Add expanded post context

Fixes #120

activities/models/post.py

@@ -128,6 +128,28 @@ class PostQuerySet(models.QuerySet):
             return query.filter(in_reply_to__isnull=True)
         return query
 
+    def visible_to(self, identity, include_replies: bool = False):
+        query = self.filter(
+            models.Q(
+                visibility__in=[
+                    Post.Visibilities.public,
+                    Post.Visibilities.local_only,
+                    Post.Visibilities.unlisted,
+                ]
+            )
+            | models.Q(
+                visibility=Post.Visibilities.followers,
+                author__inbound_follows__source=identity,
+            )
+            | models.Q(
+                visibility=Post.Visibilities.mentioned,
+                mentions=identity,
+            )
+        ).distinct()
+        if not include_replies:
+            return query.filter(in_reply_to__isnull=True)
+        return query
+
     def tagged_with(self, hashtag: str | Hashtag):
         if isinstance(hashtag, str):
             tag_q = models.Q(hashtags__contains=hashtag)
@@ -526,48 +548,6 @@ class Post(StatorModel):
                     hashtag=hashtag,
                 )
 
-    ### Actions ###
-
-    def interact_as(self, identity, type):
-        from activities.models import PostInteraction, PostInteractionStates
-
-        interaction = PostInteraction.objects.get_or_create(
-            type=type, identity=identity, post=self
-        )[0]
-        if interaction.state in [
-            PostInteractionStates.undone,
-            PostInteractionStates.undone_fanned_out,
-        ]:
-            interaction.transition_perform(PostInteractionStates.new)
-
-    def uninteract_as(self, identity, type):
-        from activities.models import PostInteraction, PostInteractionStates
-
-        for interaction in PostInteraction.objects.filter(
-            type=type, identity=identity, post=self
-        ):
-            interaction.transition_perform(PostInteractionStates.undone)
-
-    def like_as(self, identity):
-        from activities.models import PostInteraction
-
-        self.interact_as(identity, PostInteraction.Types.like)
-
-    def unlike_as(self, identity):
-        from activities.models import PostInteraction
-
-        self.uninteract_as(identity, PostInteraction.Types.like)
-
-    def boost_as(self, identity):
-        from activities.models import PostInteraction
-
-        self.interact_as(identity, PostInteraction.Types.boost)
-
-    def unboost_as(self, identity):
-        from activities.models import PostInteraction
-
-        self.uninteract_as(identity, PostInteraction.Types.boost)
-
     ### ActivityPub (outbound) ###
 
     def to_ap(self) -> dict:

activities/services/__init__.py

@@ -0,0 +1 @@
+from .post import PostService  # noqa

activities/services/post.py

@@ -0,0 +1,94 @@
+from typing import cast
+
+from activities.models import Post, PostInteraction, PostInteractionStates, PostStates
+from users.models import Identity
+
+
+class PostService:
+    """
+    High-level operations on Posts
+    """
+
+    def __init__(self, post: Post):
+        self.post = post
+
+    def interact_as(self, identity: Identity, type: str):
+        """
+        Performs an interaction on this Post
+        """
+        interaction = PostInteraction.objects.get_or_create(
+            type=type,
+            identity=identity,
+            post=self.post,
+        )[0]
+        if interaction.state in [
+            PostInteractionStates.undone,
+            PostInteractionStates.undone_fanned_out,
+        ]:
+            interaction.transition_perform(PostInteractionStates.new)
+
+    def uninteract_as(self, identity, type):
+        """
+        Undoes an interaction on this Post
+        """
+        for interaction in PostInteraction.objects.filter(
+            type=type,
+            identity=identity,
+            post=self.post,
+        ):
+            interaction.transition_perform(PostInteractionStates.undone)
+
+    def like_as(self, identity: Identity):
+        self.interact_as(identity, PostInteraction.Types.like)
+
+    def unlike_as(self, identity: Identity):
+        self.uninteract_as(identity, PostInteraction.Types.like)
+
+    def boost_as(self, identity: Identity):
+        self.interact_as(identity, PostInteraction.Types.boost)
+
+    def unboost_as(self, identity: Identity):
+        self.uninteract_as(identity, PostInteraction.Types.boost)
+
+    def context(self, identity: Identity | None) -> tuple[list[Post], list[Post]]:
+        """
+        Returns ancestor/descendant information.
+
+        Ancestors are guaranteed to be in order from closest to furthest.
+        Descendants are in depth-first order, starting with closest.
+
+        If identity is provided, includes mentions/followers-only posts they
+        can see. Otherwise, shows unlisted and above only.
+        """
+        num_ancestors = 10
+        num_descendants = 50
+        # Retrieve ancestors via parent walk
+        ancestors: list[Post] = []
+        ancestor = self.post
+        while ancestor.in_reply_to and len(ancestors) < num_ancestors:
+            ancestor = cast(Post, ancestor.in_reply_to_post())
+            if ancestor.state in [PostStates.deleted, PostStates.deleted_fanned_out]:
+                break
+            ancestors.append(ancestor)
+        # Retrieve descendants via breadth-first-search
+        descendants: list[Post] = []
+        queue = [self.post]
+        while queue and len(descendants) < num_descendants:
+            node = queue.pop()
+            child_queryset = (
+                Post.objects.not_hidden()
+                .filter(in_reply_to=node.object_uri)
+                .select_related("author", "author__domain")
+                .prefetch_related("emojis")
+                .order_by("published")
+            )
+            if identity:
+                child_queryset = child_queryset.visible_to(
+                    identity=identity, include_replies=True
+                )
+            else:
+                child_queryset = child_queryset.unlisted(include_replies=True)
+            for child in child_queryset:
+                descendants.append(child)
+                queue.append(child)
+        return ancestors, descendants

activities/views/posts.py

@@ -1,16 +1,15 @@
 from django.core.exceptions import PermissionDenied
-from django.db import models
 from django.http import Http404, JsonResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.utils.decorators import method_decorator
 from django.views.decorators.vary import vary_on_headers
 from django.views.generic import TemplateView, View
 
-from activities.models import Post, PostInteraction, PostStates
+from activities.models import PostInteraction, PostStates
+from activities.services import PostService
 from core.decorators import cache_page_by_ap_json
 from core.ld import canonicalise
 from users.decorators import identity_required
-from users.models import Identity
 from users.shortcuts import by_handle_or_404
 
 
@@ -38,44 +37,19 @@ class Individual(TemplateView):
             return super().get(request)
 
     def get_context_data(self):
-        parent = None
+        ancestors, descendants = PostService(self.post_obj).context(
-        if self.post_obj.in_reply_to:
+            self.request.identity
-            try:
+        )
-                parent = Post.by_object_uri(self.post_obj.in_reply_to, fetch=True)
-            except Post.DoesNotExist:
-                pass
         return {
             "identity": self.identity,
             "post": self.post_obj,
             "interactions": PostInteraction.get_post_interactions(
-                [self.post_obj],
+                [self.post_obj] + ancestors + descendants,
                 self.request.identity,
             ),
             "link_original": True,
-            "parent": parent,
+            "ancestors": ancestors,
-            "replies": Post.objects.filter(
+            "descendants": descendants,
-                models.Q(
-                    visibility__in=[
-                        Post.Visibilities.public,
-                        Post.Visibilities.local_only,
-                        Post.Visibilities.unlisted,
-                    ]
-                )
-                | models.Q(
-                    visibility=Post.Visibilities.followers,
-                    author__inbound_follows__source=self.identity,
-                )
-                | models.Q(
-                    visibility=Post.Visibilities.mentioned,
-                    mentions=self.identity,
-                ),
-                in_reply_to=self.post_obj.object_uri,
-            )
-            .exclude(author__restriction=Identity.Restriction.blocked)
-            .distinct()
-            .select_related("author__domain")
-            .prefetch_related("emojis")
-            .order_by("published", "created"),
         }
 
     def serve_object(self):
@@ -101,10 +75,11 @@ class Like(View):
         post = get_object_or_404(
             identity.posts.prefetch_related("attachments"), pk=post_id
         )
+        service = PostService(post)
         if self.undo:
-            post.unlike_as(self.request.identity)
+            service.unlike_as(self.request.identity)
         else:
-            post.like_as(self.request.identity)
+            service.like_as(self.request.identity)
         # Return either a redirect or a HTMX snippet
         if request.htmx:
             return render(
@@ -129,10 +104,11 @@ class Boost(View):
     def post(self, request, handle, post_id):
         identity = by_handle_or_404(self.request, handle, local=False)
         post = get_object_or_404(identity.posts, pk=post_id)
+        service = PostService(post)
         if self.undo:
-            post.unboost_as(request.identity)
+            service.unboost_as(request.identity)
         else:
-            post.boost_as(request.identity)
+            service.boost_as(request.identity)
         # Return either a redirect or a HTMX snippet
         if request.htmx:
             return render(

api/views/statuses.py

@@ -11,6 +11,7 @@ from activities.models import (
     PostStates,
     TimelineEvent,
 )
+from activities.services import PostService
 from api import schemas
 from api.views.base import api_router
 from core.models import Config
@@ -87,13 +88,10 @@ def delete_status(request, id: str):
 @identity_required
 def status_context(request, id: str):
     post = get_object_or_404(Post, pk=id)
-    parent = post.in_reply_to_post()
+    service = PostService(post)
-    ancestors = []
+    ancestors, descendants = service.context(request.identity)
-    if parent:
-        ancestors.append(parent)
-    descendants = list(Post.objects.filter(in_reply_to=post.object_uri)[:40])
     interactions = PostInteraction.get_post_interactions(
-        [post] + ancestors + descendants, request.identity
+        ancestors + descendants, request.identity
     )
     return {
         "ancestors": [p.to_mastodon_json(interactions=interactions) for p in ancestors],
@@ -107,7 +105,8 @@ def status_context(request, id: str):
 @identity_required
 def favourite_status(request, id: str):
     post = get_object_or_404(Post, pk=id)
-    post.like_as(request.identity)
+    service = PostService(post)
+    service.like_as(request.identity)
     interactions = PostInteraction.get_post_interactions([post], request.identity)
     return post.to_mastodon_json(interactions=interactions)
 
@@ -116,7 +115,8 @@ def favourite_status(request, id: str):
 @identity_required
 def unfavourite_status(request, id: str):
     post = get_object_or_404(Post, pk=id)
-    post.unlike_as(request.identity)
+    service = PostService(post)
+    service.unlike_as(request.identity)
     interactions = PostInteraction.get_post_interactions([post], request.identity)
     return post.to_mastodon_json(interactions=interactions)
 
@@ -125,7 +125,8 @@ def unfavourite_status(request, id: str):
 @identity_required
 def reblog_status(request, id: str):
     post = get_object_or_404(Post, pk=id)
-    post.boost_as(request.identity)
+    service = PostService(post)
+    service.boost_as(request.identity)
     interactions = PostInteraction.get_post_interactions([post], request.identity)
     return post.to_mastodon_json(interactions=interactions)
 
@@ -134,6 +135,7 @@ def reblog_status(request, id: str):
 @identity_required
 def unreblog_status(request, id: str):
     post = get_object_or_404(Post, pk=id)
-    post.unboost_as(request.identity)
+    service = PostService(post)
+    service.unboost_as(request.identity)
     interactions = PostInteraction.get_post_interactions([post], request.identity)
     return post.to_mastodon_json(interactions=interactions)

templates/activities/post.html

@@ -3,11 +3,11 @@
 {% block title %}Post by {{ post.author.html_name_or_handle }}{% endblock %}
 
 {% block content %}
-    {% if parent %}
+    {% for ancestor in ancestors reversed %}
-        {% include "activities/_post.html" with post=parent reply=True link_original=False %}
+        {% include "activities/_post.html" with post=ancestor reply=True link_original=False %}
-    {% endif %}
+    {% endfor %}
     {% include "activities/_post.html" %}
-    {% for reply in replies %}
+    {% for descendant in descendants %}
-        {% include "activities/_post.html" with post=reply reply=True link_original=False %}
+        {% include "activities/_post.html" with post=descendant reply=True link_original=False %}
     {% endfor %}
 {% endblock %}

tests/activities/services/test_post.py

@@ -0,0 +1,37 @@
+import pytest
+
+from activities.models import Post
+from activities.services import PostService
+from users.models import Identity
+
+
+@pytest.mark.django_db
+def test_post_context(identity: Identity):
+    """
+    Tests that post context fetching works correctly
+    """
+    post1 = Post.create_local(
+        author=identity,
+        content="<p>first</p>",
+        visibility=Post.Visibilities.public,
+    )
+    post2 = Post.create_local(
+        author=identity,
+        content="<p>second</p>",
+        visibility=Post.Visibilities.public,
+        reply_to=post1,
+    )
+    post3 = Post.create_local(
+        author=identity,
+        content="<p>third</p>",
+        visibility=Post.Visibilities.public,
+        reply_to=post2,
+    )
+    # Test the view from the start of thread
+    ancestors, descendants = PostService(post1).context(None)
+    assert ancestors == []
+    assert descendants == [post2, post3]
+    # Test the view from the end of thread
+    ancestors, descendants = PostService(post3).context(None)
+    assert ancestors == [post2, post1]
+    assert descendants == []