♻️(backend) refactor LiveKit access token handling

Switched to using query parameters instead of GET requests, enabling the
inclusion of additional parameters when calling the create endpoint via POST.

Simplified the access token generation process by removing redundant calls to
`with_identity` and consolidating token generation steps. This streamlines the
method flow by preparing all necessary data before generating the access token.

src/backend/core/api/serializers.py

@@ -123,7 +123,7 @@ class RoomSerializer(serializers.ModelSerializer):
         if role is not None or instance.is_public:
             slug = f"{instance.id!s}".replace("-", "")
 
-            username = request.GET.get("username", None)
+            username = request.query_params.get("username", None)
 
             output["livekit"] = {
                 "url": settings.LIVEKIT_CONFIGURATION["url"],

src/backend/core/utils.py

@@ -11,7 +11,7 @@ from livekit.api import AccessToken, VideoGrants
 
 
 def generate_token(room: str, user, username: Optional[str] = None) -> str:
-    """Generate a Livekit access token for a user in a specific room.
+    """Generate a LiveKit access token for a user in a specific room.
 
     Args:
         room (str): The name of the room.
@@ -22,7 +22,6 @@ def generate_token(room: str, user, username: Optional[str] = None) -> str:
     Returns:
         str: The LiveKit JWT access token.
     """
-
     video_grants = VideoGrants(
         room=room,
         room_join=True,
@@ -35,18 +34,21 @@ def generate_token(room: str, user, username: Optional[str] = None) -> str:
         ],
     )
 
-    token = AccessToken(
-        api_key=settings.LIVEKIT_CONFIGURATION["api_key"],
-        api_secret=settings.LIVEKIT_CONFIGURATION["api_secret"],
-    ).with_grants(video_grants)
-
     if user.is_anonymous:
-        token.with_identity(str(uuid4()))
+        identity = str(uuid4())
         default_username = "Anonymous"
     else:
-        token.with_identity(user.sub)
+        identity = str(user.sub)
         default_username = str(user)
 
-    token.with_name(username or default_username)
+    token = (
+        AccessToken(
+            api_key=settings.LIVEKIT_CONFIGURATION["api_key"],
+            api_secret=settings.LIVEKIT_CONFIGURATION["api_secret"],
+        )
+        .with_grants(video_grants)
+        .with_identity(identity)
+        .with_name(username or default_username)
+    )
 
     return token.to_jwt()