Unfollowing or blocking users purges timeline

Fixes #366

activities/models/post.py

@@ -928,14 +928,11 @@ class Post(StatorModel):
         try:
             cls.by_object_uri(object_uri)
         except cls.DoesNotExist:
-            InboxMessage.objects.create(
-                message={
-                    "type": "__internal__",
-                    "object": {
-                        "type": "FetchPost",
-                        "object": object_uri,
-                        "reason": reason,
-                    },
+            InboxMessage.create_internal(
+                {
+                    "type": "FetchPost",
+                    "object": object_uri,
+                    "reason": reason,
                 }
             )
 
@@ -995,7 +992,7 @@ class Post(StatorModel):
         Handles an internal fetch-request inbox message
         """
         try:
-            uri = data["object"]["object"]
+            uri = data["object"]
             if "://" in uri:
                 cls.by_object_uri(uri, fetch=True)
         except (cls.DoesNotExist, KeyError):

activities/models/timeline_event.py

@@ -166,6 +166,30 @@ class TimelineEvent(models.Model):
                 subject_identity_id=interaction.identity_id,
             ).delete()
 
+    ### Background tasks ###
+
+    @classmethod
+    def handle_clear_timeline(cls, message):
+        """
+        Internal stator handler for clearing all events by a user off another
+        user's timeline.
+        """
+        actor_id = message["actor"]
+        object_id = message["object"]
+        full_erase = message.get("fullErase", False)
+
+        if full_erase:
+            q = (
+                models.Q(subject_post__author_id=object_id)
+                | models.Q(subject_post_interaction__identity_id=object_id)
+                | models.Q(subject_identity_id=object_id)
+            )
+        else:
+            q = models.Q(
+                type=cls.Types.post, subject_post__author_id=object_id
+            ) | models.Q(type=cls.Types.boost, subject_identity_id=object_id)
+        TimelineEvent.objects.filter(q, identity_id=actor_id).delete()
+
     ### Mastodon Client API ###
 
     def to_mastodon_notification_json(self, interactions=None):

tests/activities/models/test_timeline_event.py

@@ -5,6 +5,7 @@ from activities.models import Post, TimelineEvent
 from activities.services import PostService
 from core.ld import format_ld_date
 from users.models import Block, Follow, Identity, InboxMessage
+from users.services import IdentityService
 
 
 @pytest.mark.django_db
@@ -192,3 +193,67 @@ def test_old_new_post(
         ).first()
         assert event
         assert "Hello " in event.subject_post.content
+
+
+@pytest.mark.django_db
+@pytest.mark.parametrize("full", [True, False])
+def test_clear_timeline(
+    identity: Identity,
+    remote_identity: Identity,
+    stator,
+    full: bool,
+):
+    """
+    Ensures that timeline clearing works as expected.
+    """
+    # Follow the remote user
+    service = IdentityService(remote_identity)
+    service.follow_from(identity)
+    # Create an inbound new post message mentioning us
+    message = {
+        "id": "test",
+        "type": "Create",
+        "actor": remote_identity.actor_uri,
+        "object": {
+            "id": "https://remote.test/test-post",
+            "type": "Note",
+            "published": format_ld_date(timezone.now()),
+            "attributedTo": remote_identity.actor_uri,
+            "content": f"Hello @{identity.handle}!",
+            "tag": {
+                "type": "Mention",
+                "href": identity.actor_uri,
+                "name": f"@{identity.handle}",
+            },
+        },
+    }
+    InboxMessage.objects.create(message=message)
+
+    # Run stator twice - to make fanouts and then process them
+    stator.run_single_cycle_sync()
+    stator.run_single_cycle_sync()
+
+    # Make sure it appeared on our timeline as a post and a mentioned
+    assert TimelineEvent.objects.filter(
+        type=TimelineEvent.Types.post, identity=identity
+    ).exists()
+    assert TimelineEvent.objects.filter(
+        type=TimelineEvent.Types.mentioned, identity=identity
+    ).exists()
+
+    # Now, submit either a user block (for full clear) or unfollow (for post clear)
+    if full:
+        service.block_from(identity)
+    else:
+        service.unfollow_from(identity)
+
+    # Run stator once to process the timeline clear message
+    stator.run_single_cycle_sync()
+
+    # Verify that the right things vanished
+    assert not TimelineEvent.objects.filter(
+        type=TimelineEvent.Types.post, identity=identity
+    ).exists()
+    assert TimelineEvent.objects.filter(
+        type=TimelineEvent.Types.mentioned, identity=identity
+    ).exists() == (not full)

users/models/inbox_message.py

@@ -14,7 +14,7 @@ class InboxMessageStates(StateGraph):
 
     @classmethod
     async def handle_received(cls, instance: "InboxMessage"):
-        from activities.models import Post, PostInteraction
+        from activities.models import Post, PostInteraction, TimelineEvent
         from users.models import Block, Follow, Identity, Report
 
         match instance.message_type:
@@ -148,7 +148,11 @@ class InboxMessageStates(StateGraph):
                 match instance.message_object_type:
                     case "fetchpost":
                         await sync_to_async(Post.handle_fetch_internal)(
-                            instance.message
+                            instance.message["object"]
+                        )
+                    case "cleartimeline":
+                        await sync_to_async(TimelineEvent.handle_clear_timeline)(
+                            instance.message["object"]
                         )
                     case unknown:
                         raise ValueError(
@@ -171,6 +175,18 @@ class InboxMessage(StatorModel):
 
     state = StateField(InboxMessageStates)
 
+    @classmethod
+    def create_internal(cls, payload):
+        """
+        Creates an internal action message
+        """
+        cls.objects.create(
+            message={
+                "type": "__internal__",
+                "object": payload,
+            }
+        )
+
     @property
     def message_type(self):
         return self.message["type"].lower()

users/services/identity.py

@@ -11,6 +11,7 @@ from users.models import (
     Follow,
     FollowStates,
     Identity,
+    InboxMessage,
     User,
 )
 
@@ -85,13 +86,29 @@ class IdentityService:
         existing_follow = Follow.maybe_get(from_identity, self.identity)
         if existing_follow:
             existing_follow.transition_perform(FollowStates.undone)
+            InboxMessage.create_internal(
+                {
+                    "type": "ClearTimeline",
+                    "actor": from_identity.pk,
+                    "object": self.identity.pk,
+                }
+            )
 
     def block_from(self, from_identity: Identity) -> Block:
         """
         Blocks a user.
         """
         self.unfollow_from(from_identity)
-        return Block.create_local_block(from_identity, self.identity)
+        block = Block.create_local_block(from_identity, self.identity)
+        InboxMessage.create_internal(
+            {
+                "type": "ClearTimeline",
+                "actor": from_identity.pk,
+                "object": self.identity.pk,
+                "fullErase": True,
+            }
+        )
+        return block
 
     def unblock_from(self, from_identity: Identity):
         """