#include "graph_displayer_canvas.h"
#include <cmath>

GraphDisplayerCanvas::BrokenEdge::BrokenEdge(Gnome::Canvas::Group & g, Gnome::Canvas::Points p, GraphDisplayerCanvas & gc) : Line(g), gdc(gc), isbutton(false)
{
  my_points=new Gnome::Art::Point[3];

  arrow=new Gnome::Canvas::Polygon(g);
  *arrow << Gnome::Canvas::Properties::fill_color("red");
  arrow->signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::BrokenEdge::edgeFormerEventHandler));
  arrow->lower_to_bottom();
  setPoints(p);
}

GraphDisplayerCanvas::BrokenEdge::~BrokenEdge()
{
  if(arrow)delete(arrow);
}

void GraphDisplayerCanvas::BrokenEdge::setPoints(Gnome::Canvas::Points p, bool move)
{
  bool set_arrow=false;
  //red arrow losts its position-right button
  if(!move)
    {
      if(p.size()==2)
	{
	  set_arrow=true;
	  Gnome::Canvas::Points points_with_center;
	  points_with_center.push_back(my_points[0]=p[0]);
	  points_with_center.push_back(my_points[1]=Gnome::Art::Point( (p[0].get_x()+p[1].get_x())/2+0 , (p[0].get_y()+p[1].get_y())/2 )+0 );
	  points_with_center.push_back(my_points[2]=p[1]);
	  property_points().set_value(points_with_center);
	}  
      if(p.size()==3)
	{
	  set_arrow=true;
	  property_points().set_value(p);
	  for(int i=0;i<3;i++)
	    {
	      my_points[i]=p[i];
	    }
	}
    }
  else
    {
      //arrow keeps its position-left button

//       if(p.size()==2)
//       	{
//       	  Gnome::Canvas::Points points;
//       	  my_points[0]=p[0];
//       	  my_points[2]=p[1];
//       	  for(int i=0;i<3;i++)
//       	    {
//       	      points.push_back(my_points[i]);
//       	    }
//       	  property_points().set_value(points);
//       	}
      set_arrow=true;

      //////////////////////////////////////////////////////////////////////////////////////////////////////
      /////////// keeps shape-with scalar multiplication - version 2.
      //////////////////////////////////////////////////////////////////////////////////////////////////////

      if(p.size()==2)
      	{
	  //old vector from one to the other node - a
	  xy<double> a_v(my_points[2].get_x()-my_points[0].get_x(),my_points[2].get_y()-my_points[0].get_y());
	  //new vector from one to the other node - b
	  xy<double> b_v(p[1].get_x()-p[0].get_x(),p[1].get_y()-p[0].get_y());

	  double absa=sqrt(a_v.normSquare());
	  double absb=sqrt(b_v.normSquare());

	  if((absa!=0)&&(absb!=0))
	    {
	      //old vector from one node to the breakpoint - c
	      xy<double> c_v(my_points[1].get_x()-my_points[0].get_x(),my_points[1].get_y()-my_points[0].get_y());

	      //unit vector with the same direction to a_v
	      xy<double> a_v_u(a_v.x/absa,a_v.y/absa);

	      //normal vector of unit vector with the same direction to a_v
	      xy<double> a_v_u_n(((-1)*a_v_u.y),a_v_u.x);

	      //unit vector with the same direction to b_v
	      xy<double> b_v_u(b_v.x/absb,b_v.y/absb);

	      //normal vector of unit vector with the same direction to b_v
	      xy<double> b_v_u_n(((-1)*b_v_u.y),b_v_u.x);

	      //vector c in a_v_u and a_v_u_n co-ordinate system
	      xy<double> c_a(c_v*a_v_u,c_v*a_v_u_n);

	      //new vector from one node to the breakpoint - d - we have to calculate this one
	      xy<double> d_v=absb/absa*(c_a.x*b_v_u+c_a.y*b_v_u_n);

	      my_points[1]=Gnome::Art::Point(d_v.x+p[0].get_x(),d_v.y+p[0].get_y());

	      my_points[0]=p[0];
	      my_points[2]=p[1];
	  
	      Gnome::Canvas::Points points;
	      for(int i=0;i<3;i++)
		{
		  points.push_back(my_points[i]);
		}
	      property_points().set_value(points);
	    }
	  else
	    {
	      //if distance is 0, segmentation would be occured
	      //in calculations, because of division by zero
	      //But we have luck: the edge cannot be seen in
	      //this case, so no update needed
	      set_arrow=false;
	    }
	}
    }
  if(set_arrow)
    {
      //calculating coordinates of the direction indicator arrow

      xy<gdouble> target( my_points[2].get_x(), my_points[2].get_y() );
      xy<gdouble> center( my_points[1].get_x(), my_points[1].get_y() );

      xy<gdouble> unit_vector_in_dir(target-center);
      double length=sqrt( unit_vector_in_dir.normSquare() );

      //       std::cout << target << " - " << center << " = " << unit_vector_in_dir << "    / " <<unit_vector_in_dir.normSquare() ;
      unit_vector_in_dir/=length;
      //       std::cout << " = " << unit_vector_in_dir << std::endl;

      xy<gdouble> unit_norm_vector(0-unit_vector_in_dir.y, unit_vector_in_dir.x);
      //       std::cout << unit_norm_vector << std::endl;

      {      
	//       /\       // top
	//      /  \      //
	//      -  -      // c(enter)l(eft), ccl, ccr, cr
	//       ||       //
	//       ||       // b(ottom)l, br
      }

      double size=3;

      xy<gdouble> bl (center - unit_vector_in_dir * 3 * size + unit_norm_vector * size );
      xy<gdouble> br (center - unit_vector_in_dir * 3 * size - unit_norm_vector * size );
      xy<gdouble> ccl(center + unit_vector_in_dir *  size + unit_norm_vector * size );
      xy<gdouble> ccr(center + unit_vector_in_dir *  size - unit_norm_vector * size );
      xy<gdouble> cl (center + unit_vector_in_dir *  size + unit_norm_vector * 2 * size );
      xy<gdouble> cr (center + unit_vector_in_dir *  size - unit_norm_vector * 2 * size );
      xy<gdouble> top(center + unit_vector_in_dir * 3 * size);
	 
      //std::cout << bl << " " << br << " " << ccl << " "  << ccr << " " << cl << " " << cr << " " << top << std::endl;

      Gnome::Canvas::Points arrow_points;
      arrow_points.push_back(Gnome::Art::Point( bl.x , bl.y  ) );
      arrow_points.push_back(Gnome::Art::Point( br.x , br.y  ) );
      arrow_points.push_back(Gnome::Art::Point( ccr.x, ccr.y ) );
      arrow_points.push_back(Gnome::Art::Point( cr.x , cr.y  ) );
      arrow_points.push_back(Gnome::Art::Point( top.x, top.y ) );
      arrow_points.push_back(Gnome::Art::Point( cl.x , cl.y  ) );
      arrow_points.push_back(Gnome::Art::Point( ccl.x, ccl.y ) );

      arrow->property_points().set_value(arrow_points);
    }
}

bool GraphDisplayerCanvas::BrokenEdge::edgeFormerEventHandler(GdkEvent* e)
{
  switch(e->type)
    {
    case GDK_BUTTON_PRESS:
      //we mark the location of the event to be able to calculate parameters of dragging
      if(gdc.getActualTool()!=CREATE_NODE)
	{
	  gdc.toggleEdgeActivity(this, true);
	  clicked_x=e->button.x;
	  clicked_y=e->button.y;
	  isbutton=true;
	}
      break;
    case GDK_BUTTON_RELEASE:
      if(gdc.getActualTool()!=CREATE_NODE)
	{
	  gdc.toggleEdgeActivity(this, false);
	  isbutton=false;
	}
      break;
    case GDK_MOTION_NOTIFY:
      //we only have to do sg. if the mouse button is pressed
      if(isbutton)
	{
	  //new coordinates will be the old values,
	  //because the item will be moved to the
	  //new coordinate therefore the new movement
	  //has to be calculated from here

	  double dx=e->motion.x-clicked_x;
	  double dy=e->motion.y-clicked_y;

	  Gnome::Canvas::Points points_new;

	  points_new.push_back(my_points[0]);
	  points_new.push_back(my_points[1]=Gnome::Art::Point(my_points[1].get_x()+dx,my_points[1].get_y()+dy));
	  points_new.push_back(my_points[2]);

	  setPoints(points_new);
	  gdc.textReposition(xy<double>(my_points[1].get_x(),my_points[1].get_y()));

	  clicked_x=e->motion.x;
	  clicked_y=e->motion.y;

	}
    default: break;
    }

  return true;
}

xy<double> GraphDisplayerCanvas::BrokenEdge::getArrowPos()
{
  xy<double> ret_val(my_points[1].get_x(),my_points[1].get_y());
  return ret_val;
}