from collections.abc import AsyncGenerator
from typing import Any

import pytest
from fastapi import FastAPI
from httpx import ASGITransport, AsyncClient
from piccolo.conf.apps import Finder
from piccolo.engine.postgres import PostgresEngine
from piccolo.table import create_tables, drop_tables

from zangramru.settings import settings
from zangramru.web.application import get_app
from zangramru.web.lifespan import lifespan_setup


@pytest.fixture(scope="session")
def anyio_backend() -> str:
    """
    Backend for anyio pytest plugin.

    :return: backend name.
    """
    return "asyncio"


async def drop_database(engine: PostgresEngine) -> None:
    """
    Drops test database.

    :param engine: engine connected to postgres database.
    """
    await engine.run_ddl(
        "SELECT pg_terminate_backend(pg_stat_activity.pid) "  # noqa: S608
        "FROM pg_stat_activity "
        f"WHERE pg_stat_activity.datname = '{settings.db_base}' "
        "AND pid <> pg_backend_pid();",
    )
    await engine.run_ddl(
        f"DROP DATABASE {settings.db_base};",
    )


@pytest.fixture(autouse=True)
async def setup_db() -> AsyncGenerator[None, None]:
    """
    Fixture to create all tables before test and drop them after.

    :yield: nothing.
    """
    engine = PostgresEngine(
        config={
            "database": "postgres",
            "user": settings.db_user,
            "password": settings.db_pass,
            "host": settings.db_host,
            "port": settings.db_port,
        },
    )
    await engine.start_connection_pool()

    db_exists = await engine.run_ddl(
        f"SELECT 1 FROM pg_database WHERE datname='{settings.db_base}'"  # noqa: S608
    )
    if db_exists:
        await drop_database(engine)
    await engine.run_ddl(f"CREATE DATABASE {settings.db_base}")
    tables = Finder().get_table_classes()
    create_tables(*tables, if_not_exists=True)

    yield

    drop_tables(*tables)
    await drop_database(engine)


@pytest.fixture
async def fastapi_app() -> AsyncGenerator[FastAPI, None]:
    """
    Fixture for creating FastAPI app.

    :return: fastapi app with mocked dependencies.
    """
    application = get_app()
    async with lifespan_setup(application):
        yield application


@pytest.fixture
async def client(
    fastapi_app: FastAPI, anyio_backend: Any
) -> AsyncGenerator[AsyncClient, None]:
    """
    Fixture that creates client for requesting server.

    :param fastapi_app: the application.
    :yield: client for the app.
    """
    async with AsyncClient(
        transport=ASGITransport(fastapi_app), base_url="http://test", timeout=2.0
    ) as ac:
        yield ac