from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from .config import get_settings


settings = get_settings()


def build_db_url() -> str:
    if settings.db_type == "postgresql":
        return (
            f"postgresql+psycopg2://{settings.db_user}:{settings.db_password}"
            f"@{settings.db_host}:{settings.db_port}/{settings.db_name}"
        )
    return (
        f"mysql+pymysql://{settings.db_user}:{settings.db_password}"
        f"@{settings.db_host}:{settings.db_port}/{settings.db_name}"
        "?charset=utf8mb4"
    )


engine = create_engine(
    build_db_url(),
    echo=settings.db_echo,
    pool_pre_ping=True,
)

SessionLocal = sessionmaker(bind=engine, autocommit=False, autoflush=False)


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()