#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2016 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.Drawing;
using System.Linq;
using System.Windows.Forms;

namespace HeuristicLab.Visualization {
  public abstract class ChartMode {
    protected readonly ChartControl chartControl;
    protected readonly IList<Shortcut> globalShortcuts = new List<Shortcut>();
    protected readonly IList<Shortcut> localShortcuts;
    protected Shortcut activeShortcut = null;
    protected Cursor cursor;
    protected Point buttonDownPoint;
    protected Point previousLocation;
    protected int mouseClickCount;

    public abstract Image Image { get; }
    public abstract string Text { get; }

    public virtual string ToolTipText { get { return Text; } }

    public virtual Cursor Cursor {
      get { return cursor ?? (cursor = Cursors.Default); }
    }

    private bool selected;
    public bool Selected {
      get { return selected; }
      set {
        if (selected == value) return;
        selected = value;
        if (selected) {
          chartControl.Mode = this;
          OnSelected();
        } else {
          if (chartControl.Mode == this)
            chartControl.Mode = null;
          OnDeselected();
        }
        OnSelectedChanged();
      }
    }

    public IEnumerable<Shortcut> Shortcuts { get { return globalShortcuts; } }

    protected ChartMode(ChartControl control) {
      chartControl = control;
      chartControl.ModeChanged += (sender, args) => Selected = chartControl.Mode == this;
      localShortcuts = new List<Shortcut> {
        new Shortcut(Keys.Escape) { DownAction = Deselect }
      };
    }

    public void Select() { Selected = true; }
    public void Deselect() { Selected = false; }

    protected virtual void OnSelected() { }
    protected virtual void OnDeselected() { }

    public virtual void HandleOnKeyDown(object sender, KeyEventArgs e) {
      if (activeShortcut != null) return;

      foreach (var shortcut in localShortcuts) {
        if (e.KeyCode == shortcut.Key && e.Modifiers == shortcut.Modifiers) {
          activeShortcut = shortcut;
          var downAction = shortcut.DownAction;
          if (downAction != null) downAction();
          e.Handled = true;
          break;
        }
      }
    }

    public virtual void HandleOnKeyUp(object sender, KeyEventArgs e) {
      if (activeShortcut == null) return;

      var modifiers = new List<Keys>(from key in Enum.GetValues(typeof(Keys)).Cast<Keys>()
                                     where e.Modifiers.HasFlag(key)
                                     select key);

      if (activeShortcut.Key == e.KeyCode || activeShortcut.GetModifiers().Except(modifiers).Any()) {
        var upAction = activeShortcut.UpAction;
        if (upAction != null) upAction();
        activeShortcut = null;
        e.Handled = true;
      }
    }

    public virtual void HandleOnMouseClick(object sender, MouseEventArgs e) { }
    public virtual void HandleOnMouseDoubleClick(object sender, MouseEventArgs e) { }

    public virtual void HandleOnMouseDown(object sender, MouseEventArgs e) {
      buttonDownPoint = e.Location;
      mouseClickCount = e.Clicks;
    }

    public virtual void HandleOnMouseUp(object sender, MouseEventArgs e) { }

    public virtual void HandleOnMouseMove(object sender, MouseEventArgs e) {
      previousLocation = e.Location;
    }

    public virtual void HandleOnMouseWheel(object sender, MouseEventArgs e) { }
    public virtual void HandleOnMouseEnter(object sender, EventArgs e) { }
    public virtual void HandleOnMouseLeave(object sender, EventArgs e) { }
    public virtual void HandleOnClick(object sender, EventArgs e) { }

    public event EventHandler SelectedChanged;
    protected virtual void OnSelectedChanged() {
      var handler = SelectedChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public class Shortcut {
      public Keys Key { get; private set; }
      public Keys Modifiers { get; private set; }
      public Action DownAction { get; set; }
      public Action UpAction { get; set; }

      public Shortcut(Keys key, Keys modifiers = Keys.None) {
        Key = key;
        Modifiers = modifiers;
      }

      public IEnumerable<Keys> GetModifiers() {
        var keys = new List<Keys>(from key in Enum.GetValues(typeof(Keys)).Cast<Keys>()
                                  where Modifiers.HasFlag(key)
                                  select key);
        return keys;
      }
    }
  }
}