using MQTTnet;
using MQTTnet.Diagnostics.Logger;
using MQTTnet.Internal;
using MQTTnet.Protocol;
using MQTTnet.Server;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using XiaoZhiSharp.MQTT.Common;
using XiaoZhiSharp.Utils;

namespace XiaoZhiSharp.MQTT
{
    /// <summary>
    /// MQTT通讯相关的工具类
    /// </summary>
    public class MqttNetServer
    {
        #region 变量
        /// <summary>
        /// MQTT服务
        /// </summary>
        private MqttServer _MqttServer = null;

        /// <summary>
        /// 记录日志、输出、保存等操作
        /// </summary>
        private Action<ResultMqtt> _Callback = null;
        #endregion 变量

        public static void RunEmptyServer()
        {
            var mqttServer = new MqttServerFactory().CreateMqttServer(new MqttServerOptions());
            mqttServer.StartAsync().GetAwaiter().GetResult();

            Console.WriteLine("Press any key to exit.");
            Console.ReadLine();
        }

        public static void RunEmptyServerWithLogging()
        {
            var logger = new MqttNetEventLogger();
            MqttNetConsoleLogger.ForwardToConsole(logger);

            var mqttFactory = new MqttServerFactory(logger);
            var mqttServer = mqttFactory.CreateMqttServer(new MqttServerOptions());
            mqttServer.StartAsync().GetAwaiter().GetResult();

            Console.WriteLine("Press any key to exit.");
            Console.ReadLine();
        }

        /// <summary>
        /// 创建MQTTServer并运行
        /// </summary>
        public async Task<ResultMqtt> CreateMQTTServerAndStart(MqttServerOptionsBuilder mqttServerOptionsBuilder, Action<ResultMqtt> callback)
        {
            ResultMqtt resultData_MQTT = new ResultMqtt();

            _Callback = callback;
            try
            {
                MqttServerOptions mqttServerOptions = mqttServerOptionsBuilder.Build();
                _MqttServer = new MqttServerFactory().CreateMqttServer(mqttServerOptions);  // 创建服务（配置）

                RegisterEvents(_MqttServer);

                await _MqttServer.StartAsync();  // 开启服务

                if (_MqttServer.IsStarted)
                {
                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = 1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_成功！"
                    };
                }
                else
                {
                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = -1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_失败！"
                    };
                }
            }
            catch (Exception ex)
            {
                resultData_MQTT = new ResultMqtt()
                {
                    ResultCode = -1,
                    ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_失败！错误信息：" + ex.Message
                };
            }

            _Callback?.Invoke(resultData_MQTT);
            return resultData_MQTT;
        }

        /// <summary>
        /// 简易创建MQTTServer并运行-不使用加密
        /// </summary>
        /// <param name="ip">IP</param>
        /// <param name="port">端口</param>
        /// <param name="withPersistentSessions">是否保持会话</param>
        /// <param name="callback">处理方法</param>
        /// <returns></returns>
        public async Task<ResultMqtt> CreateMQTTServerAndStart(string ip, int port, bool withPersistentSessions, Action<ResultMqtt> callback)
        {
            ResultMqtt resultData_MQTT = new ResultMqtt();
            _Callback = callback;

            try
            {

                // Extend the timestamp for all messages from clients.
                // Protect several topics from being subscribed from every client.

                //var certificate = new X509Certificate(@"C:\certs\test\test.cer", "");
                //options.TlsEndpointOptions.Certificate = certificate.Export(X509ContentType.Cert);
                //options.ConnectionBacklog = 5;
                //options.DefaultEndpointOptions.IsEnabled = true;
                //options.TlsEndpointOptions.IsEnabled = false;

                MqttServerOptionsBuilder mqttServerOptionsBuilder = new MqttServerOptionsBuilder();  // MQTT服务器配置
                mqttServerOptionsBuilder.WithDefaultEndpoint();
                mqttServerOptionsBuilder.WithDefaultEndpointBoundIPAddress(IPAddress.Parse(ip));  // 设置Server的IP
                mqttServerOptionsBuilder.WithDefaultEndpointPort(port);                           // 设置Server的端口号
                //mqttServerOptionsBuilder.WithEncryptedEndpointPort(port);                        // 使用加密的端点端口
                mqttServerOptionsBuilder.WithPersistentSessions(withPersistentSessions);  // 持续会话
                mqttServerOptionsBuilder.WithConnectionBacklog(2000);                     // 最大连接数
                //mqttServerOptionsBuilder.WithConnectionValidator(c =>  // 鉴权-方法失效
                //{
                //    if (c.Username != uName || c.Password != uPwd)
                //    {
                //        c.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
                //    }
                //})

                MqttServerOptions mqttServerOptions = mqttServerOptionsBuilder.Build();
                _MqttServer = new MqttServerFactory().CreateMqttServer(mqttServerOptions);  // 创建服务（配置）

                RegisterEvents(_MqttServer);
                _MqttServer.ValidatingConnectionAsync += ValidatingConnectionHandle;                    // 鉴权-未完

                await _MqttServer.StartAsync();  // 开启服务

                if (_MqttServer.IsStarted)
                {
                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = 1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_成功！"
                    };
                }
                else
                {
                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = -1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_失败！"
                    };
                }
            }
            catch (Exception ex)
            {
                resultData_MQTT = new ResultMqtt()
                {
                    ResultCode = -1,
                    ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了开启MQTTServer_失败！错误信息：" + ex.Message
                };
            }

            _Callback?.Invoke(resultData_MQTT);
            return resultData_MQTT;
        }

        private void RegisterEvents(MqttServer mqttServer)
        {
            mqttServer.StartedAsync += StartedHandle;  // 服务器开启事件
            mqttServer.StoppedAsync += StoppedHandle;  // 服务器关闭事件
            mqttServer.ClientConnectedAsync += ClientConnectedHandle;        // 设置客户端连接成功后的处理程序
            mqttServer.ClientDisconnectedAsync += ClientDisconnectedHandle;  // 设置客户端断开后的处理程序
            mqttServer.ClientSubscribedTopicAsync += ClientSubscribedTopicHandle;      // 设置消息订阅通知
            mqttServer.ClientUnsubscribedTopicAsync += ClientUnsubscribedTopicHandle;  // 设置消息退订通知
            mqttServer.ApplicationMessageNotConsumedAsync += ApplicationMessageNotConsumedHandle;  // 设置消息处理程序
            /*------------------------------------------*/
            mqttServer.RetainedMessageChangedAsync += MqttServer_RetainedMessageChangedAsync;
            mqttServer.RetainedMessagesClearedAsync += MqttServer_RetainedMessagesClearedAsync;
            mqttServer.LoadingRetainedMessageAsync += MqttServer_LoadingRetainedMessageAsync;
            mqttServer.InterceptingPublishAsync += MqttServer_InterceptingPublishAsync;
            mqttServer.InterceptingSubscriptionAsync += MqttServer_InterceptingSubscriptionAsync;
            //options.ApplicationMessageInterceptor = c =>
            //{
            //    if (c.ApplicationMessage.PayloadSegment == null || c.ApplicationMessage.PayloadSegment.Length == 0)
            //    {
            //        return;
            //    }

            //    try
            //    {
            //        var content = JObject.Parse(Encoding.UTF8.GetString(c.ApplicationMessage.PayloadSegment));
            //        var timestampProperty = content.Property("timestamp");
            //        if (timestampProperty != null && timestampProperty.Value.Type == JTokenType.Null)
            //        {
            //            timestampProperty.Value = DateTime.Now.ToString("O");
            //            c.ApplicationMessage.PayloadSegment = Encoding.UTF8.GetBytes(content.ToString());
            //        }
            //    }
            //    catch (Exception)
            //    {
            //    }
            //};
        }

        /// <summary>
        /// 关闭MQTTServer
        /// </summary>
        public async Task<ResultMqtt> StopMQTTServer()
        {
            ResultMqtt resultData_MQTT = new ResultMqtt();

            try
            {
                if (_MqttServer == null)
                {
                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = -1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了关闭MQTTServer_出错！MQTTServer未在运行。"
                    };
                }
                else
                {
                    foreach (var clientStatus in _MqttServer.GetClientsAsync().Result)
                    {
                        await clientStatus.DisconnectAsync();
                    }
                    await _MqttServer.StopAsync();
                    _MqttServer = null;

                    resultData_MQTT = new ResultMqtt()
                    {
                        ResultCode = 1,
                        ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了关闭MQTTServer_成功！"
                    };
                }
            }
            catch (Exception ex)
            {
                resultData_MQTT = new ResultMqtt()
                {
                    ResultCode = -1,
                    ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>执行了关闭MQTTServer_失败！错误信息：" + ex.Message
                };
            }

            _Callback?.Invoke(resultData_MQTT);
            return resultData_MQTT;
        }

        /// <summary>
        /// 获取所有的客户端
        /// </summary>
        public List<MqttClientStatus> GetClientsAsync()
        {
            return _MqttServer.GetClientsAsync().Result.ToList();
        }

        /// <summary>
        /// 发送消息-未写
        /// </summary>
        /// <param name="Topic">主题</param>
        /// <param name="msg">消息</param>
        /// <returns></returns>
        public Task SendMessage(string Topic, string msg)
        {
            try
            {
                //var clients = _MqttServer.GetClientsAsync().Result;
                //foreach (var client in clients)
                //{
                //    var imqttClient = client.GetClient();
                //    if (imqttClient != null)
                //    {

                //    }
                //}
            }
            catch { }
            return Task.CompletedTask;
        }

        #region 处理事件
        /// <summary>
        /// 开启Server的处理程序
        /// </summary>
        private Task StartedHandle(EventArgs arg)
        {
            _Callback?.Invoke(new()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>MQTTServer已开启！"
            });
            return Task.CompletedTask;
        }

        /// <summary>
        /// 关闭Server的处理程序
        /// </summary>
        private Task StoppedHandle(EventArgs arg)
        {
            _Callback?.Invoke(new()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + ">>>MQTTServer已关闭！"
            });
            return Task.CompletedTask;
        }

        /// <summary>
        /// 设置客户端连接成功后的处理程序
        /// </summary>
        private Task ClientConnectedHandle(ClientConnectedEventArgs arg)
        {
            var clients = _MqttServer.GetClientsAsync().Result;

            _Callback?.Invoke(new()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + $">>>客户端'{arg.ClientId}'已成功连接！当前客户端连接数：{clients?.Count}个。"
            });
            return Task.CompletedTask;
        }

        /// <summary>
        /// 设置客户端断开后的处理程序
        /// </summary>
        private Task ClientDisconnectedHandle(ClientDisconnectedEventArgs arg)
        {
            var clients = _MqttServer.GetClientsAsync().Result;
            _Callback?.Invoke(new ResultMqtt()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + $">>>客户端'{arg.ClientId}'已断开连接！当前客户端连接数：{clients?.Count}个。"
            });

            return Task.CompletedTask;
        }

        /// <summary>
        /// 设置消息订阅通知
        /// </summary>
        private Task ClientSubscribedTopicHandle(ClientSubscribedTopicEventArgs arg)
        {
            //if (!arg.Equals("admin"))
            //{
            //    var clients = _MqttServer.GetClientsAsync().Result;
            //    var client = clients.Where(a => a.Id == arg.ClientId).FirstOrDefault();
            //    var imqttClient = client.GetClient();
            //    if (imqttClient != null)
            //    {

            //    }
            //    client?.DisconnectAsync();

            //    return Task.CompletedTask;
            //}

            _Callback?.Invoke(new ResultMqtt()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + $">>>客户端'{arg.ClientId}'订阅了主题'{arg.TopicFilter.Topic}'，主题服务质量：'{arg.TopicFilter.QualityOfServiceLevel}'！"
            });

            return Task.CompletedTask;
        }

        /// <summary>
        /// 设置消息退订通知
        /// </summary>
        private Task ClientUnsubscribedTopicHandle(ClientUnsubscribedTopicEventArgs arg)
        {
            _Callback?.Invoke(new ResultMqtt()
            {
                ResultCode = 1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + $">>>客户端{arg.ClientId}退订了主题{arg.TopicFilter}！"
            });

            return Task.CompletedTask;
        }

        /// <summary>
        /// 鉴权-未写完
        /// </summary>
        /// <returns></returns>
        private Task ValidatingConnectionHandle(ValidatingConnectionEventArgs arg)  // 鉴权
        {
            /*
            if (arg.ClientId == "SpecialClient")
            {
                if (arg.UserName != "USER" || arg.Password != "PASS")
                {
                    arg.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
                }
            }*/
            if (arg.UserName != "Admin" || arg.Password != "Admin123")
            {

            }

            return Task.CompletedTask;//CompletedTask.Instance;
        }

        /// <summary>
        /// 设置消息处理程序
        /// </summary>
        private Task ApplicationMessageNotConsumedHandle(ApplicationMessageNotConsumedEventArgs arg)
        {
            _Callback?.Invoke(new ResultMqtt()
            {
                ResultCode = -1,
                ResultMsg = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff") + $">>>客户端：'{arg.SenderId}'发布了消息：主题：'{arg.ApplicationMessage.Topic}'！内容：'{Encoding.UTF8.GetString(arg.ApplicationMessage.Payload)}'；服务质量：{arg.ApplicationMessage.QualityOfServiceLevel}；保留：{arg.ApplicationMessage.Retain}"
            });

            return Task.CompletedTask;
        }
        #endregion 处理事件

        #region 处理事件2
        private string Filename
        {
            get
            {
                var path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"MQTT\\RetainedMessages.json");
                var osType = XiaoZhiSharp.Kernels.OperatingSystem.GetOperatingSystemType();
                var formatFileName = path.FormatPath(osType);
                return formatFileName;
            }
        }

        private Task MqttServer_RetainedMessageChangedAsync(RetainedMessageChangedEventArgs arg)
        {
            var directory = Path.GetDirectoryName(Filename);
            if (!Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }

            File.WriteAllText(Filename, JsonConvert.SerializeObject(arg.StoredRetainedMessages));
            return CompletedTask.Instance;
        }

        private Task MqttServer_RetainedMessagesClearedAsync(EventArgs arg)
        {
            File.Delete(Filename);
            return CompletedTask.Instance;
        }

        private Task MqttServer_LoadingRetainedMessageAsync(LoadingRetainedMessagesEventArgs arg)
        {
            List<MqttApplicationMessage> retainedMessages;
            if (File.Exists(Filename))
            {
                var json = File.ReadAllText(Filename);
                retainedMessages = JsonConvert.DeserializeObject<List<MqttApplicationMessage>>(json);
            }
            else
            {
                retainedMessages = new List<MqttApplicationMessage>();
            }

            arg.LoadedRetainedMessages = retainedMessages;

            return CompletedTask.Instance;
        }

        private Task MqttServer_InterceptingPublishAsync(InterceptingPublishEventArgs arg)
        {
            //MqttNetConsoleLogger.PrintToConsole(
            //    $"'{e.ClientId}' reported '{e.ApplicationMessage.Topic}' > '{Encoding.UTF8.GetString(e.ApplicationMessage.PayloadSegment ?? new byte[0])}'",
            //    ConsoleColor.Magenta);
            MqttNetConsoleLogger.PrintToConsole(
               $"'{arg.ClientId}' reported '{arg.ApplicationMessage.Topic}' > '{Encoding.UTF8.GetString(arg.ApplicationMessage.Payload)}'",
               ConsoleColor.Magenta);

            if (MqttTopicFilterComparer.Compare(arg.ApplicationMessage.Topic, "/myTopic/WithTimestamp/#") == MqttTopicFilterCompareResult.IsMatch)
            {
                // Replace the payload with the timestamp. But also extending a JSON 
                // based payload with the timestamp is a suitable use case.
                arg.ApplicationMessage.PayloadSegment = Encoding.UTF8.GetBytes(DateTime.Now.ToString("O"));
            }

            if (arg.ApplicationMessage.Topic == "not_allowed_topic")
            {
                arg.ProcessPublish = false;
                arg.CloseConnection = true;
            }

            return CompletedTask.Instance;
        }

        private Task MqttServer_InterceptingSubscriptionAsync(InterceptingSubscriptionEventArgs arg)
        {
            if (arg.TopicFilter.Topic.StartsWith("admin/foo/bar") && arg.ClientId != "theAdmin")
            {
                arg.Response.ReasonCode = MqttSubscribeReasonCode.ImplementationSpecificError;
            }

            if (arg.TopicFilter.Topic.StartsWith("the/secret/stuff") && arg.ClientId != "Imperator")
            {
                arg.Response.ReasonCode = MqttSubscribeReasonCode.ImplementationSpecificError;
                arg.CloseConnection = true;
            }

            return CompletedTask.Instance;
        }

        #endregion 处理事件2
    }
}