From 2ef709b6421b238025276aa53bf1c3764696a660 Mon Sep 17 00:00:00 2001
From: Andrew Godwin <andrew@aeracode.org>
Date: Tue, 15 Nov 2022 18:36:39 -0700
Subject: [PATCH] Accept incoming action undos

---
 activities/models/post_interaction.py | 15 +++++++++++++++
 users/models/inbox_message.py         |  8 ++++++++
 2 files changed, 23 insertions(+)

diff --git a/activities/models/post_interaction.py b/activities/models/post_interaction.py
index ea95cdf..4f1eb03 100644
--- a/activities/models/post_interaction.py
+++ b/activities/models/post_interaction.py
@@ -285,3 +285,18 @@ class PostInteraction(StatorModel):
             TimelineEvent.add_post_interaction(interaction.post.author, interaction)
         # Force it into fanned_out as it's not ours
         interaction.transition_perform(PostInteractionStates.fanned_out)
+
+    @classmethod
+    def handle_undo_ap(cls, data):
+        """
+        Handles an incoming undo for a announce/like
+        """
+        # Find it
+        interaction = cls.by_ap(data["object"])
+        # Verify the actor matches
+        if data["actor"] != interaction.identity.actor_uri:
+            raise ValueError("Actor mismatch on interaction undo")
+        # Delete all events that reference it
+        interaction.timeline_events.all().delete()
+        # Force it into undone_fanned_out as it's not ours
+        interaction.transition_perform(PostInteractionStates.undone_fanned_out)
diff --git a/users/models/inbox_message.py b/users/models/inbox_message.py
index b9bcfb4..55eb3cb 100644
--- a/users/models/inbox_message.py
+++ b/users/models/inbox_message.py
@@ -42,6 +42,14 @@ class InboxMessageStates(StateGraph):
                 match instance.message_object_type:
                     case "follow":
                         await sync_to_async(Follow.handle_undo_ap)(instance.message)
+                    case "like":
+                        await sync_to_async(PostInteraction.handle_undo_ap)(
+                            instance.message
+                        )
+                    case "announce":
+                        await sync_to_async(PostInteraction.handle_undo_ap)(
+                            instance.message
+                        )
                     case unknown:
                         raise ValueError(
                             f"Cannot handle activity of type undo.{unknown}"