embed & move covers, remove m4a support

media/media.go

@@ -0,0 +1,164 @@
+package media
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	id3v2 "github.com/bogem/id3v2" // optional alternative
+)
+
+var coverNames = []string{
+	"cover.jpg", "cover.jpeg", "cover.png",
+	"folder.jpg", "folder.jpeg", "folder.png",
+}
+
+// EmbedAlbumArtIntoFolder scans one album folder and embeds cover art.
+func EmbedAlbumArtIntoFolder(albumDir string) error {
+	coverFile, err := FindCoverImage(albumDir)
+	if err != nil {
+		fmt.Println("Could not find cover image. Skipping embed...")
+		return nil
+	}
+
+	coverData, err := os.ReadFile(coverFile)
+	if err != nil {
+		return fmt.Errorf("failed to read cover image: %w", err)
+	}
+
+	err = filepath.Walk(albumDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info.IsDir() {
+			return nil
+		}
+
+		lower := strings.ToLower(info.Name())
+		switch {
+		case strings.HasSuffix(lower, ".mp3"):
+			return embedCoverMP3(path, coverData)
+		case strings.HasSuffix(lower, ".flac"):
+			return embedCoverFLAC(path, coverData)
+		default:
+			return nil
+		}
+	})
+
+	return err
+}
+
+// -------------------------
+// Find cover image
+// -------------------------
+func FindCoverImage(dir string) (string, error) {
+	entries, _ := os.ReadDir(dir)
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		l := strings.ToLower(e.Name())
+		for _, name := range coverNames {
+			if l == name {
+				return filepath.Join(dir, e.Name()), nil
+			}
+		}
+	}
+	return "", fmt.Errorf("no cover image found in %s", dir)
+}
+
+// -------------------------
+// Embed into MP3
+// -------------------------
+func embedCoverMP3(path string, cover []byte) error {
+	tag, err := id3v2.Open(path, id3v2.Options{Parse: true})
+	if err != nil {
+		return fmt.Errorf("mp3 open: %w", err)
+	}
+	defer tag.Close()
+
+	mime := guessMimeType(cover)
+
+	pic := id3v2.PictureFrame{
+		Encoding:    id3v2.EncodingUTF8,
+		MimeType:    mime,
+		PictureType: id3v2.PTFrontCover,
+		Description: "Cover",
+		Picture:     cover,
+	}
+
+	tag.AddAttachedPicture(pic)
+
+	if err := tag.Save(); err != nil {
+		return fmt.Errorf("mp3 save: %w", err)
+	}
+
+	fmt.Println("→ Embedded art into MP3:", filepath.Base(path))
+	return nil
+}
+
+// embedCoverFLAC writes cover bytes to a tempfile and uses metaflac to import it.
+// Requires `metaflac` (from the flac package) to be installed and in PATH.
+func embedCoverFLAC(path string, cover []byte) error {
+	// Ensure metaflac exists
+	if _, err := exec.LookPath("metaflac"); err != nil {
+		return fmt.Errorf("metaflac not found in PATH; please install package 'flac' (provides metaflac): %w", err)
+	}
+
+	// Create a temp file for the cover image
+	tmp, err := os.CreateTemp("", "cover-*.img")
+	if err != nil {
+		return fmt.Errorf("creating temp file for cover: %w", err)
+	}
+	tmpPath := tmp.Name()
+	// Ensure we remove the temp file later
+	defer func() {
+		tmp.Close()
+		os.Remove(tmpPath)
+	}()
+
+	// Write cover bytes
+	if _, err := tmp.Write(cover); err != nil {
+		return fmt.Errorf("writing cover to temp file: %w", err)
+	}
+	if err := tmp.Sync(); err != nil {
+		// non-fatal, but report if it happens
+		return fmt.Errorf("sync temp cover file: %w", err)
+	}
+
+	// Remove existing PICTURE blocks (ignore non-zero exit -> continue, but report)
+	removeCmd := exec.Command("metaflac", "--remove", "--block-type=PICTURE", path)
+	removeOut, removeErr := removeCmd.CombinedOutput()
+	if removeErr != nil {
+		// metaflac returns non-zero if there were no picture blocks — that's OK.
+		// Only fail if it's some unexpected error.
+		// We'll print the output for debugging and continue.
+		fmt.Printf("metaflac --remove output (may be fine): %s\n", string(removeOut))
+	}
+
+	// Import the new picture. metaflac will auto-detect mime type from the file.
+	importCmd := exec.Command("metaflac", "--import-picture-from="+tmpPath, path)
+	importOut, importErr := importCmd.CombinedOutput()
+	if importErr != nil {
+		return fmt.Errorf("metaflac --import-picture-from failed: %v; output: %s", importErr, string(importOut))
+	}
+
+	fmt.Println("→ Embedded art into FLAC:", filepath.Base(path))
+	return nil
+}
+
+// -------------------------
+// Helpers
+// -------------------------
+func guessMimeType(data []byte) string {
+	if bytes.HasPrefix(data, []byte{0xFF, 0xD8, 0xFF}) {
+		return "image/jpeg"
+	}
+	if bytes.HasPrefix(data, []byte{0x89, 0x50, 0x4E, 0x47}) {
+		return "image/png"
+	}
+	return "image/jpeg" // fallback
+}