moviewyrm/bookwyrm/connectors/abstract_connector.py
2022-02-02 07:09:35 -08:00

349 lines
12 KiB
Python

""" functionality outline for a book data connector """
from abc import ABC, abstractmethod
import imghdr
import logging
from django.core.files.base import ContentFile
from django.db import transaction
import requests
from requests.exceptions import RequestException
from bookwyrm import activitypub, models, settings
from .connector_manager import load_more_data, ConnectorException
from .format_mappings import format_mappings
logger = logging.getLogger(__name__)
class AbstractMinimalConnector(ABC):
"""just the bare bones, for other bookwyrm instances"""
def __init__(self, identifier):
# load connector settings
info = models.Connector.objects.get(identifier=identifier)
self.connector = info
# the things in the connector model to copy over
self_fields = [
"base_url",
"books_url",
"covers_url",
"search_url",
"isbn_search_url",
"name",
"identifier",
]
for field in self_fields:
setattr(self, field, getattr(info, field))
def search(self, query, min_confidence=None, timeout=settings.QUERY_TIMEOUT):
"""free text search"""
params = {}
if min_confidence:
params["min_confidence"] = min_confidence
data = self.get_search_data(
f"{self.search_url}{query}",
params=params,
timeout=timeout,
)
results = []
for doc in self.parse_search_data(data)[:10]:
results.append(self.format_search_result(doc))
return results
def isbn_search(self, query, timeout=settings.QUERY_TIMEOUT):
"""isbn search"""
params = {}
data = self.get_search_data(
f"{self.isbn_search_url}{query}",
params=params,
timeout=timeout,
)
results = []
# this shouldn't be returning mutliple results, but just in case
for doc in self.parse_isbn_search_data(data)[:10]:
results.append(self.format_isbn_search_result(doc))
return results
def get_search_data(self, remote_id, **kwargs): # pylint: disable=no-self-use
"""this allows connectors to override the default behavior"""
return get_data(remote_id, **kwargs)
@abstractmethod
def get_or_create_book(self, remote_id):
"""pull up a book record by whatever means possible"""
@abstractmethod
def parse_search_data(self, data):
"""turn the result json from a search into a list"""
@abstractmethod
def format_search_result(self, search_result):
"""create a SearchResult obj from json"""
@abstractmethod
def parse_isbn_search_data(self, data):
"""turn the result json from a search into a list"""
@abstractmethod
def format_isbn_search_result(self, search_result):
"""create a SearchResult obj from json"""
class AbstractConnector(AbstractMinimalConnector):
"""generic book data connector"""
def __init__(self, identifier):
super().__init__(identifier)
# fields we want to look for in book data to copy over
# title we handle separately.
self.book_mappings = []
def get_or_create_book(self, remote_id):
"""translate arbitrary json into an Activitypub dataclass"""
# first, check if we have the origin_id saved
existing = models.Edition.find_existing_by_remote_id(
remote_id
) or models.Work.find_existing_by_remote_id(remote_id)
if existing:
if hasattr(existing, "default_edition"):
return existing.default_edition
return existing
# load the json data from the remote data source
data = self.get_book_data(remote_id)
if self.is_work_data(data):
try:
edition_data = self.get_edition_from_work_data(data)
except (KeyError, ConnectorException):
# hack: re-use the work data as the edition data
# this is why remote ids aren't necessarily unique
edition_data = data
work_data = data
else:
edition_data = data
try:
work_data = self.get_work_from_edition_data(data)
except (KeyError, ConnectorException) as err:
logger.exception(err)
work_data = data
if not work_data or not edition_data:
raise ConnectorException(f"Unable to load book data: {remote_id}")
with transaction.atomic():
# create activitypub object
work_activity = activitypub.Work(
**dict_from_mappings(work_data, self.book_mappings)
)
# this will dedupe automatically
work = work_activity.to_model(model=models.Work, overwrite=False)
for author in self.get_authors_from_data(work_data):
work.authors.add(author)
edition = self.create_edition_from_data(work, edition_data)
load_more_data.delay(self.connector.id, work.id)
return edition
def get_book_data(self, remote_id): # pylint: disable=no-self-use
"""this allows connectors to override the default behavior"""
return get_data(remote_id)
def create_edition_from_data(self, work, edition_data, instance=None):
"""if we already have the work, we're ready"""
mapped_data = dict_from_mappings(edition_data, self.book_mappings)
mapped_data["work"] = work.remote_id
edition_activity = activitypub.Edition(**mapped_data)
edition = edition_activity.to_model(
model=models.Edition, overwrite=False, instance=instance
)
# if we're updating an existing instance, we don't need to load authors
if instance:
return edition
if not edition.connector:
edition.connector = self.connector
edition.save(broadcast=False, update_fields=["connector"])
for author in self.get_authors_from_data(edition_data):
edition.authors.add(author)
# use the authors from the work if none are found for the edition
if not edition.authors.exists() and work.authors.exists():
edition.authors.set(work.authors.all())
return edition
def get_or_create_author(self, remote_id, instance=None):
"""load that author"""
if not instance:
existing = models.Author.find_existing_by_remote_id(remote_id)
if existing:
return existing
data = self.get_book_data(remote_id)
mapped_data = dict_from_mappings(data, self.author_mappings)
try:
activity = activitypub.Author(**mapped_data)
except activitypub.ActivitySerializerError:
return None
# this will dedupe
return activity.to_model(
model=models.Author, overwrite=False, instance=instance
)
def get_remote_id_from_model(self, obj):
"""given the data stored, how can we look this up"""
return getattr(obj, getattr(self, "generated_remote_link_field"))
def update_author_from_remote(self, obj):
"""load the remote data from this connector and add it to an existing author"""
remote_id = self.get_remote_id_from_model(obj)
return self.get_or_create_author(remote_id, instance=obj)
def update_book_from_remote(self, obj):
"""load the remote data from this connector and add it to an existing book"""
remote_id = self.get_remote_id_from_model(obj)
data = self.get_book_data(remote_id)
return self.create_edition_from_data(obj.parent_work, data, instance=obj)
@abstractmethod
def is_work_data(self, data):
"""differentiate works and editions"""
@abstractmethod
def get_edition_from_work_data(self, data):
"""every work needs at least one edition"""
@abstractmethod
def get_work_from_edition_data(self, data):
"""every edition needs a work"""
@abstractmethod
def get_authors_from_data(self, data):
"""load author data"""
@abstractmethod
def expand_book_data(self, book):
"""get more info on a book"""
def dict_from_mappings(data, mappings):
"""create a dict in Activitypub format, using mappings supplies by
the subclass"""
result = {}
for mapping in mappings:
# sometimes there are multiple mappings for one field, don't
# overwrite earlier writes in that case
if mapping.local_field in result and result[mapping.local_field]:
continue
result[mapping.local_field] = mapping.get_value(data)
return result
def get_data(url, params=None, timeout=10):
"""wrapper for request.get"""
# check if the url is blocked
if models.FederatedServer.is_blocked(url):
raise ConnectorException(f"Attempting to load data from blocked url: {url}")
try:
resp = requests.get(
url,
params=params,
headers={ # pylint: disable=line-too-long
"Accept": (
'application/json, application/activity+json, application/ld+json; profile="https://www.w3.org/ns/activitystreams"; charset=utf-8'
),
"User-Agent": settings.USER_AGENT,
},
timeout=timeout,
)
except RequestException as err:
logger.exception(err)
raise ConnectorException(err)
if not resp.ok:
raise ConnectorException()
try:
data = resp.json()
except ValueError as err:
logger.exception(err)
raise ConnectorException(err)
return data
def get_image(url, timeout=10):
"""wrapper for requesting an image"""
try:
resp = requests.get(
url,
headers={
"User-Agent": settings.USER_AGENT,
},
timeout=timeout,
)
except RequestException as err:
logger.exception(err)
return None, None
if not resp.ok:
return None, None
image_content = ContentFile(resp.content)
extension = imghdr.what(None, image_content.read())
if not extension:
logger.exception("File requested was not an image: %s", url)
return None, None
return image_content, extension
class Mapping:
"""associate a local database field with a field in an external dataset"""
def __init__(self, local_field, remote_field=None, formatter=None):
noop = lambda x: x
self.local_field = local_field
self.remote_field = remote_field or local_field
self.formatter = formatter or noop
def get_value(self, data):
"""pull a field from incoming json and return the formatted version"""
value = data.get(self.remote_field)
if not value:
return None
try:
return self.formatter(value)
except: # pylint: disable=bare-except
return None
def infer_physical_format(format_text):
"""try to figure out what the standardized format is from the free value"""
format_text = format_text.lower()
if format_text in format_mappings:
# try a direct match
return format_mappings[format_text]
# failing that, try substring
matches = [v for k, v in format_mappings.items() if k in format_text]
if not matches:
return None
return matches[0]
def unique_physical_format(format_text):
"""only store the format if it isn't diretly in the format mappings"""
format_text = format_text.lower()
if format_text in format_mappings:
# try a direct match, so saving this would be redundant
return None
return format_text