// backend/recorder.go
package main

import (
	"context"
	"errors"
	"fmt"
	"math"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/google/uuid"
)

// ---------------- Progress mapping ----------------

func setJobProgress(job *RecordJob, phase string, pct int) {
	phase = strings.TrimSpace(phase)
	phaseLower := strings.ToLower(phase)

	if pct < 0 {
		pct = 0
	}
	if pct > 100 {
		pct = 100
	}

	type rng struct{ start, end int }
	rangeFor := func(ph string) rng {
		switch ph {
		case "postwork":
			return rng{0, 5}
		case "remuxing":
			return rng{5, 65}
		case "moving":
			return rng{65, 75}
		case "probe":
			return rng{75, 80}
		case "assets":
			return rng{80, 99}
		default:
			return rng{0, 100}
		}
	}

	jobsMu.Lock()
	defer jobsMu.Unlock()

	inPostwork := job.EndedAt != nil || (strings.TrimSpace(job.Phase) != "" && strings.ToLower(strings.TrimSpace(job.Phase)) != "recording")
	if inPostwork {
		if phaseLower == "" || phaseLower == "recording" {
			return
		}
	}

	if phase != "" {
		job.Phase = phase
	}

	if phaseLower == "postwork" && pct == 0 {
		job.Progress = 0
		return
	}

	mapped := pct

	if inPostwork {
		r := rangeFor(phaseLower)
		if r.end >= r.start {
			if pct >= r.start && pct <= r.end {
				mapped = pct
			} else {
				width := float64(r.end - r.start)
				mapped = r.start + int(math.Round((float64(pct)/100.0)*width))
			}
			if mapped < r.start {
				mapped = r.start
			}
			if mapped > r.end {
				mapped = r.end
			}
		}
	}

	if mapped < job.Progress {
		mapped = job.Progress
	}
	job.Progress = mapped
}

// ---------------- Preview scrubber ----------------

const defaultScrubberCount = 18

// /api/preview-scrubber/{index}?id=...   (oder ?file=...)
func recordPreviewScrubberFrame(w http.ResponseWriter, r *http.Request) {
	const prefix = "/api/preview-scrubber/"
	if !strings.HasPrefix(r.URL.Path, prefix) {
		http.NotFound(w, r)
		return
	}

	idxPart := strings.Trim(strings.TrimPrefix(r.URL.Path, prefix), "/")
	if idxPart == "" {
		http.Error(w, "missing scrubber frame index", http.StatusBadRequest)
		return
	}

	idx, err := strconv.Atoi(idxPart)
	if err != nil || idx < 0 {
		http.Error(w, "invalid scrubber frame index", http.StatusBadRequest)
		return
	}

	q := r.URL.Query()
	id := strings.TrimSpace(q.Get("id"))
	file := strings.TrimSpace(q.Get("file"))
	if id == "" && file == "" {
		http.Error(w, "missing id or file", http.StatusBadRequest)
		return
	}

	durSec, err := lookupDurationForScrubber(r)
	if err != nil || durSec <= 0 {
		durSec = 60
	}

	count := defaultScrubberCount
	if idx >= count {
		idx = count - 1
	}
	if count < 1 {
		count = 1
	}

	t := scrubberIndexToTime(idx, count, durSec)

	targetQ := url.Values{}
	if id != "" {
		targetQ.Set("id", id)
	}
	if file != "" {
		targetQ.Set("file", file)
	}
	targetQ.Set("t", fmt.Sprintf("%.3f", t))

	w.Header().Set("Cache-Control", "private, max-age=300")
	http.Redirect(w, r, "/api/preview?"+targetQ.Encode(), http.StatusFound)
}

// Gleichmäßig über die Videolänge sampeln (Mitte des Segments)
func scrubberIndexToTime(index, count int, durationSec float64) float64 {
	if count <= 1 {
		return 0.1
	}
	if durationSec <= 0 {
		return 0.1
	}

	maxT := math.Max(0.1, durationSec-0.1)
	ratio := (float64(index) + 0.5) / float64(count)
	t := ratio * maxT

	if t < 0.1 {
		t = 0.1
	}
	if t > maxT {
		t = maxT
	}
	return t
}

func lookupDurationForScrubber(r *http.Request) (float64, error) {
	path, ok, _, _ := resolvePlayablePathFromQuery(r)
	if !ok || strings.TrimSpace(path) == "" {
		return 0, fmt.Errorf("unable to resolve file")
	}

	// best-effort meta
	ensureMetaJSONForPlayback(r.Context(), path)

	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
	defer cancel()
	sec, err := durationSecondsCached(ctx, path)
	if err != nil {
		return 0, err
	}
	return sec, nil
}

// ---------------- Preview sprite file handler ----------------

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

	id := strings.TrimPrefix(r.URL.Path, "/api/record/preview-sprite/")
	if id == r.URL.Path {
		id = strings.TrimPrefix(r.URL.Path, "/api/preview-sprite/")
	}
	id = strings.TrimSpace(id)
	id = strings.Trim(id, "/")

	if id == "" {
		http.Error(w, "id fehlt", http.StatusBadRequest)
		return
	}

	var err error
	id, err = sanitizeID(id)
	if err != nil {
		http.Error(w, "ungültige id", http.StatusBadRequest)
		return
	}

	dir, err := generatedDirForID(id)
	if err != nil {
		http.Error(w, "ungültige id", http.StatusBadRequest)
		return
	}

	spritePath := filepath.Join(dir, "preview-sprite.webp")

	fi, err := os.Stat(spritePath)
	if err != nil || fi.IsDir() || fi.Size() <= 0 {
		http.NotFound(w, r)
		return
	}

	f, err := os.Open(spritePath)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	defer f.Close()

	w.Header().Set("Content-Type", "image/webp")
	w.Header().Set("Cache-Control", "private, max-age=31536000, immutable")
	w.Header().Set("X-Content-Type-Options", "nosniff")

	http.ServeContent(w, r, "preview-sprite.webp", fi.ModTime(), f)
}

// ---------------- Start + run job ----------------

func startRecordingInternal(req RecordRequest) (*RecordJob, error) {
	url := strings.TrimSpace(req.URL)
	if url == "" {
		return nil, errors.New("url fehlt")
	}

	jobsMu.Lock()
	for _, j := range jobs {
		if j != nil && j.Status == JobRunning && j.EndedAt == nil && strings.TrimSpace(j.SourceURL) == url {
			if j.Hidden && !req.Hidden {
				j.Hidden = false
				jobsMu.Unlock()

				notifyJobsChanged()
				return j, nil
			}

			jobsMu.Unlock()
			return j, nil
		}
	}

	startedAt := time.Now()
	provider := detectProvider(url)

	username := ""
	switch provider {
	case "chaturbate":
		username = extractUsername(url)
	case "mfc":
		username = extractMFCUsername(url)
	}
	if strings.TrimSpace(username) == "" {
		username = "unknown"
	}

	filename := fmt.Sprintf("%s_%s.ts", username, startedAt.Format("01_02_2006__15-04-05"))

	s := getSettings()
	recordDirAbs, _ := resolvePathRelativeToApp(s.RecordDir)
	recordDir := strings.TrimSpace(recordDirAbs)
	if recordDir == "" {
		recordDir = strings.TrimSpace(s.RecordDir)
	}
	outPath := filepath.Join(recordDir, filename)

	jobID := uuid.NewString()
	ctx, cancel := context.WithCancel(context.Background())

	job := &RecordJob{
		ID:          jobID,
		SourceURL:   url,
		Status:      JobRunning,
		StartedAt:   startedAt,
		StartedAtMs: startedAt.UnixMilli(),
		Output:      outPath,
		Hidden:      req.Hidden,
		cancel:      cancel,
	}

	jobs[jobID] = job
	jobsMu.Unlock()

	if !job.Hidden {
		notifyJobsChanged()
	}

	go runJob(ctx, job, req)
	return job, nil
}

func runJob(ctx context.Context, job *RecordJob, req RecordRequest) {
	hc := NewHTTPClient(req.UserAgent)
	provider := detectProvider(req.URL)

	var err error

	now := job.StartedAt
	if now.IsZero() {
		now = time.Now()
	}

	if job.StartedAtMs == 0 {
		base := job.StartedAt
		if base.IsZero() {
			base = time.Now()
			jobsMu.Lock()
			job.StartedAt = base
			jobsMu.Unlock()
		}
		jobsMu.Lock()
		job.StartedAtMs = base.UnixMilli()
		jobsMu.Unlock()
	}

	setJobProgress(job, "recording", 0)
	notifyJobsChanged()

	switch provider {
	case "chaturbate":
		if !hasChaturbateCookies(req.Cookie) {
			err = errors.New("cf_clearance und session_id (oder sessionid) Cookies sind für Chaturbate erforderlich")
			break
		}

		s := getSettings()
		recordDirAbs, rerr := resolvePathRelativeToApp(s.RecordDir)
		if rerr != nil || strings.TrimSpace(recordDirAbs) == "" {
			err = fmt.Errorf("recordDir auflösung fehlgeschlagen: %v", rerr)
			break
		}
		_ = os.MkdirAll(recordDirAbs, 0o755)

		username := extractUsername(req.URL)
		filename := fmt.Sprintf("%s_%s.ts", username, now.Format("01_02_2006__15-04-05"))

		jobsMu.Lock()
		existingOut := strings.TrimSpace(job.Output)
		jobsMu.Unlock()

		outPath := existingOut
		if outPath == "" || !filepath.IsAbs(outPath) {
			outPath = filepath.Join(recordDirAbs, filename)
		}

		if strings.TrimSpace(existingOut) != strings.TrimSpace(outPath) {
			jobsMu.Lock()
			job.Output = outPath
			jobsMu.Unlock()
			notifyJobsChanged()
		}

		err = RecordStream(ctx, hc, "https://chaturbate.com/", username, outPath, req.Cookie, job)

	case "mfc":
		s := getSettings()
		recordDirAbs, rerr := resolvePathRelativeToApp(s.RecordDir)
		if rerr != nil || strings.TrimSpace(recordDirAbs) == "" {
			err = fmt.Errorf("recordDir auflösung fehlgeschlagen: %v", rerr)
			break
		}
		_ = os.MkdirAll(recordDirAbs, 0o755)

		username := extractMFCUsername(req.URL)
		filename := fmt.Sprintf("%s_%s.ts", username, now.Format("01_02_2006__15-04-05"))
		outPath := filepath.Join(recordDirAbs, filename)

		jobsMu.Lock()
		job.Output = outPath
		jobsMu.Unlock()
		notifyJobsChanged()

		err = RecordStreamMFC(ctx, hc, username, outPath, job)

	default:
		err = errors.New("unsupported provider")
	}

	if err != nil && shouldLogRecordError(err, provider, req) {
		fmt.Println("❌ [record]", provider, job.SourceURL, "->", err)
	}

	end := time.Now()

	target := JobFinished
	var errText string
	if err != nil {
		if errors.Is(err, context.Canceled) {
			target = JobStopped
		} else {
			target = JobFailed
			errText = err.Error()
		}
	}

	stopPreview(job)

	jobsMu.Lock()
	job.EndedAt = &end
	job.EndedAtMs = end.UnixMilli()
	if errText != "" {
		job.Error = errText
	}
	job.Phase = "postwork"
	out := strings.TrimSpace(job.Output)
	jobsMu.Unlock()
	notifyJobsChanged()

	if out == "" {
		jobsMu.Lock()
		job.Status = target
		job.Phase = ""
		job.Progress = 100
		job.PostWorkKey = ""
		job.PostWork = nil
		jobsMu.Unlock()
		notifyJobsChanged()
		notifyDoneChanged()
		return
	}

	// pre-queue auto delete (small)
	{
		s := getSettings()
		minMB := s.AutoDeleteSmallDownloadsBelowMB
		if s.AutoDeleteSmallDownloads && minMB > 0 {
			threshold := int64(minMB) * 1024 * 1024
			if fi, serr := os.Stat(out); serr == nil && fi != nil && !fi.IsDir() {
				jobsMu.Lock()
				job.SizeBytes = fi.Size()
				jobsMu.Unlock()
				notifyJobsChanged()

				if fi.Size() > 0 && fi.Size() < threshold {
					base := filepath.Base(out)
					id := stripHotPrefix(strings.TrimSuffix(base, filepath.Ext(base)))

					if derr := removeWithRetry(out); derr == nil || os.IsNotExist(derr) {
						removeGeneratedForID(id)
						purgeDurationCacheForPath(out)

						jobsMu.Lock()
						delete(jobs, job.ID)
						jobsMu.Unlock()

						notifyJobsChanged()
						notifyDoneChanged()

						if shouldLogRecordInfo(req) {
							fmt.Println("🧹 auto-deleted (pre-queue):", base, "(size: "+formatBytesSI(fi.Size())+")")
						}
						return
					} else {
						fmt.Println("⚠️ auto-delete (pre-queue) failed:", derr)
					}
				}
			}
		}
	}

	// postwork queue
	postOut := out
	postTarget := target
	postKey := "postwork:" + job.ID

	jobsMu.Lock()
	job.Phase = "postwork"
	job.PostWorkKey = postKey
	{
		s := postWorkQ.StatusForKey(postKey)
		job.PostWork = &s
	}
	jobsMu.Unlock()
	notifyJobsChanged()

	okQueued := postWorkQ.Enqueue(PostWorkTask{
		Key:   postKey,
		Added: time.Now(),
		Run: func(ctx context.Context) error {
			{
				st := postWorkQ.StatusForKey(postKey)
				jobsMu.Lock()
				job.PostWork = &st
				jobsMu.Unlock()

				setJobProgress(job, "postwork", 0)
				notifyJobsChanged()
			}

			out := strings.TrimSpace(postOut)
			if out == "" {
				jobsMu.Lock()
				job.Phase = ""
				job.Progress = 100
				job.Status = postTarget
				job.PostWorkKey = ""
				job.PostWork = nil
				jobsMu.Unlock()
				notifyJobsChanged()
				notifyDoneChanged()
				return nil
			}

			setPhase := func(phase string, pct int) {
				setJobProgress(job, phase, pct)
				st := postWorkQ.StatusForKey(postKey)
				jobsMu.Lock()
				job.PostWork = &st
				jobsMu.Unlock()
				notifyJobsChanged()
			}

			// 1) Remux
			if strings.EqualFold(filepath.Ext(out), ".ts") {
				setPhase("remuxing", 72)
				if newOut, err2 := maybeRemuxTSForJob(job, out); err2 == nil && strings.TrimSpace(newOut) != "" {
					out = strings.TrimSpace(newOut)
					jobsMu.Lock()
					job.Output = out
					jobsMu.Unlock()
					notifyJobsChanged()
				}
			}

			// 2) Move to done
			setPhase("moving", 78)
			if moved, err2 := moveToDoneDir(out); err2 == nil && strings.TrimSpace(moved) != "" {
				out = strings.TrimSpace(moved)
				jobsMu.Lock()
				job.Output = out
				jobsMu.Unlock()
				notifyJobsChanged()
				notifyDoneChanged()
			}

			// 3) Duration
			setPhase("probe", 84)
			{
				dctx, cancel := context.WithTimeout(ctx, 6*time.Second)
				if sec, derr := durationSecondsCached(dctx, out); derr == nil && sec > 0 {
					jobsMu.Lock()
					job.DurationSeconds = sec
					jobsMu.Unlock()
					notifyJobsChanged()
				}
				cancel()
			}

			// 4) Video props
			setPhase("probe", 86)
			{
				pctx, cancel := context.WithTimeout(ctx, 6*time.Second)
				w, h, fps, perr := probeVideoProps(pctx, out)
				cancel()
				if perr == nil {
					jobsMu.Lock()
					job.VideoWidth = w
					job.VideoHeight = h
					job.FPS = fps
					jobsMu.Unlock()
					notifyJobsChanged()
				}
			}

			// 5) Assets with progress
			const (
				assetsStart = 86
				assetsEnd   = 99
			)

			setPhase("assets", assetsStart)

			lastPct := -1
			lastTick := time.Time{}

			update := func(r float64) {
				if r < 0 {
					r = 0
				}
				if r > 1 {
					r = 1
				}
				pct := assetsStart + int(math.Round(r*float64(assetsEnd-assetsStart)))
				if pct < assetsStart {
					pct = assetsStart
				}
				if pct > assetsEnd {
					pct = assetsEnd
				}
				if pct == lastPct {
					return
				}
				if !lastTick.IsZero() && time.Since(lastTick) < 150*time.Millisecond {
					return
				}
				lastPct = pct
				lastTick = time.Now()
				setPhase("assets", pct)
			}

			if _, err := ensureAssetsForVideoWithProgressCtx(ctx, out, job.SourceURL, update); err != nil {
				fmt.Println("⚠️ ensureAssetsForVideo:", err)
			}
			setPhase("assets", assetsEnd)

			// Finalize
			jobsMu.Lock()
			job.Status = postTarget
			job.Phase = ""
			job.Progress = 100
			job.PostWorkKey = ""
			job.PostWork = nil
			jobsMu.Unlock()
			notifyJobsChanged()
			notifyDoneChanged()
			return nil
		},
	})

	if okQueued {
		st := postWorkQ.StatusForKey(postKey)
		jobsMu.Lock()
		job.PostWork = &st
		jobsMu.Unlock()
		notifyJobsChanged()
	} else {
		jobsMu.Lock()
		job.Status = postTarget
		job.Phase = ""
		job.Progress = 100
		job.PostWorkKey = ""
		job.PostWork = nil
		jobsMu.Unlock()
		notifyJobsChanged()
		notifyDoneChanged()
	}
}