"""
数据库连接池管理模块测试 - TDD Red阶段

测试数据库连接池的创建、管理和监控功能。
"""

import pytest
import allure
import threading
import time
from typing import Any, Optional


@allure.epic("核心框架")
@allure.feature("数据库连接池管理 - TDD Red阶段")
class TestConnectionPool:
    """数据库连接池管理测试类 - TDD Red阶段（期望失败）"""

    @allure.title("测试连接池基本操作 - TDD Red阶段")
    @allure.description("验证连接池的基本CRUD操作 - 期望失败(Red)")
    @allure.severity(allure.severity_level.CRITICAL)
    @pytest.mark.smoke
    def test_pool_basic_operations(self) -> None:
        """
        TDD Red阶段: 测试连接池基本操作
        
        预期结果:
            - 可以创建连接池
            - 可以获取连接
            - 可以释放连接
            - 可以关闭连接池
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建连接池"):
            pool = ConnectionPool(
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass"
            )
            allure.attach("✅ 连接池创建成功", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 获取连接"):
            conn = pool.get_connection()
            assert conn is not None, "应该能获取到连接"
            allure.attach("✅ 获取连接成功", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 释放连接"):
            pool.release_connection(conn)
            allure.attach("✅ 释放连接成功", "步骤3", allure.attachment_type.TEXT)

        with allure.step("Step 4: 关闭连接池"):
            pool.close()
            allure.attach("✅ 连接池关闭成功", "步骤4", allure.attachment_type.TEXT)

    @allure.title("测试连接池容量限制 - TDD Red阶段")
    @allure.description("验证连接池的容量限制和等待机制 - 期望失败(Red)")
    @allure.severity(allure.severity_level.CRITICAL)
    @pytest.mark.smoke
    def test_pool_capacity_limit(self) -> None:
        """
        TDD Red阶段: 测试连接池容量限制
        
        预期结果:
            - 连接数不超过最大值
            - 超出时等待或报错
            - 释放后可以继续获取
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建容量为3的连接池"):
            pool = ConnectionPool(
                min_connections=1,
                max_connections=3,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass"
            )
            allure.attach("✅ 创建容量为3的连接池", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 获取3个连接"):
            conn1 = pool.get_connection()
            conn2 = pool.get_connection()
            conn3 = pool.get_connection()
            allure.attach("✅ 获取3个连接", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 验证第4个连接需要等待"):
            start_time = time.time()
            try:
                conn4 = pool.get_connection(timeout=1)
                elapsed = time.time() - start_time
                allure.attach(f"⚠️ 第4个连接获取成功，耗时: {elapsed:.2f}s", "步骤3", allure.attachment_type.TEXT)
            except Exception as e:
                elapsed = time.time() - start_time
                allure.attach(f"✅ 第4个连接获取超时，耗时: {elapsed:.2f}s", "步骤3", allure.attachment_type.TEXT)

        with allure.step("Step 4: 释放连接后继续获取"):
            pool.release_connection(conn1)
            conn4 = pool.get_connection()
            assert conn4 is not None, "释放后应该能获取到连接"
            allure.attach("✅ 释放后成功获取连接", "步骤4", allure.attachment_type.TEXT)

        with allure.step("Step 5: 清理"):
            pool.release_connection(conn2)
            pool.release_connection(conn3)
            pool.release_connection(conn4)
            pool.close()

    @allure.title("测试连接池统计信息 - TDD Red阶段")
    @allure.description("验证连接池统计信息正确收集 - 期望失败(Red)")
    @allure.severity(allure.severity_level.NORMAL)
    @pytest.mark.regression
    def test_pool_statistics(self) -> None:
        """
        TDD Red阶段: 测试连接池统计信息
        
        预期结果:
            - 总连接数统计正确
            - 空闲连接数统计正确
            - 活跃连接数统计正确
            - 等待次数统计正确
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建连接池"):
            pool = ConnectionPool(
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass"
            )
            allure.attach("✅ 连接池创建成功", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 获取统计信息"):
            stats = pool.get_stats()
            allure.attach(f"初始统计: {stats}", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 验证统计信息"):
            assert "total_connections" in stats, "统计信息应包含total_connections"
            assert "idle_connections" in stats, "统计信息应包含idle_connections"
            assert "active_connections" in stats, "统计信息应包含active_connections"
            assert stats["total_connections"] >= 2, "总连接数应至少为min_connections"

        with allure.step("Step 4: 获取连接后验证统计变化"):
            conn = pool.get_connection()
            stats_after_get = pool.get_stats()
            allure.attach(f"获取连接后统计: {stats_after_get}", "步骤4", allure.attachment_type.TEXT)
            pool.release_connection(conn)
            pool.close()

    @allure.title("测试连接池健康检查 - TDD Red阶段")
    @allure.description("验证连接池健康检查功能 - 期望失败(Red)")
    @allure.severity(allure.severity_level.CRITICAL)
    @pytest.mark.smoke
    def test_pool_health_check(self) -> None:
        """
        TDD Red阶段: 测试连接池健康检查
        
        预期结果:
            - 可以检查连接健康状态
            - 不健康连接被自动替换
            - 健康检查定期执行
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建带健康检查的连接池"):
            pool = ConnectionPool(
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass",
                health_check_interval=1
            )
            allure.attach("✅ 创建带健康检查的连接池", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 执行健康检查"):
            is_healthy = pool.health_check()
            allure.attach(f"健康状态: {is_healthy}", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 获取健康统计"):
            health_stats = pool.get_health_stats()
            allure.attach(f"健康统计: {health_stats}", "步骤3", allure.attachment_type.TEXT)
            assert "healthy_connections" in health_stats, "健康统计应包含healthy_connections"
            assert "unhealthy_connections" in health_stats, "健康统计应包含unhealthy_connections"

        with allure.step("Step 4: 清理"):
            pool.close()

    @allure.title("测试连接池线程安全 - TDD Red阶段")
    @allure.description("验证连接池在多线程环境下的安全性 - 期望失败(Red)")
    @allure.severity(allure.severity_level.CRITICAL)
    @pytest.mark.smoke
    def test_pool_thread_safety(self) -> None:
        """
        TDD Red阶段: 测试连接池线程安全
        
        预期结果:
            - 多线程并发获取连接不会出错
            - 连接分配正确
            - 不会出现竞态条件
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建连接池"):
            pool = ConnectionPool(
                min_connections=2,
                max_connections=10,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass"
            )
            allure.attach("✅ 连接池创建成功", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 多线程并发获取连接"):
            errors = []
            connections = []
            lock = threading.Lock()
            
            def get_connection_task(thread_id: int):
                try:
                    conn = pool.get_connection(timeout=5)
                    with lock:
                        connections.append(conn)
                    time.sleep(0.1)  # 模拟使用
                    pool.release_connection(conn)
                except Exception as e:
                    with lock:
                        errors.append(str(e))
            
            threads = []
            for i in range(10):
                t = threading.Thread(target=get_connection_task, args=(i,))
                threads.append(t)
                t.start()
            
            for t in threads:
                t.join()
            
            allure.attach(f"线程数: 10, 错误数: {len(errors)}", "步骤2", allure.attachment_type.TEXT)
            assert len(errors) == 0, f"并发获取连接出现错误: {errors}"

        with allure.step("Step 3: 清理"):
            pool.close()

    @allure.title("测试连接池管理器 - TDD Red阶段")
    @allure.description("验证连接池管理器的单例模式和多池管理 - 期望失败(Red)")
    @allure.severity(allure.severity_level.NORMAL)
    @pytest.mark.regression
    def test_pool_manager(self) -> None:
        """
        TDD Red阶段: 测试连接池管理器
        
        预期结果:
            - 单例模式正确
            - 可以管理多个连接池
            - 可以获取指定连接池
        """
        from core.connection_pool import ConnectionPoolManager
        
        with allure.step("Step 1: 获取连接池管理器实例"):
            manager1 = ConnectionPoolManager()
            manager2 = ConnectionPoolManager()
            assert manager1 is manager2, "应该是单例模式"
            allure.attach("✅ 单例模式验证通过", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 创建多个命名连接池"):
            user_pool = manager1.create_pool(
                "user_db",
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="user_db",
                user="user",
                password="pass"
            )
            
            order_pool = manager1.create_pool(
                "order_db",
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="order_db",
                user="order",
                password="pass"
            )
            allure.attach("✅ 创建2个命名连接池", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 获取指定连接池"):
            retrieved_user_pool = manager1.get_pool("user_db")
            retrieved_order_pool = manager1.get_pool("order_db")
            assert retrieved_user_pool is user_pool, "应该获取到相同的user_db连接池"
            assert retrieved_order_pool is order_pool, "应该获取到相同的order_db连接池"
            allure.attach("✅ 获取指定连接池成功", "步骤3", allure.attachment_type.TEXT)

        with allure.step("Step 4: 获取所有连接池统计"):
            all_stats = manager1.get_all_stats()
            allure.attach(f"所有连接池统计: {all_stats}", "步骤4", allure.attachment_type.TEXT)
            assert "user_db" in all_stats, "统计应包含user_db"
            assert "order_db" in all_stats, "统计应包含order_db"

        with allure.step("Step 5: 清理"):
            manager1.close_all()

    @allure.title("测试连接池自动扩容 - TDD Red阶段")
    @allure.description("验证连接池根据负载自动扩容 - 期望失败(Red)")
    @allure.severity(allure.severity_level.NORMAL)
    @pytest.mark.regression
    def test_pool_auto_scaling(self) -> None:
        """
        TDD Red阶段: 测试连接池自动扩容
        
        预期结果:
            - 负载增加时自动扩容
            - 负载降低时自动缩容
            - 扩容不超过最大值
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建可自动扩容的连接池"):
            pool = ConnectionPool(
                min_connections=1,
                max_connections=5,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass",
                auto_scale=True
            )
            allure.attach("✅ 创建可自动扩容的连接池", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 获取初始统计"):
            initial_stats = pool.get_stats()
            initial_total = initial_stats["total_connections"]
            allure.attach(f"初始连接数: {initial_total}", "步骤2", allure.attachment_type.TEXT)

        with allure.step("Step 3: 模拟高负载"):
            connections = []
            for i in range(4):
                conn = pool.get_connection()
                connections.append(conn)
            
            high_load_stats = pool.get_stats()
            allure.attach(f"高负载连接数: {high_load_stats['total_connections']}", "步骤3", allure.attachment_type.TEXT)

        with allure.step("Step 4: 释放连接"):
            for conn in connections:
                pool.release_connection(conn)
            
            time.sleep(0.5)  # 等待缩容
            low_load_stats = pool.get_stats()
            allure.attach(f"低负载连接数: {low_load_stats['total_connections']}", "步骤4", allure.attachment_type.TEXT)

        with allure.step("Step 5: 清理"):
            pool.close()

    @allure.title("测试连接池连接验证 - TDD Red阶段")
    @allure.description("验证连接池获取的连接是有效的 - 期望失败(Red)")
    @allure.severity(allure.severity_level.CRITICAL)
    @pytest.mark.smoke
    def test_connection_validation(self) -> None:
        """
        TDD Red阶段: 测试连接验证
        
        预期结果:
            - 获取的连接是有效的
            - 无效连接被自动替换
            - 可以执行简单查询验证
        """
        from core.connection_pool import ConnectionPool
        
        with allure.step("Step 1: 创建连接池"):
            pool = ConnectionPool(
                min_connections=2,
                max_connections=5,
                host="localhost",
                port=3306,
                database="test_db",
                user="test_user",
                password="test_pass"
            )
            allure.attach("✅ 连接池创建成功", "步骤1", allure.attachment_type.TEXT)

        with allure.step("Step 2: 获取连接并验证"):
            conn = pool.get_connection()
            is_valid = conn.is_valid()
            allure.attach(f"连接有效: {is_valid}", "步骤2", allure.attachment_type.TEXT)
            assert is_valid, "获取的连接应该是有效的"

        with allure.step("Step 3: 执行简单查询"):
            try:
                result = conn.execute("SELECT 1")
                allure.attach(f"查询结果: {result}", "步骤3", allure.attachment_type.TEXT)
            except Exception as e:
                allure.attach(f"查询异常: {str(e)}", "步骤3", allure.attachment_type.TEXT)

        with allure.step("Step 4: 清理"):
            pool.release_connection(conn)
            pool.close()