from sqlalchemy import Boolean, Column, DateTime, Integer
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import declarative_base, sessionmaker
from sqlalchemy.sql import func

from shared.config import settings

# Database setup
engine = create_async_engine(
    settings.DATABASE_URL,
    echo=settings.DEBUG,
    future=True,
    pool_size=20,
    max_overflow=30,
    pool_pre_ping=True,
)

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

Base = declarative_base()


class BaseModel(Base):
    """Base model with common fields"""

    __abstract__ = True

    id = Column(Integer, primary_key=True, index=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())
    is_active = Column(Boolean, default=True)


async def get_db() -> AsyncSession:
    """Database session dependency"""
    async with AsyncSessionLocal() as session:
        try:
            yield session
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()


async def init_db():
    """Initialize database"""
    async with engine.begin() as conn:
        # Import all models here to ensure they are registered
        from services.calendar_service.models import CalendarEntry
        from services.emergency_service.models import EmergencyAlert
        from services.location_service.models import UserLocation
        from services.user_service.models import User

        await conn.run_sync(Base.metadata.create_all)