Add sorting by rating

src/hxbooks/library.py

@@ -9,7 +9,7 @@ from collections.abc import Sequence
 from datetime import date, datetime
 from typing import assert_never
 
-from sqlalchemy import ColumnElement, and_, func, or_, select
+from sqlalchemy import ColumnElement, Select, and_, func, or_, select
 from sqlalchemy.orm import InstrumentedAttribute, joinedload
 
 from hxbooks.search import IsOperatorValue, QueryParser, SortDirection, ValueT
@@ -313,31 +313,9 @@ def search_books_advanced(
     sort_columns = []
     for field_filter in parsed_query.field_filters:
         if field_filter.field == Field.SORT:
-            if (
-                isinstance(field_filter.value, tuple)
-                and field_filter.value[0] == Field.READ_DATE
-            ):
-                # Special handling for sorting by read date - sort by latest reading end
-                # date
-                subq = (
-                    select(
-                        Reading.book_id,
-                        func.max(Reading.end_date).label("latest_read_date"),
-                    )
-                    .where(
-                        Reading.user.has(User.username == username),
-                        Reading.end_date.isnot(None),
-                    )
-                    .group_by(Reading.book_id)
-                    .subquery()
-                )
-                query = query.outerjoin(subq, Book.id == subq.c.book_id)
-                if field_filter.value[1] == SortDirection.ASC:
-                    sort_columns.append(subq.c.latest_read_date.asc().nullslast())
-                else:
-                    sort_columns.append(subq.c.latest_read_date.desc().nullslast())
-            else:
-                sort_columns.append(_build_sort_column(field_filter.value))
+            query, sort_column = _build_sort_column(query, field_filter.value, username)
+            if sort_column is not None:
+                sort_columns.append(sort_column)
         else:
             condition = _build_field_condition(field_filter, username)
 
@@ -449,7 +427,9 @@ def _build_field_condition(
     return condition
 
 
-def _build_sort_column(value: ValueT) -> ColumnElement | None:
+def _build_sort_column(
+    query: Select, value: ValueT, username: str | None = None
+) -> tuple[Select, ColumnElement | None]:
     """Build a sort column for the 'sort' field."""
     assert isinstance(value, tuple) and len(value) == 2
     field, direction = value
@@ -476,21 +456,60 @@ def _build_sort_column(value: ValueT) -> ColumnElement | None:
             column = Book.location_shelf
         case Field.OWNER:
             column = User.username
-        # These relationship-based fields are not supported here as they need subqueries
-        case Field.RATING | Field.READ_DATE:
-            return None
+        case Field.READ_DATE:
+            # Special handling for sorting by read date - sort by latest reading end
+            # date
+            subq = (
+                select(
+                    Reading.book_id,
+                    func.max(Reading.end_date).label("latest_read_date"),
+                )
+                .where(
+                    Reading.user.has(User.username == username),
+                    Reading.end_date.isnot(None),
+                )
+                .group_by(Reading.book_id)
+                .subquery("latest_readings")
+            )
+            query = query.outerjoin(subq, Book.id == subq.c.book_id)
+            column = subq.c.latest_read_date
+        case Field.RATING:
+            # Special handling for sorting by rating - sort by latest reading rating
+            subq = (
+                select(
+                    Reading.book_id,
+                    Reading.rating.label("latest_rating"),
+                    func
+                    .row_number()
+                    .over(
+                        partition_by=Reading.book_id,
+                        order_by=Reading.end_date.desc(),
+                    )
+                    .label("rn"),
+                )
+                .where(
+                    Reading.user.has(User.username == username),
+                    Reading.rating.isnot(None),
+                    Reading.end_date.isnot(None),
+                )
+                .subquery("latest_ratings")
+            )
+            query = query.outerjoin(
+                subq, (Book.id == subq.c.book_id) & (subq.c.rn == 1)
+            )
+            column = subq.c.latest_rating
         # These fields don't make sense to sort by
         case Field.AUTHOR | Field.GENRE | Field.IS | Field.SORT:
-            return None
+            return query, None
         case _:
             assert_never(field)
 
     if direction == SortDirection.ASC:
-        return column.asc().nullslast()
+        return query, column.asc().nullslast()
     elif direction == SortDirection.DESC:
-        return column.desc().nullslast()
+        return query, column.desc().nullslast()
     else:
-        return None
+        return query, None
 
 
 def _apply_operator(

tests/test_cli.py

@@ -377,6 +377,11 @@ class TestBookSearchCommand:
                 "",
                 ["Dune", "The Fellowship", "The Hobbit", "Programming Book"],
             ),
+            (
+                "sort:rating-desc",
+                "alice",
+                ["The Hobbit", "Dune", "Programming Book", "The Fellowship"],
+            ),
         ],
     )
     def test_book_search_advanced_queries(