#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.ComponentModel;
using System.Drawing;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Hive;

namespace HeuristicLab.Clients.Hive {
  public class RefreshableHiveExperiment : IHiveItem, IDeepCloneable, IContent, IProgressReporter {
    private JobResultPoller jobResultPoller;
    private ConcurrentJobDownloader<ItemJob> jobDownloader;
    private static object locker = new object();

    private HiveExperiment hiveExperiment;
    public HiveExperiment HiveExperiment {
      get { return hiveExperiment; }
      set {
        if (value != hiveExperiment) {
          if (value == null)
            throw new ArgumentNullException();

          if (hiveExperiment != null) DergisterHiveExperimentEvents();
          hiveExperiment = value;
          if (hiveExperiment != null) RegisterHiveExperimentEvents();
          OnHiveExperimentChanged();
        }
      }
    }

    /** include jobs when refreshing **/
    private bool includeJobs;
    public bool IncludeJobs {
      get { return includeJobs; }
      set { includeJobs = value; }
    }

    private bool refreshAutomatically;
    public bool RefreshAutomatically {
      get { return refreshAutomatically; }
      set {
        lock (locker) {
          if (refreshAutomatically != value) {
            refreshAutomatically = value;
            OnRefreshAutomaticallyChanged();
          }
          if (RefreshAutomatically) {
            if (hiveExperiment.HiveJobs != null && hiveExperiment.HiveJobs.Count > 0 && (jobResultPoller == null || !jobResultPoller.IsPolling)) {
              StartResultPolling();
            }
          } else {
            StopResultPolling();
          }
        }
      }
    }

    // if true, all control buttons should be enabled. otherwise disabled (used for HiveEngine)
    private bool isControllable = true;
    public bool IsControllable {
      get { return isControllable; }
      set {
        if (value != isControllable) {
          isControllable = value;
          OnIsControllableChanged();
        }
      }
    }

    private ILog log;
    public ILog Log {
      get { return log; }
      set { log = value; }
    }
    private static object logLocker = new object();
    

    #region Constructors and Cloning
    public RefreshableHiveExperiment() {
      this.includeJobs = true;
      this.refreshAutomatically = true;
      this.HiveExperiment = new HiveExperiment();
      this.log = new Log();
      this.jobDownloader = new ConcurrentJobDownloader<ItemJob>(2, 2);
      this.jobDownloader.ExceptionOccured += new EventHandler<EventArgs<Exception>>(jobDownloader_ExceptionOccured);
    }
    public RefreshableHiveExperiment(HiveExperiment hiveExperiment) {
      this.includeJobs = true;
      this.refreshAutomatically = true;
      this.HiveExperiment = hiveExperiment;
      this.log = new Log();
      this.jobDownloader = new ConcurrentJobDownloader<ItemJob>(2, 2);
      this.jobDownloader.ExceptionOccured += new EventHandler<EventArgs<Exception>>(jobDownloader_ExceptionOccured);
    }
    protected RefreshableHiveExperiment(RefreshableHiveExperiment original, Cloner cloner) {
      cloner.RegisterClonedObject(original, this);
      this.HiveExperiment = original.HiveExperiment;
      this.IncludeJobs = original.IncludeJobs;
      this.IsControllable = original.IsControllable;
      this.Log = cloner.Clone(original.Log);
      this.RefreshAutomatically = false; // do not start results polling automatically
      this.jobDownloader = new ConcurrentJobDownloader<ItemJob>(2, 2);
      this.jobDownloader.ExceptionOccured += new EventHandler<EventArgs<Exception>>(jobDownloader_ExceptionOccured);
    }
    public IDeepCloneable Clone(Cloner cloner) {
      return new RefreshableHiveExperiment(this, cloner);
    }
    public object Clone() {
      return this.Clone(new Cloner());
    }
    #endregion

    private void hiveExperiment_HiveJobsChanged(object sender, EventArgs e) {
      if (jobResultPoller != null && jobResultPoller.IsPolling) {
        jobResultPoller.Stop();
        DeregisterResultPollingEvents();
      }
      if (hiveExperiment.HiveJobs != null && hiveExperiment.HiveJobs.Count > 0 && hiveExperiment.GetAllHiveJobs().All(x => x.Job.Id != Guid.Empty)) {
        if (this.RefreshAutomatically)
          StartResultPolling();
      }
    }

    #region JobResultPoller Events

    public void StartResultPolling() {
      if (jobResultPoller == null) {
        jobResultPoller = new JobResultPoller(hiveExperiment.Id, /*ApplicationConstants.ResultPollingInterval*/new TimeSpan(0, 0, 5)); //TODO: find a better place for ApplicationConstants
        RegisterResultPollingEvents();
        jobResultPoller.AutoResumeOnException = !IsControllable;
      }

      if (!jobResultPoller.IsPolling) {
        jobResultPoller.Start();
      }
    }

    public void StopResultPolling() {
      if (jobResultPoller != null && jobResultPoller.IsPolling) {
        jobResultPoller.Stop();
      }
    }

    private void RegisterResultPollingEvents() {
      jobResultPoller.ExceptionOccured += new EventHandler<EventArgs<Exception>>(jobResultPoller_ExceptionOccured);
      jobResultPoller.JobResultsReceived += new EventHandler<EventArgs<IEnumerable<LightweightJob>>>(jobResultPoller_JobResultReceived);
      jobResultPoller.IsPollingChanged += new EventHandler(jobResultPoller_IsPollingChanged);
    }
    private void DeregisterResultPollingEvents() {
      jobResultPoller.ExceptionOccured -= new EventHandler<EventArgs<Exception>>(jobResultPoller_ExceptionOccured);
      jobResultPoller.JobResultsReceived -= new EventHandler<EventArgs<IEnumerable<LightweightJob>>>(jobResultPoller_JobResultReceived);
      jobResultPoller.IsPollingChanged -= new EventHandler(jobResultPoller_IsPollingChanged);
    }
    private void jobResultPoller_IsPollingChanged(object sender, EventArgs e) {
      this.refreshAutomatically = jobResultPoller.IsPolling;
      OnRefreshAutomaticallyChanged();
    }
    private void jobResultPoller_JobResultReceived(object sender, EventArgs<IEnumerable<LightweightJob>> e) {
      foreach (LightweightJob lightweightJob in e.Value) {
        HiveJob hiveJob = GetHiveJobById(lightweightJob.Id);
        if (hiveJob != null) {
          // lastJobDataUpdate equals DateTime.MinValue right after it was uploaded. When the first results are polled, this value is updated
          if (hiveJob.Job.State == JobState.Offline && lightweightJob.State != JobState.Finished && lightweightJob.State != JobState.Failed && lightweightJob.State != JobState.Aborted) {
            hiveJob.Job.LastJobDataUpdate = lightweightJob.LastJobDataUpdate;
          }

          hiveJob.UpdateFromLightweightJob(lightweightJob);

          if (!hiveJob.IsFinishedJobDownloaded && !hiveJob.IsDownloading && hiveJob.Job.LastJobDataUpdate < lightweightJob.LastJobDataUpdate) {
            LogMessage(string.Format("Downloading job {0}", lightweightJob.Id));
            hiveJob.IsDownloading = true;
            jobDownloader.DownloadJob(hiveJob.Job, (localJob, itemJob) => {
              LogMessage(string.Format("Finished downloading job {0}", localJob.Id));
              HiveJob localHiveJob = GetHiveJobById(localJob.Id);

              if (itemJob == null) {
                localHiveJob.IsDownloading = false;
              }

              if (itemJob == null) {
                // something bad happened to this job. bad job, BAAAD job!
              } else {
                // if the job is paused, download but don't integrate into parent optimizer (to avoid Prepare)

                if (localJob.State == JobState.Paused) {
                  localHiveJob.ItemJob = itemJob;
                } else {
                  if (localJob.ParentJobId.HasValue) {
                    HiveJob parentHiveJob = GetHiveJobById(localJob.ParentJobId.Value);
                    parentHiveJob.IntegrateChild(itemJob, localJob.Id);
                  } else {
                    localHiveJob.ItemJob = itemJob;
                  }
                }
                localHiveJob.IsDownloading = false;
                localHiveJob.Job.LastJobDataUpdate = localJob.LastJobDataUpdate;
              }
            });
          }
        }
      }
      GC.Collect(); // force GC, because .NET is too lazy here (deserialization takes a lot of memory)
      if (AllJobsFinished()) {
        hiveExperiment.ExecutionState = Core.ExecutionState.Stopped;
        StopResultPolling();
      }
      UpdateTotalExecutionTime();
      UpdateStatistics();
    }

    // synchronized logging
    private void LogException(Exception exception) {
      lock (logLocker) {
        this.log.LogException(exception);
      }
    }
    // synchronized logging
    private void LogMessage(string message) {
      lock (logLocker) {
        this.log.LogMessage(message);
      }
    }

    public HiveJob GetHiveJobById(Guid jobId) {
      foreach (HiveJob job in hiveExperiment.HiveJobs) {
        var hj = job.GetHiveJobByJobId(jobId);
        if (hj != null)
          return hj;
      }
      return null;
    }
    private void UpdateStatistics() {
      var jobs = hiveExperiment.GetAllHiveJobs();
      hiveExperiment.JobCount = jobs.Count();
      hiveExperiment.CalculatingCount = jobs.Count(j => j.Job.State == JobState.Calculating);
      hiveExperiment.FinishedCount = jobs.Count(j => j.Job.State == JobState.Finished);
      OnJobStatisticsChanged();
    }

    public bool AllJobsFinished() {
      return hiveExperiment.GetAllHiveJobs().All(j => (j.Job.State == JobState.Finished
                                                   || j.Job.State == JobState.Aborted
                                                   || j.Job.State == JobState.Failed)
                                                   && j.IsFinishedJobDownloaded);
    }

    private void jobResultPoller_ExceptionOccured(object sender, EventArgs<Exception> e) {
      OnExceptionOccured(e.Value);
    }
    private void jobDownloader_ExceptionOccured(object sender, EventArgs<Exception> e) {
      OnExceptionOccured(e.Value);
    }
    public void UpdateTotalExecutionTime() {
      hiveExperiment.ExecutionTime = TimeSpan.FromMilliseconds(hiveExperiment.GetAllHiveJobs().Sum(x => x.Job.ExecutionTime.HasValue ? x.Job.ExecutionTime.Value.TotalMilliseconds : 0));
    }
    #endregion

    private void RegisterHiveExperimentEvents() {
      hiveExperiment.HiveJobsChanged += new EventHandler(hiveExperiment_HiveJobsChanged);
      hiveExperiment.ToStringChanged += new EventHandler(hiveExperiment_ToStringChanged);
      hiveExperiment.PropertyChanged += new PropertyChangedEventHandler(hiveExperiment_PropertyChanged);
      hiveExperiment.ItemImageChanged += new EventHandler(hiveExperiment_ItemImageChanged);
      hiveExperiment.ModifiedChanged += new EventHandler(hiveExperiment_ModifiedChanged);
      hiveExperiment.IsProgressingChanged += new EventHandler(hiveExperiment_IsProgressingChanged);
      hiveExperiment.Loaded += new EventHandler(hiveExperiment_Loaded);
    }

    private void DergisterHiveExperimentEvents() {
      hiveExperiment.HiveJobsChanged -= new EventHandler(hiveExperiment_HiveJobsChanged);
      hiveExperiment.ToStringChanged -= new EventHandler(hiveExperiment_ToStringChanged);
      hiveExperiment.PropertyChanged -= new PropertyChangedEventHandler(hiveExperiment_PropertyChanged);
      hiveExperiment.ItemImageChanged -= new EventHandler(hiveExperiment_ItemImageChanged);
      hiveExperiment.ModifiedChanged -= new EventHandler(hiveExperiment_ModifiedChanged);
      hiveExperiment.IsProgressingChanged -= new EventHandler(hiveExperiment_IsProgressingChanged);
      hiveExperiment.Loaded -= new EventHandler(hiveExperiment_Loaded);
    }

    private void hiveExperiment_Loaded(object sender, EventArgs e) {
      this.UpdateTotalExecutionTime();

      if (hiveExperiment.ExecutionState != ExecutionState.Stopped) {
        this.RefreshAutomatically = true;
      }
    }

    #region Events
    public event EventHandler RefreshAutomaticallyChanged;
    private void OnRefreshAutomaticallyChanged() {
      var handler = RefreshAutomaticallyChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

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

    public event EventHandler ModifiedChanged;
    private void hiveExperiment_ModifiedChanged(object sender, EventArgs e) {
      var handler = ModifiedChanged;
      if (handler != null) handler(sender, e);
    }

    public event EventHandler ItemImageChanged;
    private void hiveExperiment_ItemImageChanged(object sender, EventArgs e) {
      var handler = ItemImageChanged;
      if (handler != null) handler(this, e);
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void hiveExperiment_PropertyChanged(object sender, PropertyChangedEventArgs e) {
      var handler = PropertyChanged;
      if (handler != null) handler(sender, e);
    }

    public event EventHandler ToStringChanged;
    private void hiveExperiment_ToStringChanged(object sender, EventArgs e) {
      var handler = ToStringChanged;
      if (handler != null) handler(this, e);
    }

    public event EventHandler IsProgressingChanged;
    private void hiveExperiment_IsProgressingChanged(object sender, EventArgs e) {
      var handler = IsProgressingChanged;
      if (handler != null) handler(sender, e);
    }

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

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

    public event EventHandler<EventArgs<Exception>> ExceptionOccured;
    private void OnExceptionOccured(Exception exception) {
      LogException(exception);
      var handler = ExceptionOccured;
      if (handler != null) handler(this, new EventArgs<Exception>(exception));
    }
    #endregion

    public Guid Id {
      get { return hiveExperiment.Id; }
      set { hiveExperiment.Id = value; }
    }
    public bool Modified {
      get { return hiveExperiment.Modified; }
    }
    public void Store() {
      hiveExperiment.Store();
    }
    public string ItemDescription {
      get { return hiveExperiment.ItemDescription; }
    }
    public Image ItemImage {
      get { return hiveExperiment.ItemImage; }
    }
    public string ItemName {
      get { return hiveExperiment.ItemName; }
    }
    public Version ItemVersion {
      get { return hiveExperiment.ItemVersion; }
    }


    #region IProgressReporter Members
    public IProgress Progress {
      get { return HiveExperiment.Progress; }
    }

    public bool IsProgressing {
      get { return HiveExperiment.IsProgressing; }
    }
    #endregion

    public override string ToString() {
      return HiveExperiment.ToString();
    }
  }
}