from __future__ import annotations

import asyncio
import os
import sys
from collections.abc import Generator
from pathlib import Path

import pytest
from tortoise import Tortoise, expand_db_url
from tortoise.backends.base_postgres.schema_generator import BasePostgresSchemaGenerator
from tortoise.backends.mysql.schema_generator import MySQLSchemaGenerator
from tortoise.backends.sqlite.schema_generator import SqliteSchemaGenerator
from tortoise.contrib.test import MEMORY_SQLITE

from aerich.ddl.mysql import MysqlDDL
from aerich.ddl.postgres import PostgresDDL
from aerich.ddl.sqlite import SqliteDDL
from aerich.migrate import Migrate
from tests._utils import chdir, copy_files, init_db, run_shell

db_url = os.getenv("TEST_DB", MEMORY_SQLITE)
db_url_second = os.getenv("TEST_DB_SECOND", MEMORY_SQLITE)
tortoise_orm = {
    "connections": {
        "default": expand_db_url(db_url, testing=True),
        "second": expand_db_url(db_url_second, testing=True),
    },
    "apps": {
        "models": {"models": ["tests.models", "aerich.models"], "default_connection": "default"},
        "models_second": {"models": ["tests.models_second"], "default_connection": "second"},
    },
}


@pytest.fixture(scope="function", autouse=True)
def reset_migrate() -> None:
    Migrate.upgrade_operators = []
    Migrate.downgrade_operators = []
    Migrate._upgrade_fk_m2m_index_operators = []
    Migrate._downgrade_fk_m2m_index_operators = []
    Migrate._upgrade_m2m = []
    Migrate._downgrade_m2m = []


@pytest.fixture(scope="session")
def event_loop() -> Generator:
    policy = asyncio.get_event_loop_policy()
    res = policy.new_event_loop()
    asyncio.set_event_loop(res)
    res._close = res.close  # type:ignore[attr-defined]
    res.close = lambda: None  # type:ignore[method-assign]

    yield res

    res._close()  # type:ignore[attr-defined]


@pytest.fixture(scope="session", autouse=True)
async def initialize_tests(event_loop, request) -> None:
    await init_db(tortoise_orm)
    client = Tortoise.get_connection("default")
    if client.schema_generator is MySQLSchemaGenerator:
        Migrate.ddl = MysqlDDL(client)
    elif client.schema_generator is SqliteSchemaGenerator:
        Migrate.ddl = SqliteDDL(client)
    elif issubclass(client.schema_generator, BasePostgresSchemaGenerator):
        Migrate.ddl = PostgresDDL(client)
    Migrate.dialect = Migrate.ddl.DIALECT
    request.addfinalizer(lambda: event_loop.run_until_complete(Tortoise._drop_databases()))


@pytest.fixture
def new_aerich_project(tmp_path: Path):
    test_dir = Path(__file__).parent / "tests"
    asset_dir = test_dir / "assets" / "fake"
    settings_py = asset_dir / "settings.py"
    _tests_py = asset_dir / "_tests.py"
    db_py = asset_dir / "db.py"
    models_py = test_dir / "models.py"
    models_second_py = test_dir / "models_second.py"
    copy_files(settings_py, _tests_py, models_py, models_second_py, db_py, target_dir=tmp_path)
    dst_dir = tmp_path / "tests"
    dst_dir.mkdir()
    dst_dir.joinpath("__init__.py").touch()
    copy_files(test_dir / "_utils.py", test_dir / "indexes.py", target_dir=dst_dir)
    if should_remove := str(tmp_path) not in sys.path:
        sys.path.append(str(tmp_path))
    with chdir(tmp_path):
        run_shell("python db.py create", capture_output=False)
        try:
            yield
        finally:
            if not os.getenv("AERICH_DONT_DROP_FAKE_DB"):
                run_shell("python db.py drop", capture_output=False)
            if should_remove:
                sys.path.remove(str(tmp_path))