Lot of improvements/bugfixes

Better caching, and more on visibility too

migrations.py

@@ -9,9 +9,14 @@ from utils.migrations import DB
 from utils.migrations import Migration
 from utils.migrations import logger
 from utils.migrations import perform  # noqa:  just here for export
+from config import ID
+import activitypub
+
+back = activitypub.MicroblogPubBackend()
+ap.use_backend(back)
 
 
-class _1_MetaMigrationt(Migration):
+class _1_MetaMigration(Migration):
     """Add new metadata to simplify querying."""
 
     def __guess_visibility(self, data: Dict[str, Any]) -> ap.Visibility:
@@ -106,3 +111,42 @@ class _1_MetaMigrationt(Migration):
             logger.info(f"meta={set_meta}\n")
             if set_meta:
                 DB.activities.update_one({"_id": data["_id"]}, {"$set": set_meta})
+
+
+class _2_FollowMigration(Migration):
+    """Add new metadata to update the cached actor in Follow activities."""
+
+    def migrate(self) -> None:
+        actor_cache: Dict[str, Dict[str, Any]] = {}
+        for data in DB.activities.find({"type": ap.ActivityType.FOLLOW.value}):
+            if data["meta"]["actor_id"] == ID:
+                # It's a "following"
+                actor = actor_cache.get(data["meta"]["object_id"])
+                if not actor:
+                    actor = ap.parse_activity(
+                        ap.get_backend().fetch_iri(
+                            data["meta"]["object_id"], no_cache=True
+                        )
+                    ).to_dict(embed=True)
+                    if not actor:
+                        raise ValueError(f"missing actor {data!r}")
+                    actor_cache[actor["id"]] = actor
+                DB.activities.update_one(
+                    {"_id": data["_id"]}, {"$set": {"meta.object": actor}}
+                )
+
+            else:
+                # It's a "followers"
+                actor = actor_cache.get(data["meta"]["actor_id"])
+                if not actor:
+                    actor = ap.parse_activity(
+                        ap.get_backend().fetch_iri(
+                            data["meta"]["actor_id"], no_cache=True
+                        )
+                    ).to_dict(embed=True)
+                    if not actor:
+                        raise ValueError(f"missing actor {data!r}")
+                    actor_cache[actor["id"]] = actor
+                DB.activities.update_one(
+                    {"_id": data["_id"]}, {"$set": {"meta.actor": actor}}
+                )