using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Linq;
using System.Windows.Forms;
using HeuristicLab.Optimization.Views;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.PluginInfrastructure;
using HeuristicLab.Optimization;
using HeuristicLab.Common.Resources;
using System.Collections.Specialized;
using System.Threading;
using HeuristicLab.BackgroundProcessing;
using HeuristicLab.Collections;

namespace HeuristicLab.OKB.AlgorithmHost {

  [View("OKB Algorithm Host View")]
  [Content(typeof(AlgorithmHost), true)]
  public partial class AlgorithmHostView : NamedItemView {

    protected WorkerMonitor workerMonitor;

    public new AlgorithmHost Content {
      get { return (AlgorithmHost)base.Content; }
      set { base.Content = value; }
    }

    public AlgorithmHostView() {
      InitializeComponent();
      workerMonitor = new WorkerMonitor();
      workerMonitor.BackgroundWorkerException += new ThreadExceptionEventHandler(workerMonitor_BackgroundWorkerException);
      workerMonitor.CollectionChanged += new NotifyCollectionChangedEventHandler(workerMonitor_CollectionChanged);
    }

    void workerMonitor_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e) {
      if (InvokeRequired) {
        Invoke(new NotifyCollectionChangedEventHandler(workerMonitor_CollectionChanged), sender, e);
      } else {
        switch (e.Action) {
          case NotifyCollectionChangedAction.Add:
            string name = ((ObservableBackgroundWorker)e.NewItems[0]).Name;
            statusStrip.Items.Add(new ToolStripStatusLabel(name) {
              Name = name,
              BorderSides = ToolStripStatusLabelBorderSides.Left,
              BorderStyle = Border3DStyle.Etched,
            });
            break;
          case NotifyCollectionChangedAction.Remove:
            statusStrip.Items.RemoveByKey(((ObservableBackgroundWorker)e.OldItems[0]).Name);
            break;
        }
        progressBar.Visible = statusStrip.Items.Count > 0;
        if (statusStrip.Items.Count > 0) {
          okbTabPage.Text = "OKB*";
        } else {
          okbTabPage.Text = "OKB";
        }
      }
    }

    void workerMonitor_BackgroundWorkerException(object sender, ThreadExceptionEventArgs e) {
      if (InvokeRequired) {
        Invoke(new ThreadExceptionEventHandler(workerMonitor_BackgroundWorkerException), sender, e);
      } else {
        ErrorHandling.ShowErrorDialog(this, "Uncaught asynchronous exception", e.Exception);
      }
    }

    protected override void OnInitialized(EventArgs e) {
      // Set order of tab pages according to z order.
      // NOTE: This is required due to a bug in the VS designer.
      List<Control> tabPages = new List<Control>();
      for (int i = 0; i < tabControl.Controls.Count; i++) {
        tabPages.Add(tabControl.Controls[i]);
      }
      tabControl.Controls.Clear();
      foreach (Control control in tabPages)
        tabControl.Controls.Add(control);

      runsView.ItemsListView.SelectedIndexChanged += new EventHandler(ItemsListView_SelectedIndexChanged);
      base.OnInitialized(e);
    }

    void ItemsListView_SelectedIndexChanged(object sender, EventArgs e) {
      submitButton.Enabled = runsView.ItemsListView.SelectedIndices.Count > 0;
    }

    protected override void DeregisterContentEvents() {
      Content.ExceptionOccurred -= new EventHandler<EventArgs<Exception>>(Content_ExceptionOccurred);
      Content.ExecutionStateChanged -= new EventHandler(Content_ExecutionStateChanged);
      Content.ExecutionTimeChanged -= new EventHandler(Content_ExecutionTimeChanged);
      Content.Prepared -= Content_Prepared;
      Content.AlgorithmChanged -= Content_AlgorithmChanged;
      Content.ProblemChanged -= Content_ProblemChanged;
      Content.Runs.ItemsAdded -= Runs_ItemsAdded;
      base.DeregisterContentEvents();
    }

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.ExceptionOccurred += new EventHandler<EventArgs<Exception>>(Content_ExceptionOccurred);
      Content.ExecutionStateChanged += new EventHandler(Content_ExecutionStateChanged);
      Content.ExecutionTimeChanged += new EventHandler(Content_ExecutionTimeChanged);
      Content.Prepared += Content_Prepared;
      Content.AlgorithmChanged += Content_AlgorithmChanged;
      Content.ProblemChanged += Content_ProblemChanged;
      Content.Runs.ItemsAdded += Runs_ItemsAdded;
    }

    void Runs_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IRun> e) {
      if (InvokeRequired) {
        Invoke(new CollectionItemsChangedEventHandler<IRun>(Runs_ItemsAdded), sender, e);
      } else {
        if (autoSubmitCheckBox.Checked) {
          foreach (IRun run in e.Items) {
            SubmitRun(run, true);
          }
        }
      }
    }

    void Content_ProblemChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_ProblemChanged), sender, e);
      else {
        problemParameterCollectionView.Content = Content.ProblemParameters;
        SetEnableStateOfControls();
        if (!Content.HasOKBProblem)
          MessageBox.Show(ParentForm,
            "Non-OKB problem selected: You will not be able to submit results with non-OKB problems",
            "Non-OKB Problem Selected.", MessageBoxButtons.OK, MessageBoxIcon.Warning);
      }
    }

    void Content_AlgorithmChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_AlgorithmChanged), sender, e);
      else {
        algorithmParameterCollectionView.Content = Content.Algorithm.Parameters;
        resultsView.Content = Content.Algorithm.Results.AsReadOnly();
        SetEnableStateOfControls();
      }
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        algorithmParameterCollectionView.Content = null;
        problemParameterCollectionView.Content = null;
        resultsView.Content = null;
        runsView.Content = null;
        executionTimeTextBox.Text = "-";
      } else {
        algorithmParameterCollectionView.Content = Content.Parameters;
        problemParameterCollectionView.Content = Content.ProblemParameters;
        runsView.Content = Content.Runs;
        executionTimeTextBox.Text = Content.ExecutionTime.ToString();
        if (Content.StarterKit == null)
          DownloadStarterKit();
      }
      SetEnableStateOfControls();
    }

    private void DownloadStarterKit() {
      BackgroundWorker loader = new ObservableBackgroundWorker("Connecting...", workerMonitor);
      loader.DoWork += (s, a) => {
        var starterKit = Content.DownloadStarerKit();
        Content.StarterKit = starterKit;
      };
      connectButton.Enabled = false;
      SetEnableStateOfControls();
      loader.RunWorkerCompleted += (s, a) => {
        connectButton.Enabled = true;
        SetEnableStateOfControls();
      };
      loader.RunWorkerAsync();
    }

    protected override void OnReadOnlyChanged() {
      base.OnReadOnlyChanged();
      SetEnableStateOfControls();
    }

    private void SetEnableStateOfControls() {
      openAlgorithmButton.Enabled = Content != null && Content.StarterKit != null;
      openProblemButton.Enabled = Content != null && Content.StarterKit != null;
      algorithmParameterCollectionView.Enabled = Content != null && Content.Algorithm != null;
      problemParameterCollectionView.Enabled = Content != null && Content.Problem != null;
      resultsView.Enabled = Content != null;
      runsView.Enabled = Content != null;
      executionTimeTextBox.Enabled = Content != null;
      viewAlgorithmButton.Enabled = Content != null && Content.Algorithm != null;
      viewProblemButton.Enabled = Content != null && Content.Problem != null;
      SetEnabledStateOfExecutableButtons();
    }

    protected override void OnClosed(FormClosedEventArgs e) {
      if ((Content != null) && (Content.ExecutionState == ExecutionState.Started)) Content.Stop();
      base.OnClosed(e);
    }

    #region Content Events
    protected virtual void Content_Prepared(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_Prepared), sender, e);
      else
        resultsView.Content = Content.Results.AsReadOnly();
    }
    protected virtual void Content_ExecutionStateChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_ExecutionStateChanged), sender, e);
      else {
        ReadOnly = Content.ExecutionState == ExecutionState.Started;
        Locked = Content.ExecutionState == ExecutionState.Started;
        SetEnabledStateOfExecutableButtons();
      }
    }
    protected virtual void Content_ExecutionTimeChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Content_ExecutionTimeChanged), sender, e);
      else
        executionTimeTextBox.Text = Content.ExecutionTime.ToString();
    }
    protected virtual void Content_ExceptionOccurred(object sender, EventArgs<Exception> e) {
      if (InvokeRequired)
        Invoke(new EventHandler<EventArgs<Exception>>(Content_ExceptionOccurred), sender, e);
      else
        ErrorHandling.ShowErrorDialog(this, e.Value);
    }
    #endregion

    #region Control Events
    protected virtual void openAlgorithmButton_Click(object sender, EventArgs e) {
      SelectItemDialog d = new SelectItemDialog();
      foreach (var ac in Content.StarterKit.AlgorithmClasses) {
        foreach (var a in ac.Algorithms) {
          d.AddItem(a.Name, a.Description, ac.Name, a, VS2008ImageLibrary.ExecutableStopped);
        }
      }
      if (d.ShowDialog(ParentForm) == DialogResult.OK) {
        var loader = new ObservableBackgroundWorker("loading algorithm...", workerMonitor);
        loader.DoWork += (s, a) => {
          Content.OKBAlgorithm = d.Item as OKBRunner.Algorithm;
        };
        loader.RunWorkerAsync();
      }
    }
    protected virtual void openProblemButton_Click(object sender, EventArgs e) {
      SelectItemDialog d = new SelectItemDialog();
      foreach (var pc in Content.StarterKit.ProblemClasses) {
        foreach (var p in pc.Problems) {
          d.AddItem(p.Name, p.Description, pc.Name, p, VS2008ImageLibrary.Type);
        }
      }
      if (d.ShowDialog(ParentForm) == DialogResult.OK) {
        var loader = new ObservableBackgroundWorker("loading problem...", workerMonitor);
        loader.DoWork += (s, a) => {
          Content.OKBProblem = d.Item as OKBRunner.Problem;
        };
        loader.RunWorkerAsync();
      }
    }
    protected virtual void startButton_Click(object sender, EventArgs e) {
      Content.Start();
    }
    protected virtual void pauseButton_Click(object sender, EventArgs e) {
      Content.Pause();
    }
    protected virtual void stopButton_Click(object sender, EventArgs e) {
      Content.Stop();
    }
    protected virtual void resetButton_Click(object sender, EventArgs e) {
      Content.Prepare(false);
    }
    protected virtual void connectButton_Click(object sender, EventArgs e) {
      DownloadStarterKit();
    }
    #endregion

    #region Helpers
    private void SetEnabledStateOfExecutableButtons() {
      if (Content == null) {
        startButton.Enabled = pauseButton.Enabled = stopButton.Enabled = resetButton.Enabled = false;
      } else {
        startButton.Enabled = (Content.ExecutionState == ExecutionState.Prepared) || (Content.ExecutionState == ExecutionState.Paused);
        pauseButton.Enabled = Content.ExecutionState == ExecutionState.Started;
        stopButton.Enabled = (Content.ExecutionState == ExecutionState.Started) || (Content.ExecutionState == ExecutionState.Paused);
        resetButton.Enabled = Content.ExecutionState != ExecutionState.Started;
      }
    }
    #endregion

    private void submitButton_Click(object sender, EventArgs e) {
      foreach (ListViewItem item in runsView.ItemsListView.SelectedItems) {
        SubmitRun(item.Tag as IRun, false);
      }
    }

    private void SubmitRun(IRun run, bool skipConfirmation) {
      if (run == null) {
        MessageBox.Show(this, "selected item is not an IRun :`(");
      } else {
        var worker = new ObservableBackgroundWorker("Preparing submission: " + run.Name, workerMonitor);
        OKBRunner.ExperimentKit experimentKit = null;
        worker.DoWork += (s, a) => {
          experimentKit = Content.PrepareSubmission(run);
        };
        worker.RunWorkerCompleted += (s, a) => {
          if (experimentKit == null)
            return;
          if (skipConfirmation || ConfirmSubmission(experimentKit)) {
            var submitter = new ObservableBackgroundWorker("Submitting Run: " + run.Name, workerMonitor);
            submitter.DoWork += (s1, a1) => { Content.SubmitRun(experimentKit); };
            submitter.RunWorkerAsync();
          }
        };
        worker.RunWorkerAsync();
      }
    }

    private bool ConfirmSubmission(OKBRunner.ExperimentKit experimentKit) {
      return MessageBox.Show(this,
        AlgorithmHost.FormatSubmission(experimentKit),
        "Submit Run?",
        MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK;
    }

    private void viewAlgorithmButton_Click(object sender, EventArgs e) {
      if (Content.Algorithm == null) return;
      IContentView view = FindFirstView(Content.Algorithm);
      if (view == null && MessageBox.Show(ParentForm,
@"The defintion of this algorithm has been fixed inside the OKB
and should not be changed in a way that changes its behaviour

Please be careful with modifications!", "Algorithm assumed fixed!",
          MessageBoxButtons.OKCancel, MessageBoxIcon.Exclamation) == DialogResult.OK)
        view = MainFormManager.CreateDefaultView(Content.Algorithm.GetType());
      if (view != null) {
        view.Content = Content.Algorithm;
        view.Show();
      }
    }

    private void viewProblemButton_Click(object sender, EventArgs e) {
      if (Content.Problem == null) return;
      IContentView view = FindFirstView(Content.Problem);
      if (view == null && MessageBox.Show(ParentForm,
@"The defintion of this problem has been fixed inside the OKB
and should not be changed in a way that changes its behaviour.

Please be careful with modifications!", "Problem assumed fixed!",
          MessageBoxButtons.OKCancel, MessageBoxIcon.Exclamation) == DialogResult.OK)
        view = MainFormManager.CreateDefaultView(Content.Problem.GetType());
      if (view != null) {
        view.Content = Content.Problem;
        view.Show();
      }
    }

    private static IContentView FindFirstView(IContent content) {
      return MainFormManager.MainForm.Views
        .Where(v => v is IContentView)
        .Cast<IContentView>()
        .Where(v => v.Content == content)
        .FirstOrDefault();
    }

  }
}