using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.Devices.Client;
using PNC.Core.RabbleEngine.Azure;
using PNC.Core.RabbleEngine.QAD;
using NLog;
using System.Security.Cryptography.X509Certificates;
namespace QADRPCHostCMD
{
  class Program
  {
    private static DeviceClient _client = null;
    private static Logger logger = LogManager.GetCurrentClassLogger();
    private static RetryPolicy<ServiceBusTransientErrorDetectionStrategy> _retryPolicy;
    /// <summary>
    /// lazy logger...
    /// </summary>
    /// <param name="msg">message to log</param>
    /// <param name="newLine"></param>
    static void _log(string msg, bool newLine = true)
    {
      logger.Info(msg);
      if (newLine)
        Console.WriteLine(msg);
      else
        Console.Write(msg);
    }

    /// <summary>
    /// Sets a RPC handle
    /// </summary>
    /// <param name="methodName">Name of remote method</param>
    /// <param name="rpcCallback">call back function</param>
    /// <returns>outcome of operation</returns>
    static bool _setHandler(string methodName, MethodCallback rpcCallback)
    {
      // A lot going on in this method. We use the retry policy we instanciated in the main loop to set handles for RPC calling
      try
      {
        _log(string.Format("Setting handler '{0}'", methodName), false);
        _client.SetMethodHandlerAsync(methodName, rpcCallback, null).Wait();
        Console.ForegroundColor = ConsoleColor.Green;
        _log(" - Done.");
        Console.ForegroundColor = ConsoleColor.White;
        return true;
      }
      catch (Exception e)
      {
        _log(string.Format("FAULT: {0}\n\tStack Trace: {1}", e.Message, e.StackTrace));
        return false;
      }
    }

    /// <summary>
    /// Removes runtime handlers for RPC 
    /// </summary>
    /// <param name="methodName">method to remove</param>
    /// <returns>outcome of operation</returns>
    static bool _removeHandler(string methodName)
    {
      try
      {
        _log(string.Format("Setting handler '{0}'", methodName), false);
        _client?.SetMethodHandlerAsync(methodName, null, null).Wait();
        Console.ForegroundColor = ConsoleColor.Green;
        _log(" - Done.");
        Console.ForegroundColor = ConsoleColor.White;
        return true;
      }
      catch (Exception e)
      {
        _log(string.Format("FAULT: {0}\n\tStack Trace: {1}", e.Message, e.StackTrace));
        return false;
      }
    }

    /// <summary>
    /// Methods must be setup to be handled here
    /// </summary>
    static void _setupMethodHandlers()
    {
      if (!(
      _setHandler("IsValidSerial", QADRPCHost.QADRPCMethods.IsValidSerial) &&
      _setHandler("GetInventroyList", QADRPCHost.QADRPCMethods.GetInventoryList) &&
      _setHandler("MoveFGCtr", QADRPCHost.QADRPCMethods.MoveFGCtr) &&
      _setHandler("ValidateLogin", QADRPCHost.QADRPCMethods.ValidateLogin)
      // add new handler here
      )) throw new ApplicationException("Failed to initialize one or more handlers!"); // We cannot handle this exception, it must be fatal.
    }

    /// <summary>
    /// Deconstruct Method handlers here
    /// </summary>
    static void _cleanUpMethodHandlers()
    {
      if((!
      _removeHandler("IsValidSerial") &&
      _removeHandler("GetInventoryList") &&
      _removeHandler("MoveFGCtr") &&
      _removeHandler("ValidateLogin")
      )) throw new ApplicationException("Failed to unhook one or more handlers!"); // We cannot handle this exception, it must be fatal.
    }
    static void Main(string[] args)
    {
      Console.ForegroundColor = ConsoleColor.White;
      try
      {
		//Thumbprint for this device XXXXXXXXXXXXXXXXXXXXF630E82FE014B0469498
        DeviceAuthenticationWithX509Certificate certAuth = new DeviceAuthenticationWithX509Certificate("QADRPCEngine01", /* calls method to get X509 from cert store. I have confirmed the thumbprint matches whats in the device registry./*);
        _client = DeviceClient.Create("pc-iothub01.azure-devices.net", certAuth, TransportType.Mqtt);
        _setupMethodHandlers();

        Console.WriteLine();
        _log("Method listener Initialized Successfully...");
        _log("Now listening for incoming methods...");
        Console.WriteLine();
        _log("Press ESC at any time to quit.\n");

        while(true)
        {
          ConsoleKeyInfo input = Console.ReadKey();
          if (input.Key == ConsoleKey.Escape)
          {
            _log("Cleaning up method handlers...");
            _cleanUpMethodHandlers();
            _log("Done. Exiting...");
            Environment.Exit(0);
          }
        }

      }
      catch (Exception exc)
      {
        _log(exc.Message);
      }
    }


  }
}