Refactor: api file endpoint for auth

backend/api/files/serializers.py

@@ -5,28 +5,51 @@ from apps.files.models import PostFileModel
 class PostFileSerializer(serializers.ModelSerializer):
     """Serializer for PostFileModel."""
 
+    filename = serializers.SerializerMethodField()
+    thumbnails = serializers.SerializerMethodField()
+    download_url = serializers.SerializerMethodField()
+
     class Meta:
         model = PostFileModel
-        fields = ["hash_blake3", "file_type", "file", "thumbnail"]
-        # Add any other fields you need
+        fields = [
+            "hash_blake3",
+            "file_type",
+            "file",
+            "thumbnail",
+            "filename",
+            "thumbnails",
+            "download_url",
+        ]
 
-    def to_representation(self, instance):
-        """Customize the representation of the model."""
-        representation = super().to_representation(instance)
-
-        # Add file name from related model
+    def get_filename(self, obj):
         try:
-            representation["filename"] = instance.name.first().filename
+            return obj.name.first().filename
         except (AttributeError, IndexError):
-            representation["filename"] = "Unknown"
+            return "Unknown"
 
-        # Add URLs for different thumbnail sizes
-        base_url = f"/api/files/{instance.hash_blake3}/"
+    def get_thumbnails(self, obj):
+        base_url = f"/api/files/{obj.hash_blake3}/"
         thumbnails = {}
-        for size_key in THUMBNAIL_SIZES:
+        for size_key in ["sx", "sm", "md", "lg", "xl"]:
             thumbnails[size_key] = f"{base_url}?t={size_key}"
+        return thumbnails
 
-        representation["thumbnails"] = thumbnails
-        representation["download_url"] = f"{base_url}?d=0"
+    def get_download_url(self, obj):
+        return f"/api/files/{obj.hash_blake3}/?d=0"
 
-        return representation
+
+class FileResponseSerializer(serializers.Serializer):
+    """
+    Dummy serializer for file response schema documentation.
+    This is only used for OpenAPI schema generation and will never be used to serialize data.
+    """
+
+    file = serializers.FileField(help_text="The file content")
+
+
+class ErrorResponseSerializer(serializers.Serializer):
+    """
+    Serializer for error responses.
+    """
+
+    error = serializers.CharField(help_text="Error message")