == "" {
		return
	}

	// Stat
	fi, err := os.Stat(fullPath)
	if err != nil || fi == nil || fi.IsDir() {
		return
	}

	// Größe immer mitgeben (macht Sort/Anzeige einfacher)
	if job.SizeBytes <= 0 {
		job.SizeBytes = fi.Size()
	}

	// Meta.json lesen/erzeugen (best effort)
	m, ok := ensureVideoMetaForFileBestEffort(ctx, fullPath, job.SourceURL)
	if !ok || m == nil {
		return
	}

	// Optional: komplettes Meta mitsenden
	job.Meta = m

	// Und zusätzlich die "Top-Level" Felder befüllen (für Frontend bequem)
	if job.DurationSeconds <= 0 && m.DurationSeconds > 0 {
		job.DurationSeconds = m.DurationSeconds
	}
	if job.VideoWidth <= 0 && m.VideoWidth > 0 {
		job.VideoWidth = m.VideoWidth
	}
	if job.VideoHeight <= 0 && m.VideoHeight > 0 {
		job.VideoHeight = m.VideoHeight
	}
	if job.FPS <= 0 && m.FPS > 0 {
		job.FPS = m.FPS
	}
}

// ensureVideoMetaForFileBestEffort:
//   - versucht zuerst echtes Generieren (ffprobe/ffmpeg) via ensureVideoMetaForFile
//   - wenn das fehlschlägt, aber durationSecondsCacheOnly schon was weiß:
//     schreibt eine Duration-only meta.json, damit wir künftig "aus meta.json" lesen können.
func ensureVideoMetaForFileBestEffort(ctx context.Context, fullPath string, sourceURL string) (*videoMeta, bool) {
	fullPath = strings.TrimSpace(fullPath)
	if fullPath == "" {
		return nil, false
	}

	fi, err := os.Stat(fullPath)
	if err != nil || fi == nil || fi.IsDir() || fi.Size() <= 0 {
		return nil, false
	}

	// 1) Normaler Weg: meta erzeugen/lesen (ffprobe/ffmpeg)
	if m, ok := ensureVideoMetaForFile(ctx, fullPath, fi, sourceURL); ok && m != nil {
		return m, true
	}

	// 2) Fallback: wenn wir Duration schon im RAM-Cache haben -> meta.json (Duration-only) persistieren
	dur := durationSecondsCacheOnly(fullPath, fi)
	if dur <= 0 {
		return nil, false
	}

	stem := strings.TrimSuffix(filepath.Base(fullPath), filepath.Ext(fullPath))
	assetID := stripHotPrefix(strings.TrimSpace(stem))
	if assetID == "" {
		return nil, false
	}

	metaPath, err := metaJSONPathForAssetID(assetID)
	if err != nil || strings.TrimSpace(metaPath) == "" {
		return nil, false
	}

	_ = os.MkdirAll(filepath.Dir(metaPath), 0o755)
	_ = writeVideoMetaDuration(metaPath, fi, dur, sourceURL)

	// nochmal lesen/validieren
	if m, ok := readVideoMetaIfValid(metaPath, fi); ok && m != nil {
		return m, true
	}

	return nil, false
}

func (d *dummyResponseWriter) Header() http.Header {
	if d.h == nil {
		d.h = make(http.Header)
	}
	return d.h
}
func (d *dummyResponseWriter) Write(b []byte) (int, error) { return len(b), nil }
func (d *dummyResponseWriter) WriteHeader(statusCode int)  {}

var (
	jobs   = map[string]*RecordJob{}
	jobsMu = sync.Mutex{}
)

var serverStartedAt = time.Now()

var lastCPUUsageBits uint64 // atomic float64 bits

func setLastCPUUsage(v float64) { atomic.StoreUint64(&lastCPUUsageBits, math.Float64bits(v)) }
func getLastCPUUsage() float64  { return math.Float64frombits(atomic.LoadUint64(&lastCPUUsageBits)) }

func startPreviewIdleKiller() {
	t := time.NewTicker(5 * time.Second)
	go func() {
		defer t.Stop()
		for range t.C {
			jobsMu.Lock()
			list := make([]*RecordJob, 0, len(jobs))
			for _, j := range jobs {
				if j != nil {
					list = append(list, j)
				}
			}
			jobsMu.Unlock()

			for _, j := range list {
				jobsMu.Lock()
				cmdRunning := j.previewCmd != nil
				last := j.previewLastHit
				st := j.Status
				jobsMu.Unlock()

				if !cmdRunning {
					continue
				}
				// wenn Job nicht mehr läuft oder Hover weg
				if st != JobRunning || (!last.IsZero() && time.Since(last) > 10*time.Minute) {
					stopPreview(j)
				}
			}
		}
	}()
}

func init() {
	initFFmpegSemaphores()
	startAdaptiveSemController(context.Background())
	startPreviewIdleKiller()

	initSSE()
}

func publishJob(jobID string) bool {
	jobsMu.Lock()
	j := jobs[jobID]
	if j == nil || !j.Hidden {
		jobsMu.Unlock()
		return false
	}
	j.Hidden = false
	jobsMu.Unlock()

	notifyJobsChanged()
	return true
}

// ffmpeg-Binary suchen (env, neben EXE, oder PATH)
var ffmpegPath = detectFFmpegPath()

var ffprobePath = detectFFprobePath()

func detectFFprobePath() string {
	// 1) Env-Override
	if p := strings.TrimSpace(os.Getenv("FFPROBE_PATH")); p != "" {
		if abs, err := filepath.Abs(p); err == nil {
			return abs
		}
		return p
	}

	// 2) Neben ffmpeg.exe (gleicher Ordner)
	fp := strings.TrimSpace(ffmpegPath)
	if fp != "" && fp != "ffmpeg" {
		dir := filepath.Dir(fp)
		ext := ""
		if strings.HasSuffix(strings.ToLower(fp), ".exe") {
			ext = ".exe"
		}
		c := filepath.Join(dir, "ffprobe"+ext)
		if fi, err := os.Stat(c); err == nil && !fi.IsDir() {
			return c
		}
	}

	// 3) Im EXE-Ordner
	if exe, err := os.Executable(); err == nil {
		exeDir := filepath.Dir(exe)
		candidates := []string{
			filepath.Join(exeDir, "ffprobe"),
			filepath.Join(exeDir, "ffprobe.exe"),
		}
		for _, c := range candidates {
			if fi, err := os.Stat(c); err == nil && !fi.IsDir() {
				return c
			}
		}
	}

	// 4) PATH
	if lp, err := exec.LookPath("ffprobe"); err == nil {
		if abs, err2 := filepath.Abs(lp); err2 == nil {
			return abs
		}
		return lp
	}

	return "ffprobe"
}

// ---------- Dynamic Semaphore (resizeable by load controller) ----------

type DynSem struct {
	mu  sync.Mutex
	in  int
	max int
	cap int
}

func NewDynSem(initial, cap int) *DynSem {
	if cap < 1 {
		cap = 1
	}
	if initial < 1 {
		initial = 1
	}
	if initial > cap {
		initial = cap
	}
	return &DynSem{max: initial, cap: cap}
}

func (s *DynSem) Acquire(ctx context.Context) error {
	for {
		if ctx != nil && ctx.Err() != nil {
			return ctx.Err()
		}
		s.mu.Lock()
		if s.in < s.max {
			s.in++
			s.mu.Unlock()
			return nil
		}
		s.mu.Unlock()
		time.Sleep(25 * time.Millisecond)
	}
}

func (s *DynSem) Release() {
	s.mu.Lock()
	if s.in > 0 {
		s.in--
	}
	s.mu.Unlock()
}

func (s *DynSem) SetMax(n int) {
	if n < 1 {
		n = 1
	}
	if n > s.cap {
		n = s.cap
	}
	s.mu.Lock()
	s.max = n
	s.mu.Unlock()
}

func (s *DynSem) Max() int {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.max
}

func (s *DynSem) Cap() int {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.cap
}

func (s *DynSem) InUse() int {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.in
}

var (
	genSem     *DynSem
	previewSem *DynSem
	thumbSem   *DynSem
	durSem     *DynSem
)

func clamp(n, lo, hi int) int {
	if n < lo {
		return lo
	}
	if n > hi {
		return hi
	}
	return n
}

func envInt(name string) (int, bool) {
	v := strings.TrimSpace(os.Getenv(name))
	if v == "" {
		return 0, false
	}
	n, err := strconv.Atoi(v)
	if err != nil {
		return 0, false
	}
	return n, true
}

func initFFmpegSemaphores() {
	cpu := runtime.NumCPU()
	if cpu <= 0 {
		cpu = 2
	}

	// Defaults (heuristisch)
	previewN := clamp((cpu+1)/2, 1, 6) // x264 live -> konservativ
	thumbN := clamp(cpu, 2, 12)        // Frames -> darf höher
	genN := clamp((cpu+3)/4, 1, 4)     // preview.mp4 clips -> eher klein
	durN := clamp(cpu, 2, 16)          // ffprobe: darf höher, aber nicht unbegrenzt

	// ENV Overrides (optional)
	if n, ok := envInt("PREVIEW_WORKERS"); ok {
		previewN = clamp(n, 1, 32)
	}
	if n, ok := envInt("THUMB_WORKERS"); ok {
		thumbN = clamp(n, 1, 64)
	}
	if n, ok := envInt("GEN_WORKERS"); ok {
		genN = clamp(n, 1, 16)
	}
	if n, ok := envInt("DUR_WORKERS"); ok {
		durN = clamp(n, 1, 64)
	}

	// Caps (Obergrenzen) – können via ENV überschrieben werden
	previewCap := clamp(cpu, 2, 12)
	thumbCap := clamp(cpu*2, 4, 32)
	genCap := clamp((cpu+1)/2, 2, 12)
	durCap := clamp(cpu*2, 4, 32)

	if n, ok := envInt("PREVIEW_CAP"); ok {
		previewCap = clamp(n, 1, 64)
	}
	if n, ok := envInt("THUMB_CAP"); ok {
		thumbCap = clamp(n, 1, 128)
	}
	if n, ok := envInt("GEN_CAP"); ok {
		genCap = clamp(n, 1, 64)
	}
	if n, ok := envInt("DUR_CAP"); ok {
		durCap = clamp(n, 1, 128)
	}

	// Initial max (Startwerte)
	previewSem = NewDynSem(previewN, previewCap)
	thumbSem = NewDynSem(thumbN, thumbCap)
	genSem = NewDynSem(genN, genCap)
	durSem = NewDynSem(durN, durCap)

	fmt.Printf(
		"🔧 semaphores(init): preview=%d/%d thumb=%d/%d gen=%d/%d dur=%d/%d (cpu=%d)\n",
		previewSem.Max(), previewSem.Cap(),
		thumbSem.Max(), thumbSem.Cap(),
		genSem.Max(), genSem.Cap(),
		durSem.Max(), durSem.Cap(),
		cpu,
	)

	fmt.Printf(
		"🔧 semaphores: preview=%d thumb=%d gen=%d dur=%d (cpu=%d)\n",
		previewN, thumbN, genN, durN, cpu,
	)
}

func startAdaptiveSemController(ctx context.Context) {
	targetHi := 85.0
	targetLo := 65.0

	if v := strings.TrimSpace(os.Getenv("CPU_TARGET_HI")); v != "" {
		if f, err := strconv.ParseFloat(v, 64); err == nil {
			targetHi = f
		}
	}
	if v := strings.TrimSpace(os.Getenv("CPU_TARGET_LO")); v != "" {
		if f, err := strconv.ParseFloat(v, 64); err == nil {
			targetLo = f
		}
	}

	// Warmup (erste Messung kann 0 sein)
	_, _ = gocpu.Percent(200*time.Millisecond, false)

	t := time.NewTicker(2 * time.Second)
	go func() {
		defer t.Stop()

		for {
			select {
			case <-ctx.Done():
				return
			case <-t.C:
				p, err := gocpu.Percent(0, false)
				if err != nil || len(p) == 0 {
					continue
				}
				usage := p[0]
				setLastCPUUsage(usage)

				// Preview ist am teuersten → konservativ
				if usage > targetHi {
					previewSem.SetMax(previewSem.Max() - 1)
					genSem.SetMax(genSem.Max() - 1)
					thumbSem.SetMax(thumbSem.Max() - 1)
				} else if usage < targetLo {
					previewSem.SetMax(previewSem.Max() + 1)
					genSem.SetMax(genSem.Max() + 1)
					thumbSem.SetMax(thumbSem.Max() + 1)
				}

				// optional Debug:
				// fmt.Printf("CPU %.1f%% -> preview=%d thumb=%d gen=%d\n", usage, previewSem.Max(), thumbSem.Max(), genSem.Max())
			}
		}
	}()
}

type durEntry struct {
	size int64
	mod  time.Time
	sec  float64
}

var durCache = struct {
	mu sync.Mutex
	m  map[string]durEntry
}{m: map[string]durEntry{}}

var startedAtFromFilenameRe = regexp.MustCompile(
	`^(.+)_([0-9]{1,2})_([0-9]{1,2})_([0-9]{4})__([0-9]{1,2})-([0-9]{2})-([0-9]{2})$`,
)

func buildPerfSnapshot() map[string]any {
	var ms runtime.MemStats
	runtime.ReadMemStats(&ms)

	s := getSettings()
	recordDir, _ := resolvePathRelativeToApp(s.RecordDir)

	var diskFreeBytes uint64
	var diskTotalBytes uint64
	var diskUsedPercent float64
	diskPath := recordDir

	if recordDir != "" {
		if u, err := godisk.Usage(recordDir); err == nil && u != nil {
			diskFreeBytes = u.Free
			diskTotalBytes = u.Total
			diskUsedPercent = u.UsedPercent
		}
	}

	// ✅ Dynamische Disk-Schwellen (2× inFlight, Resume = +3GB)
	pauseGB, resumeGB, inFlight, pauseNeed, resumeNeed := computeDiskThresholds()

	resp := map[string]any{
		"ts":        time.Now().UTC().Format(time.RFC3339Nano),
		"serverMs":  time.Now().UTC().UnixMilli(), // ✅ für "Ping" im Frontend (Approx)
		"uptimeSec": time.Since(serverStartedAt).Seconds(),
		"cpuPercent": func() float64 {
			v := getLastCPUUsage()
			if math.IsNaN(v) || math.IsInf(v, 0) || v < 0 {
				return 0
			}
			return v
		}(),
		"diskPath":        diskPath,
		"diskFreeBytes":   diskFreeBytes,
		"diskTotalBytes":  diskTotalBytes,
		"diskUsedPercent": diskUsedPercent,
		"diskEmergency":   atomic.LoadInt32(&diskEmergency) == 1,

		// ✅ statt LowDiskPauseBelowGB aus Settings
		"diskPauseBelowGB":  pauseGB,
		"diskResumeAboveGB": resumeGB,

		// ✅ optional, aber sehr hilfreich (Debug/UI)
		"diskInFlightBytes":   inFlight,
		"diskInFlightHuman":   formatBytesSI(u64ToI64(inFlight)),
		"diskPauseNeedBytes":  pauseNeed,
		"diskPauseNeedHuman":  formatBytesSI(u64ToI64(pauseNeed)),
		"diskResumeNeedBytes": resumeNeed,
		"diskResumeNeedHuman": formatBytesSI(u64ToI64(resumeNeed)),

		"goroutines": runtime.NumGoroutine(),
		"mem": map[string]any{
			"alloc":     ms.Alloc,
			"heapAlloc": ms.HeapAlloc,
			"heapInuse": ms.HeapInuse,
			"sys":       ms.Sys,
			"numGC":     ms.NumGC,
		},
	}

	sem := map[string]any{}
	if genSem != nil {
		sem["gen"] = map[string]any{"inUse": genSem.InUse(), "cap": genSem.Cap(), "max": genSem.Max()}
	}
	if previewSem != nil {
		sem["preview"] = map[string]any{"inUse": previewSem.InUse(), "cap": previewSem.Cap(), "max": previewSem.Max()}
	}
	if thumbSem != nil {
		sem["thumb"] = map[string]any{"inUse": thumbSem.InUse(), "cap": thumbSem.Cap(), "max": thumbSem.Max()}
	}
	if durSem != nil {
		sem["dur"] = map[string]any{"inUse": durSem.InUse(), "cap": durSem.Cap(), "max": durSem.Max()}
	}
	if len(sem) > 0 {
		resp["sem"] = sem
	}

	return resp
}

func pingHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet && r.Method != http.MethodHead {
		http.Error(w, "Nur GET/HEAD erlaubt", http.StatusMethodNotAllowed)
		return
	}
	w.Header().Set("Cache-Control", "no-store")
	w.WriteHeader(http.StatusNoContent)
}

func perfHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Nur GET erlaubt", http.StatusMethodNotAllowed)
		return
	}

	resp := buildPerfSnapshot()

	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Cache-Control", "no-store")
	_ = json.NewEncoder(w).Encode(resp)
}

func perfStreamHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Nur GET erlaubt", http.StatusMethodNotAllowed)
		return
	}

	fl, ok := w.(http.Flusher)
	if !ok {
		http.Error(w, "Streaming nicht unterstützt", http.StatusInternalServerError)
		return
	}

	// Optional: client kann Intervall mitgeben: /api/perf/stream?ms=5000
	ms := 5000
	if q := r.URL.Query().Get("ms"); q != "" {
		if v, err := strconv.Atoi(q); err == nil {
			// clamp: 1000..30000
			if v < 1000 {
				v = 1000
			}
			if v > 30000 {
				v = 30000
			}
			ms = v
		}
	}

	w.Header().Set("Content-Type", "text/event-stream; charset=utf-8")
	w.Header().Set("Cache-Control", "no-store")
	w.Header().Set("Connection", "keep-alive")
	// hilfreich hinter nginx/proxies:
	w.Header().Set("X-Accel-Buffering", "no")

	ctx := r.Context()

	// sofort erstes Event schicken
	send := func() error {
		payload := buildPerfSnapshot()

		var buf bytes.Buffer
		if err := json.NewEncoder(&buf).Encode(payload); err != nil {
			return err
		}

		// event: perf
		_, _ = io.WriteString(w, "event: perf\n")
		_, _ = io.WriteString(w, "data: ")
		_, _ = w.Write(buf.Bytes())
		_, _ = io.WriteString(w, "\n")
		fl.Flush()
		return nil
	}

	// initial
	_ = send()

	t := time.NewTicker(time.Duration(ms) * time.Millisecond)
	hb := time.NewTicker(15 * time.Second) // heartbeat gegen Proxy timeouts
	defer t.Stop()
	defer hb.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			_ = send()
		case <-hb.C:
			// SSE Kommentar als Heartbeat
			_, _ = io.WriteString(w, ": keep-alive\n\n")
			fl.Flush()
		}
	}
}

// -------------------------
// Low disk space guard
//  - pausiert Autostart
//  - stoppt laufende Downloads
// -------------------------

const (
	diskGuardInterval = 5 * time.Second
)

var diskEmergency int32 // 0=false, 1=true

type diskStatusResp struct {
	Emergency      bool   `json:"emergency"`
	PauseGB        int    `json:"pauseGB"`
	ResumeGB       int    `json:"resumeGB"`
	FreeBytes      uint64 `json:"freeBytes"`
	FreeBytesHuman string `json:"freeBytesHuman"`
	RecordPath     string `json:"recordPath"`
}

func diskStatusHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet && r.Method != http.MethodHead {
		http.Error(w, "Nur GET/HEAD erlaubt", http.StatusMethodNotAllowed)
		return
	}

	s := getSettings()

	pauseGB, resumeGB, _, _, _ := computeDiskThresholds()

	recordDirAbs, _ := resolvePathRelativeToApp(s.RecordDir)
	dir := strings.TrimSpace(recordDirAbs)
	if dir == "" {
		dir = strings.TrimSpace(s.RecordDir)
	}

	free := uint64(0)
	if dir != "" {
		if u, err := godisk.Usage(dir); err == nil && u != nil {
			free = u.Free
		}
	}

	resp := diskStatusResp{
		Emergency:      atomic.LoadInt32(&diskEmergency) == 1,
		PauseGB:        pauseGB,
		ResumeGB:       resumeGB,
		FreeBytes:      free,
		FreeBytesHuman: formatBytesSI(int64(free)),
		RecordPath:     dir,
	}

	w.Header().Set("Cache-Control", "no-store")
	writeJSON(w, http.StatusOK, resp)
}

// stopJobsInternal markiert Jobs als "stopping" und cancelt sie (inkl. Preview-FFmpeg Kill).
// Nutzt 2 notify-Pushes, damit die UI Phase/Progress sofort sieht.
func stopJobsInternal(list []*RecordJob) {
	if len(list) == 0 {
		return
	}

	type payload struct {
		cmd    *exec.Cmd
		cancel context.CancelFunc
	}

	pl := make([]payload, 0, len(list))

	jobsMu.Lock()
	for _, job := range list {
		if job == nil {
			continue
		}
		job.Phase = "stopping"
		job.Progress = 10
		pl = append(pl, payload{cmd: job.previewCmd, cancel: job.cancel})
		job.previewCmd = nil
	}
	jobsMu.Unlock()

	notifyJobsChanged() // 1) UI sofort updaten (Phase/Progress)

	for _, p := range pl {
		if p.cmd != nil && p.cmd.Process != nil {
			_ = p.cmd.Process.Kill()
		}
		if p.cancel != nil {
			p.cancel()
		}
	}

	notifyJobsChanged() // 2) optional: nach Cancel/Kill nochmal pushen
}

func stopAllStoppableJobs() int {
	stoppable := make([]*RecordJob, 0, 16)

	jobsMu.Lock()
	for _, j := range jobs {
		if j == nil {
			continue
		}

		if j.Status != JobRunning {
			continue
		}

		phase := strings.ToLower(strings.TrimSpace(j.Phase))

		// ✅ Im Disk-Notfall ALLES stoppen, was noch schreibt.
		// Wir skippen nur Jobs, die sowieso schon im "stopping" sind.
		if phase == "stopping" {
			continue
		}

		stoppable = append(stoppable, j)
	}
	jobsMu.Unlock()

	stopJobsInternal(stoppable)
	return len(stoppable)
}

func shouldAutoDeleteSmallDownload(filePath string) (bool, int64, int64) {
	// returns: (shouldDelete, sizeBytes, thresholdBytes)

	s := getSettings()
	if !s.AutoDeleteSmallDownloads {
		return false, 0, 0
	}

	mb := s.AutoDeleteSmallDownloadsBelowMB
	if mb <= 0 {
		return false, 0, 0
	}

	p := strings.TrimSpace(filePath)
	if p == "" {
		return false, 0, 0
	}

	// relativ -> absolut versuchen (best effort)
	if !filepath.IsAbs(p) {
		if abs, err := resolvePathRelativeToApp(p); err == nil && strings.TrimSpace(abs) != "" {
			p = abs
		}
	}

	fi, err := os.Stat(p)
	if err != nil || fi.IsDir() {
		return false, 0, int64(mb) * 1024 * 1024
	}

	size := fi.Size()
	thr := int64(mb) * 1024 * 1024
	if size > 0 && size < thr {
		return true, size, thr
	}
	return false, size, thr
}

func sizeOfPathBestEffort(p string) uint64 {
	p = strings.TrimSpace(p)
	if p == "" {
		return 0
	}

	// relativ -> absolut versuchen
	if !filepath.IsAbs(p) {
		if abs, err := resolvePathRelativeToApp(p); err == nil && strings.TrimSpace(abs) != "" {
			p = abs
		}
	}

	fi, err := os.Stat(p)
	if err != nil || fi.IsDir() || fi.Size() <= 0 {
		return 0
	}
	return uint64(fi.Size())
}

func inFlightBytesForJob(j *RecordJob) uint64 {
	if j == nil {
		return 0
	}
	// Prefer live-tracked bytes if available (accurate & cheap).
	if j.SizeBytes > 0 {
		return uint64(j.SizeBytes)
	}
	return sizeOfPathBestEffort(j.Output)
}

const giB = uint64(1024 * 1024 * 1024)

// computeDiskThresholds:
// Pause = ceil( (2 * inFlightBytes) / GiB )
// Resume = Pause + 3 GB (Hysterese)
// Wenn inFlight==0 => Pause/Resume = 0
func computeDiskThresholds() (pauseGB int, resumeGB int, inFlight uint64, pauseNeed uint64, resumeNeed uint64) {
	inFlight = sumInFlightBytes()
	if inFlight == 0 {
		return 0, 0, 0, 0, 0
	}

	need := inFlight * 2
	pauseGB = int((need + giB - 1) / giB) // ceil

	// Safety cap (nur zur Sicherheit, falls irgendwas eskaliert)
	if pauseGB > 10_000 {
		pauseGB = 10_000
	}

	resumeGB = pauseGB + 3
	if resumeGB > 10_000 {
		resumeGB = 10_000
	}

	pauseNeed = uint64(pauseGB) * giB
	resumeNeed = uint64(resumeGB) * giB
	return
}

// ✅ Summe der "wachsenden" Daten (running + remuxing etc.)
// Idee: Für TS->MP4 Peak brauchst du grob nochmal die Größe der aktuellen Datei als Reserve.
func sumInFlightBytes() uint64 {
	var sum uint64

	jobsMu.Lock()
	defer jobsMu.Unlock()

	for _, j := range jobs {
		if j == nil {
			continue
		}
		if j.Status != JobRunning {
			continue
		}

		// Nimm die Datei, die gerade wächst.
		// In deinem System ist das typischerweise j.Output (TS oder temporäres Ziel).
		// Falls du ein separates Feld für "TempTS" o.ä. hast: hier ergänzen.
		sum += inFlightBytesForJob(j)
	}

	return sum
}

// startDiskSpaceGuard läuft im Backend und reagiert auch ohne offenen Browser.
// Bei wenig freiem Platz:
//   - Autostart pausieren
//   - laufende Jobs stoppen (nur Status=running und Phase leer)
func startDiskSpaceGuard() {
	t := time.NewTicker(diskGuardInterval)
	defer t.Stop()

	for range t.C {
		s := getSettings()

		// Pfad bestimmen, auf dem wir freien Speicher prüfen
		recordDirAbs, _ := resolvePathRelativeToApp(s.RecordDir)
		dir := strings.TrimSpace(recordDirAbs)
		if dir == "" {
			dir = strings.TrimSpace(s.RecordDir)
		}
		if dir == "" {
			continue
		}

		u, err := godisk.Usage(dir)
		if err != nil || u == nil {
			continue
		}
		free := u.Free

		// ✅ Dynamische Schwellen:
		// Pause = ceil((2 * inFlight) / GiB)
		// Resume = Pause + 3 GB
		// pauseNeed/resumeNeed sind die benötigten freien Bytes
		pauseGB, resumeGB, inFlight, pauseNeed, resumeNeed := computeDiskThresholds()

		// Wenn nichts läuft, gibt es nichts zu reservieren.
		// (Optional: Emergency zurücksetzen, damit Autostart wieder frei wird.)
		if inFlight == 0 {
			if atomic.LoadInt32(&diskEmergency) == 1 {
				atomic.StoreInt32(&diskEmergency, 0)
				fmt.Printf(
					"✅ [disk] No active jobs: emergency cleared (free=%s, path=%s)\n",
					formatBytesSI(u64ToI64(free)),
					dir,
				)
			}
			continue
		}

		// ✅ Hysterese: erst ab resumeNeed wieder "bereit"
		if atomic.LoadInt32(&diskEmergency) == 1 {
			if free >= resumeNeed {
				atomic.StoreInt32(&diskEmergency, 0)
				fmt.Printf(
					"✅ [disk] Recovered: free=%s (%dB) (>= %s, %dB) emergency cleared (pause=%dGB resume=%dGB inFlight=%s, %dB)\n",
					formatBytesSI(u64ToI64(free)), free,
					formatBytesSI(u64ToI64(resumeNeed)), resumeNeed,
					pauseGB, resumeGB,
					formatBytesSI(u64ToI64(inFlight)), inFlight,
				)
			}
			continue
		}

		// ✅ Normalzustand: solange free >= pauseNeed, nichts tun
		if free >= pauseNeed {
			continue
		}

		// ✅ Trigger: Notbremse aktivieren, Jobs stoppen
		atomic.StoreInt32(&diskEmergency, 1)
		fmt.Printf(
			"🛑 [disk] Low space: free=%s (%dB) (< %s, %dB, pause=%dGB resume=%dGB, inFlight=%s, %dB) -> stop jobs + block autostart via diskEmergency (path=%s)\n",
			formatBytesSI(u64ToI64(free)), free,
			formatBytesSI(u64ToI64(pauseNeed)), pauseNeed,
			pauseGB, resumeGB,
			formatBytesSI(u64ToI64(inFlight)), inFlight,
			dir,
		)

		stopped := stopAllStoppableJobs()
		if stopped > 0 {
			fmt.Printf("🛑 [disk] Stop requested for %d job(s)\n", stopped)
		}
	}
}

func setJobPhase(job *RecordJob, phase string, progress int) {
	if progress < 0 {
		progress = 0
	}
	if progress > 100 {
		progress = 100
	}

	jobsMu.Lock()
	job.Phase = phase
	job.Progress = progress
	jobsMu.Unlock()

	notifyJobsChanged()

}

func durationSecondsCached(ctx context.Context, path string) (float64, error) {
	fi, err := os.Stat(path)
	if err != nil {
		return 0, err
	}

	durCache.mu.Lock()
	if e, ok := durCache.m[path]; ok && e.size == fi.Size() && e.mod.Equal(fi.ModTime()) && e.sec > 0 {
		durCache.mu.Unlock()
		return e.sec, nil
	}
	durCache.mu.Unlock()

	// ✅ Concurrency Limit für ffprobe/ffmpeg
	if durSem != nil {
		// kurzer Acquire: wenn Server busy ist, lieber später erneut probieren
		cctx := ctx
		if cctx == nil {
			cctx = context.Background()
		}
		acqCtx, cancel := context.WithTimeout(cctx, 2*time.Second)
		defer cancel()

		if err := durSem.Acquire(acqCtx); err != nil {
			return 0, err
		}
		defer durSem.Release()
	}

	// 1) ffprobe (bevorzugt)
	cmd := exec.CommandContext(ctx, ffprobePath,
		"-v", "error",
		"-show_entries", "format=duration",
		"-of", "default=noprint_wrappers=1:nokey=1",
		path,
	)
	out, err := cmd.Output()
	if err == nil {
		s := strings.TrimSpace(string(out))
		sec, err2 := strconv.ParseFloat(s, 64)
		if err2 == nil && sec > 0 {
			durCache.mu.Lock()
			durCache.m[path] = durEntry{size: fi.Size(), mod: fi.ModTime(), sec: sec}
			durCache.mu.Unlock()
			return sec, nil
		}
	}

	// 2) Fallback: ffmpeg -i "Duration: HH:MM:SS.xx" parsen
	cmd2 := exec.CommandContext(ctx, ffmpegPath, "-i", path)
	b, _ := cmd2.CombinedOutput() // ffmpeg liefert hier oft ExitCode!=0, Output ist trotzdem da
	text := string(b)

	re := regexp.MustCompile(`Duration:\s*(\d+):(\d+):(\d+(?:\.\d+)?)`)
	m := re.FindStringSubmatch(text)
	if len(m) != 4 {
		return 0, fmt.Errorf("duration not found")
	}
	hh, _ := strconv.ParseFloat(m[1], 64)
	mm, _ := strconv.ParseFloat(m[2], 64)
	ss, _ := strconv.ParseFloat(m[3], 64)
	sec := hh*3600 + mm*60 + ss
	if sec <= 0 {
		return 0, fmt.Errorf("invalid duration")
	}

	durCache.mu.Lock()
	durCache.m[path] = durEntry{size: fi.Size(), mod: fi.ModTime(), sec: sec}
	durCache.mu.Unlock()
	return sec, nil
}

func detectFFmpegPath() string {
	// 0. Settings-Override (ffmpegPath in recorder_settings.json / UI)
	s := getSettings()
	if p := strings.TrimSpace(s.FFmpegPath); p != "" {
		// Relativ zur EXE auflösen, falls nötig
		if !filepath.IsAbs(p) {
			if abs, err := resolvePathRelativeToApp(p); err == nil {
				p = abs
			}
		}
		return p
	}

	// 1. Umgebungsvariable FFMPEG_PATH erlaubt Override
	if p := strings.TrimSpace(os.Getenv("FFMPEG_PATH")); p != "" {
		if abs, err := filepath.Abs(p); err == nil {
			return abs
		}
		return p
	}

	// 2. ffmpeg / ffmpeg.exe im selben Ordner wie dein Go-Programm
	if exe, err := os.Executable(); err == nil {
		exeDir := filepath.Dir(exe)
		candidates := []string{
			filepath.Join(exeDir, "ffmpeg"),
			filepath.Join(exeDir, "ffmpeg.exe"),
		}
		for _, c := range candidates {
			if fi, err := os.Stat(c); err == nil && !fi.IsDir() {
				return c
			}
		}
	}

	// 3. ffmpeg über PATH suchen und absolut machen
	if lp, err := exec.LookPath("ffmpeg"); err == nil {
		if abs, err2 := filepath.Abs(lp); err2 == nil {
			return abs
		}
		return lp
	}

	// 4. Fallback: plain "ffmpeg" – kann dann immer noch fehlschlagen
	return "ffmpeg"
}

func removeGeneratedForID(id string) {
	// ✅ canonical id: wie beim Erzeugen der generated Ordner
	id = strings.TrimSpace(id)
	if id == "" {
		return
	}

	// falls jemand "file.mp4" übergibt
	id = strings.TrimSuffix(id, filepath.Ext(id))

	// HOT Prefix weg
	id = stripHotPrefix(id)

	// wichtig: exakt gleiche Normalisierung wie überall sonst (Ordnernamen!)
	var err error
	id, err = sanitizeID(id)
	if err != nil || id == "" {
		return
	}

	// 1) NEU: generated/meta/<id>/ ...
	if root, _ := generatedMetaRoot(); strings.TrimSpace(root) != "" {
		_ = os.RemoveAll(filepath.Join(root, id))
	}

	// (optional aber sinnvoll) 1b) Legacy: generated/<id>/ (falls noch alte Assets existieren)
	if root, _ := generatedRoot(); strings.TrimSpace(root) != "" {
		_ = os.RemoveAll(filepath.Join(root, id))
	}

	// 2) Temp Preview Segmente (HLS) wegräumen
	// (%TEMP%/rec_preview/<assetID>)
	_ = os.RemoveAll(filepath.Join(os.TempDir(), "rec_preview", id))
}

func purgeDurationCacheForPath(p string) {
	p = strings.TrimSpace(p)
	if p == "" {
		return
	}
	durCache.mu.Lock()
	delete(durCache.m, p)
	durCache.mu.Unlock()
}

func renameGenerated(oldID, newID string) {
	thumbsRoot, _ := generatedThumbsRoot()
	teaserRoot, _ := generatedTeaserRoot()

	oldThumb := filepath.Join(thumbsRoot, oldID)
	newThumb := filepath.Join(thumbsRoot, newID)
	if _, err := os.Stat(oldThumb); err == nil {
		if _, err2 := os.Stat(newThumb); os.IsNotExist(err2) {
			_ = os.Rename(oldThumb, newThumb)
		} else {
			_ = os.RemoveAll(oldThumb)
		}
	}

	oldTeaser := filepath.Join(teaserRoot, oldID+".mp4")
	newTeaser := filepath.Join(teaserRoot, newID+".mp4")
	if _, err := os.Stat(oldTeaser); err == nil {
		if _, err2 := os.Stat(newTeaser); os.IsNotExist(err2) {
			_ = os.Rename(oldTeaser, newTeaser)
		} else {
			_ = os.Remove(oldTeaser)
		}
	}
}

// --- Gemeinsame Status-Werte für MFC ---
type Status int

const (
	StatusUnknown Status = iota
	StatusPublic
	StatusPrivate
	StatusOffline
	StatusNotExist
)

func (s Status) String() string {
	switch s {
	case StatusPublic:
		return "PUBLIC"
	case StatusPrivate:
		return "PRIVATE"
	case StatusOffline:
		return "OFFLINE"
	case StatusNotExist:
		return "NOTEXIST"
	default:
		return "UNKNOWN"
	}
}

// HTTPClient kapselt http.Client + Header/Cookies (wie internal.Req im DVR)
type HTTPClient struct {
	client    *http.Client
	userAgent string
}

// gemeinsamen HTTP-Client erzeugen
func NewHTTPClient(userAgent string) *HTTPClient {
	if userAgent == "" {
		// Default, falls kein UA übergeben wird
		userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"
	}

	return &HTTPClient{
		client: &http.Client{
			Timeout: 10 * time.Second,
		},
		userAgent: userAgent,
	}
}

// Request-Erstellung mit User-Agent + Cookies
func (h *HTTPClient) NewRequest(ctx context.Context, method, url, cookieStr string) (*http.Request, error) {
	req, err := http.NewRequestWithContext(ctx, method, url, nil)
	if err != nil {
		return nil, err
	}

	// Basis-Header, die immer gesetzt werden
	if h.userAgent != "" {
		req.Header.Set("User-Agent", h.userAgent)
	} else {
		req.Header.Set("User-Agent", "Mozilla/5.0")
	}
	req.Header.Set("Accept", "*/*")

	// Cookie-String wie "name=value; foo=bar"
	addCookiesFromString(req, cookieStr)

	return req, nil
}

// Seite laden + einfache Erkennung von Schutzseiten (Cloudflare / Age-Gate)
func (h *HTTPClient) FetchPage(ctx context.Context, url, cookieStr string) (string, error) {
	req, err := h.NewRequest(ctx, http.MethodGet, url, cookieStr)
	if err != nil {
		return "", err
	}

	resp, err := h.client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	body := string(data)

	// Etwas aussagekräftigere Fehler als nur "room dossier nicht gefunden"
	if strings.Contains(body, "<title>Just a moment...</title>") {
		return "", errors.New("Schutzseite von Cloudflare erhalten (\"Just a moment...\") – kein Room-HTML")
	}
	if strings.Contains(body, "Verify your age") {
		return "", errors.New("Altersverifikationsseite erhalten – kein Room-HTML")
	}

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("HTTP %d beim Laden von %s", resp.StatusCode, url)
	}

	return body, nil
}

func remuxTSToMP4(tsPath, mp4Path string) error {
	// ffmpeg -y -i in.ts -c copy -movflags +faststart out.mp4
	cmd := exec.Command(ffmpegPath,
		"-y",
		"-i", tsPath,
		"-c", "copy",
		"-movflags", "+faststart",
		mp4Path,
	)
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("ffmpeg remux failed: %v (%s)", err, stderr.String())
	}
	return nil
}

func parseFFmpegOutTime(v string) float64 {
	v = strings.TrimSpace(v)
	if v == "" {
		return 0
	}
	parts := strings.Split(v, ":")
	if len(parts) != 3 {
		return 0
	}
	h, err1 := strconv.Atoi(parts[0])
	m, err2 := strconv.Atoi(parts[1])
	s, err3 := strconv.ParseFloat(parts[2], 64) // Sekunden können Dezimalstellen haben
	if err1 != nil || err2 != nil || err3 != nil {
		return 0
	}
	return float64(h*3600+m*60) + s
}

func remuxTSToMP4WithProgress(
	ctx context.Context,
	tsPath, mp4Path string,
	durationSec float64,
	inSize int64,
	onRatio func(r float64),
) error {
	// ffmpeg progress kommt auf stdout als key=value
	cmd := exec.CommandContext(ctx, ffmpegPath,
		"-y",
		"-nostats",
		"-progress", "pipe:1",
		"-i", tsPath,
		"-c", "copy",
		"-movflags", "+faststart",
		mp4Path,
	)

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}

	var stderr bytes.Buffer
	cmd.Stderr = &stderr

	if err := cmd.Start(); err != nil {
		return err
	}

	sc := bufio.NewScanner(stdout)
	sc.Buffer(make([]byte, 0, 64*1024), 1024*1024)

	var (
		lastOutSec  float64
		lastTotalSz int64
	)

	send := func(outSec float64, totalSize int64, force bool) {
		// bevorzugt: Zeit/Dauer
		if durationSec > 0 && outSec > 0 {
			r := outSec / durationSec
			if r < 0 {
				r = 0
			}
			if r > 1 {
				r = 1
			}
			if onRatio != nil {
				onRatio(r)
			}
			return
		}

		// fallback: Bytes (bei remux meist okay-ish)
		if inSize > 0 && totalSize > 0 {
			r := float64(totalSize) / float64(inSize)
			if r < 0 {
				r = 0
			}
			if r > 1 {
				r = 1
			}
			if onRatio != nil {
				onRatio(r)
			}
			return
		}

		// force (z.B. end)
		if force && onRatio != nil {
			onRatio(1)
		}
	}

	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" {
			continue
		}
		k, v, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}

		switch k {
		case "out_time_us":
			if n, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64); err == nil && n > 0 {
				lastOutSec = float64(n) / 1_000_000.0
				send(lastOutSec, lastTotalSz, false)
			}
		case "out_time_ms":
			if n, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64); err == nil && n > 0 {
				// out_time_ms ist i.d.R. Millisekunden
				lastOutSec = float64(n) / 1_000.0
				send(lastOutSec, lastTotalSz, false)
			}
		case "out_time":
			if s := parseFFmpegOutTime(v); s > 0 {
				lastOutSec = s
				send(lastOutSec, lastTotalSz, false)
			}
		case "total_size":
			if n, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64); err == nil && n > 0 {
				lastTotalSz = n
				send(lastOutSec, lastTotalSz, false)
			}
		case "progress":
			if strings.TrimSpace(v) == "end" {
				send(lastOutSec, lastTotalSz, true)
			}
		}
	}

	if err := cmd.Wait(); err != nil {
		return fmt.Errorf("ffmpeg remux failed: %v (%s)", err, strings.TrimSpace(stderr.String()))
	}
	return nil
}

// --- MP4 Streaming Optimierung (Fast Start) ---
// "Fast Start" bedeutet: moov vor mdat (Browser kann sofort Metadaten lesen)
func isFastStartMP4(path string) (bool, error) {
	f, err := os.Open(path)
	if err != nil {
		return false, err
	}
	defer f.Close()

	for i := 0; i < 256; i++ {
		var hdr [8]byte
		if _, err := io.ReadFull(f, hdr[:]); err != nil {
			// unklar/kurz -> nicht anfassen
			return true, nil
		}

		sz32 := binary.BigEndian.Uint32(hdr[0:4])
		typ := string(hdr[4:8])

		var boxSize int64
		headerSize := int64(8)

		if sz32 == 0 {
			return true, nil
		}
		if sz32 == 1 {
			var ext [8]byte
			if _, err := io.ReadFull(f, ext[:]); err != nil {
				return true, nil
			}
			boxSize = int64(binary.BigEndian.Uint64(ext[:]))
			headerSize = 16
		} else {
			boxSize = int64(sz32)
		}

		if boxSize < headerSize {
			return true, nil
		}

		switch typ {
		case "moov":
			return true, nil
		case "mdat":
			return false, nil
		}

		if _, err := f.Seek(boxSize-headerSize, io.SeekCurrent); err != nil {
			return true, nil
		}
	}

	return true, nil
}

func ensureFastStartMP4(path string) error {
	path = strings.TrimSpace(path)
	if path == "" || !strings.EqualFold(filepath.Ext(path), ".mp4") {
		return nil
	}
	if strings.TrimSpace(ffmpegPath) == "" {
		return nil
	}

	ok, err := isFastStartMP4(path)
	if err == nil && ok {
		return nil
	}

	dir := filepath.Dir(path)
	base := filepath.Base(path)
	tmp := filepath.Join(dir, ".__faststart__"+base+".tmp")
	bak := filepath.Join(dir, ".__faststart__"+base+".bak")

	_ = os.Remove(tmp)
	_ = os.Remove(bak)

	cmd := exec.Command(ffmpegPath,
		"-y",
		"-i", path,
		"-c", "copy",
		"-movflags", "+faststart",
		tmp,
	)

	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		_ = os.Remove(tmp)
		return fmt.Errorf("ffmpeg faststart failed: %v (%s)", err, strings.TrimSpace(stderr.String()))
	}

	// atomar austauschen
	if err := os.Rename(path, bak); err != nil {
		_ = os.Remove(tmp)
		return fmt.Errorf("rename original to bak failed: %w", err)
	}
	if err := os.Rename(tmp, path); err != nil {
		_ = os.Rename(bak, path)
		_ = os.Remove(tmp)
		return fmt.Errorf("rename tmp to original failed: %w", err)
	}
	_ = os.Remove(bak)
	return nil
}

func stripHotPrefix(s string) string {
	s = strings.TrimSpace(s)
	// akzeptiere "HOT " auch case-insensitive
	if len(s) >= 4 && strings.EqualFold(s[:4], "HOT ") {
		return strings.TrimSpace(s[4:])
	}
	return s
}

func generatedRoot() (string, error) {
	return resolvePathRelativeToApp("generated")
}

func generatedMetaRoot() (string, error) {
	return resolvePathRelativeToApp(filepath.Join("generated", "meta"))
}

// generatedThumbWebPFile gibt den Pfad zu generated/<assetID>/thumbs.webp zurück.
// assetID darf "HOT " enthalten; wird entfernt und wie überall sonst sanitisiert.
func generatedThumbWebPFile(assetID string) (string, error) {
	assetID = stripHotPrefix(strings.TrimSpace(assetID))
	if assetID == "" {
		return "", fmt.Errorf("empty assetID")
	}

	// gleiche Normalisierung wie bei Ordnernamen
	var err error
	assetID, err = sanitizeID(assetID)
	if err != nil || assetID == "" {
		return "", fmt.Errorf("invalid assetID: %w", err)
	}

	dir, err := ensureGeneratedDir(assetID)
	if err != nil || strings.TrimSpace(dir) == "" {
		return "", fmt.Errorf("ensureGeneratedDir: %w", err)
	}

	return filepath.Join(dir, "thumbs.webp"), nil
}

// Legacy (falls noch alte Assets liegen):
func generatedThumbsRoot() (string, error) {
	return resolvePathRelativeToApp(filepath.Join("generated", "thumbs"))
}
func generatedTeaserRoot() (string, error) {
	return resolvePathRelativeToApp(filepath.Join("generated", "teaser"))
}

func sanitizeModelKey(k string) string {
	k = stripHotPrefix(strings.TrimSpace(k))
	if k == "" || k == "—" || strings.ContainsAny(k, `/\`) {
		return ""
	}
	return k
}

func modelKeyFromFilenameOrPath(file string, srcPath string, doneAbs string) string {
	// 1) bevorzugt aus Dateiname (OHNE Extension!)
	stem := strings.TrimSuffix(filepath.Base(strings.TrimSpace(file)), filepath.Ext(file))
	k := sanitizeModelKey(strings.TrimSpace(modelNameFromFilename(stem)))
	if k != "" {
		return k
	}

	// 2) Fallback: aus Quellpfad ableiten, wenn Datei in done/<model>/... lag
	if strings.TrimSpace(srcPath) != "" && strings.TrimSpace(doneAbs) != "" {
		srcDir := filepath.Clean(filepath.Dir(srcPath))
		doneAbs = filepath.Clean(doneAbs)

		// srcDir != doneAbs => wir sind in einem Unterordner, dessen Name i.d.R. das Model ist
		if !strings.EqualFold(srcDir, doneAbs) {
			k2 := sanitizeModelKey(filepath.Base(srcDir))
			if k2 != "" && !strings.EqualFold(k2, "keep") {
				return k2
			}
		}
	}

	return ""
}

func uniqueDestPath(dstDir, file string) (string, error) {
	dst := filepath.Join(dstDir, file)
	if _, err := os.Stat(dst); err == nil {
		ext := filepath.Ext(file)
		base := strings.TrimSuffix(file, ext)
		for i := 2; i <= 200; i++ {
			alt := fmt.Sprintf("%s__dup%d%s", base, i, ext)
			cand := filepath.Join(dstDir, alt)
			if _, err := os.Stat(cand); os.IsNotExist(err) {
				return cand, nil
			}
		}
		return "", fmt.Errorf("too many duplicates for %s", file)
	} else if err != nil && !os.IsNotExist(err) {
		return "", err
	}
	return dst, nil
}

func idFromVideoPath(videoPath string) string {
	name := filepath.Base(strings.TrimSpace(videoPath))
	return strings.TrimSuffix(name, filepath.Ext(name))
}

func assetIDForJob(job *RecordJob) string {
	if job == nil {
		return ""
	}

	// Prefer: Dateiname ohne Endung (und ohne HOT Prefix)
	out := strings.TrimSpace(job.Output)
	if out != "" {
		id := stripHotPrefix(idFromVideoPath(out))
		if strings.TrimSpace(id) != "" {
			return id
		}
	}

	// Fallback: JobID (sollte praktisch nie nötig sein)
	return strings.TrimSpace(job.ID)
}

func atomicWriteFile(dst string, data []byte) error {
	dir := filepath.Dir(dst)
	if err := os.MkdirAll(dir, 0o755); err != nil {
		return err
	}
	tmp, err := os.CreateTemp(dir, ".tmp-*")
	if err != nil {
		return err
	}
	tmpName := tmp.Name()
	_ = tmp.Chmod(0o644)

	_, werr := tmp.Write(data)
	cerr := tmp.Close()

	if werr != nil {
		_ = os.Remove(tmpName)
		return werr
	}
	if cerr != nil {
		_ = os.Remove(tmpName)
		return cerr
	}

	// ✅ Wichtig: Windows/SMB kann Rename nicht überschreiben
	_ = os.Remove(dst)

	// ✅ Wenn du renameWithRetry hast: nutzen (robuster bei Shares)
	if err := renameWithRetry(tmpName, dst); err != nil {
		_ = os.Remove(tmpName)
		return err
	}

	return nil
}

// Beim Start: loose Dateien in /done/keep (Root) in /done/keep/<model>/ einsortieren.
// Best-effort: wenn Model nicht ableitbar oder Ziel kollidiert, wird geskippt bzw. umbenannt.
func fixKeepRootFilesIntoModelSubdirs() {
	s := getSettings()

	doneAbs, err := resolvePathRelativeToApp(s.DoneDir)
	if err != nil || strings.TrimSpace(doneAbs) == "" {
		return
	}

	keepRoot := filepath.Join(doneAbs, "keep")

	ents, err := os.ReadDir(keepRoot)
	if err != nil {
		// keep existiert evtl. noch nicht -> nichts zu tun
		if os.IsNotExist(err) {
			return
		}
		fmt.Println("⚠️ keep scan failed:", err)
		return
	}

	moved := 0
	skipped := 0

	isVideo := func(name string) bool {
		low := strings.ToLower(name)
		if strings.Contains(low, ".part") || strings.Contains(low, ".tmp") {
			return false
		}
		ext := strings.ToLower(filepath.Ext(name))
		return ext == ".mp4" || ext == ".ts"
	}

	for _, e := range ents {
		if e.IsDir() {
			continue
		}

		name := e.Name()
		if !isVideo(name) {
			continue
		}

		// Quelle: /done/keep/<file>
		src := filepath.Join(keepRoot, name)

		// Model aus Dateiname ableiten (wie im keep-handler)
		stem := strings.TrimSuffix(name, filepath.Ext(name)) // ✅ ohne .mp4/.ts
		modelKey := sanitizeModelKey(strings.TrimSpace(modelNameFromFilename(stem)))

		// wenn nicht ableitbar -> skip
		if modelKey == "" || modelKey == "—" || strings.ContainsAny(modelKey, `/\`) {
			skipped++
			continue
		}

		dstDir := filepath.Join(keepRoot, modelKey)
		if err := os.MkdirAll(dstDir, 0o755); err != nil {
			fmt.Println("⚠️ keep mkdir failed:", err)
			skipped++
			continue
		}

		dst := filepath.Join(dstDir, name)

		// Wenn Ziel schon existiert -> unique Name finden
		if _, err := os.Stat(dst); err == nil {
			ext := filepath.Ext(name)
			base := strings.TrimSuffix(name, ext)

			found := false
			for i := 2; i <= 200; i++ {
				alt := fmt.Sprintf("%s__dup%d%s", base, i, ext)
				cand := filepath.Join(dstDir, alt)
				if _, err := os.Stat(cand); os.IsNotExist(err) {
					dst = cand
					found = true
					break
				}
			}
			if !found {
				fmt.Println("⚠️ keep fix: too many duplicates, skip:", name)
				skipped++
				continue
			}
		} else if err != nil && !os.IsNotExist(err) {
			fmt.Println("⚠️ keep stat dst failed:", err)
			skipped++
			continue
		}

		// Verschieben (Windows-lock robust)
		if err := renameWithRetry(src, dst); err != nil {
			fmt.Println("⚠️ keep fix rename failed:", err)
			skipped++
			continue
		}

		moved++
	}

	if moved > 0 || skipped > 0 {
		fmt.Printf("🧹 keep fix: moved=%d skipped=%d (root=%s)\n", moved, skipped, keepRoot)
	}
}

func findFinishedFileByID(id string) (string, error) {
	s := getSettings()
	recordAbs, _ := resolvePathRelativeToApp(s.RecordDir)
	doneAbs, _ := resolvePathRelativeToApp(s.DoneDir)

	base := stripHotPrefix(strings.TrimSpace(id))
	if base == "" {
		return "", fmt.Errorf("not found")
	}

	names := []string{
		base + ".mp4",
		"HOT " + base + ".mp4",
		base + ".ts",
		"HOT " + base + ".ts",
	}

	// done (root + /done/<subdir>/) + keep (root + /done/keep/<subdir>/)
	for _, name := range names {
		if p, _, ok := findFileInDirOrOneLevelSubdirs(doneAbs, name, "keep"); ok {
			return p, nil
		}
		if p, _, ok := findFileInDirOrOneLevelSubdirs(filepath.Join(doneAbs, "keep"), name, ""); ok {
			return p, nil
		}
		if p, _, ok := findFileInDirOrOneLevelSubdirs(recordAbs, name, ""); ok {
			return p, nil
		}
	}

	return "", fmt.Errorf("not found")
}

const maxInt64 = int64(^uint64(0) >> 1)

func removeJobsByOutputBasename(file string) {
	file = strings.TrimSpace(file)
	if file == "" {
		return
	}

	removed := false
	jobsMu.Lock()
	for id, j := range jobs {
		if j == nil {
			continue
		}
		out := strings.TrimSpace(j.Output)
		if out == "" {
			continue
		}
		if filepath.Base(out) == file {
			delete(jobs, id)
			removed = true
		}
	}
	jobsMu.Unlock()

	if removed {
		notifyJobsChanged()
	}
}

func renameJobsOutputBasename(oldFile, newFile string) {
	oldFile = strings.TrimSpace(oldFile)
	newFile = strings.TrimSpace(newFile)
	if oldFile == "" || newFile == "" {
		return
	}

	changed := false
	jobsMu.Lock()
	for _, j := range jobs {
		if j == nil {
			continue
		}
		out := strings.TrimSpace(j.Output)
		if out == "" {
			continue
		}
		if filepath.Base(out) == oldFile {
			j.Output = filepath.Join(filepath.Dir(out), newFile)
			changed = true
		}
	}
	jobsMu.Unlock()

	if changed {
		notifyJobsChanged()
	}
}

// nimmt jetzt *HTTPClient entgegen
func FetchPlaylist(ctx context.Context, hc *HTTPClient, hlsSource, httpCookie string) (*Playlist, error) {
	if hlsSource == "" {
		return nil, errors.New("HLS-URL leer")
	}

	req, err := hc.NewRequest(ctx, http.MethodGet, hlsSource, httpCookie)
	if err != nil {
		return nil, fmt.Errorf("Fehler beim Erstellen der Playlist-Request: %w", err)
	}

	resp, err := hc.client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("Fehler beim Laden der Playlist: %w", err)
	}
	defer resp.Body.Close()

	playlist, listType, err := m3u8.DecodeFrom(resp.Body, true)
	if err != nil || listType != m3u8.MASTER {
		return nil, errors.New("keine gültige Master-Playlist")
	}

	master := playlist.(*m3u8.MasterPlaylist)
	var bestURI string
	var bestWidth int
	var bestFramerate int

	for _, variant := range master.Variants {
		if variant == nil || variant.Resolution == "" {
			continue
		}

		parts := strings.Split(variant.Resolution, "x")
		if len(parts) != 2 {
			continue
		}

		width, err := strconv.Atoi(parts[0])
		if err != nil {
			continue
		}

		fr := 30
		if strings.Contains(variant.Name, "FPS:60.0") {
			fr = 60
		}

		if width > bestWidth || (width == bestWidth && fr > bestFramerate) {
			bestWidth = width
			bestFramerate = fr
			bestURI = variant.URI
		}
	}

	if bestURI == "" {
		return nil, errors.New("keine gültige Auflösung gefunden")
	}

	root := hlsSource[:strings.LastIndex(hlsSource, "/")+1]
	return &Playlist{
		PlaylistURL: root + bestURI,
		RootURL:     root,
		Resolution:  bestWidth,
		Framerate:   bestFramerate,
	}, nil
}

func readLine() string {
	r := bufio.NewReader(os.Stdin)
	s, _ := r.ReadString('\n')
	return strings.TrimRight(s, "\r\n")
}

func fileExists(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}