"""Async SQLModel database configuration for Supabase/PostgreSQL."""
import ssl
from typing import AsyncGenerator

from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession, create_async_engine
from sqlalchemy.orm import sessionmaker
from sqlmodel import SQLModel

from ..core.config.config import settings

# Supabase requires SSL but we need to handle certificate verification
# For Supabase connection pooler, use a more permissive SSL context
ssl_context = ssl.create_default_context()
ssl_context.check_hostname = False
ssl_context.verify_mode = ssl.CERT_NONE

engine: AsyncEngine = create_async_engine(
    settings.DATABASE_URL,
    echo=settings.DEBUG,
    # Disable prepared statement cache for pgbouncer transaction/statement mode
    connect_args={"ssl": ssl_context, "statement_cache_size": 0},
)

AsyncSessionLocal = sessionmaker(
    bind=engine,
    class_=AsyncSession,
    expire_on_commit=False,
)


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    """FastAPI dependency to provide an async database session."""
    async with AsyncSessionLocal() as session:
        yield session


async def init_db() -> None:
    """Create tables if they do not exist."""
    async with engine.begin() as conn:
        await conn.run_sync(SQLModel.metadata.create_all)


async def dispose_engine() -> None:
    """Dispose the async engine (called on shutdown)."""
    await engine.dispose()