# tests/unit/test_context.py
from __future__ import annotations

from unittest.mock import AsyncMock, Mock, patch
import pytest

from dataloader.context import AppContext, get_session


@pytest.mark.unit
class TestAppContext:
    """
    Unit тесты для AppContext.
    """

    def test_init_creates_empty_context(self):
        """
        Тест создания пустого контекста.
        """
        ctx = AppContext()

        assert ctx._engine is None
        assert ctx._sessionmaker is None
        assert ctx._context_vars_container is not None

    def test_engine_property_raises_when_not_initialized(self):
        """
        Тест, что engine выбрасывает RuntimeError, если не инициализирован.
        """
        ctx = AppContext()

        with pytest.raises(RuntimeError, match="Database engine is not initialized"):
            _ = ctx.engine

    def test_engine_property_returns_engine_when_initialized(self):
        """
        Тест, что engine возвращает движок после инициализации.
        """
        ctx = AppContext()
        mock_engine = Mock()
        ctx._engine = mock_engine

        assert ctx.engine == mock_engine

    def test_sessionmaker_property_raises_when_not_initialized(self):
        """
        Тест, что sessionmaker выбрасывает RuntimeError, если не инициализирован.
        """
        ctx = AppContext()

        with pytest.raises(RuntimeError, match="Sessionmaker is not initialized"):
            _ = ctx.sessionmaker

    def test_sessionmaker_property_returns_sessionmaker_when_initialized(self):
        """
        Тест, что sessionmaker возвращает фабрику после инициализации.
        """
        ctx = AppContext()
        mock_sm = Mock()
        ctx._sessionmaker = mock_sm

        assert ctx.sessionmaker == mock_sm

    @pytest.mark.asyncio
    async def test_on_startup_initializes_engine_and_sessionmaker(self):
        """
        Тест, что on_startup инициализирует engine и sessionmaker.
        """
        ctx = AppContext()

        mock_engine = Mock()
        mock_sm = Mock()

        with patch("dataloader.logger.logger.setup_logging") as mock_setup_logging, \
             patch("dataloader.storage.engine.create_engine", return_value=mock_engine) as mock_create_engine, \
             patch("dataloader.storage.engine.create_sessionmaker", return_value=mock_sm) as mock_create_sm, \
             patch("dataloader.context.APP_CONFIG") as mock_config:

            mock_config.pg.url = "postgresql://test"

            await ctx.on_startup()

            mock_setup_logging.assert_called_once()
            mock_create_engine.assert_called_once_with("postgresql://test")
            mock_create_sm.assert_called_once_with(mock_engine)
            assert ctx._engine == mock_engine
            assert ctx._sessionmaker == mock_sm

    @pytest.mark.asyncio
    async def test_on_shutdown_disposes_engine(self):
        """
        Тест, что on_shutdown закрывает движок БД.
        """
        ctx = AppContext()

        mock_engine = AsyncMock()
        ctx._engine = mock_engine

        await ctx.on_shutdown()

        mock_engine.dispose.assert_called_once()

    @pytest.mark.asyncio
    async def test_on_shutdown_does_nothing_when_no_engine(self):
        """
        Тест, что on_shutdown безопасно работает без движка.
        """
        ctx = AppContext()

        await ctx.on_shutdown()

        assert ctx._engine is None

    def test_get_logger_returns_logger(self):
        """
        Тест получения логгера.
        """
        ctx = AppContext()

        with patch("dataloader.logger.logger.get_logger") as mock_get_logger:
            mock_logger = Mock()
            mock_get_logger.return_value = mock_logger

            logger = ctx.get_logger("test_module")

            mock_get_logger.assert_called_once_with("test_module")
            assert logger == mock_logger

    def test_get_logger_without_name(self):
        """
        Тест получения логгера без указания имени.
        """
        ctx = AppContext()

        with patch("dataloader.logger.logger.get_logger") as mock_get_logger:
            mock_logger = Mock()
            mock_get_logger.return_value = mock_logger

            logger = ctx.get_logger()

            mock_get_logger.assert_called_once_with(None)
            assert logger == mock_logger

    def test_get_context_vars_container_returns_container(self):
        """
        Тест получения контейнера контекстных переменных.
        """
        ctx = AppContext()

        container = ctx.get_context_vars_container()

        assert container == ctx._context_vars_container


@pytest.mark.unit
class TestGetSession:
    """
    Unit тесты для get_session dependency.
    """

    @pytest.mark.asyncio
    async def test_get_session_yields_session(self):
        """
        Тест, что get_session возвращает сессию.
        """
        mock_session = AsyncMock()

        mock_context_manager = AsyncMock()
        mock_context_manager.__aenter__.return_value = mock_session
        mock_context_manager.__aexit__.return_value = None

        mock_sm = Mock(return_value=mock_context_manager)

        with patch("dataloader.context.APP_CTX") as mock_ctx:
            mock_ctx.sessionmaker = mock_sm

            async for session in get_session():
                assert session == mock_session

    @pytest.mark.asyncio
    async def test_get_session_closes_session_after_use(self):
        """
        Тест, что get_session закрывает сессию после использования.
        """
        mock_session = AsyncMock()
        mock_exit = AsyncMock(return_value=None)

        mock_context_manager = AsyncMock()
        mock_context_manager.__aenter__.return_value = mock_session
        mock_context_manager.__aexit__ = mock_exit

        mock_sm = Mock(return_value=mock_context_manager)

        with patch("dataloader.context.APP_CTX") as mock_ctx:
            mock_ctx.sessionmaker = mock_sm

            async for session in get_session():
                pass

            assert mock_exit.call_count == 1