using Edge.Core.IndustryStandardInterface.NetworkController;
using Microsoft.Extensions.Logging;
using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Diagnostics;
using MQTTnet.Protocol;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DeviceInfoToAliIotHubViaGateway
{
    class FastMqttClient : IMqttClientNetworkController
    {
        private IMqttClient mqttClient;
        public string Name => this.GetType().FullName;

        public event EventHandler<OnMqttMessageReceivedEventArg> OnMessageReceived;
        public event EventHandler<NetworkControllerOnStateChangeEventArg> OnNetworkControllerStateChange;

        private ILogger logger = null;
        public FastMqttClient(ILogger logger)
        {
            this.logger = logger;
            // Write all trace messages to the console window.
            //MqttNetGlobalLogger.LogMessagePublished += (s, e) =>
            //{
            //    //var trace = $">> [{e.TraceMessage.ThreadId}] [{e.TraceMessage.Source}] [{e.TraceMessage.Level}]: {e.TraceMessage.Message}";
            //    var trace = $"{e.TraceMessage.Message}";
            //    if (e.TraceMessage.Exception != null)
            //        trace += Environment.NewLine + e.TraceMessage.Exception.ToString();
            //    this.logger.LogTrace(trace);
            //};
            // Create a new MQTT client.
            var factory = new MqttFactory();
            this.mqttClient = factory.CreateMqttClient();
            this.mqttClient.ApplicationMessageReceivedAsync += e =>
            {
                //Console.WriteLine("### RECEIVED APPLICATION MESSAGE ###");
                //Console.WriteLine($"+ Topic = {e.ApplicationMessage.Topic}");
                //Console.WriteLine($"+ Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");
                //Console.WriteLine($"+ QoS = {e.ApplicationMessage.QualityOfServiceLevel}");
                //Console.WriteLine($"+ Retain = {e.ApplicationMessage.Retain}");
                //Console.WriteLine();
                this.logger.LogDebug($"======>>>FastMqttClient received at topic: {e.ApplicationMessage.Topic} with payload: {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");
                var safe = this.OnMessageReceived;
                safe?.Invoke(this, new OnMqttMessageReceivedEventArg(new MqttMessage()
                {
                    Message = e.ApplicationMessage.Payload,
                    Topic = e.ApplicationMessage.Topic,
                }));
                return Task.CompletedTask;
            };
        }

        public async Task<bool> CloseAsync()
        {
            this.logger.LogInformation($"Closing FastMqttClient");
            return true;
        }

        public async Task<bool> ConfigNetworkAsync(params string[] parameters)
        {
            throw new NotImplementedException();
        }

        public async Task<bool> ConnectAsync(string clientId, string userName, string password)
        {
            // Create TCP based options using the builder.
            var options = new MqttClientOptionsBuilder()
                .WithClientId(clientId)
                .WithTcpServer(this.mqttServerUrl, this.mqttServerPort)
                .WithCredentials(userName, password).WithTls()
                // aliyun require a high value on this period, like 2m, otherwise, rejected
                .WithKeepAlivePeriod(new TimeSpan(0, 2, 0))
                .WithCleanSession(true)
                .Build();
            this.logger.LogInformation($"Connecting to mqtt server with url: {this.mqttServerUrl + "-" + this.mqttServerPort}, clientId: {clientId}, userName: {userName}, pwd: {password}");
            var result = await this.mqttClient.ConnectAsync(options);
            this.logger.LogInformation($"   Connect result is: {result.ResultCode}");
            if (result.ResultCode == MqttClientConnectResultCode.Success)
                return true;
            else
                return false;
        }

        public async Task<bool> DisconnectAsync()
        {
            this.logger.LogInformation($"Disconnecting FastMqttClient");
            await this.mqttClient.DisconnectAsync();
            return true;
        }

        private string mqttServerUrl;
        private int mqttServerPort;
        public async Task<bool> OpenAsync(string mqttServerUrl, int port)
        {
            this.mqttServerUrl = mqttServerUrl;
            this.mqttServerPort = port;
            return true;
        }

        public async Task<bool> PublishAsync(int msgId, string topic, byte[] byteMsg, Mqtt_QosLevel qosLevel, bool retain)
        {
            MqttClientPublishResult result = null;
            MqttApplicationMessage mqttMsg = new MqttApplicationMessage();
            mqttMsg.Payload = byteMsg;
            mqttMsg.Retain = retain;
            mqttMsg.Topic = topic;
            if (qosLevel == Mqtt_QosLevel.AtMostOnce)
                mqttMsg.QualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce;
            else if (qosLevel == Mqtt_QosLevel.AtLeastOnce)
                mqttMsg.QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce;
            else if (qosLevel == Mqtt_QosLevel.ExactlyOnce)
                mqttMsg.QualityOfServiceLevel = MqttQualityOfServiceLevel.ExactlyOnce;
            result = await this.mqttClient.PublishAsync(mqttMsg);
            if (result.ReasonCode == MqttClientPublishReasonCode.Success)
                return true;
            return false;
        }

        public async Task<NetworkState> QueryStatusAsync()
        {
            return NetworkState.NetworkConnected;
        }

        public async Task<bool> ResetAsync()
        {
            await this.mqttClient.DisconnectAsync();
            return true;
        }

        public async Task<bool> SubscribeAsync(int msgId, string topic, Mqtt_QosLevel qosLevel)
        {
            MqttClientSubscribeResult results = null;
            if (qosLevel == Mqtt_QosLevel.AtMostOnce)
                results = await this.mqttClient.SubscribeAsync(topic, MqttQualityOfServiceLevel.AtMostOnce);
            else if (qosLevel == Mqtt_QosLevel.AtLeastOnce)
                results = await this.mqttClient.SubscribeAsync(topic, MqttQualityOfServiceLevel.AtLeastOnce);
            else if (qosLevel == Mqtt_QosLevel.ExactlyOnce)
                results = await this.mqttClient.SubscribeAsync(topic, MqttQualityOfServiceLevel.ExactlyOnce);
            if (results.Items.First().ResultCode == MqttClientSubscribeResultCode.GrantedQoS0
                || results.Items.First().ResultCode == MqttClientSubscribeResultCode.GrantedQoS1
                || results.Items.First().ResultCode == MqttClientSubscribeResultCode.GrantedQoS2)
                return true;
            else
                return false;
        }

        public async Task<bool> UnsubscribeAsync(int msgId, string topic)
        {
            var result = await this.mqttClient.UnsubscribeAsync(topic);
            if (result.Items.First().ResultCode == MqttClientUnsubscribeResultCode.Success)
                return true;
            else
                return false;
        }
    }
}