Replace encode/databases with psycopg & pydantic model validation

.gitignore

@@ -43,7 +43,6 @@ db.sqlite3
 
 # ignore python environments
 venv
-fmtm-env
 
 # project related
 temp_webmaps/local_only

docker-compose.yml

@@ -48,7 +48,9 @@ services:
     env_file: .env
     environment:
       LANG: en-GB.utf8
-      # POSTGRES_INITDB_ARGS: "--locale-provider=icu --icu-locale=en-GB"
+      POSTGRES_INITDB_ARGS: "--locale-provider=icu --icu-locale=en-GB"
+    ports:
+      - "5467:5432"
     networks:
       - dtm-network
     restart: unless-stopped
@@ -100,5 +102,5 @@ services:
       - .env
     networks:
       - dtm-network
-    entrypoint: ["pdm", "run", "alembic", "upgrade", "head"]
+    entrypoint: ["alembic", "upgrade", "head"]
     restart: "no"

src/backend/app/db/database.py

@@ -1,32 +1,73 @@
 """Config for the DTM database connection."""
 
-from databases import Database
+from typing import AsyncGenerator
+from fastapi import Request
+from psycopg import Connection
+from psycopg_pool import AsyncConnectionPool
 from app.config import settings
 
 
-class DatabaseConnection:
-    """Manages database connection (sqlalchemy & encode databases)"""
+async def get_db_connection_pool() -> AsyncConnectionPool:
+    """Get the connection pool for psycopg."""
+    return AsyncConnectionPool(conninfo=settings.DTM_DB_URL.unicode_string())
 
-    def __init__(self):
-        self.database = Database(
-            settings.DTM_DB_URL.unicode_string(),
-            min_size=5,
-            max_size=20,
-        )
 
-    async def connect(self):
-        """Connect to the database."""
-        await self.database.connect()
+async def get_db(request: Request) -> AsyncGenerator[Connection, None]:
+    """Get a connection from the psycopg pool.
 
-    async def disconnect(self):
-        """Disconnect from the database."""
-        await self.database.disconnect()
+    Info on connections vs cursors:
+    https://www.psycopg.org/psycopg3/docs/advanced/async.html
 
+    Here we are getting a connection from the pool, which will be returned
+    after the session ends / endpoint finishes processing.
 
-db_connection = DatabaseConnection()
+    In summary:
+    - Connection is created on endpoint call.
+    - Cursors are used to execute commands throughout endpoint.
+      Note it is possible to create multiple cursors from the connection,
+      but all will be executed in the same db 'transaction'.
+    - Connection is closed on endpoint finish.
 
+    -----------------------------------
+    To use the connection in endpoints:
+    -----------------------------------
 
-async def get_db():
-    """Get the encode database connection"""
-    await db_connection.connect()
-    yield db_connection.database
+    @app.get("/something/")
+    async def do_stuff(db = Depends(get_db)):
+        async with db.cursor() as cursor:
+            await cursor.execute("SELECT * FROM items")
+            result = await cursor.fetchall()
+            return result
+
+    -----------------------------------
+    Additionally, the connection could be passed through to a function to
+    utilise the Pydantic model serialisation on the cursor:
+    -----------------------------------
+
+    from psycopg.rows import class_row
+    async def get_user_by_id(db: Connection, id: int):
+        async with conn.cursor(row_factory=class_row(User)) as cur:
+            await cur.execute(
+                '''
+                SELECT id, first_name, last_name, dob
+                FROM (VALUES
+                    (1, 'John', 'Doe', '2000-01-01'::date),
+                    (2, 'Jane', 'White', NULL)
+                ) AS data (id, first_name, last_name, dob)
+                WHERE id = %(id)s;
+                ''',
+                {"id": id},
+            )
+            obj = await cur.fetchone()
+
+            # reveal_type(obj) would return 'Optional[User]' here
+
+            if not obj:
+                raise KeyError(f"user {id} not found")
+
+            # reveal_type(obj) would return 'User' here
+
+            return obj
+    """
+    async with request.app.state.db_pool.connection() as conn:
+        yield conn

src/backend/app/drones/drone_crud.py

@@ -1,14 +1,14 @@
-from app.drones import drone_schemas
 from app.models.enums import HTTPStatus
-from databases import Database
 from loguru import logger as log
 from fastapi import HTTPException
-from asyncpg import UniqueViolationError
+from psycopg import Connection
+
+# from asyncpg import UniqueViolationError
 from typing import List
 from app.drones.drone_schemas import DroneOut
 
 
-async def read_all_drones(db: Database) -> List[DroneOut]:
+async def read_all_drones(db: Connection) -> List[DroneOut]:
     """
     Retrieves all drone records from the database.
 
@@ -32,7 +32,7 @@ async def read_all_drones(db: Database) -> List[DroneOut]:
         ) from e
 
 
-async def delete_drone(db: Database, drone_id: int) -> bool:
+async def delete_drone(db: Connection, drone_id: int) -> bool:
     """
     Deletes a drone record from the database, along with associated drone flights.
 
@@ -63,7 +63,7 @@ async def delete_drone(db: Database, drone_id: int) -> bool:
         ) from e
 
 
-async def get_drone(db: Database, drone_id: int):
+async def get_drone(db: Connection, drone_id: int):
     """
     Retrieves a drone record from the database.
 
@@ -87,44 +87,3 @@ async def get_drone(db: Database, drone_id: int):
         raise HTTPException(
             status_code=HTTPStatus.INTERNAL_SERVER_ERROR, detail="Retrieval failed"
         ) from e
-
-
-async def create_drone(db: Database, drone_info: drone_schemas.DroneIn):
-    """
-    Creates a new drone record in the database.
-
-    Args:
-        db (Database): The database connection object.
-        drone (drone_schemas.DroneIn): The schema object containing drone details.
-
-    Returns:
-        The ID of the newly created drone record.
-    """
-    try:
-        insert_query = """
-            INSERT INTO drones (
-                model, manufacturer, camera_model, sensor_width, sensor_height,
-                max_battery_health, focal_length, image_width, image_height,
-                max_altitude, max_speed, weight, created
-            ) VALUES (
-                :model, :manufacturer, :camera_model, :sensor_width, :sensor_height,
-                :max_battery_health, :focal_length, :image_width, :image_height,
-                :max_altitude, :max_speed, :weight, CURRENT_TIMESTAMP
-            )
-            RETURNING id
-        """
-        result = await db.execute(insert_query, drone_info.__dict__)
-        return result
-
-    except UniqueViolationError as e:
-        log.exception("Unique constraint violation: %s", e)
-        raise HTTPException(
-            status_code=HTTPStatus.CONFLICT,
-            detail="A drone with this model already exists",
-        )
-
-    except Exception as e:
-        log.exception(e)
-        raise HTTPException(
-            status_code=HTTPStatus.INTERNAL_SERVER_ERROR, detail="Drone creation failed"
-        ) from e

src/backend/app/drones/drone_deps.py

@@ -0,0 +1,20 @@
+from typing import Annotated
+from fastapi import Depends, HTTPException, Path
+from psycopg import Connection
+from app.db import database
+from app.drones.drone_schemas import DbDrone
+from app.models.enums import HTTPStatus
+
+
+async def get_drone_by_id(
+    drone_id: Annotated[
+        int,
+        Path(description="Drone ID."),
+    ],
+    db: Annotated[Connection, Depends(database.get_db)],
+) -> DbDrone:
+    """Get a single project by id."""
+    try:
+        return await DbDrone.one(db, drone_id)
+    except KeyError as e:
+        raise HTTPException(status_code=HTTPStatus.NOT_FOUND) from e

src/backend/app/drones/drone_routes.py

@@ -1,45 +1,48 @@
+from typing import Annotated
 from app.users.user_deps import login_required
 from app.users.user_schemas import AuthUser
 from app.models.enums import HTTPStatus
 from fastapi import APIRouter, Depends, HTTPException
-from app.db.database import get_db
+from app.db import database
 from app.config import settings
-from app.drones import drone_schemas
-from databases import Database
-from app.drones import drone_crud
-from typing import List
+from app.drones import drone_schemas, drone_deps
+from psycopg import Connection
 
 
 router = APIRouter(
     prefix=f"{settings.API_PREFIX}/drones",
+    tags=["Drones"],
     responses={404: {"description": "Not found"}},
 )
 
 
-@router.get("/", tags=["Drones"], response_model=List[drone_schemas.DroneOut])
+@router.get("/", response_model=list[drone_schemas.DroneOut])
 async def read_drones(
-    db: Database = Depends(get_db),
-    user_data: AuthUser = Depends(login_required),
+    db: Annotated[Connection, Depends(database.get_db)],
 ):
-    """
-    Retrieves all drone records from the database.
+    """Get all drones."""
+    try:
+        return await drone_schemas.DbDrone.all(db)
+    except KeyError as e:
+        raise HTTPException(status_code=HTTPStatus.NOT_FOUND) from e
 
-    Args:
-        db (Database, optional): The database session object.
-        user_data (AuthUser, optional): The authenticated user data.
 
-    Returns:
-        List[drone_schemas.DroneOut]: A list of all drone records.
-    """
-    drones = await drone_crud.read_all_drones(db)
-    return drones
+@router.post("/create_drone")
+async def create_drone(
+    drone_info: drone_schemas.DroneIn,
+    db: Annotated[Connection, Depends(database.get_db)],
+    user_data: Annotated[AuthUser, Depends(login_required)],
+):
+    """Create a new drone in database"""
+    drone_id = await drone_schemas.DbDrone.create(db, drone_info)
+    return {"message": "Drone created successfully", "drone_id": drone_id}
 
 
-@router.delete("/{drone_id}", tags=["Drones"])
+@router.delete("/{drone_id}")
 async def delete_drone(
-    drone_id: int,
-    db: Database = Depends(get_db),
-    user_data: AuthUser = Depends(login_required),
+    drone: Annotated[drone_schemas.DbDrone, Depends(drone_deps.get_drone_by_id)],
+    db: Annotated[Connection, Depends(database.get_db)],
+    user_data: Annotated[AuthUser, Depends(login_required)],
 ):
     """
     Deletes a drone record from the database.
@@ -52,42 +55,18 @@ async def delete_drone(
     Returns:
         dict: A success message if the drone was deleted.
     """
-    success = await drone_crud.delete_drone(db, drone_id)
-    if not success:
-        raise HTTPException(status_code=HTTPStatus.NOT_FOUND, detail="Drone not found")
-    return {"message": "Drone deleted successfully"}
-
 
-@router.post("/create_drone", tags=["Drones"])
-async def create_drone(
-    drone_info: drone_schemas.DroneIn,
-    db: Database = Depends(get_db),
-    user_data: AuthUser = Depends(login_required),
-):
-    """
-    Creates a new drone record in the database.
-
-    Args:
-        drone_info (drone_schemas.DroneIn): The schema object containing drone details.
-        db (Database, optional): The database session object.
-        user_data (AuthUser, optional): The authenticated user data.
-
-    Returns:
-        dict: A dictionary containing a success message and the ID of the newly created drone.
-    """
-    drone_id = await drone_crud.create_drone(db, drone_info)
-    if not drone_id:
-        raise HTTPException(
-            status_code=HTTPStatus.BAD_REQUEST, detail="Drone creation failed"
-        )
-    return {"message": "Drone created successfully", "drone_id": drone_id}
+    # TODO: Check user role, Admin can only do this.
+    # After user roles introduction
+    drone_id = await drone_schemas.DbDrone.delete(db, drone.id)
+    return {"message": f"Drone successfully deleted {drone_id}"}
 
 
-@router.get("/{drone_id}", tags=["Drones"], response_model=drone_schemas.DroneOut)
+@router.get("/{drone_id}", response_model=drone_schemas.DbDrone)
 async def read_drone(
-    drone_id: int,
-    db: Database = Depends(get_db),
-    user_data: AuthUser = Depends(login_required),
+    drone: Annotated[drone_schemas.DbDrone, Depends(drone_deps.get_drone_by_id)],
+    db: Annotated[Connection, Depends(database.get_db)],
+    user_data: Annotated[AuthUser, Depends(login_required)],
 ):
     """
     Retrieves a drone record from the database.
@@ -100,7 +79,4 @@ async def read_drone(
     Returns:
         dict: The drone record if found.
     """
-    drone = await drone_crud.get_drone(db, drone_id)
-    if not drone:
-        raise HTTPException(status_code=HTTPStatus.NOT_FOUND, detail="Drone not found")
     return drone