using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using MQTTnet.Extensions.ManagedClient;
using MQTTnet;
using MQTTnet.Client.Options;
using System.Security.Cryptography.X509Certificates;
using System.IO;

namespace IoTClient.Tool.Controls
{
    public partial class MQTTControl : UserControl
    {
        public MQTTControl()
        {
            InitializeComponent();
            CheckForIllegalCrossThreadCalls = false;
            Size = new Size(880, 450);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            but_Subscribe.Enabled = false;
            but_Publish.Enabled = false;
            but_Stop.Enabled = false;
            txt_ClientID.Text = Guid.NewGuid().ToString();
            checkBox1_CheckedChanged(null, null);
        }

        private IManagedMqttClient mqttClient;
        private async void but_start_ClickAsync(object sender, EventArgs even)
        {
            but_Stop_Click(null, null);
            var factory = new MqttFactory();
            mqttClient = factory.CreateManagedMqttClient();
            var mqttClientOptions = new MqttClientOptionsBuilder()
                             .WithClientId(txt_ClientID.Text?.Trim())
                             .WithTcpServer(txt_Address.Text?.Trim(), int.Parse(txt_Port.Text?.Trim()))
                             .WithCredentials(txt_UserName.Text, txt_Password.Text);

            if (checkBox1.Checked)
            {
                if (!File.Exists(txt_ca_file.Text))
                {
                    MessageBox.Show($"没有找到文件:{txt_ca_file.Text}");
                    return;
                }
                if (!File.Exists(txt_pfx_file.Text))
                {
                    MessageBox.Show($"没有找到文件:{txt_pfx_file.Text}");
                    return;
                }
                var caCert = X509Certificate.CreateFromCertFile(txt_ca_file.Text);
                var clientCert = new X509Certificate2(txt_pfx_file.Text);
                mqttClientOptions = mqttClientOptions.WithTls(new MqttClientOptionsBuilderTlsParameters()
                {
                    UseTls = true,
                    SslProtocol = System.Security.Authentication.SslProtocols.Tls12,
                    CertificateValidationHandler = (o) =>
                    {
                        return true;
                    },
                    Certificates = new List<X509Certificate>(){
                                    caCert, clientCert
                                 }
                });
            }

            var options = new ManagedMqttClientOptionsBuilder()
                        .WithAutoReconnectDelay(TimeSpan.FromSeconds(5))
                        .WithClientOptions(mqttClientOptions.Build())
                        .Build();

            await mqttClient.StartAsync(options);

            mqttClient.UseDisconnectedHandler(e =>
            {
                WriteLine_1("### 服务器断开连接 ###");
            });


            mqttClient.UseApplicationMessageReceivedHandler(e =>
            {
                WriteLine_1("### 收到消息 ###");
                WriteLine_1($"+ Topic = {e.ApplicationMessage.Topic}");
                try
                {
                    WriteLine_1($"+ Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");
                }
                catch { }
                WriteLine_1($"+ QoS = {e.ApplicationMessage.QualityOfServiceLevel}");
                WriteLine_1($"+ Retain = {e.ApplicationMessage.Retain}");
                WriteLine_1();
            });

            mqttClient.UseConnectedHandler(e =>
            {
                WriteLine_1("### 连接到服务 ###");

                but_Start.Enabled = false;
                but_Subscribe.Enabled = true;
                but_Publish.Enabled = true;
                but_Stop.Enabled = true;
            });
        }

        private async void but_Stop_Click(object sender, EventArgs e)
        {
            if (mqttClient != null)
            {
                if (mqttClient.IsStarted)
                    await mqttClient.StopAsync();
                mqttClient.Dispose();
            }
            but_Subscribe.Enabled = false;
            but_Publish.Enabled = false;
            but_Stop.Enabled = false;
            but_Start.Enabled = true;
        }

        private void WriteLine_1(string msg = "")
        {
            txt_msg.AppendText($"{msg} \r\n");
        }

        private void WriteLine_2(string msg = "")
        {
            textBox2.AppendText($"{msg}\r\n");
        }

        private async void but_Subscribe_ClickAsync(object sender, EventArgs e)
        {
            // Subscribe to a topic
            var topic = txt_subscribe_topic.Text?.Trim();
            if (string.IsNullOrWhiteSpace(topic))
            {
                WriteLine_1("### 请输入Topic ###");
                return;
            }

            await mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).Build());

            WriteLine_1("### 订阅 ###");
        }

        private async void but_Publish_Click(object sender, EventArgs e)
        {
            var topic = txt_publish_topic.Text?.Trim();
            var payload = txt_publish_payload.Text?.Trim();
            if (string.IsNullOrWhiteSpace(topic))
            {
                WriteLine_1("### 请输入Topic ###");
                return;
            }
            var result = await mqttClient.PublishAsync(topic, payload);
            WriteLine_2($"topic:{topic} payload:{payload} {result.ReasonCode}");
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            txt_Port.Text = checkBox1.Checked ? "8883" : "1883";
            txt_pfx_file.Enabled = checkBox1.Checked;
            txt_ca_file.Enabled = checkBox1.Checked;
        }

        private void txt_ca_file_Click(object sender, EventArgs e)
        {
            OpenFileDialog fileDialog = new OpenFileDialog();
            fileDialog.Multiselect = true;
            fileDialog.Title = "请选择文件";
            fileDialog.Filter = "所有文件(*crt*)|*.crt*"; //设置要选择的文件的类型
            if (fileDialog.ShowDialog() == DialogResult.OK)
            {
                txt_ca_file.Text = fileDialog.FileName;//返回文件的完整路径   
                txt_ca_file.Select(txt_ca_file.Text.Length, 1);
            }
        }

        private void txt_pfx_file_Click(object sender, EventArgs e)
        {
            OpenFileDialog fileDialog = new OpenFileDialog();
            fileDialog.Multiselect = true;
            fileDialog.Title = "请选择文件";
            fileDialog.Filter = "所有文件(*pfx*)|*.pfx*"; //设置要选择的文件的类型
            if (fileDialog.ShowDialog() == DialogResult.OK)
            {
                txt_pfx_file.Text = fileDialog.FileName;//返回文件的完整路径           
                txt_pfx_file.Select(txt_pfx_file.Text.Length, 1);
            }
        }
    }
}