import asyncio
import os
from collections.abc import AsyncGenerator
from typing import Generator

import pytest
from sqlalchemy import create_engine
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

from alembic import command
from alembic.config import Config
from app.infrastructure.config import settings
from app.infrastructure.database.models import Base


def _sync_url(db_url: str) -> str:
    return db_url.replace("+aiosqlite", "").replace("+asyncpg", "")


def _build_alembic_config(db_url: str) -> Config:
    alembic_cfg = Config("alembic.ini")
    alembic_cfg.set_main_option("sqlalchemy.url", db_url)
    return alembic_cfg


@pytest.fixture(scope="session")
def event_loop() -> Generator[asyncio.AbstractEventLoop]:
    loop = asyncio.get_event_loop_policy().new_event_loop()
    yield loop
    loop.close()


@pytest.fixture(scope="session", autouse=True)
def setup_database() -> Generator[None]:
    db_url = os.environ.get("DB_URL", settings.database_url)
    sync_engine = create_engine(_sync_url(db_url))
    Base.metadata.drop_all(sync_engine)
    Base.metadata.create_all(sync_engine)
    sync_engine.dispose()

    alembic_cfg = _build_alembic_config(db_url)
    command.stamp(alembic_cfg, "head")
    yield


@pytest.fixture
async def db_session() -> AsyncGenerator[AsyncSession]:
    db_url = os.environ.get("DB_URL", settings.database_url)
    test_engine = create_async_engine(db_url)
    session_factory = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)

    async with session_factory() as session:
        yield session

    await test_engine.dispose()