#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 HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using System.Reflection;
using System.IO;
using HeuristicLab.Persistence.Default.Xml;
using System.Diagnostics;
using HeuristicLab.Optimization;
using System.Linq;
using Microsoft.Hpc.Scheduler;
using System.ServiceModel;
using HeuristicLab.MPIAlgorithmRunner;
using HeuristicLab.Operators.MPISupport;
using Microsoft.Hpc.Scheduler.Properties;
using System.Xml;
using System.ComponentModel;

namespace HeuristicLab.MPIEngine {
  /// <summary>
  /// Represents an engine that executes its steps in parallel (if possible) using multiple threads.
  /// This engine is suitable for parallel processing on shared memory systems which provide multiple cores.
  /// </summary>
  [StorableClass]
  [Item("MPI Engine", "Engine for parallel execution of algorithms using multiple processes (suitable for distributed memory systems with multiple cores).")]
  public class MPIEngine : Engine {
    private string username;

    [Category("MPISettings")]
    [Browsable(true)]
    public string UserName {
      get {
        return username;
      }

      set {
        username = value;
      }
    }

    private string password;

    [Category("MPISettings")]
    [Browsable(true)]
    [PasswordPropertyText(true)]
    public string Password {
      get {
        return password;
      }

      set {
        password = value;
      }
    }

    [Storable]
    private string headNode;

    [Category("MPISettings")]
    [Browsable(true)]
    public string HeadNode {
      get {
        return headNode;
      }

      set {
        headNode = value;
      }
    }

    [Storable]
    private string path;

    [Category("MPISettings")]
    [Browsable(true)]
    public string Path {
      get {
        return path;
      }

      set {
        path = value;
      }
    }

    [Storable]
    private int updateInterval;

    [Category("MPISettings")]
    [Browsable(true)]
    public int UpdateInterval {
      get {
        return updateInterval;
      }

      set {
        updateInterval = value;
      }
    }

    [Storable]
    private int cpuPerNode;

    [Category("MPISettings")]
    [Browsable(true)]
    public int CpuPerNode {
      get {
        return cpuPerNode;
      }

      set {
        cpuPerNode = value;
      }
    }

    [Storable]
    private List<string> requestedNodes;

    [Category("MPISettings")]
    [Browsable(true)]
    public List<string> RequestedNodes {
      get {
        return requestedNodes;
      }

      set {
        requestedNodes = value;
      }
    }

    [StorableConstructor]
    protected MPIEngine(bool deserializing) : base(deserializing) { }

    protected MPIEngine(MPIEngine original, Cloner cloner) : base(original, cloner) {
      username = original.username;
      password = original.password;
      headNode = original.headNode;
      path = original.path;
      updateInterval = original.updateInterval;
      cpuPerNode = original.cpuPerNode;
      requestedNodes = new List<string>();
      foreach (string node in original.requestedNodes)
        requestedNodes.Add(node);
    }

    public MPIEngine() : base() {
      username = @"user";
      password = @"password";
      headNode = "blade00.hpc.fh-hagenberg.at";
      path = @"C:\public\MPISupport";
      updateInterval = 5000;
      cpuPerNode = 3;
      requestedNodes = new List<string>();
      requestedNodes.Add("BLADE00");
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new MPIEngine(this, cloner);
    }

    private IAlgorithm algorithm;

    public override void Start() {
      if (ExecutionStack.Count == 1) {
        ExecutionContext context = ExecutionStack.First() as ExecutionContext;

        ExecutionContext algorithmContext = context.Parent as ExecutionContext;

        EngineAlgorithm alg = typeof(ExecutionContext).InvokeMember("parameterizedItem",
          BindingFlags.GetField | BindingFlags.NonPublic |
          BindingFlags.Instance, null, algorithmContext, null) as EngineAlgorithm;

        alg = alg.Clone() as EngineAlgorithm;
        alg.Engine = new SequentialEngine.SequentialEngine();

        algorithm = alg;
      }

      base.Start();
    }

    protected override void OnPaused() {
      base.OnPaused();

      Stop();
    }

    protected override void Run(System.Threading.CancellationToken cancellationToken) {
      if (ExecutionStack.Count == 1) {
        ExecutionContext context = ExecutionStack.Pop() as ExecutionContext;

        IScope globalScope = context.Scope;

        string exec = @"mpiexec";
        string args = @"-c " + cpuPerNode + " /genvlist CCP_JOBID " + path + @"\HeuristicLab.MPIAlgorithmRunner-3.3.exe";

        IScheduler scheduler = new Scheduler();
        scheduler.Connect(headNode);

        ISchedulerJob job = scheduler.CreateJob();
        job.Name = "HeuristicLab.MPIEngine";
        foreach (string requestedNode in requestedNodes)
          job.RequestedNodes.Add(requestedNode);
        ISchedulerTask task = job.CreateTask();
        task.Name = "HeuristicLab.MPIAlgorithmRunner";
        task.CommandLine = exec + " " + args;
        task.StdOutFilePath = "stdout.txt";
        task.StdErrFilePath = "stderr.txt";
        task.WorkDirectory = path;
        task.MinimumNumberOfCores = task.MaximumNumberOfCores = cpuPerNode * requestedNodes.Count;
        job.AddTask(task);

        scheduler.SubmitJob(job, username, password);

        try {
          string address = null;
          int timeout = 10;

          while (address == null && timeout > 0) {
            cancellationToken.ThrowIfCancellationRequested();

            ISchedulerJob schedulerJob = scheduler.OpenJob(job.Id);
            if (schedulerJob != null) {
              NameValue property = schedulerJob.GetCustomProperties().FirstOrDefault(p => p.Name == "address");

              if (property != null) {
                address = property.Value;
              } else {
                System.Threading.Thread.Sleep(1000);
                timeout--;
              }
            }            
          }

          if (address == null) {
            throw new Exception("A timeout occurred when starting the MPIAlgorithmRunner");
          }

          NetTcpBinding netTCPBinding = new NetTcpBinding(SecurityMode.None);
          netTCPBinding.TransferMode = TransferMode.Streamed;
          netTCPBinding.MaxReceivedMessageSize = int.MaxValue;
          ChannelFactory<IAlgorithmBroker> factory = new ChannelFactory<IAlgorithmBroker>(netTCPBinding, address);
          IAlgorithmBroker proxy = factory.CreateChannel();

          Stream stream = new MemoryStream();
          XmlGenerator.Serialize(algorithm, stream);
          stream = new MemoryStream((stream as MemoryStream).GetBuffer());

          proxy.TransmitAlgorithm(stream);
          proxy.SetUpdateInterval(updateInterval);

          while (!proxy.IsAlgorithmTerminated()) {
            cancellationToken.ThrowIfCancellationRequested();

            ItemList<ResultCollection> results = StreamingHelper.StreamItem(proxy.GetResults()) as ItemList<ResultCollection>;

            ResultCollection resultCollection = (globalScope.Variables["Results"].Value as ResultCollection);

            if (resultCollection != null && results != null) {
              if (!resultCollection.ContainsKey("MPIResults"))
                resultCollection.Add(new Result("MPIResults", results));

              resultCollection["MPIResults"].Value = results;
            }

            System.Threading.Thread.Sleep(updateInterval);
          }
        }
        catch (Exception e) {
          scheduler.CancelJob(job.Id, "Exception: " + e.GetType());
          throw e;
        }
      }
    }
  }
}