takahe/activities/models/post.py

711 lines
25 KiB
Python

import re
from collections.abc import Iterable
from typing import Optional
import httpx
import urlman
from asgiref.sync import async_to_sync, sync_to_async
from django.conf import settings
from django.contrib.postgres.indexes import GinIndex
from django.db import models, transaction
from django.template.defaultfilters import linebreaks_filter
from django.utils import timezone
from django.utils.safestring import mark_safe
from activities.models.fan_out import FanOut
from activities.models.hashtag import Hashtag
from core.html import sanitize_post, strip_html
from core.ld import canonicalise, format_ld_date, get_list, parse_ld_date
from stator.models import State, StateField, StateGraph, StatorModel
from users.models.identity import Identity, IdentityStates
from users.models.system_actor import SystemActor
class PostStates(StateGraph):
new = State(try_interval=300)
fanned_out = State(externally_progressed=True)
deleted = State(try_interval=300)
deleted_fanned_out = State()
edited = State(try_interval=300)
edited_fanned_out = State(externally_progressed=True)
new.transitions_to(fanned_out)
fanned_out.transitions_to(deleted)
fanned_out.transitions_to(edited)
deleted.transitions_to(deleted_fanned_out)
edited.transitions_to(edited_fanned_out)
edited_fanned_out.transitions_to(edited)
edited_fanned_out.transitions_to(deleted)
@classmethod
async def targets_fan_out(cls, post: "Post", type_: str) -> None:
# Fan out to each target
for follow in await post.aget_targets():
await FanOut.objects.acreate(
identity=follow,
type=type_,
subject_post=post,
)
@classmethod
async def handle_new(cls, instance: "Post"):
"""
Creates all needed fan-out objects for a new Post.
"""
post = await instance.afetch_full()
await cls.targets_fan_out(post, FanOut.Types.post)
await post.ensure_hashtags()
return cls.fanned_out
@classmethod
async def handle_deleted(cls, instance: "Post"):
"""
Creates all needed fan-out objects needed to delete a Post.
"""
post = await instance.afetch_full()
await cls.targets_fan_out(post, FanOut.Types.post_deleted)
return cls.deleted_fanned_out
@classmethod
async def handle_edited(cls, instance: "Post"):
"""
Creates all needed fan-out objects for an edited Post.
"""
post = await instance.afetch_full()
await cls.targets_fan_out(post, FanOut.Types.post_edited)
await post.ensure_hashtags()
return cls.edited_fanned_out
class PostQuerySet(models.QuerySet):
def public(self, include_replies: bool = False):
query = self.filter(
visibility__in=[
Post.Visibilities.public,
Post.Visibilities.local_only,
],
)
if not include_replies:
return query.filter(in_reply_to__isnull=True)
return query
def local_public(self, include_replies: bool = False):
query = self.filter(
visibility__in=[
Post.Visibilities.public,
Post.Visibilities.local_only,
],
author__local=True,
)
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)
else:
tag_q = models.Q(hashtags__contains=hashtag.hashtag)
if hashtag.aliases:
for alias in hashtag.aliases:
tag_q |= models.Q(hashtags__contains=alias)
return self.filter(tag_q)
class PostManager(models.Manager):
def get_queryset(self):
return PostQuerySet(self.model, using=self._db)
def public(self, include_replies: bool = False):
return self.get_queryset().public(include_replies=include_replies)
def local_public(self, include_replies: bool = False):
return self.get_queryset().local_public(include_replies=include_replies)
def tagged_with(self, hashtag: str | Hashtag):
return self.get_queryset().tagged_with(hashtag=hashtag)
class Post(StatorModel):
"""
A post (status, toot) that is either local or remote.
"""
class Visibilities(models.IntegerChoices):
public = 0
local_only = 4
unlisted = 1
followers = 2
mentioned = 3
# The author (attributedTo) of the post
author = models.ForeignKey(
"users.Identity",
on_delete=models.CASCADE,
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,
)
# Hashtags in the post
hashtags = models.JSONField(blank=True, null=True)
# When the post was originally created (as opposed to when we received it)
published = models.DateTimeField(default=timezone.now)
# If the post has been edited after initial publication
edited = models.DateTimeField(blank=True, null=True)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
objects = PostManager()
class Meta:
indexes = [
GinIndex(fields=["hashtags"], name="hashtags_gin"),
]
class urls(urlman.Urls):
view = "{self.author.urls.view}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/"
action_delete = "{view}delete/"
action_edit = "{view}edit/"
action_reply = "/compose/?reply_to={self.id}"
admin_edit = "/djadmin/activities/post/{self.id}/change/"
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}"
def get_absolute_url(self):
return self.urls.view
def absolute_object_uri(self):
"""
Returns an object URI that is always absolute, for sending out to
other servers.
"""
if self.local:
return self.author.absolute_profile_uri() + f"posts/{self.id}/"
else:
return self.object_uri
def in_reply_to_post(self) -> Optional["Post"]:
"""
Returns the actual Post object we're replying to, if we can find it
"""
return (
Post.objects.filter(object_uri=self.in_reply_to)
.select_related("author")
.first()
)
ain_reply_to_post = sync_to_async(in_reply_to_post)
### Content cleanup and extraction ###
mention_regex = re.compile(
r"(^|[^\w\d\-_])@([\w\d\-_]+(?:@[\w\d\-_]+\.[\w\d\-_\.]+)?)"
)
def linkify_mentions(self, content, local=False):
"""
Links mentions _in the context of the post_ - as in, using the mentions
property as the only source (as we might be doing this without other
DB access allowed)
"""
possible_matches = {}
for mention in self.mentions.all():
if local:
url = str(mention.urls.view)
else:
url = mention.absolute_profile_uri()
possible_matches[mention.username] = url
possible_matches[f"{mention.username}@{mention.domain_id}"] = url
collapse_name: dict[str, str] = {}
def replacer(match):
precursor = match.group(1)
handle = match.group(2).lower()
if "@" in handle:
short_handle = handle.split("@", 1)[0]
else:
short_handle = handle
if handle in possible_matches:
if short_handle not in collapse_name:
collapse_name[short_handle] = handle
elif collapse_name.get(short_handle) != handle:
short_handle = handle
return f'{precursor}<a href="{possible_matches[handle]}">@{short_handle}</a>'
else:
return match.group()
return mark_safe(self.mention_regex.sub(replacer, content))
def safe_content_local(self):
"""
Returns the content formatted for local display
"""
return Hashtag.linkify_hashtags(
self.linkify_mentions(sanitize_post(self.content), local=True)
)
def safe_content_remote(self):
"""
Returns the content formatted for remote consumption
"""
return self.linkify_mentions(sanitize_post(self.content))
def safe_content_plain(self):
"""
Returns the content formatted as plain text
"""
return self.linkify_mentions(sanitize_post(self.content))
### Async helpers ###
async def afetch_full(self) -> "Post":
"""
Returns a version of the object with all relations pre-loaded
"""
return (
await Post.objects.select_related("author", "author__domain")
.prefetch_related("mentions", "mentions__domain", "attachments")
.aget(pk=self.pk)
)
### Local creation/editing ###
@classmethod
def create_local(
cls,
author: Identity,
content: str,
summary: str | None = None,
visibility: int = Visibilities.public,
reply_to: Optional["Post"] = None,
attachments: list | None = None,
) -> "Post":
with transaction.atomic():
# Find mentions in this post
mentions = cls.mentions_from_content(content, author)
if reply_to:
mentions.add(reply_to.author)
# Maintain local-only for replies
if reply_to.visibility == reply_to.Visibilities.local_only:
visibility = reply_to.Visibilities.local_only
# Find hashtags in this post
hashtags = Hashtag.hashtags_from_content(content) or None
# Strip all HTML and apply linebreaks filter
content = linebreaks_filter(strip_html(content))
# Make the Post object
post = cls.objects.create(
author=author,
content=content,
summary=summary or None,
sensitive=bool(summary),
local=True,
visibility=visibility,
hashtags=hashtags,
in_reply_to=reply_to.object_uri if reply_to else None,
)
post.object_uri = post.urls.object_uri
post.url = post.absolute_object_uri()
post.mentions.set(mentions)
if attachments:
post.attachments.set(attachments)
post.save()
return post
def edit_local(
self,
content: str,
summary: str | None = None,
visibility: int = Visibilities.public,
attachments: list | None = None,
):
with transaction.atomic():
# Strip all HTML and apply linebreaks filter
self.content = linebreaks_filter(strip_html(content))
self.summary = summary or None
self.sensitive = bool(summary)
self.visibility = visibility
self.edited = timezone.now()
self.hashtags = Hashtag.hashtags_from_content(content) or None
self.mentions.set(self.mentions_from_content(content, self.author))
self.attachments.set(attachments or [])
self.save()
@classmethod
def mentions_from_content(cls, content, author) -> set[Identity]:
mention_hits = cls.mention_regex.findall(content)
mentions = set()
for precursor, handle in mention_hits:
handle = handle.lower()
if "@" in handle:
username, domain = handle.split("@", 1)
else:
username = handle
domain = author.domain_id
identity = Identity.by_username_and_domain(
username=username,
domain=domain,
fetch=True,
)
if identity is not None:
mentions.add(identity)
return mentions
async def ensure_hashtags(self) -> None:
"""
Ensure any of the already parsed hashtags from this Post
have a corresponding Hashtag record.
"""
# Ensure hashtags
if self.hashtags:
for hashtag in self.hashtags:
await Hashtag.objects.aget_or_create(
hashtag=hashtag,
)
### ActivityPub (outbound) ###
def to_ap(self) -> dict:
"""
Returns the AP JSON for this object
"""
value = {
"to": "as:Public",
"cc": [],
"type": "Note",
"id": self.object_uri,
"published": format_ld_date(self.published),
"attributedTo": self.author.actor_uri,
"content": self.safe_content_remote(),
"as:sensitive": self.sensitive,
"url": self.absolute_object_uri(),
"tag": [],
"attachment": [],
}
if self.summary:
value["summary"] = self.summary
if self.in_reply_to:
value["inReplyTo"] = self.in_reply_to
if self.edited:
value["updated"] = format_ld_date(self.edited)
# Mentions
for mention in self.mentions.all():
value["tag"].append(
{
"href": mention.actor_uri,
"name": "@" + mention.handle,
"type": "Mention",
}
)
value["cc"].append(mention.actor_uri)
# Attachments
for attachment in self.attachments.all():
value["attachment"].append(attachment.to_ap())
# Remove fields if they're empty
for field in ["cc", "tag", "attachment"]:
if not value[field]:
del value[field]
return value
def to_create_ap(self):
"""
Returns the AP JSON to create this object
"""
object = self.to_ap()
return {
"to": object["to"],
"cc": object.get("cc", []),
"type": "Create",
"id": self.object_uri + "#create",
"actor": self.author.actor_uri,
"object": object,
}
def to_update_ap(self):
"""
Returns the AP JSON to update this object
"""
object = self.to_ap()
return {
"to": object["to"],
"cc": object.get("cc", []),
"type": "Update",
"id": self.object_uri + "#update",
"actor": self.author.actor_uri,
"object": object,
}
def to_delete_ap(self):
"""
Returns the AP JSON to create this object
"""
object = self.to_ap()
return {
"to": object["to"],
"cc": object.get("cc", []),
"type": "Delete",
"id": self.object_uri + "#delete",
"actor": self.author.actor_uri,
"object": object,
}
async def aget_targets(self) -> Iterable[Identity]:
"""
Returns a list of Identities that need to see posts and their changes
"""
targets = set()
async for mention in self.mentions.all():
targets.add(mention)
# Then, if it's not mentions only, also deliver to followers
if self.visibility != Post.Visibilities.mentioned:
async for follower in self.author.inbound_follows.select_related("source"):
targets.add(follower.source)
# If it's a reply, always include the original author if we know them
reply_post = await self.ain_reply_to_post()
if reply_post:
targets.add(reply_post.author)
# If this is a remote post or local-only, filter to only include
# local identities
if not self.local or self.visibility == Post.Visibilities.local_only:
targets = {target for target in targets if target.local}
# If it's a local post, include the author
if self.local:
targets.add(self.author)
return targets
### 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=data["content"],
local=False,
)
created = True
else:
raise KeyError(f"No post with ID {data['id']}", data)
if update or created:
post.content = data["content"]
post.summary = data.get("summary")
post.sensitive = data.get("as:sensitive", False)
post.url = data.get("url")
post.published = parse_ld_date(data.get("published"))
post.edited = parse_ld_date(data.get("updated"))
post.in_reply_to = data.get("inReplyTo")
# Mentions and hashtags
post.hashtags = []
for tag in get_list(data, "tag"):
if tag["type"].lower() == "mention":
mention_identity = Identity.by_actor_uri(tag["href"], create=True)
post.mentions.add(mention_identity)
elif tag["type"].lower() == "as:hashtag":
post.hashtags.append(tag["name"].lstrip("#"))
elif tag["type"].lower() == "http://joinmastodon.org/ns#emoji":
# TODO: Handle incoming emoji
pass
else:
raise ValueError(f"Unknown tag type {tag['type']}")
# Visibility and to
# (a post is public if it's ever to/cc as:Public, otherwise we
# regard it as unlisted for now)
targets = get_list(data, "to") + get_list(data, "cc")
post.visibility = Post.Visibilities.unlisted
for target in targets:
if target.lower() == "as:public":
post.visibility = Post.Visibilities.public
# Attachments
# These have no IDs, so we have to wipe them each time
post.attachments.all().delete()
for attachment in get_list(data, "attachment"):
if "http://joinmastodon.org/ns#focalPoint" in attachment:
focal_x, focal_y = attachment[
"http://joinmastodon.org/ns#focalPoint"
]["@list"]
else:
focal_x, focal_y = None, None
post.attachments.create(
remote_url=attachment["url"],
mimetype=attachment["mediaType"],
name=attachment.get("name"),
width=attachment.get("width"),
height=attachment.get("height"),
blurhash=attachment.get("http://joinmastodon.org/ns#blurhash"),
focal_x=focal_x,
focal_y=focal_y,
)
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:
try:
response = async_to_sync(SystemActor().signed_request)(
method="get", uri=object_uri
)
except (httpx.RequestError, httpx.ConnectError):
raise cls.DoesNotExist(f"Could not fetch {object_uri}")
if response.status_code in [404, 410]:
raise cls.DoesNotExist(f"No post at {object_uri}")
if response.status_code >= 500:
raise cls.DoesNotExist(f"Server error fetching {object_uri}")
if response.status_code >= 400:
raise cls.DoesNotExist(
f"Error fetching post from {object_uri}: {response.status_code}",
{response.content},
)
post = cls.by_ap(
canonicalise(response.json(), include_security=True),
create=True,
update=True,
)
# We may need to fetch the author too
if post.author.state == IdentityStates.outdated:
async_to_sync(post.author.fetch_actor)()
return post
else:
raise cls.DoesNotExist(f"Cannot find Post with URI {object_uri}")
@classmethod
def handle_create_ap(cls, data):
"""
Handles an incoming create request
"""
with transaction.atomic():
# 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, stator will fan it out locally
cls.by_ap(data["object"], create=True, update=True)
@classmethod
def handle_update_ap(cls, data):
"""
Handles an incoming update request
"""
with transaction.atomic():
# 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)
# Find it and update it
cls.by_ap(data["object"], create=False, update=True)
@classmethod
def handle_delete_ap(cls, data):
"""
Handles an incoming delete request
"""
with transaction.atomic():
# 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
"""
response = httpx.get(
self.object_uri,
headers={
"Accept": "application/json",
"User-Agent": settings.TAKAHE_USER_AGENT,
},
follow_redirects=True,
)
if 200 <= response.status_code < 300:
return self.by_ap(
canonicalise(response.json(), include_security=True),
update=True,
)