using System;
using System.Collections.Generic;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Aliyun.Acs.Core.Logging;
using Microsoft.Extensions.DependencyInjection;
using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Client.Options;
using NCC.Dependency;
using NCC.Extend.Entitys;
using NCC.Extend.Interfaces.MqttPublisher;
using NCC.Extend.Interfaces.UavOrder;
using Serilog;
using SqlSugar;
using Yitter.IdGenerator;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Net;
using System.Linq;

namespace NCC.Extend;

/// <summary>
/// MQTT 发布与订阅统一服务
/// </summary>
public class MqttPublisherService : IMqttPublisherService, ITransient, IDisposable
{
    /// <summary>
    /// MQTT 客户端对象（用于连接、发布、订阅等操作）
    /// </summary>
    private readonly IMqttClient _mqttClient;

    /// <summary>
    /// MQTT 连接参数配置
    /// </summary>
    private readonly IMqttClientOptions _mqttOptions;
    private readonly IServiceProvider _serviceProvider;
    private readonly ISqlSugarClient _db;
    private readonly Dictionary<string, (bool isOnline, DateTime lastCheck)> _onlineStatusCache = new Dictionary<string, (bool, DateTime)>();
    private readonly object _cacheLock = new object();
    private readonly Timer _healthCheckTimer; // 健康检查定时器
    private readonly int _healthCheckInterval = 5 * 60 * 1000; // 5分钟检查一次
    /// <summary>
    /// 构造函数：初始化客户端和配置、注册事件
    /// </summary>
    public MqttPublisherService(IServiceProvider serviceProvider, ISqlSugarClient db)
    {
        _serviceProvider = serviceProvider;
        _db = db;
        // 创建 MQTT 客户端实例
        var factory = new MqttFactory();
        _mqttClient = factory.CreateMqttClient();

        // 构建连接配置（MQTT 服务器地址、端口、用户名密码、客户端 ID）
        _mqttOptions = new MqttClientOptionsBuilder()
            .WithTcpServer("mqtt.cqjiangzhichao.cn", 1883)     // Broker 地址
            .WithCredentials("wrjservice", "P@ssw0rd")         // 账号密码
            .WithClientId("server_publisher")                  // 客户端 ID，必须唯一
            .Build();

        // 连接成功事件：订阅所有设备的响应主题（如 device/xxx/response）
        _mqttClient.UseConnectedHandler(async e =>
        {
            Log.Information("MQTT 已连接成功");
            // 订阅所有设备的响应主题（+ 代表通配符）
            await _mqttClient.SubscribeAsync("device/+/response");
            Log.Information("已订阅通用响应 topic: device/+/response");
        });

        // 连接断开事件
        _mqttClient.UseDisconnectedHandler(async e =>
        {
            Log.Warning("MQTT 已断开连接");
            int retryInterval = 5; // 秒
            while (!_mqttClient.IsConnected)
            {
                try
                {
                    Log.Information($"尝试在 {retryInterval} 秒后重新连接 MQTT...");
                    await Task.Delay(TimeSpan.FromSeconds(retryInterval));
                    await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
                    Log.Information("MQTT 重连成功");
                    
                    // 重连成功后重新订阅主题
                    try
                    {
                        await _mqttClient.SubscribeAsync("device/+/response");
                        Log.Information("重连后重新订阅主题成功: device/+/response");
                    }
                    catch (Exception subEx)
                    {
                        Log.Error($"重连后重新订阅主题失败: {subEx.Message}");
                    }
                    
                    break; // 重连成功后跳出循环
                }
                catch (Exception ex)
                {
                    Log.Error($"MQTT 重连失败: {ex.Message}");
                    // 重连失败后继续循环，但增加延迟避免频繁重试
                    await Task.Delay(TimeSpan.FromSeconds(retryInterval * 2));
                }
            }
        });
        // 收到消息事件：处理设备回传的消息
        _mqttClient.UseApplicationMessageReceivedHandler(e =>
        {
            try
            {
                // 获取 topic 和 payload 内容
                var topic = e.ApplicationMessage.Topic;
                var payload = Encoding.UTF8.GetString(e.ApplicationMessage.Payload ?? Array.Empty<byte>());
                Log.Information($"收到 MQTT 消息，Topic: {topic}, Payload: {payload}");
                // 反序列化 JSON 内容为 MqttContent 实体
                var content = JsonSerializer.Deserialize<MqttContent>(payload);
                if (content != null)
                {
                    // 从 topic 中提取设备 ID，例如 device/abc123/response
                    var topicParts = topic.Split('/');
                    var deviceId = topicParts.Length >= 2 ? topicParts[1] : "unknown";
                    Log.Information($"{topicParts[0]}: {deviceId})");
                    UavMqttMessageLogEntity logEntity = new UavMqttMessageLogEntity
                    {
                        Id = YitIdHelper.NextId().ToString(),
                        MessageType = "response",
                        Topic = topic,
                        Payload = payload,
                        DeviceId = deviceId,
                        Processed = 1,
                        Status = "success",
                        CreatedAt = DateTime.Now,
                    };
                    if (!payload.Contains("\"status\":\"received\""))
                    {
                        //判断两秒内，Payload一样的话，就不处理了
                        var twoSecondsAgo = DateTime.Now.AddSeconds(-2);
                        var lastLog = _db.Queryable<UavMqttMessageLogEntity>().Where(p => p.DeviceId == deviceId && p.Payload == payload && p.CreatedAt >= twoSecondsAgo).Any();
                        if (lastLog == false)
                        {
                            Log.Information($"[订阅消息] 处理新消息：设备 {deviceId}，内容：{payload}");
                            var orderService = _serviceProvider.GetRequiredService<IUavOrderService>();
                            orderService.HandleSubscribeMessage(payload);
                        }
                        else
                        {
                            Log.Information($"[订阅消息] 接收到重复的消息，已忽略：设备 {deviceId}，内容：{payload}");
                        }
                        //只保存正常消息
                        _db.Insertable(logEntity).ExecuteCommand();
                    }
                    else
                    {
                        Log.Debug($"[订阅消息] 接收到确认消息，不处理：设备 {deviceId}，内容：{payload}");
                        // 保存确认消息到日志
                        _db.Insertable(logEntity).ExecuteCommand();
                    }
                }
            }
            catch (Exception ex)
            {
                Log.Error($"消息处理异常: {ex.Message}");
            }
        });

        // 初始化健康检查定时器
        _healthCheckTimer = new Timer(HealthCheckCallback, null, _healthCheckInterval, _healthCheckInterval);
        Log.Information("MQTT健康检查定时器已启动，每5分钟检查一次");
    }

    /// <summary>
    /// 健康检查定时器回调方法
    /// </summary>
    private async void HealthCheckCallback(object state)
    {
        try
        {
            Log.Debug("执行定时MQTT健康检查...");
            await PerformHealthCheckAndRepairAsync();
        }
        catch (Exception ex)
        {
            Log.Error($"定时健康检查执行失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 向指定 Topic 发布 MQTT 消息
    /// </summary>
    /// <param name="topic">主题路径，例如 device/{id}/command</param>
    /// <param name="payload">发送的 JSON 字符串内容</param>
    /// <returns>是否成功发送</returns>
    public async Task<bool> PublishAsync(string topic, string payload)
    {
        try
        {
            // 如果未连接则先连接
            if (!_mqttClient.IsConnected)
            {
                Log.Warning($"MQTT 未连接，尝试重新连接...");
                await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
                
                // 等待连接稳定
                int retryCount = 0;
                while (!_mqttClient.IsConnected && retryCount < 3)
                {
                    await Task.Delay(1000);
                    retryCount++;
                }
                
                if (!_mqttClient.IsConnected)
                {
                    Log.Error("MQTT 连接失败，无法发送消息");
                    return false;
                }
            }

            // 构建 MQTT 消息
            var message = new MqttApplicationMessageBuilder()
                .WithTopic(topic)
                .WithPayload(payload)
                .WithAtLeastOnceQoS()     // QoS 1：至少送达一次
                .WithRetainFlag(false)    // 不保留历史消息
                .Build();

            // 异步发送
            await _mqttClient.PublishAsync(message);
            Log.Information($"MQTT 发布成功 -> Topic: {topic}, Payload: {payload}");
            var topicParts = topic.Split('/');
            UavMqttMessageLogEntity logEntity = new UavMqttMessageLogEntity
            {
                    Id = YitIdHelper.NextId().ToString(),
                MessageType = "send",
                Topic = topic,
                Payload = payload,
                DeviceId = topicParts[1],
                Processed = 1,
                Status = "success",
                CreatedAt = DateTime.Now,
            };
            _db.Insertable(logEntity).ExecuteCommand();
            return true;
        }
        catch (Exception ex)
        {
            Log.Error($"MQTT 发送失败：{ex.Message}");
            
            // 记录失败的消息到数据库
            try
            {
                var topicParts = topic.Split('/');
                UavMqttMessageLogEntity logEntity = new UavMqttMessageLogEntity
                {
                    Id = YitIdHelper.NextId().ToString(),
                    MessageType = "send",
                    Topic = topic,
                    Payload = payload,
                    DeviceId = topicParts.Length > 1 ? topicParts[1] : "unknown",
                    Processed = 0,
                    Status = "failed",
                    CreatedAt = DateTime.Now,
                };
                _db.Insertable(logEntity).ExecuteCommand();
            }
            catch (Exception logEx)
            {
                Log.Error($"记录失败消息到数据库时出错：{logEx.Message}");
            }
            
            return false;
        }
    }

    /// <summary>
    /// 手动启动 MQTT 客户端（推荐在程序启动时调用）
    /// </summary>
    public async Task StartAsync()
    {
        if (!_mqttClient.IsConnected)
        {
            await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
        }
        
        // 确保订阅状态正常
        await EnsureSubscriptionAsync();
    }
    
    /// <summary>
    /// 确保订阅状态正常，如果订阅丢失则重新订阅
    /// </summary>
    private async Task EnsureSubscriptionAsync()
    {
        try
        {
            if (_mqttClient.IsConnected)
            {
                // 检查订阅状态，如果订阅丢失则重新订阅
                Log.Information("检查MQTT订阅状态...");
                await _mqttClient.SubscribeAsync("device/+/response");
                Log.Information("MQTT订阅状态正常: device/+/response");
            }
        }
        catch (Exception ex)
        {
            Log.Warning($"检查订阅状态时出错: {ex.Message}");
        }
    }

    /// <summary>
    /// 查询指定clientId是否在线（通过EMQX管理API，带缓存）
    /// </summary>
    /// <param name="clientId">要查询的客户端ID</param>
    /// <returns>在线返回true，不在线返回false</returns>
    public async Task<dynamic> IsClientOnlineAsync(string clientId)
    {
        if (string.IsNullOrEmpty(clientId))
        {
            Log.Warning("设备ID为空，无法查询在线状态");
            return false;
        }

        // 检查缓存 - 增加缓存时间到60秒，减少API调用
        lock (_cacheLock)
        {
            if (_onlineStatusCache.TryGetValue(clientId, out var cacheEntry))
            {
                var (isOnline, lastCheck) = cacheEntry;
                var cacheAge = DateTime.Now - lastCheck;
                
                // 如果缓存时间小于60秒，直接返回缓存结果
                if (cacheAge.TotalSeconds < 60)
                {
                    Log.Debug($"使用缓存结果：设备 {clientId} 在线状态 = {isOnline}");
                    return isOnline;
                }
            }
        }

        // 使用静态HttpClient以提高性能
        using (var client = new HttpClient())
        {
            client.Timeout = TimeSpan.FromSeconds(3); // 减少超时时间到3秒
            
            // 使用你的EMQX管理账号密码
            var byteArray = Encoding.ASCII.GetBytes("285f888395fa6906:9BAdZeir9C3IVweof9Ate8HfQpn2u6GrH8Q9ArAF9Bb26tnI");
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(byteArray));
            
            // 减少重试次数，提高响应速度
            int maxRetries = 1;
            for (int retry = 0; retry <= maxRetries; retry++)
            {
                try
                {
                    // 查询指定客户端
                    var clientUrl = $"http://mqtt.cqjiangzhichao.cn/api/v5/clients/{clientId}";
                    var response = await client.GetAsync(clientUrl);
                    bool isOnline = false;
                    
                    if (response.StatusCode == HttpStatusCode.OK)
                    {
                        Log.Debug($"设备 {clientId} 在线状态查询成功");
                        isOnline = true;
                    }
                    else if (response.StatusCode == HttpStatusCode.NotFound)
                    {
                        Log.Debug($"设备 {clientId} 不在线");
                        isOnline = false;
                    }
                    else
                    {
                        Log.Warning($"查询设备 {clientId} 在线状态失败，状态码: {response.StatusCode}，重试次数: {retry + 1}");
                        if (retry == maxRetries)
                        {
                            Log.Error($"查询设备 {clientId} 在线状态最终失败，状态码: {response.StatusCode}");
                            isOnline = false;
                        }
                        else
                        {
                            await Task.Delay(500); // 减少等待时间到500ms
                            continue;
                        }
                    }
                    
                    // 更新缓存
                    lock (_cacheLock)
                    {
                        _onlineStatusCache[clientId] = (isOnline, DateTime.Now);
                    }
                    return isOnline;
                }
                catch (TaskCanceledException ex)
                {
                    Log.Warning($"查询设备 {clientId} 在线状态超时，重试次数: {retry + 1}");
                    if (retry == maxRetries)
                    {
                        Log.Error($"查询设备 {clientId} 在线状态最终超时");
                        // 更新缓存为false
                        lock (_cacheLock)
                        {
                            _onlineStatusCache[clientId] = (false, DateTime.Now);
                        }
                        return false;
                    }
                    await Task.Delay(500); // 减少等待时间到500ms
                }
                catch (Exception ex)
                {
                    Log.Error($"查询设备 {clientId} 在线状态异常: {ex.Message}，重试次数: {retry + 1}");
                    if (retry == maxRetries)
                    {
                        // 更新缓存为false
                        lock (_cacheLock)
                        {
                            _onlineStatusCache[clientId] = (false, DateTime.Now);
                        }
                        return false;
                    }
                    await Task.Delay(500); // 减少等待时间到500ms
                }
            }
            
            // 更新缓存为false
            lock (_cacheLock)
            {
                _onlineStatusCache[clientId] = (false, DateTime.Now);
            }
            return false;
        }
    }

    /// <summary>
    /// 批量查询设备在线状态（提高效率）
    /// </summary>
    /// <param name="clientIds">要查询的客户端ID列表</param>
    /// <returns>在线状态字典</returns>
    public async Task<Dictionary<string, bool>> BatchCheckOnlineStatusAsync(List<string> clientIds)
    {
        if (clientIds == null || clientIds.Count == 0)
        {
            return new Dictionary<string, bool>();
        }

        var result = new Dictionary<string, bool>();
        var needQueryIds = new List<string>();

        // 先检查缓存
        lock (_cacheLock)
        {
            foreach (var clientId in clientIds)
            {
                if (_onlineStatusCache.TryGetValue(clientId, out var cacheEntry))
                {
                    var (isOnline, lastCheck) = cacheEntry;
                    var cacheAge = DateTime.Now - lastCheck;
                    
                    // 如果缓存时间小于60秒，使用缓存结果
                    if (cacheAge.TotalSeconds < 60)
                    {
                        result[clientId] = isOnline;
                        continue;
                    }
                }
                needQueryIds.Add(clientId);
            }
        }

        // 如果没有需要查询的设备，直接返回缓存结果
        if (needQueryIds.Count == 0)
        {
            return result;
        }

        // 批量查询在线状态
        using (var client = new HttpClient())
        {
            client.Timeout = TimeSpan.FromSeconds(5);
            
            var byteArray = Encoding.ASCII.GetBytes("285f888395fa6906:9BAdZeir9C3IVweof9Ate8HfQpn2u6GrH8Q9ArAF9Bb26tnI");
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(byteArray));

            // 并行查询多个设备
            var tasks = needQueryIds.Select(async clientId =>
            {
                try
                {
                    var clientUrl = $"http://mqtt.cqjiangzhichao.cn/api/v5/clients/{clientId}";
                    var response = await client.GetAsync(clientUrl);
                    bool isOnline = response.StatusCode == HttpStatusCode.OK;
                    
                    // 更新缓存
                    lock (_cacheLock)
                    {
                        _onlineStatusCache[clientId] = (isOnline, DateTime.Now);
                    }
                    
                    return new { ClientId = clientId, IsOnline = isOnline };
                }
                catch (Exception ex)
                {
                    Log.Warning($"批量查询设备 {clientId} 在线状态失败: {ex.Message}");
                    // 更新缓存为false
                    lock (_cacheLock)
                    {
                        _onlineStatusCache[clientId] = (false, DateTime.Now);
                    }
                    return new { ClientId = clientId, IsOnline = false };
                }
            });

            var queryResults = await Task.WhenAll(tasks);
            
            // 合并结果
            foreach (var queryResult in queryResults)
            {
                result[queryResult.ClientId] = queryResult.IsOnline;
            }
        }

        return result;
    }

    /// <summary>
    /// 清理过期的缓存数据（建议定期调用）
    /// </summary>
    public void CleanupExpiredCache()
    {
        lock (_cacheLock)
        {
            var now = DateTime.Now;
            var expiredKeys = new List<string>();
            
            foreach (var kvp in _onlineStatusCache)
            {
                var (isOnline, lastCheck) = kvp.Value;
                var cacheAge = now - lastCheck;
                
                // 如果缓存时间超过5分钟，标记为过期
                if (cacheAge.TotalMinutes > 5)
                {
                    expiredKeys.Add(kvp.Key);
                }
            }
            
            // 删除过期的缓存
            foreach (var key in expiredKeys)
            {
                _onlineStatusCache.Remove(key);
            }
            
            if (expiredKeys.Count > 0)
            {
                Log.Information($"清理了 {expiredKeys.Count} 个过期的在线状态缓存");
            }
        }
    }

    #region 私有回调逻辑

    #endregion

    /// <summary>
    /// 检查MQTT连接健康状态
    /// </summary>
    /// <returns>连接状态信息</returns>
    public async Task<dynamic> GetConnectionHealthAsync()
    {
        try
        {
            if (_mqttClient.IsConnected)
            {
                try
                {
                    await _mqttClient.PingAsync(CancellationToken.None);
                    Log.Debug("MQTT Ping 成功");
                    return new
                    {
                        IsConnected = true,
                        ConnectionTime = DateTime.Now,
                        LastPing = DateTime.Now,
                        ClientId = _mqttOptions.ClientId,
                        BrokerAddress = "mqtt.cqjiangzhichao.cn:1883"
                    };
                }
                catch (Exception pingEx)
                {
                    Log.Warning($"MQTT Ping 失败: {pingEx.Message}");
                    return new
                    {
                        IsConnected = false,
                        ConnectionTime = (DateTime?)null,
                        LastPing = DateTime.Now,
                        ClientId = _mqttOptions.ClientId,
                        BrokerAddress = "mqtt.cqjiangzhichao.cn:1883",
                        PingError = pingEx.Message
                    };
                }
            }
            else
            {
                return new
                {
                    IsConnected = false,
                    ConnectionTime = (DateTime?)null,
                    LastPing = DateTime.Now,
                    ClientId = _mqttOptions.ClientId,
                    BrokerAddress = "mqtt.cqjiangzhichao.cn:1883"
                };
            }
        }
        catch (Exception ex)
        {
            Log.Error($"获取连接健康状态失败: {ex.Message}");
            return new
            {
                IsConnected = false,
                Error = ex.Message,
                Timestamp = DateTime.Now
            };
        }
    }

    /// <summary>
    /// 强制重新连接MQTT
    /// </summary>
    /// <returns>重连是否成功</returns>
    public async Task<bool> ForceReconnectAsync()
    {
        try
        {
            if (_mqttClient.IsConnected)
            {
                await _mqttClient.DisconnectAsync();
                Log.Information("MQTT 主动断开连接");
            }

            await Task.Delay(2000); // 等待2秒后重连
            
            await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
            Log.Information("MQTT 强制重连成功");
            
            // 重连后重新订阅
            await EnsureSubscriptionAsync();
            return true;
        }
        catch (Exception ex)
        {
            Log.Error($"MQTT 强制重连失败: {ex.Message}");
            return false;
        }
    }

    /// <summary>
    /// 定期健康检查和自动修复（建议每5分钟调用一次）
    /// </summary>
    /// <returns>修复是否成功</returns>
    public async Task<bool> PerformHealthCheckAndRepairAsync()
    {
        try
        {
            Log.Information("开始MQTT健康检查...");
            
            // 检查连接状态
            if (!_mqttClient.IsConnected)
            {
                Log.Warning("MQTT连接已断开，尝试重新连接...");
                await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
                await EnsureSubscriptionAsync();
                return true;
            }
            
            // 检查连接质量（发送Ping）
            try
            {
                await _mqttClient.PingAsync(CancellationToken.None);
                Log.Debug("MQTT Ping 成功，连接质量良好");
            }
            catch (Exception pingEx)
            {
                Log.Warning($"MQTT Ping 失败，连接可能有问题: {pingEx.Message}");
                
                // Ping失败，尝试重新连接
                Log.Information("尝试重新建立连接...");
                await _mqttClient.DisconnectAsync();
                await Task.Delay(1000);
                await _mqttClient.ConnectAsync(_mqttOptions, CancellationToken.None);
                await EnsureSubscriptionAsync();
                return true;
            }
            
            // 检查订阅状态
            await EnsureSubscriptionAsync();
            
            Log.Information("MQTT健康检查完成，状态正常");
            return true;
        }
        catch (Exception ex)
        {
            Log.Error($"MQTT健康检查失败: {ex.Message}");
            return false;
        }
    }

    /// <summary>
    /// 获取当前订阅的主题列表
    /// </summary>
    /// <returns>订阅的主题列表</returns>
    public async Task<List<string>> GetSubscribedTopicsAsync()
    {
        try
        {
            // 注意：MQTTnet可能不直接提供获取订阅列表的方法
            // 这里返回我们已知的订阅主题
            return new List<string> { "device/+/response" };
        }
        catch (Exception ex)
        {
            Log.Error($"获取订阅主题列表失败: {ex.Message}");
            return new List<string>();
        }
    }

    /// <summary>
    /// 释放资源
    /// </summary>
    public void Dispose()
    {
        try
        {
            _healthCheckTimer?.Dispose();
            Log.Information("MQTT健康检查定时器已释放");
        }
        catch (Exception ex)
        {
            Log.Error($"释放MQTT资源时出错: {ex.Message}");
        }
    }
}