Refactor database connection handling in API endpoints

- Removed direct pool checks and replaced them with a centralized database initialization method in `init_db`.
- Updated API endpoints in `admin.py`, `collection.py`, `pins.py`, and `watched.py` to ensure the database connection pool is initialized before usage.
- Enhanced error handling to raise HTTP exceptions if the database is unavailable.
- Improved the `init_db` function in `database.py` to prevent multiple simultaneous initializations using an asyncio lock.

backend/app/api/admin.py

@@ -1,7 +1,6 @@
 """Admin API endpoints"""
 from fastapi import APIRouter, HTTPException, Header
 from typing import Optional
-from app.core.database import pool
 from app.core.config import settings
 from app.services.sync import sync_all_arrs
 

backend/app/api/collection.py

@@ -1,7 +1,6 @@
 """Collection API endpoints"""
 from fastapi import APIRouter, Query
 from typing import List, Optional
-from app.core.database import pool
 import json
 
 router = APIRouter()
@@ -15,17 +14,20 @@ async def get_collection_summary(
     Get collection summary by country and media type.
     Returns counts per country per media type.
     """
-    # Pool should be initialized on startup, but check just in case
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    # Ensure pool is initialized
+    from app.core.database import init_db, pool as db_pool
+    await init_db()
+    
+    if db_pool is None:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=503, detail="Database not available")
     
     # Parse types filter
     type_filter = []
     if types:
         type_filter = [t.strip() for t in types.split(",") if t.strip() in ["movie", "show", "music"]]
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             # Build query
             query = """

backend/app/api/pins.py

@@ -3,7 +3,7 @@ from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
 from typing import Optional
 from uuid import UUID
-from app.core.database import pool
+from app.core.database import init_db, pool as db_pool
 
 router = APIRouter()
 
@@ -16,12 +16,11 @@ class PinCreate(BaseModel):
 @router.get("")
 async def list_pins():
     """List all manual pins"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = """
                 SELECT id, country_code, label, pinned_at
@@ -46,12 +45,11 @@ async def list_pins():
 @router.post("")
 async def create_pin(pin: PinCreate):
     """Create a new manual pin"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = """
                 INSERT INTO moviemap.manual_pin (country_code, label)
@@ -68,12 +66,11 @@ async def create_pin(pin: PinCreate):
 @router.delete("/{pin_id}")
 async def delete_pin(pin_id: UUID):
     """Delete a manual pin"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = "DELETE FROM moviemap.manual_pin WHERE id = %s RETURNING id"
             await cur.execute(query, (str(pin_id),))

backend/app/api/watched.py

@@ -4,7 +4,7 @@ from pydantic import BaseModel
 from typing import Optional
 from datetime import datetime
 from uuid import UUID
-from app.core.database import pool
+from app.core.database import init_db, pool as db_pool
 import json
 
 router = APIRouter()
@@ -30,12 +30,11 @@ class WatchedItemUpdate(BaseModel):
 @router.get("/summary")
 async def get_watched_summary():
     """Get watched items summary by country"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = """
                 SELECT 
@@ -63,12 +62,11 @@ async def get_watched_summary():
 @router.get("")
 async def list_watched_items():
     """List all watched items"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = """
                 SELECT 
@@ -100,15 +98,14 @@ async def list_watched_items():
 @router.post("")
 async def create_watched_item(item: WatchedItemCreate):
     """Create a new watched item"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
     if item.media_type not in ["movie", "show"]:
         raise HTTPException(status_code=400, detail="media_type must be 'movie' or 'show'")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = """
                 INSERT INTO moviemap.watched_item 
@@ -136,12 +133,11 @@ async def create_watched_item(item: WatchedItemCreate):
 @router.patch("/{item_id}")
 async def update_watched_item(item_id: UUID, item: WatchedItemUpdate):
     """Update a watched item"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             # Build dynamic update query
             updates = []
@@ -189,12 +185,11 @@ async def update_watched_item(item_id: UUID, item: WatchedItemUpdate):
 @router.delete("/{item_id}")
 async def delete_watched_item(item_id: UUID):
     """Delete a watched item"""
-    # Pool should be initialized on startup
-    if not pool:
-        from app.core.database import init_db
-        await init_db()
+    await init_db()
+    if db_pool is None:
+        raise HTTPException(status_code=503, detail="Database not available")
     
-    async with pool.connection() as conn:
+    async with db_pool.connection() as conn:
         async with conn.cursor() as cur:
             query = "DELETE FROM moviemap.watched_item WHERE id = %s RETURNING id"
             await cur.execute(query, (str(item_id),))