moviewyrm/bookwyrm/models/fields.py
2020-12-03 13:00:04 -08:00

215 lines
7.1 KiB
Python

''' activitypub-aware django model fields '''
import re
from uuid import uuid4
import dateutil.parser
from dateutil.parser import ParserError
from django.contrib.auth.models import AbstractUser
from django.contrib.postgres.fields import ArrayField as DjangoArrayField
from django.core.exceptions import ValidationError
from django.core.files.base import ContentFile
from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from bookwyrm import activitypub
from bookwyrm.settings import DOMAIN
from bookwyrm.connectors import get_image
def validate_remote_id(value):
''' make sure the remote_id looks like a url '''
if not re.match(r'^http.?:\/\/[^\s]+$', value):
raise ValidationError(
_('%(value)s is not a valid remote_id'),
params={'value': value},
)
class ActivitypubFieldMixin:
''' make a database field serializable '''
def __init__(self, *args, \
activitypub_field=None, activitypub_wrapper=None, **kwargs):
if activitypub_wrapper:
self.activitypub_wrapper = activitypub_field
self.activitypub_field = activitypub_wrapper
else:
self.activitypub_field = activitypub_field
super().__init__(*args, **kwargs)
def field_to_activity(self, value):
''' formatter to convert a model value into activitypub '''
if hasattr(self, 'activitypub_wrapper'):
return {self.activitypub_wrapper: value}
return value
def field_from_activity(self, value):
''' formatter to convert activitypub into a model value '''
if hasattr(self, 'activitypub_wrapper'):
value = value.get(self.activitypub_wrapper)
return value
def get_activitypub_field(self):
''' model_field_name to activitypubFieldName '''
if self.activitypub_field:
return self.activitypub_field
name = self.name.split('.')[-1]
components = name.split('_')
return components[0] + ''.join(x.title() for x in components[1:])
class RemoteIdField(ActivitypubFieldMixin, models.CharField):
''' a url that serves as a unique identifier '''
def __init__(self, *args, max_length=255, validators=None, **kwargs):
validators = validators or [validate_remote_id]
super().__init__(
*args, max_length=max_length, validators=validators,
**kwargs
)
class UsernameField(ActivitypubFieldMixin, models.CharField):
''' activitypub-aware username field '''
def __init__(self, activitypub_field='preferredUsername'):
self.activitypub_field = activitypub_field
super(ActivitypubFieldMixin, self).__init__(
_('username'),
max_length=150,
unique=True,
validators=[AbstractUser.username_validator],
error_messages={
'unique': _('A user with that username already exists.'),
},
)
def deconstruct(self):
''' implementation of models.Field deconstruct '''
name, path, args, kwargs = super().deconstruct()
del kwargs['verbose_name']
del kwargs['max_length']
del kwargs['unique']
del kwargs['validators']
del kwargs['error_messages']
return name, path, args, kwargs
def field_to_activity(self, value):
return value.split('@')[0]
class ForeignKey(ActivitypubFieldMixin, models.ForeignKey):
''' activitypub-aware foreign key field '''
def field_to_activity(self, value):
if not value:
return None
return value.remote_id
class OneToOneField(ActivitypubFieldMixin, models.OneToOneField):
''' activitypub-aware foreign key field '''
def field_to_activity(self, value):
if not value:
return None
return value.to_activity()
class ManyToManyField(ActivitypubFieldMixin, models.ManyToManyField):
''' activitypub-aware many to many field '''
def __init__(self, *args, link_only=False, **kwargs):
self.link_only = link_only
super().__init__(*args, **kwargs)
def field_to_activity(self, value):
if self.link_only:
return '%s/followers' % value.instance.remote_id
return [i.remote_id for i in value.all()]
class TagField(ManyToManyField):
''' special case of many to many that uses Tags '''
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.activitypub_field = 'tag'
def field_to_activity(self, value):
tags = []
for item in value.all():
activity_type = item.__class__.__name__
if activity_type == 'User':
activity_type = 'Mention'
tags.append(activitypub.Link(
href=item.remote_id,
name=getattr(item, item.name_field),
type=activity_type
))
return tags
def image_serializer(value):
''' helper for serializing images '''
if value and hasattr(value, 'url'):
url = value.url
else:
return None
url = 'https://%s%s' % (DOMAIN, url)
return activitypub.Image(url=url)
class ImageField(ActivitypubFieldMixin, models.ImageField):
''' activitypub-aware image field '''
def field_to_activity(self, value):
return image_serializer(value)
def field_from_activity(self, value):
image_slug = value
# when it's an inline image (User avatar/icon, Book cover), it's a json
# blob, but when it's an attached image, it's just a url
if isinstance(image_slug, dict):
url = image_slug.get('url')
elif isinstance(image_slug, str):
url = image_slug
else:
return None
if not url:
return None
response = get_image(url)
if not response:
return None
image_name = str(uuid4()) + '.' + url.split('.')[-1]
image_content = ContentFile(response.content)
return [image_name, image_content]
class DateTimeField(ActivitypubFieldMixin, models.DateTimeField):
''' activitypub-aware datetime field '''
def field_to_activity(self, value):
if not value:
return None
return value.isoformat()
def field_from_activity(self, value):
try:
date_value = dateutil.parser.parse(value)
try:
return timezone.make_aware(date_value)
except ValueError:
return date_value
except (ParserError, TypeError):
return None
class ArrayField(ActivitypubFieldMixin, DjangoArrayField):
''' activitypub-aware array field '''
def field_to_activity(self, value):
return [str(i) for i in value]
class CharField(ActivitypubFieldMixin, models.CharField):
''' activitypub-aware char field '''
class TextField(ActivitypubFieldMixin, models.TextField):
''' activitypub-aware text field '''
class BooleanField(ActivitypubFieldMixin, models.BooleanField):
''' activitypub-aware boolean field '''
class IntegerField(ActivitypubFieldMixin, models.IntegerField):
''' activitypub-aware boolean field '''