C# file to drive robots from within AutoCAD via our Node/Cylon.js web-service

drive-robot.cs

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Runtime;
using System.Globalization;
using System.Net;
using System.Web.Script.Serialization;

namespace DriveRobots
{
  public static class Extensions
  {
    public static string ToTitleCase(this string str)
    {
      return CultureInfo.CurrentCulture.TextInfo.ToTitleCase(str.ToLower());
    }
  }

  public class Commands
  {
    private static string _lastBot = "";
    const string host = "http://localhost:8080";
    const string root = host + "/api/robots";

    [CommandMethod("DR")]
    public void DriveRobot()
    {
      var doc = Application.DocumentManager.MdiActiveDocument;
      if (doc == null)
        return;
      var ed = doc.Editor;
      var db = doc.Database;

      using (var wc = new WebClient())
      {
        string[] names = null;
        try
        {
          var json = wc.DownloadString(root);
          names = new JavaScriptSerializer().Deserialize<string[]>(json);
        }
        catch (System.Exception ex)
        {
          ed.WriteMessage("\nCan't access robot web-service: {0}.", ex.Message);
          return;
        }

        // Ask the user for the robot to control

        var pko = new PromptKeywordOptions("\nRobot name");
        foreach (var name in names)
        {
          pko.Keywords.Add(name.ToTitleCase());
        }

        // If a bot was selected previously, set it as the default

        if (!string.IsNullOrEmpty(_lastBot))
        {
          pko.Keywords.Default = _lastBot;
        }
        var pkr = ed.GetKeywords(pko);

        if (pkr.Status != PromptStatus.OK)
          return;

        _lastBot = pkr.StringResult;
        var botUrl = root + "/" + _lastBot.ToLower();

        // Start by getting the bot - this should wake it, if needed

        try
        {
          wc.DownloadString(botUrl);
        }
        catch (System.Exception ex)
        {
          ed.WriteMessage("\nCan't connect to {0}: {1}.", _lastBot, ex.Message);
          return;
        }

        // The direction can be one of the four main directions or a number

        var pio = new PromptIntegerOptions("\nDirection");
        pio.Keywords.Add("Left");
        pio.Keywords.Add("Right");
        pio.Keywords.Add("Forward");
        pio.Keywords.Add("Backward");
        pio.AppendKeywordsToMessage = true;

        // Set the direction depending on which was chosen

        var pir = ed.GetInteger(pio);
        var direction = "";
        if (pir.Status == PromptStatus.Keyword)
        {
          direction = pir.StringResult;
        }
        else if (pir.Status == PromptStatus.OK)
        {
          direction = pir.Value.ToString();
        }
        else return;

        // Generate the URL to direct the robot

        var dirUrl = botUrl + "/" + direction.ToLower();

        // Our move command

        try
        {
          wc.DownloadString(dirUrl);            
        }
        catch (System.Exception ex)
        {
          ed.WriteMessage("\nCan't move {0}: {1}.", _lastBot, ex.Message);
        }
      }
    }
  }
}