from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from sqlalchemy.exc import SQLAlchemyError
from fastapi import HTTPException
from .settings import settings
import logging

logger = logging.getLogger(__name__)

DATABASE_URL = settings.DATABASE_URL

connect_args = {"connect_timeout": 10}
if settings.DB_SSL:
    connect_args["sslmode"] = "require"

engine = create_engine(
    DATABASE_URL,
    pool_pre_ping=True,
    pool_recycle=300,
    pool_size=20,
    max_overflow=30,
    pool_timeout=30,
    pool_reset_on_return='commit',
    connect_args=connect_args,
    echo=False,
    future=True
)

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

def get_db():
    db = SessionLocal()
    try:
        yield db
    except HTTPException:
        raise
    except SQLAlchemyError as e:
        logger.error(f"Database error: {e}")
        db.rollback()
        raise
    except Exception as e:
        logger.error(f"Unexpected database session error: {e}")
        db.rollback()
        raise
    finally:
        db.close()