"""
Database configuration for SQLite with SQLAlchemy.
"""
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
from sqlalchemy.orm import DeclarativeBase
import os

# Database configuration
DB_NAME = os.getenv("DB_NAME", "apigateway")
ENV = os.getenv("ENVIRONMENT", "production")
DB_FILENAME = f"{DB_NAME}_{ENV}.db"

# Database URL - SQLite file in the same directory
DATABASE_URL = os.getenv("DATABASE_URL", f"sqlite+aiosqlite:///./{DB_FILENAME}")

# Create async engine
engine = create_async_engine(
    DATABASE_URL,
    echo=False,  # Set to True for SQL debugging
    future=True
)

# Session factory
async_session_maker = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False
)


class Base(DeclarativeBase):
    """Base class for SQLAlchemy models."""
    pass


async def get_db() -> AsyncSession:
    """
    Dependency injection for database sessions.
    Yields a database session and ensures cleanup.
    """
    async with async_session_maker() as session:
        try:
            yield session
        finally:
            await session.close()


async def init_db():
    """
    Initialize the database by creating all tables.
    """
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)