From b522f43ffccd71b4610cd92a47358fd34bcf77f6 Mon Sep 17 00:00:00 2001
From: Andrew Godwin <andrew@aeracode.org>
Date: Sat, 31 Dec 2022 14:47:46 -0700
Subject: [PATCH] Improve interaction fanout

---
 activities/models/post_interaction.py | 50 +++++++++++----------------
 1 file changed, 20 insertions(+), 30 deletions(-)

diff --git a/activities/models/post_interaction.py b/activities/models/post_interaction.py
index a9d27e8..2589dca 100644
--- a/activities/models/post_interaction.py
+++ b/activities/models/post_interaction.py
@@ -3,10 +3,8 @@ from django.utils import timezone
 
 from activities.models.fan_out import FanOut
 from activities.models.post import Post
-from activities.models.timeline_event import TimelineEvent
 from core.ld import format_ld_date, get_str_or_id, parse_ld_date
 from stator.models import State, StateField, StateGraph, StatorModel
-from users.models.follow import Follow
 from users.models.identity import Identity
 
 
@@ -30,33 +28,37 @@ class PostInteractionStates(StateGraph):
         Creates all needed fan-out objects for a new PostInteraction.
         """
         interaction = await instance.afetch_full()
-        # Boost: send a copy to all people who follow this user
+        # Boost: send a copy to all people who follow this user (limiting
+        # to just local follows if it's a remote post)
         if interaction.type == interaction.Types.boost:
             async for follow in interaction.identity.inbound_follows.filter(
                 boosts=True
             ).select_related("source", "target"):
-                if follow.source.local or follow.target.local:
+                if interaction.post.local or follow.source.local:
                     await FanOut.objects.acreate(
                         type=FanOut.Types.interaction,
                         identity_id=follow.source_id,
                         subject_post=interaction.post,
                         subject_post_interaction=interaction,
                     )
-            # And one to the post's author
-            await FanOut.objects.acreate(
-                type=FanOut.Types.interaction,
-                identity_id=interaction.post.author_id,
-                subject_post=interaction.post,
-                subject_post_interaction=interaction,
-            )
-        # Like: send a copy to the original post author only
+            # And one to the post's author, if the booster is local or they are
+            if interaction.identity.local or interaction.post.local:
+                await FanOut.objects.acreate(
+                    type=FanOut.Types.interaction,
+                    identity_id=interaction.post.author_id,
+                    subject_post=interaction.post,
+                    subject_post_interaction=interaction,
+                )
+        # Like: send a copy to the original post author only,
+        # if the liker is local or they are
         elif interaction.type == interaction.Types.like:
-            await FanOut.objects.acreate(
-                type=FanOut.Types.interaction,
-                identity_id=interaction.post.author_id,
-                subject_post=interaction.post,
-                subject_post_interaction=interaction,
-            )
+            if interaction.identity.local or interaction.post.local:
+                await FanOut.objects.acreate(
+                    type=FanOut.Types.interaction,
+                    identity_id=interaction.post.author_id,
+                    subject_post=interaction.post,
+                    subject_post_interaction=interaction,
+                )
         else:
             raise ValueError("Cannot fan out unknown type")
         # And one for themselves if they're local and it's a boost
@@ -291,18 +293,6 @@ class PostInteraction(StatorModel):
                 # That post is gone, boss
                 # TODO: Limited retry state?
                 return
-            # Boosts (announces) go to everyone who follows locally
-            if interaction.type == cls.Types.boost:
-                for follow in Follow.objects.filter(
-                    target=interaction.identity, source__local=True, boosts=True
-                ):
-                    TimelineEvent.add_post_interaction(follow.source, interaction)
-            # Likes go to just the author of the post
-            elif interaction.type == cls.Types.like:
-                TimelineEvent.add_post_interaction(interaction.post.author, interaction)
-            # Force it into fanned_out as it's not ours
-            interaction.transition_perform(PostInteractionStates.fanned_out)
-            # Recalculate post stats
             interaction.post.calculate_stats()
 
     @classmethod