import asyncio
import logging
from datetime import datetime
from typing import AsyncGenerator

import pytest
import pytest_asyncio
from _pytest.config import Config
from litestar.testing import AsyncTestClient
from sqlalchemy import event
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker

from app.lib import settings
from app.lib.sqlalchemy_plugin import DBConnectionSettings, create_db_engine
from app.lib.test_extras.db_setup import TestingDatabaseSetup
from main import app

# A Guide To Database Unit Testing with Pytest and SQLAlchemy
# https://coderpad.io/blog/development/a-guide-to-database-unit-testing-with-pytest-and-sqlalchemy/


engine = create_db_engine(
    connection_settings=DBConnectionSettings(
        username=settings.testing.DB_USER,
        password=settings.testing.DB_PASSWORD,
        host=settings.testing.DB_HOST,
        port=settings.testing.DB_PORT,
        database=settings.testing.DB_NAME,
    )
)


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


@pytest_asyncio.fixture(scope="function")
async def db_session() -> AsyncGenerator[AsyncSession, None]:
    """The expectation with async_sessions is that the
    transactions be called on the connection object instead of the
    session object.
    Detailed explanation of async transactional tests
    <https://github.com/sqlalchemy/sqlalchemy/issues/5811>
    """

    async with engine.connect() as connection:
        trans = await connection.begin()
        async with async_session_factory(bind=connection) as async_session:
            nested = await connection.begin_nested()

            @event.listens_for(async_session.sync_session, "after_transaction_end")
            def end_savepoint(session, transaction):
                nonlocal nested

                if not nested.is_active:
                    nested = connection.sync_connection.begin_nested()

            yield async_session

            await trans.rollback()

    await engine.dispose(close=True)


pytest_plugins = ()


@pytest.fixture(scope="function")
def async_client() -> AsyncTestClient:
    return AsyncTestClient(app=app)


def pytest_configure(config: Config) -> None:
    logging.info(f"Starting tests: {datetime.utcnow()}")
    db_setup = TestingDatabaseSetup(options=settings.testing)
    asyncio.run(db_setup.init_db())
    print()


def pytest_unconfigure(config: Config) -> None:
    logging.info(f"Ending tests: {datetime.utcnow()}")
    db_setup = TestingDatabaseSetup(options=settings.testing)
    asyncio.run(db_setup.tear_down_db())