from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, Session
from sqlalchemy.pool import QueuePool
from .settings import settings


# Database setup with connection pooling
engine = create_engine(
    settings.DATABASE_URL,
    poolclass=QueuePool,
    pool_size=10,           # Number of connections to maintain in the pool
    max_overflow=20,        # Additional connections that can be created on demand
    pool_timeout=30,        # Timeout for getting connection from pool
    pool_recycle=3600,      # Recycle connections after 1 hour
    pool_pre_ping=True,     # Validate connections before use
    echo=False              # Set to True for SQL query logging
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def get_db() -> Session:
    """Dependency to get database session"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()