moviewyrm/bookwyrm/views/helpers.py
2021-04-01 20:30:50 -07:00

236 lines
7.6 KiB
Python

""" helper functions used in various views """
import re
from requests import HTTPError
from django.core.exceptions import FieldError
from django.db.models import Count, Max, Q
from bookwyrm import activitypub, models
from bookwyrm.connectors import ConnectorException, get_data
from bookwyrm.status import create_generated_note
from bookwyrm.utils import regex
def get_user_from_username(viewer, username):
""" helper function to resolve a localname or a username to a user """
# raises DoesNotExist if user is now found
try:
return models.User.viewer_aware_objects(viewer).get(localname=username)
except models.User.DoesNotExist:
return models.User.viewer_aware_objects(viewer).get(username=username)
def is_api_request(request):
""" check whether a request is asking for html or data """
return "json" in request.headers.get("Accept", "") or request.path[-5:] == ".json"
def is_bookwyrm_request(request):
""" check if the request is coming from another bookwyrm instance """
user_agent = request.headers.get("User-Agent")
if user_agent is None or re.search(regex.bookwyrm_user_agent, user_agent) is None:
return False
return True
def object_visible_to_user(viewer, obj):
""" is a user authorized to view an object? """
if not obj:
return False
# viewer can't see it if the object's owner blocked them
if viewer in obj.user.blocks.all():
return False
# you can see your own posts and any public or unlisted posts
if viewer == obj.user or obj.privacy in ["public", "unlisted"]:
return True
# you can see the followers only posts of people you follow
if obj.privacy == "followers" and obj.user.followers.filter(id=viewer.id).first():
return True
# you can see dms you are tagged in
if isinstance(obj, models.Status):
if obj.privacy == "direct" and obj.mention_users.filter(id=viewer.id).first():
return True
return False
def privacy_filter(viewer, queryset, privacy_levels=None, following_only=False):
""" filter objects that have "user" and "privacy" fields """
privacy_levels = privacy_levels or ["public", "unlisted", "followers", "direct"]
# if there'd a deleted field, exclude deleted items
try:
queryset = queryset.filter(deleted=False)
except FieldError:
pass
# exclude blocks from both directions
if not viewer.is_anonymous:
blocked = models.User.objects.filter(id__in=viewer.blocks.all()).all()
queryset = queryset.exclude(Q(user__in=blocked) | Q(user__blocks=viewer))
# you can't see followers only or direct messages if you're not logged in
if viewer.is_anonymous:
privacy_levels = [p for p in privacy_levels if not p in ["followers", "direct"]]
# filter to only privided privacy levels
queryset = queryset.filter(privacy__in=privacy_levels)
# only include statuses the user follows
if following_only:
queryset = queryset.exclude(
~Q( # remove everythign except
Q(user__in=viewer.following.all())
| Q(user=viewer) # user following
| Q(mention_users=viewer) # is self # mentions user
),
)
# exclude followers-only statuses the user doesn't follow
elif "followers" in privacy_levels:
queryset = queryset.exclude(
~Q( # user isn't following and it isn't their own status
Q(user__in=viewer.following.all()) | Q(user=viewer)
),
privacy="followers", # and the status is followers only
)
# exclude direct messages not intended for the user
if "direct" in privacy_levels:
try:
queryset = queryset.exclude(
~Q(Q(user=viewer) | Q(mention_users=viewer)), privacy="direct"
)
except FieldError:
queryset = queryset.exclude(~Q(user=viewer), privacy="direct")
return queryset
def handle_remote_webfinger(query):
""" webfingerin' other servers """
user = None
# usernames could be @user@domain or user@domain
if not query:
return None
if query[0] == "@":
query = query[1:]
try:
domain = query.split("@")[1]
except IndexError:
return None
try:
user = models.User.objects.get(username=query)
except models.User.DoesNotExist:
url = "https://%s/.well-known/webfinger?resource=acct:%s" % (domain, query)
try:
data = get_data(url)
except (ConnectorException, HTTPError):
return None
for link in data.get("links"):
if link.get("rel") == "self":
try:
user = activitypub.resolve_remote_id(
link["href"], model=models.User
)
except KeyError:
return None
return user
def get_edition(book_id):
""" look up a book in the db and return an edition """
book = models.Book.objects.select_subclasses().get(id=book_id)
if isinstance(book, models.Work):
book = book.get_default_edition()
return book
def handle_reading_status(user, shelf, book, privacy):
""" post about a user reading a book """
# tell the world about this cool thing that happened
try:
message = {
"to-read": "wants to read",
"reading": "started reading",
"read": "finished reading",
}[shelf.identifier]
except KeyError:
# it's a non-standard shelf, don't worry about it
return
status = create_generated_note(user, message, mention_books=[book], privacy=privacy)
status.save()
def is_blocked(viewer, user):
""" is this viewer blocked by the user? """
if viewer.is_authenticated and viewer in user.blocks.all():
return True
return False
def get_discover_books():
""" list of books for the discover page """
return list(
set(
models.Edition.objects.filter(
review__published_date__isnull=False,
review__deleted=False,
review__user__local=True,
review__privacy__in=["public", "unlisted"],
)
.exclude(cover__exact="")
.annotate(Max("review__published_date"))
.order_by("-review__published_date__max")[:6]
)
)
def get_suggested_users(user):
""" bookwyrm users you don't already know """
return (
get_annotated_users(
user,
~Q(id=user.id),
~Q(followers=user),
~Q(follower_requests=user),
bookwyrm_user=True,
)
.order_by("-mutuals", "-last_active_date")
.all()[:5]
)
def get_annotated_users(user, *args, **kwargs):
""" Users, annotated with things they have in common """
return (
models.User.objects.filter(discoverable=True, is_active=True, *args, **kwargs)
.exclude(Q(id__in=user.blocks.all()) | Q(blocks=user))
.annotate(
mutuals=Count(
"following",
filter=Q(
~Q(id=user.id),
~Q(id__in=user.following.all()),
following__in=user.following.all(),
),
distinct=True,
),
shared_books=Count(
"shelfbook",
filter=Q(
~Q(id=user.id),
shelfbook__book__parent_work__in=[
s.book.parent_work for s in user.shelfbook_set.all()
],
),
distinct=True,
),
)
)