// backend/record_paths.go
package main

import (
	"fmt"
	"net/http"
	"net/url"
	"os"
	"path"
	"path/filepath"
	"strings"
)

// ---------- Basic query helpers ----------

func q(r *http.Request, key string) string {
	return strings.TrimSpace(r.URL.Query().Get(key))
}

// file query -> safe basename (no traversal) + url decode
func safeBasenameQuery(r *http.Request, key string) (string, bool, error) {
	raw := strings.TrimSpace(r.URL.Query().Get(key))
	if raw == "" {
		return "", false, nil
	}
	dec, err := url.QueryUnescape(raw)
	if err != nil {
		return "", false, err
	}
	dec = strings.TrimSpace(dec)
	if !isSafeBasename(dec) {
		return "", false, fmt.Errorf("invalid basename")
	}
	return dec, true, nil
}

func isAllowedVideoExt(name string) bool {
	ext := strings.ToLower(filepath.Ext(name))
	return ext == ".mp4" || ext == ".ts"
}

// ---------- Safe path pieces ----------

func isSafeRelDir(rel string) bool {
	rel = strings.TrimSpace(rel)
	if rel == "" {
		return false
	}
	// normalize to slash for validation
	rel = filepath.ToSlash(rel)
	if strings.HasPrefix(rel, "/") {
		return false
	}
	clean := path.Clean(rel) // path.Clean => forward slashes
	if clean == "." {
		return true
	}
	if strings.HasPrefix(clean, "../") || clean == ".." {
		return false
	}
	// prevent weird traversal
	if strings.Contains(clean, `\`) {
		return false
	}
	return true
}

func isSafeBasename(name string) bool {
	name = strings.TrimSpace(name)
	if name == "" {
		return false
	}
	if strings.Contains(name, "/") || strings.Contains(name, "\\") {
		return false
	}
	return filepath.Base(name) == name
}

func setNoStoreHeaders(w http.ResponseWriter) {
	// verhindert Browser/Proxy Caching (wichtig für Logs/Status)
	w.Header().Set("Cache-Control", "no-store, max-age=0")
	w.Header().Set("Pragma", "no-cache")
	w.Header().Set("Expires", "0")
}

// ---------- Resolve dirs ----------

func exeDir() (string, error) {
	exePath, err := os.Executable()
	if err != nil {
		return "", err
	}

	exePath, err = filepath.Abs(exePath)
	if err != nil {
		return "", err
	}

	return filepath.Dir(exePath), nil
}

func resolvePathRelativeToApp(p string) (string, error) {
	p = strings.TrimSpace(p)
	if p == "" {
		return "", nil
	}

	p = filepath.Clean(filepath.FromSlash(p))
	if filepath.IsAbs(p) {
		return p, nil
	}

	baseDir, err := exeDir()
	if err == nil {
		low := strings.ToLower(baseDir)

		// Heuristik: go run / tests -> exe liegt in Temp/go-build
		isTemp := strings.Contains(low, `\appdata\local\temp`) ||
			strings.Contains(low, `\temp\`) ||
			strings.Contains(low, `\tmp\`) ||
			strings.Contains(low, `\go-build`) ||
			strings.Contains(low, `/tmp/`) ||
			strings.Contains(low, `/go-build`)

		if !isTemp {
			return filepath.Join(baseDir, p), nil
		}
	}

	// Fallback: Working Directory (Dev)
	wd, err := os.Getwd()
	if err != nil {
		return "", err
	}
	return filepath.Join(wd, p), nil
}

func getRecordingsDir() string {
	s := getSettings()

	abs, err := resolvePathRelativeToApp(s.RecordDir)
	if err == nil && strings.TrimSpace(abs) != "" {
		return abs
	}

	// Fallback (falls resolve fehlschlägt)
	return strings.TrimSpace(s.RecordDir)
}

func getKeepDir() string {
	s := getSettings()

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

	return filepath.Join(doneAbs, "keep")
}

func getDoneDir() string {
	s := getSettings()

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

	return strings.TrimSpace(s.DoneDir)
}

// ---------- Finders ----------

func findVideoPath(file string) (string, error) {
	base := filepath.Base(file) // verhindert path traversal

	roots := []string{
		getRecordingsDir(),
		getDoneDir(),
		getKeepDir(),
	}

	// 1) direkt in den Roots
	for _, root := range roots {
		root = strings.TrimSpace(root)
		if root == "" {
			continue
		}
		p := filepath.Join(root, base)
		if st, err := os.Stat(p); err == nil && !st.IsDir() {
			return p, nil
		}
	}

	// 2) 1 Ebene Unterordner: root/*/file
	for _, root := range roots {
		root = strings.TrimSpace(root)
		if root == "" {
			continue
		}
		matches, _ := filepath.Glob(filepath.Join(root, "*", base))
		for _, p := range matches {
			if st, err := os.Stat(p); err == nil && !st.IsDir() {
				return p, nil
			}
		}
	}

	return "", os.ErrNotExist
}

func findFileInDirOrOneLevelSubdirs(root string, file string, skipDirName string) (string, os.FileInfo, bool) {
	// direct
	p := filepath.Join(root, file)
	if fi, err := os.Stat(p); err == nil && !fi.IsDir() && fi.Size() > 0 {
		return p, fi, true
	}

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

	for _, e := range entries {
		if !e.IsDir() {
			continue
		}
		if skipDirName != "" && e.Name() == skipDirName {
			continue
		}
		pp := filepath.Join(root, e.Name(), file)
		if fi, err := os.Stat(pp); err == nil && !fi.IsDir() && fi.Size() > 0 {
			return pp, fi, true
		}
	}

	return "", nil, false
}

func resolveDoneFileByName(doneAbs string, file string) (full string, from string, fi os.FileInfo, err error) {
	// 1) done (root + /done/<subdir>/)  — "keep" wird übersprungen
	if p, fi, ok := findFileInDirOrOneLevelSubdirs(doneAbs, file, "keep"); ok {
		return p, "done", fi, nil
	}

	// 2) keep (root + /done/keep/<subdir>/)
	keepDir := filepath.Join(doneAbs, "keep")
	if p, fi, ok := findFileInDirOrOneLevelSubdirs(keepDir, file, ""); ok {
		return p, "keep", fi, nil
	}

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

func isTrashPath(p string) bool {
	p = strings.ReplaceAll(p, "\\", "/")
	return strings.Contains(p, "/.trash/") || strings.HasSuffix(p, "/.trash")
}

func durationFromMetaIfFresh(videoPath, assetDir string, fi os.FileInfo) (float64, bool) {
	metaPath := filepath.Join(assetDir, "meta.json")
	return readVideoMetaDuration(metaPath, fi)
}

// durationSecondsCacheOnly returns a cached duration if available and still fresh.
// It relies on your existing durCache implementation elsewhere.
func durationSecondsCacheOnly(path string, fi os.FileInfo) float64 {
	durCache.mu.Lock()
	e, ok := durCache.m[path]
	durCache.mu.Unlock()

	if ok && e.size == fi.Size() && e.mod.Equal(fi.ModTime()) && e.sec > 0 {
		return e.sec
	}
	return 0
}

// ---------- Playback resolver (shared by video + scrubber/meta) ----------

// resolves a playable file path from ?file=... (done/keep/record) or ?id=... (jobs map)
// returns absolute cleaned path
func resolvePlayablePathFromQuery(r *http.Request) (string, bool, int, string) {
	// returns: (path, ok, httpStatus, errMsg)

	// 1) file mode
	if file, ok, err := safeBasenameQuery(r, "file"); err != nil {
		return "", false, http.StatusBadRequest, "ungültiger file"
	} else if ok {
		if !isAllowedVideoExt(file) {
			return "", false, http.StatusForbidden, "nicht erlaubt"
		}

		s := getSettings()
		recordAbs, err := resolvePathRelativeToApp(s.RecordDir)
		if err != nil {
			return "", false, http.StatusInternalServerError, "recordDir auflösung fehlgeschlagen: " + err.Error()
		}
		doneAbs, err := resolvePathRelativeToApp(s.DoneDir)
		if err != nil {
			return "", false, http.StatusInternalServerError, "doneDir auflösung fehlgeschlagen: " + err.Error()
		}

		// candidates: allow .ts and fallback to .mp4
		ext := strings.ToLower(filepath.Ext(file))
		names := []string{file}
		if ext == ".ts" {
			names = append(names, strings.TrimSuffix(file, ext)+".mp4")
		}

		for _, name := range names {
			if p, _, ok := findFileInDirOrOneLevelSubdirs(doneAbs, name, "keep"); ok {
				return filepath.Clean(strings.TrimSpace(p)), true, 0, ""
			}
			if p, _, ok := findFileInDirOrOneLevelSubdirs(filepath.Join(doneAbs, "keep"), name, ""); ok {
				return filepath.Clean(strings.TrimSpace(p)), true, 0, ""
			}
			if p, _, ok := findFileInDirOrOneLevelSubdirs(recordAbs, name, ""); ok {
				return filepath.Clean(strings.TrimSpace(p)), true, 0, ""
			}
		}
		return "", false, http.StatusNotFound, "datei nicht gefunden"
	}

	// 2) id mode
	id := strings.TrimSpace(r.URL.Query().Get("id"))
	if id == "" {
		return "", false, http.StatusBadRequest, "id fehlt"
	}

	jobsMu.Lock()
	job, ok := jobs[id]
	jobsMu.Unlock()
	if !ok {
		return "", false, http.StatusNotFound, "job nicht gefunden"
	}

	outPath := filepath.Clean(strings.TrimSpace(job.Output))
	if outPath == "" {
		return "", false, http.StatusNotFound, "output fehlt"
	}

	if !filepath.IsAbs(outPath) {
		abs, err := resolvePathRelativeToApp(outPath)
		if err != nil {
			return "", false, http.StatusInternalServerError, "pfad auflösung fehlgeschlagen: " + err.Error()
		}
		outPath = abs
	}

	fi, err := os.Stat(outPath)
	if err != nil || fi == nil || fi.IsDir() || fi.Size() == 0 {
		return "", false, http.StatusNotFound, "datei nicht gefunden"
	}

	return outPath, true, 0, ""
}