feat(infrastructure): add basic project setup

backend/app/db.py

@@ -0,0 +1,49 @@
+import os
+from typing import AsyncGenerator
+
+from fastapi import Depends
+from fastapi_users.db import SQLAlchemyBaseUserTableUUID, SQLAlchemyUserDatabase
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.ext.declarative import DeclarativeMeta, declarative_base
+from sqlalchemy.orm import sessionmaker
+
+DATABASE_URL = os.getenv("DATABASE_URL")
+if not DATABASE_URL:
+    mariadb_host = os.getenv("MARIADB_HOST", "localhost")
+    mariadb_port = os.getenv("MARIADB_PORT", "3306")
+    mariadb_db = os.getenv("MARIADB_DB", "group_project")
+    mariadb_user = os.getenv("MARIADB_USER", "root")
+    mariadb_password = os.getenv("MARIADB_PASSWORD", "strongpassword")
+    if mariadb_host and mariadb_db and mariadb_user and mariadb_password:
+        # Use MariaDB/MySQL over async driver
+        DATABASE_URL = f"mysql+asyncmy://{mariadb_user}:{mariadb_password}@{mariadb_host}:{mariadb_port}/{mariadb_db}"
+    else:
+        raise Exception("Only MariaDB is supported. Please set the DATABASE_URL environment variable.")
+
+Base: DeclarativeMeta = declarative_base()
+
+
+class User(SQLAlchemyBaseUserTableUUID, Base):
+    pass
+
+
+engine = create_async_engine(
+    DATABASE_URL,
+    pool_pre_ping=True,
+    echo=os.getenv("SQL_ECHO", "0") == "1",
+)
+async_session_maker = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)
+
+
+async def create_db_and_tables():
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+
+
+async def get_async_session() -> AsyncGenerator[AsyncSession, None]:
+    async with async_session_maker() as session:
+        yield session
+
+
+async def get_user_db(session: AsyncSession = Depends(get_async_session)):
+    yield SQLAlchemyUserDatabase(session, User)