#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 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.ServiceModel;
using HeuristicLab.Clients.Hive.SlaveCore.ServiceContracts;
using HeuristicLab.Common;
using HeuristicLab.Core;

namespace HeuristicLab.Clients.Hive.SlaveCore.Views {

  [CallbackBehavior(ConcurrencyMode = ConcurrencyMode.Reentrant)]
  [Item("SlaveItem", "Represents a slave which receives messages from the core")]
  public class SlaveItem : Item, ISlaveCommunicationCallbacks, IDisposable {
    ISlaveCommunication pipeProxy;
    DuplexChannelFactory<ISlaveCommunication> pipeFactory;

    public SlaveItem() {
    }

    private void RegisterEvents() {
      pipeFactory.Faulted += new EventHandler(pipeFactory_Faulted);
      pipeFactory.Closed += new EventHandler(pipeFactory_Closed);
      pipeFactory.Opened += new EventHandler(pipeFactory_Opened);
    }

    private void DeregisterEvents() {
      pipeFactory.Faulted -= new EventHandler(pipeFactory_Faulted);
      pipeFactory.Closed -= new EventHandler(pipeFactory_Closed);
      pipeFactory.Opened -= new EventHandler(pipeFactory_Opened);
    }

    void pipeFactory_Opened(object sender, EventArgs e) {
      OnMessageLogged("Connection to Slave core established");
    }

    void pipeFactory_Closed(object sender, EventArgs e) {
      OnMessageLogged("Connection to Slave core closed");
    }

    void pipeFactory_Faulted(object sender, EventArgs e) {
      OnMessageLogged("Connection to Slave core faulted");
    }

    public void Open() {
      //TODO: read info from app.config
      pipeFactory = new DuplexChannelFactory<ISlaveCommunication>(this,
        new NetNamedPipeBinding(), new EndpointAddress("net.pipe://localhost/HeuristicLabSlaveCom"));

      pipeProxy = pipeFactory.CreateChannel();
      RegisterEvents();

      try {
        pipeProxy.Subscribe();
      }
      catch (Exception e) {
        OnMessageLogged("Couldn't connect to Slave core. Is it possible that the Slave Core isn't running?\nException is: " + e.ToString());
      }
    }

    public void ReconnectToSlaveCore() {
      try {
        pipeProxy = pipeFactory.CreateChannel();
        pipeProxy.Subscribe();
      }
      catch (Exception e) {
        OnMessageLogged("Couldn't connect to Slave core. Is it possible that the Slave Core isn't running?\nException is: " + e.ToString());
      }
    }

    public bool isClosed() {
      if (pipeFactory == null) return true;
      return pipeFactory.State == CommunicationState.Closed;
    }

    public void PauseAll() {
      try {
        if (pipeFactory.State != CommunicationState.Faulted && pipeFactory.State != CommunicationState.Closed)
          pipeProxy.PauseAll();
      }
      catch (Exception e) {
        OnMessageLogged("Error soft pausening core: " + e.ToString());
      }
    }

    public void StopAll() {
      try {
        if (pipeFactory.State != CommunicationState.Faulted && pipeFactory.State != CommunicationState.Closed)
          pipeProxy.StopAll();
      }
      catch (Exception e) {
        OnMessageLogged("Error hard pausening core: " + e.ToString());
      }
    }

    public void RestartCore() {
      try {
        if (pipeFactory.State != CommunicationState.Faulted && pipeFactory.State != CommunicationState.Closed)
          pipeProxy.Restart();
      }
      catch (Exception e) {
        OnMessageLogged("Error restarting core: " + e.ToString());
      }
    }

    public void Sleep() {
      try {
        if (pipeFactory.State != CommunicationState.Faulted && pipeFactory.State != CommunicationState.Closed)
          pipeProxy.Sleep();
      }
      catch (Exception e) {
        OnMessageLogged("Error sending core to sleep: " + e.ToString());
      }
    }

    public void Close() {
      if (pipeFactory.State != CommunicationState.Closed) {
        pipeProxy.Unsubscribe();
        pipeFactory.Close();
      }
    }

    public event EventHandler<EventArgs<StatusCommons>> SlaveStatusChanged;
    public void OnStatusChanged(StatusCommons status) {
      var handler = SlaveStatusChanged;
      if (handler != null) handler(this, new EventArgs<StatusCommons>(status));
    }

    public event EventHandler<EventArgs<string>> SlaveMessageLogged;
    public void OnMessageLogged(string message) {
      var handler = SlaveMessageLogged;
      if (handler != null) handler(this, new EventArgs<string>(message));
    }

    public event EventHandler SlaveShutdown;
    public void OnShutdown() {
      var handler = SlaveShutdown;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public void Dispose() {
      DeregisterEvents();
      Close();
    }

    public override Common.IDeepCloneable Clone(Common.Cloner cloner) {
      throw new NotImplementedException("It's not allowed to clone a SlaveItem!");
    }
  }
}