using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Configuration;
using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Protocol;

namespace OpenAuth.WebApi;

public class MqttClientManager
{
    private IMqttClient _outBoundClient;
    private IMqttClient _inBoundClient;


    public MqttClientManager()
    {
        var mqttFactory = new MqttFactory();
        _outBoundClient = mqttFactory.CreateMqttClient();
        _inBoundClient = mqttFactory.CreateMqttClient();
        // 创建配置构建器
        var builder = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddJsonFile(
                $"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Development"}.json",
                optional: true)
            .AddEnvironmentVariables();
        // 构建配置
        var configuration = builder.Build();
        // 读取连接字符串
        var serverIp = configuration["MQTT:Server"];
        var port = configuration["MQTT:Port"];
        var username = configuration["MQTT:UserName"];
        var password = configuration["MQTT:Password"];
        ConnectAsync(serverIp, int.Parse(port), username, password).Wait();
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="server"></param>
    /// <param name="port"></param>
    /// <param name="username"></param>
    /// <param name="password"></param>
    public async Task ConnectAsync(string server, int port, string username = null, string password = null)
    {
        var inboundOptions = new MqttClientOptionsBuilder()
            .WithClientId(Guid.NewGuid() + "_inbound")
            .WithTcpServer(server, port)
            .WithCredentials(username, password)
            .Build();
        var outboundOptions = new MqttClientOptionsBuilder()
            .WithClientId(Guid.NewGuid() + "_outbound")
            .WithTcpServer(server, port)
            .WithCredentials(username, password)
            .Build();

        await _outBoundClient.ConnectAsync(inboundOptions, CancellationToken.None);
        await _inBoundClient.ConnectAsync(outboundOptions, CancellationToken.None);
    }

    public async Task SubscribeAsync(string topic,
        Func<MqttApplicationMessageReceivedEventArgs, Task> handler)
    { 
        await _inBoundClient.SubscribeAsync(topic, MqttQualityOfServiceLevel.AtLeastOnce, CancellationToken.None);
        _inBoundClient.ApplicationMessageReceivedAsync += handler;
    }

    public async Task UnsubscribeAsync(string topic)
    {
        await _inBoundClient.UnsubscribeAsync(topic, CancellationToken.None);
    }

    /// <summary>
    /// 向主题发布消息
    /// </summary>
    /// <param name="topic">主题</param>
    /// <param name="message">json</param>
    public async Task PublishAsync(string topic, string message)
    {
        Console.WriteLine($"Publish: {topic} - {message}");
        // MqttChannelAdapter 
        var mqttMsg = new MqttApplicationMessageBuilder()
            .WithTopic(topic)
            .WithPayload(message)
            // 级别 0 1 2
            .WithQualityOfServiceLevel(MqttQualityOfServiceLevel.AtLeastOnce)
            .Build();
        await _outBoundClient.PublishAsync(mqttMsg, CancellationToken.None);
    }
}