import os
from typing import AsyncGenerator
import ssl

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.orm import declarative_base

# Get DATABASE_URL and ensure it uses asyncpg
DATABASE_URL = os.getenv("DATABASE_URL", "")

# Force asyncpg driver if not specified
if DATABASE_URL.startswith("postgresql://"):
    DATABASE_URL = DATABASE_URL.replace("postgresql://", "postgresql+asyncpg://", 1)

# Remove sslmode parameter if present (asyncpg doesn't support it)
if "?sslmode=" in DATABASE_URL:
    DATABASE_URL = DATABASE_URL.split("?sslmode=")[0]

# Create SSL context for asyncpg
ssl_context = ssl.create_default_context()
ssl_context.check_hostname = False
ssl_context.verify_mode = ssl.CERT_NONE

engine = create_async_engine(
    DATABASE_URL,
    echo=True,
    future=True,
    connect_args={
        "ssl": ssl_context,
    },
)

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

Base = declarative_base()


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    """Get database session."""
    async with AsyncSessionLocal() as session:
        yield session


async def init_db() -> None:
    """Initialize database - create all tables."""
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)