#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2011 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HeuristicLab.Optimization;
using HeuristicLab.Persistence.Default.Xml;
using System.Threading;
using HeuristicLab.Operators.MPISupport;
using HeuristicLab.Core;
using Microsoft.Hpc.Scheduler;
using System.ServiceModel;
using System.Net;

namespace HeuristicLab.MPIAlgorithmRunner {
  class Program {
    private static void SetJobStatus(string address) {
      Console.WriteLine("Started service... at " + address);

      // Discover the job's context from the environment
      String headNodeName = System.Environment.GetEnvironmentVariable("CCP_SCHEDULER");
      int jobId = System.Convert.ToInt32(System.Environment.GetEnvironmentVariable("CCP_JOBID"));

      Console.WriteLine(jobId + "@" + headNodeName); 

      // Connect to the head node and get the job
      IScheduler scheduler = new Scheduler();
      scheduler.Connect(headNodeName);
      ISchedulerJob job = scheduler.OpenJob(jobId);

      job.SetCustomProperty("address", address);

      job.Commit();
    }

    private static string GetAddress(ServiceHost service) {
      IPHostEntry IPHost = Dns.GetHostByName(Dns.GetHostName());
      string address = "net.tcp://" + IPHost.AddressList[0].ToString() + ":" + service.ChannelDispatchers[0].Listener.Uri.Port + "/AlgorithmBroker";

      return address;
    }

    static void Main(string[] args) {
      using (new MPI.Environment(ref args)) {
        int clients = MPI.Communicator.world.Group.Size - 1;
        Console.WriteLine("Clients: " + clients);

        MPI.Communicator communicator = MPI.Communicator.world.Clone() as MPI.Communicator;

        if (communicator.Rank == 0) {
          ServiceHost service = AlgorithmBroker.StartService(communicator);
          AlgorithmBroker broker = (service.SingletonInstance as AlgorithmBroker);

          string address = GetAddress(service);
          SetJobStatus(address);

          bool[] finished = new bool[clients];
          int finishedCount = 0;

          while (finishedCount != clients) {
            ItemList<ResultCollection> results = new ItemList<ResultCollection>();

            for (int i = 0; i < clients; i++) {
              if (!finished[i]) {
                int client = i + 1;
                ResultCollection result = communicator.Receive<MPITransportWrapper<ResultCollection>>(client, 1).InnerItem;

                Console.WriteLine("Received result " + result);

                if (results.Count != clients) {
                  results.Add(result);
                } else {
                  results[i] = result;
                }

                Console.WriteLine("Probing...");
                if (communicator.ImmediateProbe(client, 2) != null) {
                  finished[i] = true;
                  finishedCount++;
                }
              }
            }

            Console.WriteLine("Update results");
            lock (broker.resultLocker)
              broker.Results = results;
          }

          lock (broker.ExitWaitHandle) {
            broker.Terminated = true;
          }

          broker.ExitWaitHandle.WaitOne();
          Console.WriteLine("Finished.");
          Thread.Sleep(1000);
          service.Close();
        } else {
          Program p = new Program();
          p.StartAlgorithm(communicator);
        }
      }
    }

    private EventWaitHandle waitHandle;

    public void StartAlgorithm(MPI.Communicator communicator) {
      IAlgorithm alg = communicator.Receive<MPITransportWrapper<IAlgorithm>>(0, 0).InnerItem;
      int updateInterval = communicator.Receive<int>(0, 1);

      Console.WriteLine("Starting algorithm...");

      alg.Prepare(true);
      waitHandle = new EventWaitHandle(false, EventResetMode.ManualReset);
      alg.Started += new EventHandler(alg_Started);
      alg.Start();

      waitHandle.WaitOne();

      alg.Started -= new EventHandler(alg_Started);

      while (alg.ExecutionState != ExecutionState.Stopped) {
        Console.WriteLine("Pausing alg...");
        alg.Pause();

        while (alg.ExecutionState == ExecutionState.Started) {
          Thread.Sleep(100);
        }

        communicator.Send<MPITransportWrapper<ResultCollection>>(
          new MPITransportWrapper<ResultCollection>(alg.Results), 0, 1);

        Console.WriteLine("Sending update...");

        Console.WriteLine("Resuming alg...");
        if (alg.ExecutionState == ExecutionState.Paused)
          alg.Start();
        Thread.Sleep(updateInterval);
      }

      communicator.Send<int>(communicator.Rank, 0, 2);
      communicator.Send<MPITransportWrapper<ResultCollection>>(
          new MPITransportWrapper<ResultCollection>(alg.Results), 0, 1);
    }

    void alg_Started(object sender, EventArgs e) {
      waitHandle.Set();
    }
  }
}