using System;
using System.Windows.Forms;
using HeuristicLab.Common;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;
using HeuristicLab.Operators.Views;
using HeuristicLab.Optimization;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Operators {

  [View("EngineAlgorithmOperator View")]
  [Content(typeof(EngineAlgorithmOperator), IsDefaultView = true)]
  public sealed partial class EngineAlgorithmOperatorView : AlgorithmOperatorView {

    private TypeSelectorDialog algorithmTypeSelectorDialog;

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

    public EngineAlgorithmOperatorView() {
      InitializeComponent();
    }

    protected override void DeregisterContentEvents() {
      Content.AlgorithmChanged -= new EventHandler(Content_AlgorithmChanged);
      base.DeregisterContentEvents();
    }

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.AlgorithmChanged += new EventHandler(Content_AlgorithmChanged);
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        algorithmViewHost.Content = null;
      } else {
        algorithmViewHost.Content = Content.Algorithm;
      }
    }


    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
    }

    #region Event Handlers (Content)
    void Content_AlgorithmChanged(object sender, EventArgs e) {
      if (InvokeRequired) {
        Invoke(new EventHandler(Content_AlgorithmChanged), sender, e);
      } else {
        algorithmViewHost.Content = Content.Algorithm;
      }
    }
    #endregion

    #region Event Handlers (child controls)
    private void algorithmTabPage_DragDrop(object sender, DragEventArgs e) {
      if (e.Effect != DragDropEffects.None) {
        EngineAlgorithm algorithm = e.Data.GetData("Value") as EngineAlgorithm;
        if ((e.Effect & DragDropEffects.Copy) == DragDropEffects.Copy)
          algorithm = (EngineAlgorithm)algorithm.Clone();
        Content.Algorithm = algorithm;
      }
    }

    private void algorithmTabPage_DragEnterOver(object sender, DragEventArgs e) {
      e.Effect = DragDropEffects.None;
      Type type = e.Data.GetData("Type") as Type;
      if ((type != null) && (typeof(EngineAlgorithm).IsAssignableFrom(type))) {
        if ((e.KeyState & 32) == 32) e.Effect = DragDropEffects.Link;  // ALT key
        else if ((e.KeyState & 4) == 4) e.Effect = DragDropEffects.Move;  // SHIFT key
        else if ((e.AllowedEffect & DragDropEffects.Copy) == DragDropEffects.Copy) e.Effect = DragDropEffects.Copy;
        else if ((e.AllowedEffect & DragDropEffects.Move) == DragDropEffects.Move) e.Effect = DragDropEffects.Move;
        else if ((e.AllowedEffect & DragDropEffects.Link) == DragDropEffects.Link) e.Effect = DragDropEffects.Link;
      }
    }

    private void newAlgorithmButton_Click(object sender, System.EventArgs e) {
      if (algorithmTypeSelectorDialog == null) {
        algorithmTypeSelectorDialog = new TypeSelectorDialog();
        algorithmTypeSelectorDialog.Caption = "Select Algorithm";
        algorithmTypeSelectorDialog.TypeSelector.Caption = "Available Algorithm";
        algorithmTypeSelectorDialog.TypeSelector.Configure(typeof(EngineAlgorithm), false, true);
      }
      if (algorithmTypeSelectorDialog.ShowDialog(this) == DialogResult.OK) {
        try {
          Content.Algorithm = (EngineAlgorithm)algorithmTypeSelectorDialog.TypeSelector.CreateInstanceOfSelectedType();
        } catch (Exception ex) {
          ErrorHandling.ShowErrorDialog(this, ex);
        }
      }
    }

    private void openAlgorithmButton_Click(object sender, System.EventArgs e) {
      openFileDialog.Title = "Open Algorithm";
      if (openFileDialog.ShowDialog(this) == DialogResult.OK) {
        newAlgorithmButton.Enabled = openAlgorithmButton.Enabled = false;
        algorithmViewHost.Enabled = false;

        ContentManager.LoadAsync(openFileDialog.FileName, delegate(IStorableContent content, Exception error) {
          try {
            if (error != null) throw error;
            EngineAlgorithm algorithm = content as EngineAlgorithm;
            if (algorithm == null)
              Invoke(new Action(() =>
                MessageBox.Show(this, "The selected file does not contain an engine algorithm.", "Invalid File", MessageBoxButtons.OK, MessageBoxIcon.Error)));
            else
              Content.Algorithm = algorithm;
          } catch (Exception ex) {
            Invoke(new Action(() => ErrorHandling.ShowErrorDialog(this, ex)));
          } finally {
            Invoke(new Action(delegate() {
              algorithmViewHost.Enabled = true;
              newAlgorithmButton.Enabled = openAlgorithmButton.Enabled = true;
            }));
          }
        });
      }
    }
    #endregion
  }
}