# File : app/database/connection.py
# Purpose : Async SQLAlchemy engine for PostgreSQL (user/document metadata only)

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import declarative_base, sessionmaker
from app.config import get_settings

settings = get_settings()

engine = create_async_engine(
    settings.database_url,
    echo=False,
    pool_pre_ping=True,
    pool_size=10,
    max_overflow=20,
)

AsyncSessionLocal = sessionmaker(
    bind=engine,
    class_=AsyncSession,
    expire_on_commit=False,
)

Base = declarative_base()


async def get_db():
    async with AsyncSessionLocal() as session:
        try:
            yield session
        finally:
            await session.close()


async def init_db():
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    print("[DB] Tables created successfully")