start looking at cover.jpg, handle more errors gracefully, reorganize code

main.go

@@ -7,6 +7,7 @@ import (
 	"image"
 	"log"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -34,12 +35,12 @@ func main() {
 		o, _ := c.Output()
 		remoteResp := strings.Split(string(o), "\n")
 
-		filepath, err := getAttribute(remoteResp, "file ")
+		path, err := getAttribute(remoteResp, "file ")
 		if err != nil {
-			log.Fatal(err.Error())
+			log.Fatalln(err.Error())
 		}
 
-		if filepath != prevFilepath {
+		if path != prevFilepath {
 			//Album
 			album, err := getAttribute(remoteResp, "tag album ")
 			if err != nil {
@@ -58,31 +59,50 @@ func main() {
 
 			// Image
 			img := make([]byte, 0)
-			if strings.HasSuffix(filepath, ".flac") {
+
-				img, err = getFlacArt(filepath)
+			switch {
+			case hasFlacTrackArt(path):
+				img, err = getFlacArt(path)
 				if err != nil {
-					img = defaultArt()
+					img, err = getCoverJpg(path)
+					if err != nil {
+						log.Println(err.Error())
+						img = getDefaultArt()
+					}
 				}
-			} else if strings.HasSuffix(filepath, ".mp3") {
+			case hasMp3TrackArt(path):
-				img, err = getMP3Art(filepath)
+				img, err = getMP3Art(path)
 				if err != nil {
-					img = defaultArt()
+					img, err = getCoverJpg(path)
+					if err != nil {
+						log.Println(err.Error())
+						img = getDefaultArt()
+					}
 				}
-			} else {
+			case hasCoverJpg(path):
-				img = defaultArt()
+				img, err = getCoverJpg(path)
+				if err != nil {
+					log.Println(err.Error())
+					img = getDefaultArt()
+				}
+			default:
+				img = getDefaultArt()
 			}
 
 			imgBuff := bytes.NewBuffer(img)
 
 			imgOrig, _, err := image.Decode(imgBuff)
 			if err != nil {
-				log.Fatal(err.Error())
+				log.Panic(err.Error())
 			}
 			imgOut := image.NewRGBA(image.Rect(0, 0, IMAGE_SIZE, IMAGE_SIZE))
 
 			draw.BiLinear.Scale(imgOut, imgOut.Rect, imgOrig, imgOrig.Bounds(), draw.Over, nil)
 
-			jpeg.Encode(imgBuff, imgOut, nil)
+			err = jpeg.Encode(imgBuff, imgOut, nil)
+			if err != nil {
+				log.Panic(err.Error())
+			}
 
 			writeTxt("SongAlbum", album)
 			writeTxt("SongArtist", artist)
@@ -90,11 +110,87 @@ func main() {
 			writeJpg("AlbumArt", img)
 
 		}
-		prevFilepath = filepath
+		prevFilepath = path
 		time.Sleep(TIMER * time.Second)
 	}
 }
 
+// has
+
+func hasFlacTrackArt(s string) bool {
+	// dumb check
+	if !strings.HasSuffix(s, ".flac") {
+		return false
+	}
+
+	//  is parsable
+	f, err := flac.ParseFile(s)
+	if err != nil {
+		return false
+	}
+
+	// has any frames
+	if len(f.Meta) == 0 {
+		return false
+	}
+
+	// has any pictures
+	for _, metadata := range f.Meta {
+		if metadata.Type == flac.Picture {
+			return true
+		}
+	}
+
+	// no pictures
+	return false
+}
+
+func hasMp3TrackArt(s string) bool {
+	// dumb check
+	if !strings.HasSuffix(s, ".mp3") {
+		return false
+	}
+
+	// is parsable
+	m, err := id3v2.Open(s, id3v2.Options{Parse: true})
+	if err != nil {
+		return false
+	}
+	defer m.Close()
+
+	// has a picture
+	pic := m.GetFrames(m.CommonID("Attached picture"))
+	if pic != nil {
+		return true
+	}
+
+	// no pictures
+	return false
+}
+
+func hasCoverJpg(s string) bool {
+	exts := []string{".jpg", ".jpeg", ".png", ".gif"} // 'hasCoverJpg' is a misnomer, check all sane image types
+	dir := filepath.Dir(s)
+	file, err := os.Open(dir)
+	if err != nil {
+		log.Printf("can't open %v; %v\n", dir, err.Error())
+		return false
+	}
+	defer file.Close()
+	indexes, _ := file.ReadDir(0)
+	for i := range indexes {
+		for _, key := range exts {
+			if "cover"+key == indexes[i].Name() {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+// get
+
 func getFlacArt(s string) ([]byte, error) {
 	f, err := flac.ParseFile(s)
 	if err != nil {
@@ -102,6 +198,7 @@ func getFlacArt(s string) ([]byte, error) {
 	}
 	for _, metadata := range f.Meta {
 		if metadata.Type == flac.Picture {
+			// do not care if it has multiple pictures, pick the first one.
 			pic, err := flacpicture.ParseFromMetaDataBlock(*metadata)
 			return pic.ImageData, err
 		}
@@ -117,12 +214,44 @@ func getMP3Art(s string) ([]byte, error) {
 	defer tags.Close()
 	pic := tags.GetFrames(tags.CommonID("Attached picture"))
 	if pic != nil {
-		return pic[0].(id3v2.PictureFrame).Picture, nil //i literally do not care if it has multiple pictures, pick the first one.
+		// do not care if it has multiple pictures, pick the first one.
+		return pic[0].(id3v2.PictureFrame).Picture, nil
 	}
 	return nil, errors.New("no image found")
 }
 
-func defaultArt() []byte {
+func getCoverJpg(s string) ([]byte, error) {
+	exts := []string{".jpg", ".jpeg", ".png", ".gif"}
+	dir := filepath.Dir(s)
+	file, err := os.Open(dir)
+	if err != nil {
+		return nil, fmt.Errorf("can't open %v; %v", dir, err.Error())
+	}
+	defer file.Close()
+	indexes, _ := file.ReadDir(0)
+	for i := range indexes {
+		for _, key := range exts {
+			if "cover"+key == indexes[i].Name() {
+				cover, err := os.Open(dir + "/" + indexes[i].Name())
+				if err != nil {
+					return nil, fmt.Errorf("can't open %v", indexes[i].Name())
+				}
+				defer cover.Close()
+				info, err := indexes[i].Info()
+				if err != nil {
+					return nil, fmt.Errorf("cant stat %v; %v", indexes[i].Name(), err.Error())
+				}
+				art := make([]byte, info.Size())
+
+				cover.Read(art)
+				return art, nil
+			}
+		}
+	}
+	return nil, errors.New("cover not found")
+}
+
+func getDefaultArt() []byte {
 	file, err := os.Open("default.jpg")
 	if err != nil {
 		log.Fatal(err.Error())
@@ -138,6 +267,23 @@ func defaultArt() []byte {
 	return art
 }
 
+func getAttribute(input []string, prefix string) (string, error) {
+	var attr string
+	for i := range input {
+		has := strings.HasPrefix(input[i], prefix)
+		if has {
+			attr = input[i]
+		}
+	}
+	attr, b := strings.CutPrefix(attr, prefix)
+	if !b {
+		return "", fmt.Errorf("did not find prefix \"%v\"", prefix)
+	}
+	return attr, nil
+}
+
+// write
+
 func writeJpg(filename string, input []byte) {
 	os.Mkdir("output", 0755)
 	f, err := os.Create("./output/" + filename + ".jpg")
@@ -159,18 +305,3 @@ func writeTxt(filename, input string) {
 
 	f.Write([]byte(input))
 }
-
-func getAttribute(input []string, prefix string) (string, error) {
-	var attr string
-	for i := range input {
-		has := strings.HasPrefix(input[i], prefix)
-		if has {
-			attr = input[i]
-		}
-	}
-	attr, b := strings.CutPrefix(attr, prefix)
-	if !b {
-		return "", fmt.Errorf("did not find prefix \"%v\"", prefix)
-	}
-	return attr, nil
-}