using System;
using System.Diagnostics;
using System.Text.RegularExpressions;

namespace Mqtt_SWB_Dashboard {
  class Mosquitto : IDisposable {
    private Process p;
    private String message;

    public delegate void MqttMessage(Object sender, MqttEventArgs e);
    public event MqttMessage MessageIncomming;

    public Mosquitto() {
      //mosquitto_sub --cafile ca.pem --cert cert.pem --key cert.key -h swb.broker.flex4grid.eu -p 8883 -t /# -v
      this.message = "";
      this.p = new Process();
      this.p.StartInfo.FileName = "mosquitto_sub.exe";
      this.p.StartInfo.Arguments = "--cafile ca.pem --cert cert.pem --key cert.key -h swb.broker.flex4grid.eu -p 8883 -t /# -v -d";
      this.p.StartInfo.CreateNoWindow = true;
      this.p.StartInfo.UseShellExecute = false;
      this.p.StartInfo.RedirectStandardOutput = true;
      this.p.OutputDataReceived += this.P_OutputDataReceived;
      this.p.Start();
      this.p.BeginOutputReadLine();
    }

    private void P_OutputDataReceived(Object sender, DataReceivedEventArgs e) {
      if (e.Data != null) {
        if (e.Data.StartsWith("Client mosqsub")) {
          if (this.message != "" && this.message.IndexOf(" received PUBLISH ") > 0) {
            MatchCollection matches = (new Regex("^Client mosqsub\\|.*received PUBLISH \\(.*,.*,.*,.*, '(.*)'.*\\)\\)\n[^ ]* (.*)$", RegexOptions.IgnoreCase | RegexOptions.Singleline)).Matches(this.message);
            String topic = matches[0].Groups[1].Value;
            String message = matches[0].Groups[2].Value.Trim();
            this.MessageIncomming?.Invoke(this, new MqttEventArgs(message, topic));
          }
          this.message = e.Data + "\n";
        } else {
          this.message += e.Data + "\n";
        }
      }
    }

    #region IDisposable Support
    private bool disposedValue = false; // Dient zur Erkennung redundanter Aufrufe.

    protected virtual void Dispose(Boolean disposing) {
      if (!this.disposedValue) {
        if (disposing) {
          this.p.CancelOutputRead();
          this.p.Kill();
          this.p.Close();
        }
        this.p = null;
        this.disposedValue = true;
      }
    }

    ~Mosquitto() {
      Dispose(false);
    }

    public void Dispose() {
      Dispose(true);
      GC.SuppressFinalize(this);
    }
    #endregion
  }
  class MqttEventArgs : EventArgs {
    public MqttEventArgs() : base() { }
    public MqttEventArgs(String message, String topic) {
      this.Topic = topic;
      this.Message = message;
      this.Date = DateTime.Now;
    }

    public String Topic { get; private set; }
    public String Message { get; private set; }
    public DateTime Date { get; private set; }
  }
}