import datetime
import json

import asyncpg
from sqlalchemy import func
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
from sqlalchemy.ext.asyncio import AsyncAttrs, create_async_engine, async_sessionmaker
from config import Config
from loguru import logger


class Base(AsyncAttrs, DeclarativeBase):
    created_at: Mapped[datetime.datetime] = mapped_column(server_default=func.now())
    modified_at: Mapped[datetime.datetime] = mapped_column(server_default=func.now(), onupdate=func.now())


class Engine:
    _engine = None

    @property
    def engine(self):
        return self._engine

    def __init__(self):
        if self._engine is None:
            self._engine = create_async_engine(str(Config.postgres_url), pool_size=20, max_overflow=0)


engine = Engine()
Session = async_sessionmaker(engine.engine, expire_on_commit=False)