feat: Implement pagination for extractions and playlists with total count in responses

app/repositories/extraction.py

@@ -1,6 +1,6 @@
 """Extraction repository for database operations."""
 
-from sqlalchemy import asc, desc, or_
+from sqlalchemy import asc, desc, func, or_
 from sqlmodel import select
 from sqlmodel.ext.asyncio.session import AsyncSession
 
@@ -65,9 +65,11 @@ class ExtractionRepository(BaseRepository[Extraction]):
         sort_by: str = "created_at",
         sort_order: str = "desc",
         status_filter: str | None = None,
-    ) -> list[tuple[Extraction, User]]:
+        limit: int = 50,
+        offset: int = 0,
+    ) -> tuple[list[tuple[Extraction, User]], int]:
         """Get extractions for a user with filtering, search, and sorting."""
-        query = (
+        base_query = (
             select(Extraction, User)
             .join(User, Extraction.user_id == User.id)
             .where(Extraction.user_id == user_id)
@@ -76,7 +78,7 @@ class ExtractionRepository(BaseRepository[Extraction]):
         # Apply search filter
         if search:
             search_pattern = f"%{search}%"
-            query = query.where(
+            base_query = base_query.where(
                 or_(
                     Extraction.title.ilike(search_pattern),
                     Extraction.url.ilike(search_pattern),
@@ -86,17 +88,26 @@ class ExtractionRepository(BaseRepository[Extraction]):
 
         # Apply status filter
         if status_filter:
-            query = query.where(Extraction.status == status_filter)
+            base_query = base_query.where(Extraction.status == status_filter)
 
-        # Apply sorting
+        # Get total count before pagination
+        count_query = select(func.count()).select_from(
+            base_query.subquery()
+        )
+        count_result = await self.session.exec(count_query)
+        total_count = count_result.one()
+
+        # Apply sorting and pagination
         sort_column = getattr(Extraction, sort_by, Extraction.created_at)
         if sort_order.lower() == "asc":
-            query = query.order_by(asc(sort_column))
+            base_query = base_query.order_by(asc(sort_column))
         else:
-            query = query.order_by(desc(sort_column))
+            base_query = base_query.order_by(desc(sort_column))
 
-        result = await self.session.exec(query)
-        return list(result.all())
+        paginated_query = base_query.limit(limit).offset(offset)
+        result = await self.session.exec(paginated_query)
+        
+        return list(result.all()), total_count
 
     async def get_all_extractions_filtered(
         self,
@@ -104,14 +115,16 @@ class ExtractionRepository(BaseRepository[Extraction]):
         sort_by: str = "created_at",
         sort_order: str = "desc",
         status_filter: str | None = None,
-    ) -> list[tuple[Extraction, User]]:
+        limit: int = 50,
+        offset: int = 0,
+    ) -> tuple[list[tuple[Extraction, User]], int]:
         """Get all extractions with filtering, search, and sorting."""
-        query = select(Extraction, User).join(User, Extraction.user_id == User.id)
+        base_query = select(Extraction, User).join(User, Extraction.user_id == User.id)
 
         # Apply search filter
         if search:
             search_pattern = f"%{search}%"
-            query = query.where(
+            base_query = base_query.where(
                 or_(
                     Extraction.title.ilike(search_pattern),
                     Extraction.url.ilike(search_pattern),
@@ -121,14 +134,23 @@ class ExtractionRepository(BaseRepository[Extraction]):
 
         # Apply status filter
         if status_filter:
-            query = query.where(Extraction.status == status_filter)
+            base_query = base_query.where(Extraction.status == status_filter)
 
-        # Apply sorting
+        # Get total count before pagination
+        count_query = select(func.count()).select_from(
+            base_query.subquery()
+        )
+        count_result = await self.session.exec(count_query)
+        total_count = count_result.one()
+
+        # Apply sorting and pagination
         sort_column = getattr(Extraction, sort_by, Extraction.created_at)
         if sort_order.lower() == "asc":
-            query = query.order_by(asc(sort_column))
+            base_query = base_query.order_by(asc(sort_column))
         else:
-            query = query.order_by(desc(sort_column))
+            base_query = base_query.order_by(desc(sort_column))
 
-        result = await self.session.exec(query)
-        return list(result.all())
+        paginated_query = base_query.limit(limit).offset(offset)
+        result = await self.session.exec(paginated_query)
+        
+        return list(result.all()), total_count

app/repositories/playlist.py

@@ -343,7 +343,9 @@ class PlaylistRepository(BaseRepository[Playlist]):
         offset: int = 0,
         favorites_only: bool = False,
         current_user_id: int | None = None,
-    ) -> list[dict]:
+        *,
+        return_count: bool = False,
+    ) -> list[dict] | tuple[list[dict], int]:
         """Search and sort playlists with optional statistics."""
         try:
             if include_stats and sort_by in (
@@ -491,6 +493,14 @@ class PlaylistRepository(BaseRepository[Playlist]):
                     # Default sorting by name ascending
                     subquery = subquery.order_by(Playlist.name.asc())
 
+            # Get total count if requested
+            total_count = 0
+            if return_count:
+                # Create count query from the subquery before pagination
+                count_query = select(func.count()).select_from(subquery.subquery())
+                count_result = await self.session.exec(count_query)
+                total_count = count_result.one()
+
             # Apply pagination
             if offset > 0:
                 subquery = subquery.offset(offset)
@@ -532,4 +542,6 @@ class PlaylistRepository(BaseRepository[Playlist]):
             )
             raise
         else:
+            if return_count:
+                return playlists, total_count
             return playlists