import os
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
from sqlalchemy.orm import DeclarativeBase

DATABASE_URL = os.getenv(
    "DATABASE_URL",
    "postgresql+asyncpg://kitchen:kitchen_secret@localhost:5432/kitchen_gp"
)

# Convert standard postgres URL to asyncpg format
if DATABASE_URL.startswith("postgresql://"):
    DATABASE_URL = DATABASE_URL.replace("postgresql://", "postgresql+asyncpg://", 1)

engine = create_async_engine(
    DATABASE_URL,
    echo=False,
    pool_size=10,      # Default is 5
    max_overflow=20,   # Default is 10 - allows burst to 30 connections
    pool_pre_ping=True # Verify connections are alive before use
)

AsyncSessionLocal = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False
)


class Base(DeclarativeBase):
    pass


async def get_db():
    async with AsyncSessionLocal() as session:
        try:
            yield session
        finally:
            await session.close()