#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.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace HeuristicLab.Visualization {
  public abstract class LinearPrimitiveBase : PrimitiveBase {
    protected IGroup SelectionRectangles;

    private PointD myStart;
    public virtual PointD Start {
      get { return myStart; }
    }
    private PointD myEnd;
    public virtual PointD End {
      get { return myEnd; }
    }
    public virtual SizeD Size {
      get { return new SizeD(End.X - Start.X, End.Y - Start.Y); }
    }
    public virtual double Length {
      get { return (Start - End).Length; }
    }

    protected LinearPrimitiveBase(IChart chart, PointD start, PointD end)
      : base(chart) {
      SelectionRectangles = new Group(chart);
      myStart = start;
      myEnd = end;
    }
    protected LinearPrimitiveBase(IChart chart, PointD start, PointD end, Pen pen, Brush brush)
      : base(chart, pen, brush) {
      SelectionRectangles = new Group(chart);
      myStart = start;
      myEnd = end;
    }

    public virtual void SetPosition(PointD start, PointD end) {
      myStart = start;
      myEnd = end;
      OnRedrawRequired();
    }

    public override void Move(Offset delta) {
      SetPosition(Start + delta, End + delta);
    }

    public override void Move(PointD point, Offset delta) {
      if (Selected && SelectionRectangles.ContainsPoint(point)) {
        var rect = (SelectionRectangle)SelectionRectangles.GetPrimitive(point);
        if (rect.Point == Start) {
          SetPosition(Start + delta, End);
        } else if (rect.Point == End) {
          SetPosition(Start, End + delta);
        }
      } else SetPosition(Start + delta, End + delta);
    }

    public override void SnapToGrid(IGrid grid) {
      var bl = grid.GetBottomLeftGridPoint(Start);
      var ur = grid.GetUpperRightGridPoint(Start);
      var sx = Math.Abs(bl.X - Start.X) <= Math.Abs(ur.X - Start.X) ? bl.X : ur.X;
      var sy = Math.Abs(bl.Y - Start.Y) <= Math.Abs(ur.Y - Start.Y) ? bl.Y : ur.Y;

      var end = new PointD(End.X + (sx - Start.X), End.Y + (sy - Start.Y));

      bl = grid.GetBottomLeftGridPoint(end);
      ur = grid.GetUpperRightGridPoint(end);
      var ex = Math.Abs(bl.X - end.X) <= Math.Abs(ur.X - end.X) ? bl.X : ur.X;
      var ey = Math.Abs(bl.Y - end.Y) <= Math.Abs(ur.Y - end.Y) ? bl.Y : ur.Y;

      SetPosition(new PointD(sx, sy), new PointD(ex, ey));
    }

    public override void SnapToGrid(PointD point, IGrid grid) {
      if (Selected && SelectionRectangles.ContainsPoint(point)) {
        var rect = (SelectionRectangle)SelectionRectangles.GetPrimitive(point);
        if (rect.Point == Start) {
          var bl = grid.GetBottomLeftGridPoint(Start);
          var ur = grid.GetUpperRightGridPoint(Start);
          var sx = Math.Abs(bl.X - Start.X) <= Math.Abs(ur.X - Start.X) ? bl.X : ur.X;
          var sy = Math.Abs(bl.Y - Start.Y) <= Math.Abs(ur.Y - Start.Y) ? bl.Y : ur.Y;
          SetPosition(new PointD(sx, sy), End);
        } else if (rect.Point == End) {
          var bl = grid.GetBottomLeftGridPoint(End);
          var ur = grid.GetUpperRightGridPoint(End);
          var ex = Math.Abs(bl.X - End.X) <= Math.Abs(ur.X - End.X) ? bl.X : ur.X;
          var ey = Math.Abs(bl.Y - End.Y) <= Math.Abs(ur.Y - End.Y) ? bl.Y : ur.Y;
          SetPosition(Start, new PointD(ex, ey));
        }
      } else SnapToGrid(grid);
    }

    public override bool ContainsPoint(PointD point) {
      if (Selected && SelectionRectangles.GetPrimitive(point) != null) return true;
      return false;
    }

    public override Cursor GetCursor(PointD point) {
      if (Selected) {
        var cursor = SelectionRectangles.GetCursor(point);
        if (cursor != null) return cursor;
      }
      return base.GetCursor(point);
    }

    public override void PostDraw(Graphics graphics) {
      SelectionRectangles.Clear();
      if (Selected) {
        var pen = new Pen(Color.LightGray, 3) { DashStyle = DashStyle.Dash };
        graphics.DrawLine(pen,
                          Chart.TransformWorldToPixel(Start),
                          Chart.TransformWorldToPixel(End));
        SelectionRectangles.Add(new SelectionRectangle(Chart, Start, Cursors.SizeAll));
        SelectionRectangles.Add(new SelectionRectangle(Chart, End, Cursors.SizeAll));

        SelectionRectangles.Draw(graphics);
      }
    }
  }
}