#!/usr/bin/env python3
"""
数据库连接池管理模块演示脚本

展示数据库连接池的核心功能。
"""

import time
import threading
from core.connection_pool import ConnectionPool, pool_manager


def demo_basic_operations():
    """演示基本操作"""
    print("\n" + "="*60)
    print("演示1: 连接池基本操作")
    print("="*60)
    
    pool = ConnectionPool(
        min_connections=2,
        max_connections=5,
        host="localhost",
        port=3306,
        database="test_db",
        user="test_user",
        password="test_pass"
    )
    
    # 获取连接
    conn = pool.get_connection()
    print(f"✅ 获取连接成功: {conn.id}")
    
    # 执行查询
    result = conn.execute("SELECT 1")
    print(f"✅ 执行查询: {result}")
    
    # 释放连接
    pool.release_connection(conn)
    print("✅ 释放连接成功")
    
    # 关闭连接池
    pool.close()
    print("✅ 连接池关闭成功")


def demo_capacity_limit():
    """演示容量限制"""
    print("\n" + "="*60)
    print("演示2: 连接池容量限制")
    print("="*60)
    
    pool = ConnectionPool(
        min_connections=1,
        max_connections=3,
        host="localhost",
        port=3306,
        database="test_db",
        user="test_user",
        password="test_pass"
    )
    
    # 获取3个连接
    conn1 = pool.get_connection()
    conn2 = pool.get_connection()
    conn3 = pool.get_connection()
    print("✅ 获取3个连接")
    
    # 尝试获取第4个连接（应该超时）
    print("⏱️ 尝试获取第4个连接（应该超时）...")
    try:
        conn4 = pool.get_connection(timeout=1)
        print(f"⚠️ 获取到第4个连接: {conn4.id}")
    except Exception as e:
        print(f"✅ 第4个连接获取超时: {str(e)}")
    
    # 释放一个连接
    pool.release_connection(conn1)
    print("✅ 释放连接1")
    
    # 现在可以获取新连接
    conn4 = pool.get_connection()
    print(f"✅ 释放后成功获取新连接: {conn4.id}")
    
    # 清理
    pool.release_connection(conn2)
    pool.release_connection(conn3)
    pool.release_connection(conn4)
    pool.close()


def demo_statistics():
    """演示统计信息"""
    print("\n" + "="*60)
    print("演示3: 连接池统计信息")
    print("="*60)
    
    pool = ConnectionPool(
        min_connections=2,
        max_connections=5,
        host="localhost",
        port=3306,
        database="test_db",
        user="test_user",
        password="test_pass"
    )
    
    # 获取初始统计
    stats = pool.get_stats()
    print(f"✅ 初始统计:")
    print(f"   总连接数: {stats['total_connections']}")
    print(f"   空闲连接: {stats['idle_connections']}")
    print(f"   活跃连接: {stats['active_connections']}")
    
    # 获取连接
    conn = pool.get_connection()
    stats_after_get = pool.get_stats()
    print(f"\n✅ 获取连接后统计:")
    print(f"   空闲连接: {stats_after_get['idle_connections']}")
    print(f"   活跃连接: {stats_after_get['active_connections']}")
    print(f"   总获取次数: {stats_after_get['total_get_count']}")
    
    # 释放连接
    pool.release_connection(conn)
    stats_after_release = pool.get_stats()
    print(f"\n✅ 释放连接后统计:")
    print(f"   空闲连接: {stats_after_release['idle_connections']}")
    print(f"   活跃连接: {stats_after_release['active_connections']}")
    print(f"   总释放次数: {stats_after_release['total_release_count']}")
    
    pool.close()


def demo_health_check():
    """演示健康检查"""
    print("\n" + "="*60)
    print("演示4: 连接池健康检查")
    print("="*60)
    
    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
    )
    
    # 执行健康检查
    is_healthy = pool.health_check()
    print(f"✅ 健康检查结果: {is_healthy}")
    
    # 获取健康统计
    health_stats = pool.get_health_stats()
    print(f"✅ 健康统计:")
    print(f"   健康连接: {health_stats['healthy_connections']}")
    print(f"   不健康连接: {health_stats['unhealthy_connections']}")
    print(f"   健康检查次数: {health_stats['health_check_count']}")
    
    pool.close()


def demo_thread_safety():
    """演示线程安全"""
    print("\n" + "="*60)
    print("演示5: 连接池线程安全")
    print("="*60)
    
    pool = ConnectionPool(
        min_connections=2,
        max_connections=10,
        host="localhost",
        port=3306,
        database="test_db",
        user="test_user",
        password="test_pass"
    )
    
    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))
    
    # 创建10个线程并发获取连接
    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()
    
    print(f"✅ 10个线程并发获取连接完成")
    print(f"✅ 错误数: {len(errors)}")
    print(f"✅ 成功获取连接数: {len(connections)}")
    
    pool.close()


def demo_pool_manager():
    """演示连接池管理器"""
    print("\n" + "="*60)
    print("演示6: 连接池管理器")
    print("="*60)
    
    # 创建多个命名连接池
    user_pool = pool_manager.create_pool(
        "user_db",
        min_connections=2,
        max_connections=5,
        host="localhost",
        port=3306,
        database="user_db",
        user="user",
        password="pass"
    )
    
    order_pool = pool_manager.create_pool(
        "order_db",
        min_connections=2,
        max_connections=5,
        host="localhost",
        port=3306,
        database="order_db",
        user="order",
        password="pass"
    )
    
    print("✅ 创建2个命名连接池: user_db, order_db")
    
    # 获取指定连接池
    retrieved_user_pool = pool_manager.get_pool("user_db")
    retrieved_order_pool = pool_manager.get_pool("order_db")
    print(f"✅ 获取user_db连接池: {retrieved_user_pool is user_pool}")
    print(f"✅ 获取order_db连接池: {retrieved_order_pool is order_pool}")
    
    # 获取所有统计信息
    all_stats = pool_manager.get_all_stats()
    print(f"✅ 所有连接池统计: {list(all_stats.keys())}")
    for name, stats in all_stats.items():
        print(f"   {name}: 总连接数={stats['total_connections']}")
    
    pool_manager.close_all()
    print("✅ 关闭所有连接池")


def main():
    """主函数"""
    print("\n" + "="*60)
    print("数据库连接池管理模块演示")
    print("="*60)
    
    demo_basic_operations()
    demo_capacity_limit()
    demo_statistics()
    demo_health_check()
    demo_thread_safety()
    demo_pool_manager()
    
    print("\n" + "="*60)
    print("✅ 所有演示完成!")
    print("="*60)


if __name__ == "__main__":
    main()