using CoreAgent.WebSocketTransport.Interfaces;
using CoreAgent.WebSocketTransport.Services;
using Microsoft.Extensions.Logging;

namespace CoreAgent.WebSocketTransport.Examples;

/// <summary>
/// 消息通道管理器测试示例
/// 验证 MessageChannelManager 和 ChannelMessageChannel 的修复
/// </summary>
public class ChannelManagerTestExample
{
    private readonly IMessageChannelManager _channelManager;
    private readonly ILogger<ChannelManagerTestExample> _logger;

    public ChannelManagerTestExample(IMessageChannelManager channelManager, ILogger<ChannelManagerTestExample> logger)
    {
        _channelManager = channelManager;
        _logger = logger;
    }

    /// <summary>
    /// 测试基本功能
    /// </summary>
    public async Task TestBasicFunctionalityAsync()
    {
        _logger.LogInformation("开始测试基本功能");

        try
        {
            // 测试发送消息
            await _channelManager.SendChannel.WriteAsync("Test message 1");
            await _channelManager.SendChannel.WriteAsync("Test message 2");
            //await _channelManager.PriorityChannel.WriteAsync("Priority message");

            _logger.LogInformation("消息发送成功");

            // 测试读取消息
            if (_channelManager.SendChannel.TryRead(out var message1))
            {
                _logger.LogInformation($"读取到发送消息: {message1}");
            }

            if (_channelManager.PriorityChannel.TryRead(out var priorityMessage))
            {
                _logger.LogInformation($"读取到优先级消息: {priorityMessage}");
            }

            // 测试状态信息
            var statusInfo = _channelManager.GetStatusInfo();
            _logger.LogInformation($"通道状态: 发送={statusInfo.SendChannelCount}, 接收={statusInfo.ReceiveChannelCount}, 优先级={statusInfo.PriorityChannelCount}");

            _logger.LogInformation("基本功能测试通过");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "基本功能测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试异步操作
    /// </summary>
    public async Task TestAsyncOperationsAsync()
    {
        _logger.LogInformation("开始测试异步操作");

        try
        {
            // 启动异步接收任务
            var receiveTask = Task.Run(async () =>
            {
                try
                {
                    // 等待消息可读
                    var hasData = await _channelManager.ReceiveChannel.WaitToReadAsync(CancellationToken.None);
                    if (hasData)
                    {
                        var message = await _channelManager.ReceiveChannel.ReadAsync(CancellationToken.None);
                        _logger.LogInformation($"异步接收到消息: {message}");
                    }
                }
                catch (OperationCanceledException)
                {
                    _logger.LogInformation("异步接收被取消");
                }
            });

            // 发送消息到接收通道
            await _channelManager.ReceiveChannel.WriteAsync("Async test message");

            // 等待接收任务完成
            await receiveTask;

            _logger.LogInformation("异步操作测试通过");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "异步操作测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试批量操作
    /// </summary>
    public async Task TestBatchOperationsAsync()
    {
        _logger.LogInformation("开始测试批量操作");

        try
        {
            // 批量发送消息
            for (int i = 0; i < 10; i++)
            {
                await _channelManager.SendChannel.WriteAsync($"Batch message {i}");
            }

            // 检查状态
            var statusBefore = _channelManager.GetStatusInfo();
            _logger.LogInformation($"批量发送后状态: 发送队列={statusBefore.SendChannelCount}");

            // 清空通道
            _channelManager.ClearAllChannels();

            // 检查清空后状态
            var statusAfter = _channelManager.GetStatusInfo();
            _logger.LogInformation($"清空后状态: 发送队列={statusAfter.SendChannelCount}");

            if (statusAfter.SendChannelCount == 0)
            {
                _logger.LogInformation("批量操作测试通过");
            }
            else
            {
                throw new Exception("清空操作失败");
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "批量操作测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试错误处理
    /// </summary>
    public async Task TestErrorHandlingAsync()
    {
        _logger.LogInformation("开始测试错误处理");

        try
        {
            // 测试空消息
            try
            {
                await _channelManager.SendChannel.WriteAsync(null!);
                throw new Exception("应该抛出 ArgumentNullException");
            }
            catch (ArgumentNullException)
            {
                _logger.LogInformation("空消息检查通过");
            }

            // 测试已释放的通道
            _channelManager.Dispose();

            try
            {
                await _channelManager.SendChannel.WriteAsync("test");
                throw new Exception("应该抛出 ObjectDisposedException");
            }
            catch (ObjectDisposedException)
            {
                _logger.LogInformation("已释放检查通过");
            }

            _logger.LogInformation("错误处理测试通过");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "错误处理测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试性能
    /// </summary>
    public async Task TestPerformanceAsync()
    {
        _logger.LogInformation("开始测试性能");

        try
        {
            const int messageCount = 1000;
            const int batchSize = 100;
            
            // 清空通道，确保测试环境干净
            _channelManager.ClearAllChannels();
            
            var stopwatch = System.Diagnostics.Stopwatch.StartNew();
            var memoryBefore = GC.GetTotalMemory(false);

            // 批量发送 - 使用更高效的方式
            var sendTasks = new List<ValueTask>(batchSize);
            for (int i = 0; i < messageCount; i++)
            {
                sendTasks.Add(_channelManager.SendChannel.WriteAsync($"Performance test message {i}"));
                
                // 每 batchSize 个任务等待一次，避免创建过多任务
                if (sendTasks.Count >= batchSize || i == messageCount - 1)
                {
                    // 等待所有 ValueTask 完成
                    foreach (var task in sendTasks)
                    {
                        await task;
                    }
                    sendTasks.Clear();
                }
            }
            
            stopwatch.Stop();
            var sendTime = stopwatch.ElapsedMilliseconds;
            var memoryAfterSend = GC.GetTotalMemory(false);

            _logger.LogInformation($"发送 {messageCount} 条消息耗时: {sendTime}ms, 内存增长: {memoryAfterSend - memoryBefore} bytes");

            // 验证发送的消息数量
            var statusAfterSend = _channelManager.GetStatusInfo();
            if (statusAfterSend.SendChannelCount != messageCount)
            {
                throw new Exception($"发送后消息数量不匹配: 期望={messageCount}, 实际={statusAfterSend.SendChannelCount}");
            }

            // 批量读取 - 使用更高效的方式
            stopwatch.Restart();
            var readCount = 0;
            var readMessages = new List<object>(batchSize);
            
            while (readCount < messageCount)
            {
                // 批量读取
                while (readMessages.Count < batchSize && _channelManager.SendChannel.TryRead(out var message))
                {
                    readMessages.Add(message);
                    readCount++;
                }
                
                // 处理批量读取的消息
                if (readMessages.Count > 0)
                {
                    // 这里可以添加消息处理逻辑
                    readMessages.Clear();
                }
                
                // 如果还有消息但当前批次已满，继续下一轮
                if (readCount < messageCount && readMessages.Count == 0)
                {
                    await Task.Delay(1); // 短暂延迟，避免CPU占用过高
                }
            }
            
            stopwatch.Stop();
            var readTime = stopwatch.ElapsedMilliseconds;
            var memoryAfterRead = GC.GetTotalMemory(false);

            _logger.LogInformation($"读取 {readCount} 条消息耗时: {readTime}ms, 内存增长: {memoryAfterRead - memoryAfterSend} bytes");

            // 验证读取后的状态
            var statusAfterRead = _channelManager.GetStatusInfo();
            if (statusAfterRead.SendChannelCount != 0)
            {
                throw new Exception($"读取后通道应该为空: 实际={statusAfterRead.SendChannelCount}");
            }

            // 性能指标计算
            var totalTime = sendTime + readTime;
            var messagesPerSecond = (messageCount * 1000.0) / totalTime;
            var totalMemoryGrowth = memoryAfterRead - memoryBefore;

            _logger.LogInformation($"性能测试结果:");
            _logger.LogInformation($"  总耗时: {totalTime}ms");
            _logger.LogInformation($"  发送耗时: {sendTime}ms ({sendTime * 100.0 / totalTime:F1}%)");
            _logger.LogInformation($"  读取耗时: {readTime}ms ({readTime * 100.0 / totalTime:F1}%)");
            _logger.LogInformation($"  消息吞吐量: {messagesPerSecond:F0} 消息/秒");
            _logger.LogInformation($"  总内存增长: {totalMemoryGrowth} bytes");
            _logger.LogInformation($"  平均每条消息内存: {totalMemoryGrowth / (double)messageCount:F1} bytes");

            if (readCount == messageCount)
            {
                _logger.LogInformation("性能测试通过");
            }
            else
            {
                throw new Exception($"消息数量不匹配: 期望={messageCount}, 实际={readCount}");
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "性能测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试通道完成
    /// </summary>
    public async Task TestChannelCompletionAsync()
    {
        _logger.LogInformation("开始测试通道完成");

        try
        {
            // 发送一些消息
            await _channelManager.SendChannel.WriteAsync("Message before completion");
            await _channelManager.ReceiveChannel.WriteAsync("Receive message before completion");

            // 完成通道
            _channelManager.CompleteAllChannels();

            // 检查完成状态
            var statusInfo = _channelManager.GetStatusInfo();
            if (statusInfo.SendChannelCompleted && statusInfo.ReceiveChannelCompleted && statusInfo.PriorityChannelCompleted)
            {
                _logger.LogInformation("通道完成测试通过");
            }
            else
            {
                throw new Exception("通道完成状态不正确");
            }

            // 尝试发送消息到已完成的通道
            try
            {
                await _channelManager.SendChannel.WriteAsync("Message after completion");
                throw new Exception("应该抛出 InvalidOperationException");
            }
            catch (InvalidOperationException)
            {
                _logger.LogInformation("已完成通道写入检查通过");
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "通道完成测试失败");
            throw;
        }
    }

    /// <summary>
    /// 测试 WaitToReadAsync 方法
    /// </summary>
    public async Task TestWaitToReadAsyncAsync()
    {
        _logger.LogInformation("开始测试 WaitToReadAsync 方法");

        try
        {
            // 测试空通道的等待
            var waitTask = _channelManager.SendChannel.WaitToReadAsync(CancellationToken.None);
            
            // 等待一小段时间，应该返回 false（没有数据）
            await Task.Delay(100);
            
            if (waitTask.IsCompleted)
            {
                var hasData = await waitTask;
                if (!hasData)
                {
                    _logger.LogInformation("空通道等待测试通过");
                }
                else
                {
                    throw new Exception("空通道应该返回 false");
                }
            }

            // 测试有数据的等待
            var sendTask = _channelManager.SendChannel.WriteAsync("Test message for WaitToReadAsync");
            var waitTask2 = _channelManager.SendChannel.WaitToReadAsync(CancellationToken.None);
            
            await sendTask;
            var hasData2 = await waitTask2;
            
            if (hasData2)
            {
                _logger.LogInformation("有数据通道等待测试通过");
            }
            else
            {
                throw new Exception("有数据的通道应该返回 true");
            }

            // 清理
            _channelManager.SendChannel.TryRead(out _);

            _logger.LogInformation("WaitToReadAsync 测试通过");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "WaitToReadAsync 测试失败");
            throw;
        }
    }

    /// <summary>
    /// 运行所有测试
    /// </summary>
    public async Task RunAllTestsAsync()
    {
        _logger.LogInformation("开始运行所有测试");

        try
        {
            await TestBasicFunctionalityAsync();
            await TestAsyncOperationsAsync();
            await TestWaitToReadAsyncAsync();
            await TestBatchOperationsAsync();
            await TestPerformanceAsync();
            await TestChannelCompletionAsync();
            // 注意：TestErrorHandlingAsync 会释放通道管理器，所以放在最后
            await TestErrorHandlingAsync();

            _logger.LogInformation("所有测试通过！");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "测试失败");
            throw;
        }
    }
}