#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 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 HeuristicLab.Visualization;

namespace HeuristicLab.Networks.Views.NetworkVisualization {
  public class ConnectionLine : Line {
    protected PortRectangle startPortRectangle;
    public PortRectangle StartPortRectangle {
      get { return startPortRectangle; }
      set {
        if (startPortRectangle == value) return;
        if (startPortRectangle != null) DeregisterPortRectangleEvents(startPortRectangle);
        startPortRectangle = value;
        if (startPortRectangle != null) RegisterPortRectangleEvents(startPortRectangle);
        OnStartPortRectangleChanged();
      }
    }

    protected PortRectangle endPortRectangle;
    public PortRectangle EndPortRectangle {
      get { return endPortRectangle; }
      set {
        if (endPortRectangle == value) return;
        if (endPortRectangle != null) DeregisterPortRectangleEvents(endPortRectangle);
        endPortRectangle = value;
        if (endPortRectangle != null) RegisterPortRectangleEvents(endPortRectangle);
        OnEndPortRectangleChanged();
      }
    }

    public ConnectionLine(IChart chart, PortRectangle start, PortRectangle end)
      : base(chart, start.Point, end.Point) {
      StartPortRectangle = start;
      EndPortRectangle = end;
    }

    protected virtual void RegisterPortRectangleEvents(PortRectangle portRectangle) {
      portRectangle.RedrawRequired += PortRectangle_RedrawRequired;
    }

    protected virtual void DeregisterPortRectangleEvents(PortRectangle portRectangle) {
      portRectangle.RedrawRequired -= PortRectangle_RedrawRequired;
    }

    #region Overrides
    public override void Move(Offset delta) { }
    public override void Move(PointD point, Offset delta) { }

    public override void Draw(Graphics graphics) {
      base.Draw(graphics);

      var startP = Chart.TransformWorldToPixel(Start);
      var endP = Chart.TransformWorldToPixel(End);

      if (startP == endP) return;

      double length = Math.Sqrt(Math.Pow(startP.X - endP.X, 2.0) + Math.Pow(startP.Y - endP.Y, 2));
      double ax = (endP.X - startP.X) / length, ay = (endP.Y - startP.Y) / length;
      double bx = -2.5 * ax - ay, by = -2.5 * ay + ax;
      double cx = -2.5 * ax + ay, cy = -2.5 * ay - ax;
      double mul = 4 * Chart.WorldToPixelRatio.Width;
      bx *= mul; by *= mul;
      cx *= mul; cy *= mul;
      var p1 = new Point((int)Math.Round(endP.X + bx), (int)Math.Round(endP.Y + by));
      var p2 = new Point((int)Math.Round(endP.X + cx), (int)Math.Round(endP.Y + cy));
      graphics.FillPolygon(Pen.Brush, new[] { p1, endP, p2 });
    }

    public override void PostDraw(Graphics graphics) {
      if (Selected) {
        using (var pen = new Pen(Color.LightGray, 3) { DashStyle = DashStyle.Dash })
          graphics.DrawLine(pen, Chart.TransformWorldToPixel(Start), Chart.TransformWorldToPixel(End));
      }
    }
    #endregion

    #region Events
    public event EventHandler StartPortRectangleChanged;
    protected virtual void OnStartPortRectangleChanged() {
      var handler = StartPortRectangleChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler EndPortRectangleChanged;
    protected virtual void OnEndPortRectangleChanged() {
      var handler = EndPortRectangleChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }
    #endregion

    #region Event Handlers
    private void PortRectangle_RedrawRequired(object sender, EventArgs e) {
      SetPosition(startPortRectangle.Point, endPortRectangle.Point);
    }
    #endregion
  }
}