from typing import Generator
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, Session
from sqlalchemy.pool import QueuePool

from utils.config import settings

# Create PostgreSQL engine with proper configuration
engine = create_engine(
    settings.DATABASE_URL,
    poolclass=QueuePool,
    pool_size=20,  # Maximum number of connections to keep open
    max_overflow=10,  # Maximum number of connections that can be created beyond pool_size
    pool_timeout=30,  # Timeout for getting connection from pool
    pool_pre_ping=True,  # Enable connection health checks
    echo=settings.LOG_LEVEL == "DEBUG",  # Log SQL queries in debug mode
)

# Create session factory
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# Create base class for models
Base = declarative_base()


def get_db() -> Generator[Session, None, None]:
    """Dependency to get database session"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


async def init_db() -> None:
    """Initialize database tables"""
    # Import all models to ensure they're registered
    from adapters.postgres import models  # noqa: F401

    # Create all tables
    Base.metadata.create_all(bind=engine)