Get outbound likes/boosts and their undos working

5 files changed, 195 insertions, 25 deletions

diff --git a/activities/models/__init__.py b/activities/models/__init__.py
index a0680ad..48ba879 100644
--- a/activities/models/__init__.py
+++ b/activities/models/__init__.py
@@ -1,4 +1,4 @@
-from .fan_out import FanOut  # noqa
-from .post import Post  # noqa
-from .post_interaction import PostInteraction  # noqa
+from .fan_out import FanOut, FanOutStates  # noqa
+from .post import Post, PostStates  # noqa
+from .post_interaction import PostInteraction, PostInteractionStates  # noqa
 from .timeline_event import TimelineEvent  # noqa
diff --git a/activities/models/fan_out.py b/activities/models/fan_out.py
index dbe86c0..771be19 100644
--- a/activities/models/fan_out.py
+++ b/activities/models/fan_out.py
@@ -38,6 +38,40 @@ class FanOutStates(StateGraph):
                     key_id=post.author.public_key_id,
                 )
             return cls.sent
+        # Handle boosts/likes
+        elif fan_out.type == FanOut.Types.interaction:
+            interaction = await fan_out.subject_post_interaction.afetch_full()
+            if fan_out.identity.local:
+                # Make a timeline event directly
+                await sync_to_async(TimelineEvent.add_post_interaction)(
+                    identity=fan_out.identity,
+                    interaction=interaction,
+                )
+            else:
+                # Send it to the remote inbox
+                await HttpSignature.signed_request(
+                    uri=fan_out.identity.inbox_uri,
+                    body=canonicalise(interaction.to_ap()),
+                    private_key=interaction.identity.private_key,
+                    key_id=interaction.identity.public_key_id,
+                )
+        # Handle undoing boosts/likes
+        elif fan_out.type == FanOut.Types.undo_interaction:
+            interaction = await fan_out.subject_post_interaction.afetch_full()
+            if fan_out.identity.local:
+                # Delete any local timeline events
+                await sync_to_async(TimelineEvent.delete_post_interaction)(
+                    identity=fan_out.identity,
+                    interaction=interaction,
+                )
+            else:
+                # Send an undo to the remote inbox
+                await HttpSignature.signed_request(
+                    uri=fan_out.identity.inbox_uri,
+                    body=canonicalise(interaction.to_undo_ap()),
+                    private_key=interaction.identity.private_key,
+                    key_id=interaction.identity.public_key_id,
+                )
         else:
             raise ValueError(f"Cannot fan out with type {fan_out.type}")
 
@@ -50,6 +84,7 @@ class FanOut(StatorModel):
     class Types(models.TextChoices):
         post = "post"
         interaction = "interaction"
+        undo_interaction = "undo_interaction"
 
     state = StateField(FanOutStates)
 
diff --git a/activities/models/post.py b/activities/models/post.py
index 74b335b..22e6412 100644
--- a/activities/models/post.py
+++ b/activities/models/post.py
@@ -2,7 +2,7 @@ from typing import Dict, Optional
 
 import httpx
 import urlman
-from django.db import models
+from django.db import models, transaction
 from django.utils import timezone
 
 from activities.models.fan_out import FanOut
@@ -99,7 +99,12 @@ class Post(StatorModel):
 
     class urls(urlman.Urls):
         view = "{self.author.urls.view}posts/{self.id}/"
-        object_uri = "{self.author.urls.actor}posts/{self.id}/"
+        view_nice = "{self.author.urls.view_nice}posts/{self.id}/"
+        object_uri = "{self.author.actor_uri}posts/{self.id}/"
+        action_like = "{view}like/"
+        action_unlike = "{view}unlike/"
+        action_boost = "{view}boost/"
+        action_unboost = "{view}unboost/"
 
         def get_scheme(self, url):
             return "https"
@@ -130,16 +135,17 @@ class Post(StatorModel):
     def create_local(
         cls, author: Identity, content: str, summary: Optional[str] = None
     ) -> "Post":
-        post = cls.objects.create(
-            author=author,
-            content=content,
-            summary=summary or None,
-            sensitive=bool(summary),
-            local=True,
-        )
-        post.object_uri = post.author.actor_uri + f"posts/{post.id}/"
-        post.url = post.object_uri
-        post.save()
+        with transaction.atomic():
+            post = cls.objects.create(
+                author=author,
+                content=content,
+                summary=summary or None,
+                sensitive=bool(summary),
+                local=True,
+            )
+            post.object_uri = post.urls.object_uri
+            post.url = post.urls.view_nice
+            post.save()
         return post
 
     ### ActivityPub (outbound) ###
@@ -179,7 +185,7 @@ class Post(StatorModel):
             "content": self.safe_content,
             "to": "as:Public",
             "as:sensitive": self.sensitive,
-            "url": self.urls.view.full(),  # type: ignore
+            "url": self.urls.view_nice if self.local else self.url,
         }
         if self.summary:
             value["summary"] = self.summary
@@ -257,7 +263,7 @@ class Post(StatorModel):
                         create=True,
                         update=True,
                     )
-            raise ValueError(f"Cannot find Post with URI {object_uri}")
+            raise cls.DoesNotExist(f"Cannot find Post with URI {object_uri}")
 
     @classmethod
     def handle_create_ap(cls, data):
@@ -275,6 +281,22 @@ class Post(StatorModel):
         # Force it into fanned_out as it's not ours
         post.transition_perform(PostStates.fanned_out)
 
+    @classmethod
+    def handle_delete_ap(cls, data):
+        """
+        Handles an incoming create request
+        """
+        # Find our post by ID if we have one
+        try:
+            post = cls.by_object_uri(data["object"]["id"])
+        except cls.DoesNotExist:
+            # It's already been deleted
+            return
+        # Ensure the actor on the request authored the post
+        if not post.author.actor_uri == data["actor"]:
+            raise ValueError("Actor on delete does not match object")
+        post.delete()
+
     def debug_fetch(self):
         """
         Fetches the Post from its original URL again and updates us with it
diff --git a/activities/models/post_interaction.py b/activities/models/post_interaction.py
index 151ab45..ea95cdf 100644
--- a/activities/models/post_interaction.py
+++ b/activities/models/post_interaction.py
@@ -14,9 +14,13 @@ from users.models.identity import Identity
 
 class PostInteractionStates(StateGraph):
     new = State(try_interval=300)
-    fanned_out = State()
+    fanned_out = State(externally_progressed=True)
+    undone = State(try_interval=300)
+    undone_fanned_out = State()
 
     new.transitions_to(fanned_out)
+    fanned_out.transitions_to(undone)
+    undone.transitions_to(undone_fanned_out)
 
     @classmethod
     async def handle_new(cls, instance: "PostInteraction"):
@@ -31,26 +35,74 @@ class PostInteractionStates(StateGraph):
             ):
                 if follow.source.local or follow.target.local:
                     await FanOut.objects.acreate(
-                        identity_id=follow.source_id,
                         type=FanOut.Types.interaction,
-                        subject_post=interaction,
+                        identity_id=follow.source_id,
+                        subject_post=interaction.post,
+                        subject_post_interaction=interaction,
                     )
         # Like: send a copy to the original post author only
         elif interaction.type == interaction.Types.like:
             await FanOut.objects.acreate(
-                identity_id=interaction.post.author_id,
                 type=FanOut.Types.interaction,
-                subject_post=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
-        if interaction.identity.local:
+        # And one for themselves if they're local and it's a boost
+        if (
+            interaction.type == PostInteraction.Types.boost
+            and interaction.identity.local
+        ):
             await FanOut.objects.acreate(
                 identity_id=interaction.identity_id,
                 type=FanOut.Types.interaction,
-                subject_post=interaction,
+                subject_post=interaction.post,
+                subject_post_interaction=interaction,
+            )
+        return cls.fanned_out
+
+    @classmethod
+    async def handle_undone(cls, instance: "PostInteraction"):
+        """
+        Creates all needed fan-out objects to undo a PostInteraction.
+        """
+        interaction = await instance.afetch_full()
+        # Undo Boost: send a copy to all people who follow this user
+        if interaction.type == interaction.Types.boost:
+            async for follow in interaction.identity.inbound_follows.select_related(
+                "source", "target"
+            ):
+                if follow.source.local or follow.target.local:
+                    await FanOut.objects.acreate(
+                        type=FanOut.Types.undo_interaction,
+                        identity_id=follow.source_id,
+                        subject_post=interaction.post,
+                        subject_post_interaction=interaction,
+                    )
+        # Undo Like: send a copy to the original post author only
+        elif interaction.type == interaction.Types.like:
+            await FanOut.objects.acreate(
+                type=FanOut.Types.undo_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
+        if (
+            interaction.type == PostInteraction.Types.boost
+            and interaction.identity.local
+        ):
+            await FanOut.objects.acreate(
+                identity_id=interaction.identity_id,
+                type=FanOut.Types.undo_interaction,
+                subject_post=interaction.post,
+                subject_post_interaction=interaction,
             )
+        return cls.undone_fanned_out
 
 
 class PostInteraction(StatorModel):
@@ -95,6 +147,35 @@ class PostInteraction(StatorModel):
     class Meta:
         index_together = [["type", "identity", "post"]]
 
+    ### Display helpers ###
+
+    @classmethod
+    def get_post_interactions(cls, posts, identity):
+        """
+        Returns a dict of {interaction_type: set(post_ids)} for all the posts
+        and the given identity, for use in templates.
+        """
+        # Bulk-fetch any interactions
+        ids_with_interaction_type = cls.objects.filter(
+            identity=identity,
+            post_id__in=[post.pk for post in posts],
+            type__in=[cls.Types.like, cls.Types.boost],
+            state__in=[PostInteractionStates.new, PostInteractionStates.fanned_out],
+        ).values_list("post_id", "type")
+        # Make it into the return dict
+        result = {}
+        for post_id, interaction_type in ids_with_interaction_type:
+            result.setdefault(interaction_type, set()).add(post_id)
+        return result
+
+    @classmethod
+    def get_event_interactions(cls, events, identity):
+        """
+        Returns a dict of {interaction_type: set(post_ids)} for all the posts
+        within the events and the given identity, for use in templates.
+        """
+        return cls.get_post_interactions([e.subject_post for e in events], identity)
+
     ### Async helpers ###
 
     async def afetch_full(self):
@@ -111,6 +192,9 @@ class PostInteraction(StatorModel):
         """
         Returns the AP JSON for this object
         """
+        # Create an object URI if we don't have one
+        if self.object_uri is None:
+            self.object_uri = self.identity.actor_uri + f"#{self.type}/{self.id}"
         if self.type == self.Types.boost:
             value = {
                 "type": "Announce",
@@ -132,6 +216,18 @@ class PostInteraction(StatorModel):
             raise ValueError("Cannot turn into AP")
         return value
 
+    def to_undo_ap(self) -> Dict:
+        """
+        Returns the AP JSON to undo this object
+        """
+        object = self.to_ap()
+        return {
+            "id": object["id"] + "/undo",
+            "type": "Undo",
+            "actor": self.identity.actor_uri,
+            "object": object,
+        }
+
     ### ActivityPub (inbound) ###
 
     @classmethod
diff --git a/activities/models/timeline_event.py b/activities/models/timeline_event.py
index 6dba32c..29dec19 100644
--- a/activities/models/timeline_event.py
+++ b/activities/models/timeline_event.py
@@ -114,3 +114,20 @@ class TimelineEvent(models.Model):
                 subject_identity_id=interaction.identity_id,
                 subject_post_interaction=interaction,
             )[0]
+
+    @classmethod
+    def delete_post_interaction(cls, identity, interaction):
+        if interaction.type == interaction.Types.like:
+            cls.objects.filter(
+                identity=identity,
+                type=cls.Types.liked,
+                subject_post_id=interaction.post_id,
+                subject_identity_id=interaction.identity_id,
+            ).delete()
+        elif interaction.type == interaction.Types.boost:
+            cls.objects.filter(
+                identity=identity,
+                type__in=[cls.Types.boosted, cls.Types.boost],
+                subject_post_id=interaction.post_id,
+                subject_identity_id=interaction.identity_id,
+            ).delete()