from typing import Dict, Optional import httpx import urlman from django.db import models from django.utils import timezone from activities.models.fan_out import FanOut from activities.models.timeline_event import TimelineEvent from core.html import sanitize_post from core.ld import canonicalise, format_ld_date, parse_ld_date from stator.models import State, StateField, StateGraph, StatorModel from users.models.follow import Follow from users.models.identity import Identity class PostStates(StateGraph): new = State(try_interval=300) fanned_out = State() new.transitions_to(fanned_out) @classmethod async def handle_new(cls, instance: "Post"): """ Creates all needed fan-out objects for a new Post. """ await instance.afan_out() return cls.fanned_out class Post(StatorModel): """ A post (status, toot) that is either local or remote. """ class Visibilities(models.IntegerChoices): public = 0 unlisted = 1 followers = 2 mentioned = 3 # The author (attributedTo) of the post author = models.ForeignKey( "users.Identity", on_delete=models.PROTECT, related_name="posts", ) # The state the post is in state = StateField(PostStates) # If it is our post or not local = models.BooleanField() # The canonical object ID object_uri = models.CharField(max_length=500, blank=True, null=True, unique=True) # Who should be able to see this Post visibility = models.IntegerField( choices=Visibilities.choices, default=Visibilities.public, ) # The main (HTML) content content = models.TextField() # If the contents of the post are sensitive, and the summary (content # warning) to show if it is sensitive = models.BooleanField(default=False) summary = models.TextField(blank=True, null=True) # The public, web URL of this Post on the original server url = models.CharField(max_length=500, blank=True, null=True) # The Post it is replying to as an AP ID URI # (as otherwise we'd have to pull entire threads to use IDs) in_reply_to = models.CharField(max_length=500, blank=True, null=True) # The identities the post is directly to (who can see it if not public) to = models.ManyToManyField( "users.Identity", related_name="posts_to", blank=True, ) # The identities mentioned in the post mentions = models.ManyToManyField( "users.Identity", related_name="posts_mentioning", blank=True, ) # When the post was originally created (as opposed to when we received it) published = models.DateTimeField(default=timezone.now) created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class urls(urlman.Urls): view = "{self.author.urls.view}posts/{self.id}/" object_uri = "{self.author.urls.actor}posts/{self.id}/" def get_scheme(self, url): return "https" def get_hostname(self, url): return self.instance.author.domain.uri_domain def __str__(self): return f"{self.author} #{self.id}" @property def safe_content(self): return sanitize_post(self.content) ### Async helpers ### async def afetch_full(self): """ Returns a version of the object with all relations pre-loaded """ return await Post.objects.select_related("author", "author__domain").aget( pk=self.pk ) ### Local creation ### @classmethod 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() return post ### ActivityPub (outbound) ### async def afan_out(self): """ Creates FanOuts for a new post """ # Send a copy to all people who follow this user post = await self.afetch_full() async for follow in post.author.inbound_follows.select_related( "source", "target" ): if follow.source.local or follow.target.local: await FanOut.objects.acreate( identity_id=follow.source_id, type=FanOut.Types.post, subject_post=post, ) # And one for themselves if they're local if post.author.local: await FanOut.objects.acreate( identity_id=post.author_id, type=FanOut.Types.post, subject_post=post, ) def to_ap(self) -> Dict: """ Returns the AP JSON for this object """ value = { "type": "Note", "id": self.object_uri, "published": format_ld_date(self.published), "attributedTo": self.author.actor_uri, "content": self.safe_content, "to": "as:Public", "as:sensitive": self.sensitive, "url": self.urls.view.full(), # type: ignore } if self.summary: value["summary"] = self.summary return value def to_create_ap(self): """ Returns the AP JSON to create this object """ return { "type": "Create", "id": self.object_uri + "#create", "actor": self.author.actor_uri, "object": self.to_ap(), } ### ActivityPub (inbound) ### @classmethod def by_ap(cls, data, create=False, update=False) -> "Post": """ Retrieves a Post instance by its ActivityPub JSON object. Optionally creates one if it's not present. Raises KeyError if it's not found and create is False. """ # Do we have one with the right ID? created = False try: post = cls.objects.get(object_uri=data["id"]) except cls.DoesNotExist: if create: # Resolve the author author = Identity.by_actor_uri(data["attributedTo"], create=create) post = cls.objects.create( object_uri=data["id"], author=author, content=sanitize_post(data["content"]), local=False, ) created = True else: raise KeyError(f"No post with ID {data['id']}", data) if update or created: post.content = sanitize_post(data["content"]) post.summary = data.get("summary", None) post.sensitive = data.get("as:sensitive", False) post.url = data.get("url", None) post.published = parse_ld_date(data.get("published", None)) # TODO: to # TODO: mentions # TODO: visibility post.save() return post @classmethod def by_object_uri(cls, object_uri, fetch=False): """ Gets the post by URI - either looking up locally, or fetching from the other end if it's not here. """ try: return cls.objects.get(object_uri=object_uri) except cls.DoesNotExist: if fetch: # Go grab the data from the URI response = httpx.get( object_uri, headers={"Accept": "application/json"}, follow_redirects=True, ) if 200 <= response.status_code < 300: return cls.by_ap( canonicalise(response.json(), include_security=True), create=True, update=True, ) raise ValueError(f"Cannot find Post with URI {object_uri}") @classmethod def handle_create_ap(cls, data): """ Handles an incoming create request """ # Ensure the Create actor is the Post's attributedTo if data["actor"] != data["object"]["attributedTo"]: raise ValueError("Create actor does not match its Post object", data) # Create it post = cls.by_ap(data["object"], create=True, update=True) # Make timeline events as appropriate for follow in Follow.objects.filter(target=post.author, source__local=True): TimelineEvent.add_post(follow.source, post) # Force it into fanned_out as it's not ours post.transition_perform(PostStates.fanned_out) def debug_fetch(self): """ Fetches the Post from its original URL again and updates us with it """ response = httpx.get( self.object_uri, headers={"Accept": "application/json"}, follow_redirects=True, ) if 200 <= response.status_code < 300: return self.by_ap( canonicalise(response.json(), include_security=True), update=True, )