Fix: Include backend/audio Django app in repository

backend/audio/serializers.py

@@ -0,0 +1,65 @@
+"""Audio serializers"""
+
+from rest_framework import serializers
+from audio.models import Audio, AudioProgress
+
+
+class AudioSerializer(serializers.ModelSerializer):
+    """Audio file serializer"""
+
+    class Meta:
+        model = Audio
+        fields = [
+            'id', 'youtube_id', 'title', 'description', 'channel_id',
+            'channel_name', 'duration', 'file_path', 'file_size',
+            'thumbnail_url', 'published_date', 'downloaded_date',
+            'view_count', 'like_count', 'audio_format', 'bitrate',
+            'play_count', 'last_played'
+        ]
+        read_only_fields = ['id', 'downloaded_date', 'play_count', 'last_played']
+
+
+class AudioListSerializer(serializers.Serializer):
+    """Audio list response"""
+    data = AudioSerializer(many=True)
+    paginate = serializers.BooleanField(default=True)
+
+
+class AudioProgressSerializer(serializers.ModelSerializer):
+    """Audio progress serializer"""
+
+    class Meta:
+        model = AudioProgress
+        fields = ['id', 'audio', 'position', 'completed', 'last_updated']
+        read_only_fields = ['id', 'last_updated']
+
+
+class AudioProgressUpdateSerializer(serializers.Serializer):
+    """Update audio progress"""
+    position = serializers.IntegerField(min_value=0)
+    completed = serializers.BooleanField(default=False)
+
+
+class AudioListQuerySerializer(serializers.Serializer):
+    """Query parameters for audio list"""
+    channel = serializers.CharField(required=False)
+    playlist = serializers.CharField(required=False)
+    status = serializers.ChoiceField(
+        choices=['played', 'unplayed', 'continue'],
+        required=False
+    )
+    sort = serializers.ChoiceField(
+        choices=['published', 'downloaded', 'views', 'likes', 'duration'],
+        default='published'
+    )
+    order = serializers.ChoiceField(
+        choices=['asc', 'desc'],
+        default='desc'
+    )
+
+
+class PlayerSerializer(serializers.Serializer):
+    """Audio player data"""
+    audio = AudioSerializer()
+    progress = AudioProgressSerializer(required=False)
+    stream_url = serializers.URLField()