Squash merge audio-player-component into main

backend/metadata/metadata.go

@@ -0,0 +1,52 @@
+package metadata
+
+import (
+	"fmt"
+	"os"
+)
+
+// AudioFileExtension represents a supported audio file extension.
+type AudioFileExtension string
+
+// Supported audio file extensions.
+const (
+	MP3  AudioFileExtension = ".mp3"
+	FLAC AudioFileExtension = ".flac"
+	OGG  AudioFileExtension = ".ogg"
+	WAV  AudioFileExtension = ".wav"
+)
+
+// SupportedFileExtensions lists all supported audio formats.
+var SupportedFileExtensions = []AudioFileExtension{MP3, FLAC, OGG, WAV}
+
+// GetSupportedFileType checks if a file extension is supported.
+func GetSupportedFileType(ext string) (AudioFileExtension, bool) {
+	for _, supported := range SupportedFileExtensions {
+		if string(supported) == ext {
+			return supported, true
+		}
+	}
+
+	return "", false
+}
+
+// GetTrackLengthMillis returns the duration of an audio file in milliseconds.
+func GetTrackLengthMillis(path string) (int64, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return 0, fmt.Errorf("could not open file: %w", err)
+	}
+
+	streamer, format, err := DecodeFile(f)
+	if err != nil {
+		f.Close()
+
+		return 0, fmt.Errorf("error decoding file: %w", err)
+	}
+
+	lengthMillis := int64(float64(streamer.Len()*1000) / float64(format.SampleRate))
+	streamer.Close()
+	f.Close()
+
+	return lengthMillis, nil
+}