import pytest
from unittest.mock import MagicMock, patch, AsyncMock
from core.managers.redis_manager import RedisManager


class TestRedisManager:
    def test_singleton_pattern(self):
        """测试单例模式。"""
        instance1 = RedisManager()
        instance2 = RedisManager()
        assert instance1 is instance2

    @pytest.mark.asyncio
    async def test_initialize_success(self):
        """测试 Redis 初始化成功。"""
        # 重置单例
        if hasattr(RedisManager, "_instance"):
            del RedisManager._instance
        # 确保类有 _instance 属性
        if not hasattr(RedisManager, "_instance"):
            RedisManager._instance = None
        # 重置 Redis 连接
        RedisManager._redis = None
            
        # 模拟全局配置
        with patch('core.managers.redis_manager.config') as mock_config:
            mock_config.redis.host = "localhost"
            mock_config.redis.port = 6379
            mock_config.redis.db = 0
            mock_config.redis.password = "test_password"
            
            # 模拟 Redis 客户端
            with patch('core.managers.redis_manager.redis') as mock_redis_module:
                mock_redis = AsyncMock()
                mock_redis.ping.return_value = True
                mock_redis_module.Redis.return_value = mock_redis
                
                manager = RedisManager()
                await manager.initialize()
                
                # 验证 Redis 连接
                mock_redis_module.Redis.assert_called_once_with(
                    host="localhost",
                    port=6379,
                    db=0,
                    password="test_password",
                    decode_responses=True
                )
                mock_redis.ping.assert_called_once()
                assert manager._redis is mock_redis

    @pytest.mark.asyncio
    async def test_initialize_connection_error(self):
        """测试 Redis 连接失败。"""
        # 重置单例
        if hasattr(RedisManager, "_instance"):
            del RedisManager._instance
        # 确保类有 _instance 属性
        if not hasattr(RedisManager, "_instance"):
            RedisManager._instance = None
        # 重置 Redis 连接
        RedisManager._redis = None
            
        # 模拟全局配置
        with patch('core.managers.redis_manager.config') as mock_config:
            mock_config.redis.host = "localhost"
            mock_config.redis.port = 6379
            mock_config.redis.db = 0
            mock_config.redis.password = "test_password"
            
            # 模拟 Redis 连接错误
            with patch('core.managers.redis_manager.redis') as mock_redis_module:
                mock_redis_module.Redis.side_effect = Exception("Connection refused")
                
                manager = RedisManager()
                await manager.initialize()
                
                # 验证 Redis 未初始化
                assert manager._redis is None

    def test_redis_property_uninitialized(self):
        """测试 Redis 属性在未初始化时抛出异常。"""
        # 重置单例
        if hasattr(RedisManager, "_instance"):
            del RedisManager._instance
        # 确保类有 _instance 属性
        if not hasattr(RedisManager, "_instance"):
            RedisManager._instance = None
        # 重置 Redis 连接
        RedisManager._redis = None
            
        manager = RedisManager()
        manager._redis = None
        
        with pytest.raises(ConnectionError, match="Redis 未初始化或连接失败，请先调用 initialize()"):
            _ = manager.redis

    @pytest.mark.asyncio
    async def test_get_method(self):
        """测试 get 方法。"""
        # 重置单例
        if hasattr(RedisManager, "_instance"):
            del RedisManager._instance
        # 确保类有 _instance 属性
        if not hasattr(RedisManager, "_instance"):
            RedisManager._instance = None
        # 重置 Redis 连接
        RedisManager._redis = None
            
        manager = RedisManager()
        mock_redis = AsyncMock()
        mock_redis.get.return_value = "test_value"
        manager._redis = mock_redis
        
        result = await manager.get("test_key")
        assert result == "test_value"
        mock_redis.get.assert_called_once_with("test_key")

    @pytest.mark.asyncio
    async def test_set_method(self):
        """测试 set 方法。"""
        # 重置单例
        if hasattr(RedisManager, "_instance"):
            del RedisManager._instance
        # 确保类有 _instance 属性
        if not hasattr(RedisManager, "_instance"):
            RedisManager._instance = None
        # 重置 Redis 连接
        RedisManager._redis = None
            
        manager = RedisManager()
        mock_redis = AsyncMock()
        mock_redis.set.return_value = True
        manager._redis = mock_redis
        
        result = await manager.set("test_key", "test_value", ex=3600)
        assert result is True
        mock_redis.set.assert_called_once_with("test_key", "test_value", ex=3600)