// backend\tasks_cleanup.go

package main

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"sync/atomic"
	"time"
)

type cleanupCandidate struct {
	path string
	name string
	size int64
}

type recordCleanupFile struct {
	path    string
	name    string
	lowName string
	size    int64
	modTime time.Time
}

type recordCleanupDeleteCandidate struct {
	file   recordCleanupFile
	reason string
}

type cleanupResp struct {
	// Small / broken downloads cleanup
	ScannedFiles             int    `json:"scannedFiles"`
	DeletedFiles             int    `json:"deletedFiles"`
	DeletedBrokenFiles       int    `json:"deletedBrokenFiles"`
	DeletedLowRatedFiles     int    `json:"deletedLowRatedFiles"`
	SkippedFiles             int    `json:"skippedFiles"`
	DeletedBytes             int64  `json:"deletedBytes"`
	DeletedBytesHuman        string `json:"deletedBytesHuman"`
	DeletedRecordOrphans     int    `json:"deletedRecordOrphans"`
	DeletedRecordOrphanBytes int64  `json:"deletedRecordOrphanBytes"`

	DeletedMuxingTemps  int `json:"deletedMuxingTemps"`
	DeletedAudioOrphans int `json:"deletedAudioOrphans"`
	DeletedTSOrphans    int `json:"deletedTSOrphans"`

	ErrorCount int `json:"errorCount"`

	// Generated-GC
	GeneratedOrphansChecked           int    `json:"generatedOrphansChecked"`
	GeneratedOrphansRemoved           int    `json:"generatedOrphansRemoved"`
	GeneratedOrphansRemovedBytes      int64  `json:"generatedOrphansRemovedBytes"`
	GeneratedOrphansRemovedBytesHuman string `json:"generatedOrphansRemovedBytesHuman"`
}

// Optional: falls du später Threshold per Body überschreiben willst.
// Frontend sendet aktuell nichts -> wir nutzen Settings.
type cleanupReq struct {
	BelowMB *int `json:"belowMB,omitempty"`
}

type cleanupTaskConfig struct {
	DoneAbs        string
	RecordAbs      string
	BelowMB        int
	DeleteLowRated bool
	MaxStars       int
	QueuedText     string
	RunningText    string
}

type cleanupTaskJob struct {
	State  CleanupTaskState
	Cancel context.CancelFunc
}

var cleanupJobsMu sync.Mutex
var cleanupJobs = map[string]*cleanupTaskJob{}

const startupCleanupInitialDelay = 8 * time.Second

func createCleanupJob(jobID string, text string, cancel context.CancelFunc) CleanupTaskState {
	st := CleanupTaskState{
		ID:          jobID,
		Queued:      true,
		Running:     false,
		Cancellable: cancel != nil,
		QueuedAt:    time.Now(),
		StartedAt:   time.Time{},
		FinishedAt:  nil,
		Text:        strings.TrimSpace(text),
		Error:       "",
		CurrentFile: "",
		Done:        0,
		Total:       0,
	}

	cleanupJobsMu.Lock()
	cleanupJobs[jobID] = &cleanupTaskJob{
		State:  st,
		Cancel: cancel,
	}
	cleanupJobsMu.Unlock()

	publishTaskState()
	return st
}

func snapshotCleanupJobs() []CleanupTaskState {
	cleanupJobsMu.Lock()
	defer cleanupJobsMu.Unlock()

	now := time.Now()
	out := make([]CleanupTaskState, 0, len(cleanupJobs))

	for id, job := range cleanupJobs {
		if job == nil {
			delete(cleanupJobs, id)
			continue
		}

		st := job.State
		if !st.Queued && !st.Running && st.FinishedAt != nil && now.Sub(*st.FinishedAt) > 4*time.Second {
			delete(cleanupJobs, id)
			continue
		}

		out = append(out, st)
	}

	return out
}

func updateCleanupJobState(jobID string, fn func(st *CleanupTaskState)) (CleanupTaskState, bool) {
	cleanupJobsMu.Lock()
	job := cleanupJobs[jobID]
	if job == nil {
		cleanupJobsMu.Unlock()
		return CleanupTaskState{}, false
	}

	fn(&job.State)
	st := job.State
	cleanupJobsMu.Unlock()

	publishTaskState()
	return st, true
}

func removeCleanupJob(jobID string) {
	cleanupJobsMu.Lock()
	delete(cleanupJobs, jobID)
	cleanupJobsMu.Unlock()

	publishTaskState()
}

func finishCleanupJob(jobID string, text string, err error) {
	now := time.Now()

	updateCleanupJobState(jobID, func(st *CleanupTaskState) {
		st.Queued = false
		st.Running = false
		st.FinishedAt = &now
		st.CurrentFile = ""

		if err == nil {
			st.Error = ""
			st.Text = strings.TrimSpace(text)
			if st.Total > 0 {
				st.Done = st.Total
			}
			return
		}

		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
			st.Error = "Abgebrochen"
			st.Text = "Abgebrochen."
		} else {
			st.Error = strings.TrimSpace(err.Error())
			st.Text = ""
		}
	})

	time.AfterFunc(4*time.Second, func() {
		removeCleanupJob(jobID)
	})
}

func cleanupTaskConfigFromSettings(req *cleanupReq, queuedText string, runningText string) (cleanupTaskConfig, error) {
	s := getSettings()

	doneAbs, err := resolvePathRelativeToApp(s.DoneDir)
	if err != nil || strings.TrimSpace(doneAbs) == "" {
		return cleanupTaskConfig{}, fmt.Errorf("doneDir auflösung fehlgeschlagen")
	}

	recordAbs, err := resolvePathRelativeToApp(s.RecordDir)
	if err != nil || strings.TrimSpace(recordAbs) == "" {
		recordAbs = strings.TrimSpace(s.RecordDir)
	}

	mb := int(s.AutoDeleteSmallDownloadsBelowMB)
	if req != nil && req.BelowMB != nil {
		mb = *req.BelowMB
	}
	if mb < 0 {
		mb = 0
	}

	return cleanupTaskConfig{
		DoneAbs:        doneAbs,
		RecordAbs:      recordAbs,
		BelowMB:        mb,
		DeleteLowRated: s.AutoDeleteLowRatedDownloads,
		MaxStars:       clampAutoDeleteRatingStars(s.AutoDeleteLowRatedDownloadsMaxStars),
		QueuedText:     strings.TrimSpace(queuedText),
		RunningText:    strings.TrimSpace(runningText),
	}, nil
}

func startCleanupTask(parentCtx context.Context, jobPrefix string, cfg cleanupTaskConfig) CleanupTaskState {
	if parentCtx == nil {
		parentCtx = context.Background()
	}

	jobPrefix = strings.TrimSpace(jobPrefix)
	if jobPrefix == "" {
		jobPrefix = "cleanup"
	}

	queuedText := strings.TrimSpace(cfg.QueuedText)
	if queuedText == "" {
		queuedText = "Wartet…"
	}

	runningText := strings.TrimSpace(cfg.RunningText)
	if runningText == "" {
		runningText = "Räume auf…"
	}

	jobID := newTaskID(jobPrefix)
	ctx, cancel := context.WithCancel(parentCtx)
	st := createCleanupJob(jobID, queuedText, cancel)

	go func(jobID string, ctx context.Context, cancel context.CancelFunc, cfg cleanupTaskConfig, runningText string) {
		defer cancel()

		if err := acquireExclusiveTask(ctx); err != nil {
			finishCleanupJob(jobID, "", err)
			return
		}
		defer releaseExclusiveTask()

		updateCleanupJobState(jobID, func(st *CleanupTaskState) {
			st.Queued = false
			st.Running = true
			st.StartedAt = time.Now()
			st.Text = runningText
		})

		resp := cleanupResp{}

		if cfg.BelowMB > 0 || cfg.DeleteLowRated {
			threshold := int64(cfg.BelowMB) * 1024 * 1024
			if err := cleanupSmallFiles(ctx, jobID, cfg.DoneAbs, threshold, cfg.DeleteLowRated, cfg.MaxStars, &resp); err != nil {
				finishCleanupJob(jobID, "", err)
				return
			}
		}

		// Neuer Cleanup-Abschnitt: alten 100%-Fortschritt vom Small-Files-Scan zurücksetzen.
		updateCleanupJobState(jobID, func(st *CleanupTaskState) {
			st.Queued = false
			st.Running = true
			if st.StartedAt.IsZero() {
				st.StartedAt = time.Now()
			}
			st.Done = 0
			st.Total = 0
			st.CurrentFile = ""
			st.Text = "Räume Record-Reste auf…"
			st.Error = ""
			st.FinishedAt = nil
		})

		if err := cleanupRecordDirOrphanAVFiles(ctx, jobID, cfg.RecordAbs, &resp); err != nil {
			finishCleanupJob(jobID, "", err)
			return
		}

		select {
		case <-ctx.Done():
			finishCleanupJob(jobID, "", ctx.Err())
			return
		default:
		}

		updateCleanupJobState(jobID, func(st *CleanupTaskState) {
			st.Queued = false
			st.Running = true
			st.Done = 0
			st.Total = 0
			st.CurrentFile = ""
			st.Text = "Räume Generated-Assets auf…"
			st.Error = ""
			st.FinishedAt = nil
		})

		gcStats := triggerGeneratedGarbageCollectorSync()

		resp.GeneratedOrphansChecked = gcStats.Checked
		resp.GeneratedOrphansRemoved = gcStats.Removed
		resp.GeneratedOrphansRemovedBytes = gcStats.RemovedBytes
		resp.GeneratedOrphansRemovedBytesHuman = formatBytesSI(gcStats.RemovedBytes)

		resp.DeletedBytes += gcStats.RemovedBytes
		resp.DeletedBytesHuman = formatBytesSI(resp.DeletedBytes)

		if resp.DeletedFiles > 0 || resp.GeneratedOrphansRemoved > 0 {
			notifyDoneChanged()
		}

		finishCleanupJob(
			jobID,
			cleanupProgressText(resp),
			nil,
		)
	}(jobID, ctx, cancel, cfg, runningText)

	return st
}

func startCleanupTaskOnceOnStartup(parentCtx context.Context) {
	if parentCtx == nil {
		parentCtx = context.Background()
	}

	appGo("startup-cleanup", func() {
		timer := time.NewTimer(startupCleanupInitialDelay)
		defer timer.Stop()

		select {
		case <-parentCtx.Done():
			return
		case <-timer.C:
		}

		cfg, err := cleanupTaskConfigFromSettings(nil, "Wartet…", "Räume auf…")
		if err != nil {
			appLogln("⚠️ [startup-cleanup] cleanup config failed:", err)
			return
		}

		startCleanupTask(parentCtx, "cleanup-startup", cfg)
	})
}

// /api/settings/cleanup (POST)
// - löscht kleine Dateien < threshold MB (mp4/ts; skip .part/.tmp; skip keep-Ordner)
// - räumt Orphans (preview/thumbs + generated) auf
func settingsCleanupHandler(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodPost:
		var req cleanupReq
		if r.Body != nil {
			_ = json.NewDecoder(r.Body).Decode(&req)
		}

		cfg, err := cleanupTaskConfigFromSettings(&req, "Wartet…", "Räume auf…")
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}

		st := startCleanupTask(context.Background(), "cleanup", cfg)

		writeJSON(w, http.StatusOK, st)
		return

	case http.MethodDelete:
		id := strings.TrimSpace(r.URL.Query().Get("id"))
		if id == "" {
			http.Error(w, "id fehlt", http.StatusBadRequest)
			return
		}

		cleanupJobsMu.Lock()
		job := cleanupJobs[id]
		cleanupJobsMu.Unlock()

		if job != nil && job.Cancel != nil {
			job.Cancel()
		}

		w.WriteHeader(http.StatusNoContent)
		return

	default:
		http.Error(w, "Nur POST/DELETE erlaubt", http.StatusMethodNotAllowed)
		return
	}
}

func cleanupProgressText(resp cleanupResp) string {
	parts := []string{
		fmt.Sprintf("gelöscht: %d/%d", resp.DeletedFiles, resp.ScannedFiles),
	}

	if resp.DeletedBrokenFiles > 0 {
		parts = append(parts, fmt.Sprintf("defekt: %d", resp.DeletedBrokenFiles))
	}

	if resp.DeletedLowRatedFiles > 0 {
		parts = append(parts, fmt.Sprintf("Rating: %d", resp.DeletedLowRatedFiles))
	}

	if resp.DeletedRecordOrphans > 0 {
		parts = append(parts, fmt.Sprintf("Records: %d", resp.DeletedRecordOrphans))
	}

	if resp.DeletedTSOrphans > 0 {
		parts = append(parts, fmt.Sprintf("TS ohne Audio: %d", resp.DeletedTSOrphans))
	}

	if resp.DeletedAudioOrphans > 0 {
		parts = append(parts, fmt.Sprintf("Audio ohne TS: %d", resp.DeletedAudioOrphans))
	}

	if resp.DeletedMuxingTemps > 0 {
		parts = append(parts, fmt.Sprintf("Muxing-Temp: %d", resp.DeletedMuxingTemps))
	}

	if resp.GeneratedOrphansRemoved > 0 {
		parts = append(parts, fmt.Sprintf("Generated: %d", resp.GeneratedOrphansRemoved))
	}

	if resp.ErrorCount > 0 {
		parts = append(parts, fmt.Sprintf("Fehler: %d", resp.ErrorCount))
	}

	parts = append(parts, fmt.Sprintf("freigegeben: %s", formatBytesSI(resp.DeletedBytes)))

	return strings.Join(parts, " · ")
}

func cleanupVideoLooksBroken(ctx context.Context, path string) (bool, string) {
	path = strings.TrimSpace(path)
	if path == "" {
		return false, ""
	}

	ext := strings.ToLower(filepath.Ext(path))
	if ext != ".mp4" && ext != ".ts" {
		return false, ""
	}

	fi, err := os.Stat(path)
	if err != nil || fi == nil || fi.IsDir() || fi.Size() <= 0 {
		return true, "file missing/empty"
	}

	// Erst ffprobe/duration: wenn keine Dauer lesbar ist, ist die Datei meistens kaputt.
	dctx, cancel := context.WithTimeout(ctx, 8*time.Second)
	dur, derr := durationSecondsCached(dctx, path)
	dctxErr := dctx.Err()
	cancel()

	if errors.Is(dctxErr, context.DeadlineExceeded) || errors.Is(dctxErr, context.Canceled) {
		// Timeout beim Prüfen nicht als "kaputt" werten, um keine guten Dateien wegen Last zu löschen.
		return false, "duration check timeout"
	}

	if derr != nil || dur <= 0 {
		if derr != nil {
			return true, "duration failed: " + derr.Error()
		}
		return true, "duration <= 0"
	}

	// Danach konservative Decode-Prüfung am Ende.
	// Diese Funktion nutzt du bereits nach dem Remux in recorder.go.
	vctx, vcancel := context.WithTimeout(ctx, 20*time.Second)
	verr := validateVideoDecodesNearEnd(vctx, path)
	vctxErr := vctx.Err()
	vcancel()

	if errors.Is(vctxErr, context.DeadlineExceeded) || errors.Is(vctxErr, context.Canceled) {
		return false, "decode check timeout"
	}

	if verr != nil {
		return true, "decode failed: " + verr.Error()
	}

	return false, ""
}

const (
	cleanupRecordOrphanMinAge = 60 * time.Second
	cleanupRecordStableDelay  = 1200 * time.Millisecond
)

func cleanupRecordPathKey(path string) string {
	path = filepath.Clean(strings.TrimSpace(path))
	if path == "" {
		return ""
	}
	return strings.ToLower(path)
}

func cleanupRecordPathIsActive(path string, activePaths map[string]struct{}) bool {
	key := cleanupRecordPathKey(path)
	if key == "" || activePaths == nil {
		return false
	}

	_, ok := activePaths[key]
	return ok
}

func snapshotCleanupRecordActivePaths() map[string]struct{} {
	active := make(map[string]struct{}, 32)

	add := func(path string) {
		key := cleanupRecordPathKey(path)
		if key != "" {
			active[key] = struct{}{}
		}
	}

	jobsMu.RLock()
	defer jobsMu.RUnlock()

	for _, j := range jobs {
		if j == nil {
			continue
		}

		out := filepath.Clean(strings.TrimSpace(j.Output))
		add(out)

		for _, sidecar := range postworkAudioSidecarCandidatesForOutput(out) {
			add(sidecar)
		}
	}

	return active
}

func cleanupAudioSidecarNamesForTS(tsName string) []string {
	tsName = strings.TrimSpace(filepath.Base(tsName))
	if tsName == "" || strings.HasPrefix(tsName, ".") || !strings.EqualFold(filepath.Ext(tsName), ".ts") {
		return nil
	}

	base := strings.TrimSuffix(tsName, filepath.Ext(tsName))
	if strings.TrimSpace(base) == "" {
		return nil
	}

	names := []string{
		base + ".audio.m4s",
		"." + base + ".audio.m4s",
	}

	if canonical := strings.TrimSpace(canonicalAssetIDFromName(base)); canonical != "" && !strings.EqualFold(canonical, base) {
		names = append(names,
			canonical+".audio.m4s",
			"."+canonical+".audio.m4s",
		)
	}

	return names
}

func cleanupHasAudioSidecarForTS(tsName string, filesByLowName map[string]recordCleanupFile) bool {
	for _, sidecarName := range cleanupAudioSidecarNamesForTS(tsName) {
		f, ok := filesByLowName[strings.ToLower(sidecarName)]
		if ok && f.size > 0 {
			return true
		}
	}
	return false
}

func cleanupWaitForStableRecordCandidates(
	ctx context.Context,
	candidates []recordCleanupDeleteCandidate,
	activePaths map[string]struct{},
	resp *cleanupResp,
) ([]recordCleanupDeleteCandidate, error) {
	if len(candidates) == 0 {
		return nil, nil
	}

	now := time.Now()
	pendingStable := make([]recordCleanupDeleteCandidate, 0, len(candidates))
	ready := make([]recordCleanupDeleteCandidate, 0, len(candidates))

	for _, candidate := range candidates {
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		default:
		}

		if now.Sub(candidate.file.modTime) < cleanupRecordOrphanMinAge {
			resp.SkippedFiles++
			continue
		}

		if cleanupRecordPathIsActive(candidate.file.path, activePaths) {
			resp.SkippedFiles++
			continue
		}

		if candidate.file.size <= 0 {
			ready = append(ready, candidate)
			continue
		}

		pendingStable = append(pendingStable, candidate)
	}

	if len(pendingStable) == 0 {
		return ready, nil
	}

	timer := time.NewTimer(cleanupRecordStableDelay)
	select {
	case <-ctx.Done():
		timer.Stop()
		return nil, ctx.Err()
	case <-timer.C:
	}

	for _, candidate := range pendingStable {
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		default:
		}

		fi, err := os.Stat(candidate.file.path)
		if err != nil || fi == nil || fi.IsDir() {
			resp.SkippedFiles++
			continue
		}

		if fi.Size() != candidate.file.size {
			resp.SkippedFiles++
			continue
		}

		candidate.file.size = fi.Size()
		candidate.file.modTime = fi.ModTime()
		ready = append(ready, candidate)
	}

	return ready, nil
}

func cleanupDeleteRecordOrphanCandidate(candidate recordCleanupDeleteCandidate, resp *cleanupResp) {
	if resp == nil {
		return
	}

	file := candidate.file

	if err := removeWithRetry(file.path); err != nil && !os.IsNotExist(err) {
		resp.ErrorCount++
		appLogln("⚠️ cleanup record orphan konnte nicht gelöscht werden:", file.name, candidate.reason, err)
		return
	}

	resp.DeletedFiles++
	resp.DeletedRecordOrphans++
	resp.DeletedBytes += file.size
	resp.DeletedRecordOrphanBytes += file.size

	if strings.HasSuffix(file.lowName, ".muxing.ts") {
		resp.DeletedMuxingTemps++
	} else if strings.HasSuffix(file.lowName, ".audio.m4s") {
		resp.DeletedAudioOrphans++
	} else if !strings.HasPrefix(file.name, ".") && strings.EqualFold(filepath.Ext(file.name), ".ts") {
		resp.DeletedTSOrphans++
	}

	purgeDurationCacheForPath(file.path)

	base := strings.TrimSuffix(filepath.Base(file.path), filepath.Ext(file.path))
	base = strings.TrimPrefix(base, ".")
	base = strings.TrimSuffix(base, ".audio")
	base = strings.TrimSuffix(base, ".muxing")

	if strings.TrimSpace(base) != "" {
		removeGeneratedForID(stripHotPrefix(base))
	}

	appLogln("🧹 cleanup deleted record orphan:", file.name, "reason:", candidate.reason, "size=", file.size)
}

func cleanupRecordDirOrphanAVFiles(ctx context.Context, jobID string, recordAbs string, resp *cleanupResp) error {
	recordAbs = strings.TrimSpace(recordAbs)
	if recordAbs == "" || resp == nil {
		return nil
	}

	entries, err := os.ReadDir(recordAbs)
	if err != nil {
		return nil
	}

	files := make([]recordCleanupFile, 0, len(entries))
	filesByLowName := make(map[string]recordCleanupFile, len(entries))

	for _, e := range entries {
		if e == nil || e.IsDir() {
			continue
		}

		name := strings.TrimSpace(e.Name())
		if name == "" {
			continue
		}

		info, err := e.Info()
		if err != nil || info == nil || info.IsDir() {
			continue
		}

		file := recordCleanupFile{
			path:    filepath.Join(recordAbs, name),
			name:    name,
			lowName: strings.ToLower(name),
			size:    info.Size(),
			modTime: info.ModTime(),
		}

		files = append(files, file)
		filesByLowName[file.lowName] = file
	}

	audioSidecarMatchedByLowName := make(map[string]bool, len(files))
	for _, file := range files {
		if strings.HasPrefix(file.name, ".") || !strings.EqualFold(filepath.Ext(file.name), ".ts") || file.size <= 0 {
			continue
		}

		for _, sidecarName := range cleanupAudioSidecarNamesForTS(file.name) {
			lowSidecarName := strings.ToLower(sidecarName)
			if _, ok := filesByLowName[lowSidecarName]; ok {
				audioSidecarMatchedByLowName[lowSidecarName] = true
			}
		}
	}

	updateCleanupJobState(jobID, func(st *CleanupTaskState) {
		st.Queued = false
		st.Running = true
		if st.StartedAt.IsZero() {
			st.StartedAt = time.Now()
		}
		st.Done = 0
		st.Total = len(files)
		st.CurrentFile = ""
		st.Text = "Suche Record-Reste…"
		st.Error = ""
		st.FinishedAt = nil
	})

	activePaths := snapshotCleanupRecordActivePaths()
	candidates := make([]recordCleanupDeleteCandidate, 0, 64)
	lastProgressAt := time.Time{}

	updateProgress := func(done, total int, currentFile, text string, force bool) {
		now := time.Now()
		if !force && now.Sub(lastProgressAt) < 250*time.Millisecond && done%100 != 0 {
			return
		}
		lastProgressAt = now

		updateCleanupJobState(jobID, func(st *CleanupTaskState) {
			st.Done = done
			st.Total = total
			st.CurrentFile = strings.TrimSpace(currentFile)
			if strings.TrimSpace(text) != "" {
				st.Text = text
			}
		})
	}

	for i, file := range files {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		updateProgress(i+1, len(files), file.name, "Suche Record-Reste…", false)

		// Fall 0:
		// alte .muxing.ts sind temporäre Remux-/Muxing-Reste.
		if strings.HasSuffix(file.lowName, ".muxing.ts") {
			resp.ScannedFiles++
			candidates = append(candidates, recordCleanupDeleteCandidate{
				file:   file,
				reason: "stale muxing temp",
			})
			continue
		}

		// Fall 1:
		// foo.ts existiert, aber kein passendes foo.audio.m4s/.foo.audio.m4s.
		if !strings.HasPrefix(file.name, ".") && strings.EqualFold(filepath.Ext(file.name), ".ts") {
			resp.ScannedFiles++

			if cleanupHasAudioSidecarForTS(file.name, filesByLowName) {
				continue
			}

			candidates = append(candidates, recordCleanupDeleteCandidate{
				file:   file,
				reason: "missing audio sidecar",
			})
			continue
		}

		// Fall 2:
		// foo.audio.m4s/.foo.audio.m4s existiert, aber foo.ts fehlt.
		if strings.HasSuffix(file.lowName, ".audio.m4s") {
			resp.ScannedFiles++

			if audioSidecarMatchedByLowName[file.lowName] {
				continue
			}

			candidates = append(candidates, recordCleanupDeleteCandidate{
				file:   file,
				reason: "missing ts file",
			})
			continue
		}
	}

	updateProgress(len(files), len(files), "", "Prüfe stabile Record-Reste…", true)

	stableCandidates, err := cleanupWaitForStableRecordCandidates(ctx, candidates, activePaths, resp)
	if err != nil {
		return err
	}

	updateProgress(0, len(stableCandidates), "", "Lösche Record-Reste…", true)
	activePaths = snapshotCleanupRecordActivePaths()

	for i, candidate := range stableCandidates {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		updateProgress(i+1, len(stableCandidates), candidate.file.name, "Lösche Record-Reste…", false)
		if cleanupRecordPathIsActive(candidate.file.path, activePaths) {
			resp.SkippedFiles++
			continue
		}

		cleanupDeleteRecordOrphanCandidate(candidate, resp)
	}

	updateProgress(len(stableCandidates), len(stableCandidates), "", cleanupProgressText(*resp), true)

	return nil
}

func clampAutoDeleteRatingStars(v int) int {
	if v < 1 {
		return 3
	}
	if v > 5 {
		return 5
	}
	return v
}

func ratingStarsForVideoPath(videoPath string) (int, bool, error) {
	videoPath = strings.TrimSpace(videoPath)
	if videoPath == "" {
		return 0, false, nil
	}

	base := strings.TrimSuffix(filepath.Base(videoPath), filepath.Ext(videoPath))
	assetID := stripHotPrefix(base)
	if strings.TrimSpace(assetID) == "" {
		return 0, false, nil
	}

	metaPath, err := generatedMetaFile(assetID)
	if err != nil {
		return 0, false, err
	}

	m, ok := readVideoMetaLoose(metaPath)
	if !ok || m == nil {
		return 0, false, nil
	}

	ai := pickAnalysisAIForGoal(m.Analysis, "highlights")
	if ai == nil || ai.Rating == nil {
		return 0, false, nil
	}

	stars := ai.Rating.Stars
	if stars <= 0 && ai.Rating.Score > 0 {
		stars = starsFromHighlightScore(ai.Rating.Score)
	}
	if stars < 1 || stars > 5 {
		return 0, false, nil
	}

	return stars, true, nil
}

func deleteDoneVideoAndGenerated(videoPath string) (int64, error) {
	videoPath = filepath.Clean(strings.TrimSpace(videoPath))
	if videoPath == "" {
		return 0, nil
	}

	ext := strings.ToLower(filepath.Ext(videoPath))
	if ext != ".mp4" && ext != ".ts" {
		return 0, nil
	}

	fi, err := os.Stat(videoPath)
	if err != nil {
		if os.IsNotExist(err) {
			return 0, nil
		}
		return 0, err
	}
	if fi == nil || fi.IsDir() {
		return 0, nil
	}

	name := filepath.Base(videoPath)
	base := strings.TrimSuffix(name, filepath.Ext(name))
	assetID := stripHotPrefix(base)

	// Stoppt ggf. laufende Asset-/Enrich-Tasks für genau diese Datei,
	// damit Windows-Dateihandles nicht blockieren.
	releaseFileForMutation(name)

	if err := removeWithRetry(videoPath); err != nil && !os.IsNotExist(err) {
		return 0, err
	}

	if strings.TrimSpace(assetID) != "" {
		removeGeneratedForID(assetID)
	}

	purgeDurationCacheForPath(videoPath)
	return fi.Size(), nil
}

func autoDeleteLowRatedDownloadAfterAnalysis(ctx context.Context, videoPath string, rating *aiRatingMeta) {
	select {
	case <-ctx.Done():
		return
	default:
	}

	videoPath = strings.TrimSpace(videoPath)
	if videoPath == "" {
		return
	}

	s := getSettings()
	if !s.AutoDeleteLowRatedDownloads {
		return
	}

	maxStars := clampAutoDeleteRatingStars(s.AutoDeleteLowRatedDownloadsMaxStars)

	stars := 0

	if rating != nil {
		stars = rating.Stars
		if stars <= 0 && rating.Score > 0 {
			stars = starsFromHighlightScore(rating.Score)
		}
	}

	// Wichtig für Background-/Regenerate-Analyse:
	// Dort wird rating teilweise als nil übergeben, obwohl es kurz vorher
	// in meta.json gespeichert wurde. Dann lesen wir die Sterne aus der Meta.
	if stars <= 0 {
		if metaStars, ok, err := ratingStarsForVideoPath(videoPath); err != nil {
			appLogln("⚠️ [rating-delete] rating lookup failed:", filepath.Base(videoPath), err)
		} else if ok {
			stars = metaStars
		}
	}

	if stars < 1 || stars > 5 {
		appLogf(
			"ℹ️ [rating-delete] übersprungen, kein gültiges Rating: %s stars=%d threshold<=%d",
			filepath.Base(videoPath),
			stars,
			maxStars,
		)
		return
	}

	if stars > maxStars {
		appLogf(
			"ℹ️ [rating-delete] behalten: %s stars=%d threshold<=%d",
			filepath.Base(videoPath),
			stars,
			maxStars,
		)
		return
	}

	deletedBytes, err := deleteDoneVideoAndGenerated(videoPath)
	if err != nil {
		appLogln("⚠️ [rating-delete] konnte Download nicht löschen:", filepath.Base(videoPath), err)
		return
	}

	appLogf(
		"🗑️ [rating-delete] gelöscht nach Analyse: %s stars=%d threshold<=%d bytes=%s",
		filepath.Base(videoPath),
		stars,
		maxStars,
		formatBytesSI(deletedBytes),
	)

	notifyDoneChanged()
}

func cleanupSmallFiles(ctx context.Context, jobID string, doneAbs string, threshold int64, deleteLowRated bool, maxStars int, resp *cleanupResp) error {
	isCandidate := 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"
	}

	candidates := make([]cleanupCandidate, 0, 1024)

	collectCandidates := func(dir string, allowSubdirs bool) error {
		ents, err := os.ReadDir(dir)
		if err != nil {
			return nil
		}

		for _, e := range ents {
			select {
			case <-ctx.Done():
				return ctx.Err()
			default:
			}

			full := filepath.Join(dir, e.Name())

			if e.IsDir() {
				if !allowSubdirs {
					continue
				}
				if e.Name() == "keep" {
					continue
				}

				sub, err := os.ReadDir(full)
				if err != nil {
					continue
				}

				for _, se := range sub {
					if se.IsDir() {
						continue
					}

					name := se.Name()
					if !isCandidate(name) {
						resp.SkippedFiles++
						continue
					}

					p := filepath.Join(full, name)
					fi, err := os.Stat(p)
					if err != nil || fi.IsDir() || fi.Size() <= 0 {
						resp.SkippedFiles++
						continue
					}

					candidates = append(candidates, cleanupCandidate{
						path: p,
						name: name,
						size: fi.Size(),
					})
				}
				continue
			}

			name := e.Name()
			if !isCandidate(name) {
				resp.SkippedFiles++
				continue
			}

			fi, err := os.Stat(full)
			if err != nil || fi.IsDir() || fi.Size() <= 0 {
				resp.SkippedFiles++
				continue
			}

			candidates = append(candidates, cleanupCandidate{
				path: full,
				name: name,
				size: fi.Size(),
			})
		}
		return nil
	}

	if err := collectCandidates(doneAbs, true); err != nil {
		return err
	}

	resp.ScannedFiles = len(candidates)

	updateCleanupJobState(jobID, func(st *CleanupTaskState) {
		st.Queued = false
		st.Running = true
		if st.StartedAt.IsZero() {
			st.StartedAt = time.Now()
		}
		st.Done = 0
		st.Total = resp.ScannedFiles
		st.CurrentFile = ""
		st.Text = cleanupProgressText(*resp)
		st.Error = ""
		st.FinishedAt = nil
	})

	for i, c := range candidates {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}
		deleteReason := ""

		if threshold > 0 && c.size < threshold {
			deleteReason = "small"
		} else if deleteLowRated {
			stars, ok, err := ratingStarsForVideoPath(c.path)
			if err != nil {
				appLogln("⚠️ cleanup rating check failed:", filepath.Base(c.path), err)
			} else if ok && stars <= maxStars {
				deleteReason = "rating"
				appLogf(
					"🧹 cleanup deleting low-rated video: %s stars=%d threshold<=%d",
					filepath.Base(c.path),
					stars,
					maxStars,
				)
			}
		}

		if deleteReason == "" {
			broken, why := cleanupVideoLooksBroken(ctx, c.path)
			if broken {
				deleteReason = "broken"
				appLogln("🧹 cleanup deleting broken video:", filepath.Base(c.path), why)
			}
		}

		if deleteReason != "" {
			deletedBytes, derr := deleteDoneVideoAndGenerated(c.path)
			if derr == nil {
				resp.DeletedFiles++
				if deletedBytes > 0 {
					resp.DeletedBytes += deletedBytes
				} else {
					resp.DeletedBytes += c.size
				}

				switch deleteReason {
				case "broken":
					resp.DeletedBrokenFiles++
				case "rating":
					resp.DeletedLowRatedFiles++
				}
			} else {
				resp.ErrorCount++
			}
		}

		updateCleanupJobState(jobID, func(st *CleanupTaskState) {
			st.Queued = false
			st.Running = true
			if st.StartedAt.IsZero() {
				st.StartedAt = time.Now()
			}
			st.Done = i + 1
			st.Total = resp.ScannedFiles
			st.CurrentFile = c.name
			st.Text = cleanupProgressText(*resp)
			st.Error = ""
			st.FinishedAt = nil
		})
	}

	return nil
}

var generatedGCRunning int32

type generatedGCStats struct {
	Checked      int
	Removed      int
	RemovedBytes int64
}

func dirSizeBytes(root string) int64 {
	root = strings.TrimSpace(root)
	if root == "" {
		return 0
	}

	var total int64

	_ = filepath.WalkDir(root, func(p string, d fs.DirEntry, err error) error {
		if err != nil {
			return nil
		}
		if d.IsDir() {
			return nil
		}

		info, err := d.Info()
		if err != nil {
			return nil
		}
		if info.Size() > 0 {
			total += info.Size()
		}
		return nil
	})

	return total
}

func removeDirIfEmpty(dir string) (bool, error) {
	dir = strings.TrimSpace(dir)
	if dir == "" {
		return false, nil
	}

	entries, err := os.ReadDir(dir)
	if err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, err
	}

	if len(entries) > 0 {
		return false, nil
	}

	if err := os.Remove(dir); err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, err
	}

	return true, nil
}

// Läuft synchron und liefert Zahlen zurück (für /api/settings/cleanup Response).
func triggerGeneratedGarbageCollectorSync() generatedGCStats {
	// nur 1 GC gleichzeitig
	if !atomic.CompareAndSwapInt32(&generatedGCRunning, 0, 1) {
		appLogln("🧹 [gc] skip: already running")
		return generatedGCStats{}
	}
	defer atomic.StoreInt32(&generatedGCRunning, 0)

	stats := runGeneratedGarbageCollector()
	return stats
}

// Läuft 1× nach Serverstart (mit Delay), löscht /generated/* Orphans.
func startGeneratedGarbageCollector() {
	go func() {
		time.Sleep(3 * time.Second)
		triggerGeneratedGarbageCollectorSync()
	}()
}

func collectLiveIDsFromTrash(trashDir string, live map[string]struct{}) {
	trashDir = strings.TrimSpace(trashDir)
	if trashDir == "" || live == nil {
		return
	}

	entries, err := os.ReadDir(trashDir)
	if err != nil {
		return
	}

	for _, e := range entries {
		if e == nil || e.IsDir() {
			continue
		}

		name := strings.TrimSpace(e.Name())
		if name == "" {
			continue
		}

		// last.json ignorieren
		if strings.EqualFold(name, "last.json") {
			continue
		}

		// Format in .trash:
		// <token>__<original-file>
		parts := strings.SplitN(name, "__", 2)
		if len(parts) != 2 {
			continue
		}

		originalFile := strings.TrimSpace(parts[1])
		if originalFile == "" {
			continue
		}

		ext := strings.ToLower(filepath.Ext(originalFile))
		if ext != ".mp4" && ext != ".ts" {
			continue
		}

		full := filepath.Join(trashDir, name)
		fi, err := os.Stat(full)
		if err != nil || fi == nil || fi.IsDir() || fi.Size() <= 0 {
			continue
		}

		id := stripHotPrefix(strings.TrimSuffix(filepath.Base(originalFile), ext))
		id = strings.TrimSpace(id)
		if id == "" {
			continue
		}

		if sid, err := sanitizeID(id); err == nil && sid != "" {
			live[sid] = struct{}{}
		}
	}
}

// Core-Logik ohne Delay (für manuelle Trigger, z.B. nach Cleanup)
// Liefert Stats zurück, damit /api/settings/cleanup die Zahlen anzeigen kann.
func runGeneratedGarbageCollector() generatedGCStats {
	stats := generatedGCStats{}

	s := getSettings()

	doneAbs, err := resolvePathRelativeToApp(s.DoneDir)
	if err != nil {
		appLogln("🧹 [gc] resolve doneDir failed:", err)
		return stats
	}
	doneAbs = strings.TrimSpace(doneAbs)
	if doneAbs == "" {
		return stats
	}

	// 1) Live-IDs sammeln: alle mp4/ts unter /done (rekursiv), .trash zunächst ignorieren
	live := make(map[string]struct{}, 4096)

	_ = filepath.WalkDir(doneAbs, func(p string, d fs.DirEntry, err error) error {
		if err != nil {
			return nil
		}

		name := d.Name()

		if d.IsDir() {
			if strings.EqualFold(name, ".trash") {
				return fs.SkipDir
			}
			return nil
		}

		ext := strings.ToLower(filepath.Ext(name))
		if ext != ".mp4" && ext != ".ts" {
			return nil
		}

		info, err := d.Info()
		if err != nil || info.IsDir() || info.Size() <= 0 {
			return nil
		}

		base := strings.TrimSuffix(name, ext)
		id, err := sanitizeID(stripHotPrefix(base))
		if err != nil || id == "" {
			return nil
		}

		live[id] = struct{}{}
		return nil
	})

	// 1a) Dateien in .trash ebenfalls als "live" behandeln,
	// damit ihre Generated-Dateien erst gelöscht werden,
	// wenn sie wirklich endgültig aus .trash verschwinden.
	collectLiveIDsFromTrash(filepath.Join(doneAbs, ".trash"), live)

	// 1b) Auch aktuell laufende / nachbearbeitete Jobs als "live" behandeln.
	// Zusätzlich separat merken, damit leere Ordner aktiver Jobs nicht gelöscht werden.
	activeJobIDs := make(map[string]struct{}, 128)

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

		id := strings.TrimSpace(assetIDForJob(j))
		if id == "" {
			continue
		}

		live[id] = struct{}{}
		activeJobIDs[id] = struct{}{}
	}
	jobsMu.RUnlock()

	// 2) /generated/meta/<id> prüfen
	metaRoot, err := generatedMetaRoot()
	if err == nil {
		metaRoot = strings.TrimSpace(metaRoot)
	}
	if err != nil || metaRoot == "" {
		return stats
	}

	removedMeta := 0
	checkedMeta := 0
	removedBytes := int64(0)

	if entries, err := os.ReadDir(metaRoot); err == nil {
		for _, e := range entries {
			if !e.IsDir() {
				continue
			}

			id := strings.TrimSpace(e.Name())
			if id == "" || strings.HasPrefix(id, ".") {
				continue
			}

			checkedMeta++

			orphanDir := filepath.Join(metaRoot, id)

			// Leere generated/meta/<id>-Ordner immer entfernen,
			// außer ein aktiver Job könnte gerade hinein schreiben.
			if _, active := activeJobIDs[id]; !active {
				if removedEmpty, err := removeDirIfEmpty(orphanDir); err == nil && removedEmpty {
					removedMeta++
					continue
				}
			}

			if _, ok := live[id]; ok {
				continue
			}

			orphanBytes := dirSizeBytes(orphanDir)

			removeGeneratedForID(id)

			// Falls removeGeneratedForID nur Dateien gelöscht hat, den nun leeren Ordner entfernen.
			if removedEmpty, err := removeDirIfEmpty(orphanDir); err == nil && removedEmpty {
				// ok
			}

			if _, err := os.Stat(orphanDir); os.IsNotExist(err) {
				removedMeta++
				removedBytes += orphanBytes
			}
		}
	}

	//fmt.Printf("🧹 [gc] generated/meta checked=%d removed_orphans=%d bytes=%d\n", checkedMeta, removedMeta, removedBytes)
	stats.Checked += checkedMeta
	stats.Removed += removedMeta
	stats.RemovedBytes += removedBytes

	return stats
}