Display search results in api mode and regular

bookwyrm/book_search.py

@@ -0,0 +1,120 @@
+""" using a bookwyrm instance as a source of book data """
+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.connectors.abstract_connector import SearchResult
+from bookwyrm.settings import MEDIA_FULL_URL
+
+
+# pylint: disable=arguments-differ
+def search(query, min_confidence=0, filters=None):
+    """search your local database"""
+    filters = filters or []
+    if not query:
+        return []
+    # first, try searching unqiue identifiers
+    results = search_identifiers(query, *filters)
+    if not results:
+        # then try searching title/author
+        results = search_title_author(query, min_confidence, *filters)
+    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):
+    """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")
+    return (
+        results.annotate(default_id=Subquery(default_editions.values("id")[:1])).filter(
+            default_id=F("id")
+        )
+        or results
+    )
+
+
+def search_title_author(query, min_confidence, *filters):
+    """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
+    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:
+            yield default
+        else:
+            yield editions.first()