using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace WeifenLuo.WinFormsUI.Docking {
  internal abstract class InertButtonBase : Control {
    protected InertButtonBase() {
      SetStyle(ControlStyles.SupportsTransparentBackColor, true);
      BackColor = Color.Transparent;
    }

    public abstract Bitmap Image {
      get;
    }

    private bool m_isMouseOver = false;
    protected bool IsMouseOver {
      get { return m_isMouseOver; }
      private set {
        if (m_isMouseOver == value)
          return;

        m_isMouseOver = value;
        Invalidate();
      }
    }

    protected override Size DefaultSize {
      get { return Resources.DockPane_Close.Size; }
    }

    protected override void OnMouseMove(MouseEventArgs e) {
      base.OnMouseMove(e);
      bool over = ClientRectangle.Contains(e.X, e.Y);
      if (IsMouseOver != over)
        IsMouseOver = over;
    }

    protected override void OnMouseEnter(EventArgs e) {
      base.OnMouseEnter(e);
      if (!IsMouseOver)
        IsMouseOver = true;
    }

    protected override void OnMouseLeave(EventArgs e) {
      base.OnMouseLeave(e);
      if (IsMouseOver)
        IsMouseOver = false;
    }

    protected override void OnPaint(PaintEventArgs e) {
      if (IsMouseOver && Enabled) {
        using (Pen pen = new Pen(ForeColor)) {
          e.Graphics.DrawRectangle(pen, Rectangle.Inflate(ClientRectangle, -1, -1));
        }
      }

      using (ImageAttributes imageAttributes = new ImageAttributes()) {
        ColorMap[] colorMap = new ColorMap[2];
        colorMap[0] = new ColorMap();
        colorMap[0].OldColor = Color.FromArgb(0, 0, 0);
        colorMap[0].NewColor = ForeColor;
        colorMap[1] = new ColorMap();
        colorMap[1].OldColor = Image.GetPixel(0, 0);
        colorMap[1].NewColor = Color.Transparent;

        imageAttributes.SetRemapTable(colorMap);

        e.Graphics.DrawImage(
           Image,
           new Rectangle(0, 0, Image.Width, Image.Height),
           0, 0,
           Image.Width,
           Image.Height,
           GraphicsUnit.Pixel,
           imageAttributes);
      }

      base.OnPaint(e);
    }

    public void RefreshChanges() {
      if (IsDisposed)
        return;

      bool mouseOver = ClientRectangle.Contains(PointToClient(Control.MousePosition));
      if (mouseOver != IsMouseOver)
        IsMouseOver = mouseOver;

      OnRefreshChanges();
    }

    protected virtual void OnRefreshChanges() {
    }
  }
}