bookwyrm/bookwyrm/book_search.py
2021-09-30 10:47:53 -07:00

156 lines
4.9 KiB
Python

""" using a bookwyrm instance as a source of book data """
from dataclasses import asdict, dataclass
from functools import reduce
import operator
from django.contrib.postgres.search import SearchRank, SearchQuery
from django.db.models import OuterRef, Subquery, F, Q
from bookwyrm import models
from bookwyrm.settings import MEDIA_FULL_URL
# pylint: disable=arguments-differ
def search(query, min_confidence=0, filters=None, return_first=False):
"""search your local database"""
filters = filters or []
if not query:
return []
# first, try searching unqiue identifiers
results = search_identifiers(query, *filters, return_first=return_first)
if not results:
# then try searching title/author
results = search_title_author(
query, min_confidence, *filters, return_first=return_first
)
return results
def isbn_search(query):
"""search your local database"""
if not query:
return []
filters = [{f: query} for f in ["isbn_10", "isbn_13"]]
results = models.Edition.objects.filter(
reduce(operator.or_, (Q(**f) for f in filters))
).distinct()
# when there are multiple editions of the same work, pick the default.
# it would be odd for this to happen.
default_editions = models.Edition.objects.filter(
parent_work=OuterRef("parent_work")
).order_by("-edition_rank")
results = (
results.annotate(default_id=Subquery(default_editions.values("id")[:1])).filter(
default_id=F("id")
)
or results
)
return results
def format_search_result(search_result):
"""convert a book object into a search result object"""
cover = None
if search_result.cover:
cover = f"{MEDIA_FULL_URL}{search_result.cover}"
return SearchResult(
title=search_result.title,
key=search_result.remote_id,
author=search_result.author_text,
year=search_result.published_date.year
if search_result.published_date
else None,
cover=cover,
confidence=search_result.rank if hasattr(search_result, "rank") else 1,
connector="",
).json()
def search_identifiers(query, *filters, return_first=False):
"""tries remote_id, isbn; defined as dedupe fields on the model"""
# pylint: disable=W0212
or_filters = [
{f.name: query}
for f in models.Edition._meta.get_fields()
if hasattr(f, "deduplication_field") and f.deduplication_field
]
results = models.Edition.objects.filter(
*filters, reduce(operator.or_, (Q(**f) for f in or_filters))
).distinct()
if results.count() <= 1:
return results
# when there are multiple editions of the same work, pick the default.
# it would be odd for this to happen.
default_editions = models.Edition.objects.filter(
parent_work=OuterRef("parent_work")
).order_by("-edition_rank")
results = (
results.annotate(default_id=Subquery(default_editions.values("id")[:1])).filter(
default_id=F("id")
)
or results
)
if return_first:
return results.first()
return results
def search_title_author(query, min_confidence, *filters, return_first=False):
"""searches for title and author"""
query = SearchQuery(query, config="simple") | SearchQuery(query, config="english")
results = (
models.Edition.objects.filter(*filters, search_vector=query)
.annotate(rank=SearchRank(F("search_vector"), query))
.filter(rank__gt=min_confidence)
.order_by("-rank")
)
# when there are multiple editions of the same work, pick the closest
editions_of_work = results.values("parent_work__id").values_list("parent_work__id")
# filter out multiple editions of the same work
list_results = []
for work_id in set(editions_of_work):
editions = results.filter(parent_work=work_id)
default = editions.order_by("-edition_rank").first()
default_rank = default.rank if default else 0
# if mutliple books have the top rank, pick the default edition
if default_rank == editions.first().rank:
result = default
else:
result = editions.first()
if return_first:
return result
list_results.append(result)
return list_results
@dataclass
class SearchResult:
"""standardized search result object"""
title: str
key: str
connector: object
view_link: str = None
author: str = None
year: str = None
cover: str = None
confidence: int = 1
def __repr__(self):
# pylint: disable=consider-using-f-string
return "<SearchResult key={!r} title={!r} author={!r}>".format(
self.key, self.title, self.author
)
def json(self):
"""serialize a connector for json response"""
serialized = asdict(self)
del serialized["connector"]
return serialized