feat(submissions): auto-replace player in scopes, cancel sync + info about the sync

polylan_submitter/submissions/signals.py

@@ -1,15 +1,13 @@
+from django.db import transaction
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 from asgiref.sync import async_to_sync
 from channels.layers import get_channel_layer
 
-from submissions.models import Submission, SubmissionFile, ImageCrop
+from submissions.models import Submission, SubmissionFile, ImageCrop, Scope
 from submissions.schemas import SubmissionOut, SubmissionFileOut, ImageCropOut
 
 
-channel_layer = get_channel_layer()
-
-
 @receiver(post_save, sender=Submission)
 def broadcast_submission_update(sender, instance, created, **kwargs):
     if not instance.user:
@@ -18,7 +16,7 @@ def broadcast_submission_update(sender, instance, created, **kwargs):
     user_group_name = f"submissions_user_{instance.user.id}"
     submission_data = SubmissionOut.from_orm(instance).dict()
 
-    async_to_sync(channel_layer.group_send)(
+    async_to_sync(get_channel_layer().group_send)(
         user_group_name,
         {
             "type": "submission.updated",
@@ -36,7 +34,7 @@ def broadcast_submission_file_update(sender, instance, created, **kwargs):
     user_group_name = f"submissions_user_{submission.user.id}"
     file_data = SubmissionFileOut.from_orm(instance).dict()
 
-    async_to_sync(channel_layer.group_send)(
+    async_to_sync(get_channel_layer().group_send)(
         user_group_name,
         {
             "type": "submission.file.updated",
@@ -54,10 +52,43 @@ def broadcast_image_crop_update(sender, instance, created, **kwargs):
     user_group_name = f"submissions_user_{submission.user.id}"
     crop_data = ImageCropOut.from_orm(instance).dict()
 
-    async_to_sync(channel_layer.group_send)(
+    async_to_sync(get_channel_layer().group_send)(
         user_group_name,
         {
             "type": "submission.crop.updated",
             "crop": crop_data,
         },
     )
+
+
+def broadcast_scope_updates(changes: dict[Scope, set[int]], /):
+    """Tell users their scope changed (closed/opened, (un)assigned), once the
+    current transaction commits, so the frontend can move them to the right
+    match without a refresh.
+
+    Args:
+        changes: Changed scopes, each with every user id that was or now is
+            assigned to it.
+    """
+
+    def send():
+        channel_layer = get_channel_layer()
+        for scope, user_ids in changes.items():
+            assigned_ids = set(scope.assigned_users.values_list("id", flat=True))
+            for user_id in user_ids:
+                async_to_sync(channel_layer.group_send)(
+                    f"submissions_user_{user_id}",
+                    {
+                        "type": "scope.updated",
+                        "scope": {
+                            "id": str(scope.id),
+                            "is_active": scope.is_active,
+                            "assigned": user_id in assigned_ids,
+                        },
+                    },
+                )
+
+    if changes:
+        # robust: a websocket hiccup only gets logged, it mustn't fail the
+        # (already committed) sync or admin save
+        transaction.on_commit(send, robust=True)