import uuid
from datetime import datetime

from sqlalchemy import String, Text, DateTime, Integer, ForeignKey, JSON, Enum as SAEnum
from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker, AsyncSession
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


class Base(DeclarativeBase):
    pass


def gen_uuid():
    return str(uuid.uuid4())


engine = None
async_session_maker: async_sessionmaker[AsyncSession] | None = None


async def init_db(database_url: str):
    global engine, async_session_maker

    engine = create_async_engine(
        database_url,
        echo=False,
        pool_size=20,
        max_overflow=10,
        pool_pre_ping=True,
    )
    async_session_maker = async_sessionmaker(engine, expire_on_commit=False)

    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)


async def get_session() -> AsyncSession:
    if async_session_maker is None:
        raise RuntimeError("Database not initialized")
    async with async_session_maker() as session:
        yield session