// Copyright (c) 2008  GeometryFactory Sarl (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// 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.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// 
//
// Author(s)     : Andreas Fabri <Andreas.Fabri@geometryfactory.com>
//                 Laurent Rineau <Laurent.Rineau@geometryfactory.com>
#ifndef CGAL_QT_CONVERTER_H
#define CGAL_QT_CONVERTER_H

#include <CGAL/license/GraphicsView.h>


#include <QtMath>
#include <QPointF>
#include <QLineF>
#include <QRectF>
#include <QPainterPath>
#include <QPolygonF>
#include <list>

#include <CGAL/intersection_2.h>
#include <CGAL/auto_link/Qt.h>

#include <boost/mpl/has_xxx.hpp>

namespace CGAL {

namespace internal {

BOOST_MPL_HAS_XXX_TRAIT_DEF( Circular_arc_point_2 )

template < class K, bool b = has_Circular_arc_point_2< K >::value >
struct get_Circular_arc_point_2
{
    struct type { };
};

template < class K >
struct get_Circular_arc_point_2< K, true >
{
    typedef typename K::Circular_arc_point_2 type;
};

}

namespace Qt {

template <typename K>
class Converter {
public:
  typedef typename K::Point_2              CGAL_Point_2;
  typedef typename K::Segment_2            CGAL_Segment_2;
  typedef typename K::Ray_2                CGAL_Ray_2;
  typedef typename K::Line_2               CGAL_Line_2;
  typedef typename K::Triangle_2           CGAL_Triangle_2;
  typedef typename K::Iso_rectangle_2      CGAL_Iso_rectangle_2;
  typedef typename internal::get_Circular_arc_point_2< K >::type
    CGAL_Circular_arc_point_2;

private:
  bool clippingRectIsInitialized;
  CGAL_Iso_rectangle_2 clippingRect;
  

public:

  Converter()
    : clippingRectIsInitialized(false)
  {
  }

  Converter(QRectF rect)
  {
    if(rect.isValid()) {
      clippingRect = this->operator()(rect);
      clippingRectIsInitialized = true;
    }
    else
      clippingRectIsInitialized = false;
  }

  CGAL_Point_2 operator()(const QPointF& qp) const
  {
    return CGAL_Point_2(qp.x(), qp.y());
  }


  QPointF operator()(const CGAL_Point_2& p) const
  {
    return QPointF(to_double(p.x()), to_double(p.y()));
  }

  QPointF operator()(const CGAL_Circular_arc_point_2& p) const
  {
    return QPointF(to_double(p.x()), to_double(p.y()));
  }

      
  CGAL_Segment_2 operator()(const QLineF& qs) const
  {
    return CGAL_Segment_2(operator()(qs.p1()), operator()(qs.p2()));
  }
 
  QLineF operator()(const CGAL_Segment_2 &s) const
  {
    return QLineF(operator()(s.source()), operator()(s.target()));
  }

  
  CGAL_Iso_rectangle_2 operator()(const QRectF& qr) const
  {
    return CGAL_Iso_rectangle_2(operator()(qr.bottomLeft()), operator()(qr.topRight()));
  }


  QRectF operator()(const CGAL_Iso_rectangle_2& r) const
  {
    return QRectF(operator()(r[3]), operator()(r[1])).normalized();  // top left, bottom right
  }


  QRectF operator()(const CGAL::Bbox_2& bb) const
  {
    return QRectF(bb.xmin(),
		  bb.ymin(),
		  bb.xmax()-bb.xmin(),
		  bb.ymax()-bb.ymin());
  }

     
  QLineF operator()(const CGAL_Ray_2 &r) const
  {
    CGAL_assertion(clippingRectIsInitialized);
    Object o = CGAL::intersection(r, clippingRect);
    typedef CGAL_Segment_2 Segment_2;
    typedef CGAL_Point_2 Point_2;
    if(const Segment_2 *s = CGAL::object_cast<Segment_2>(&o)){
      return this->operator()(*s);
    } else if(const Point_2 *p = CGAL::object_cast<Point_2>(&o)){
      return QLineF(operator()(*p), operator()(*p));
    }
    return QLineF();
  }

  QLineF operator()(const CGAL_Line_2 &l) const
  {
    CGAL_assertion(clippingRectIsInitialized);
    Object o = CGAL::intersection(l, clippingRect);
    typedef CGAL_Segment_2 Segment_2;
    typedef CGAL_Point_2 Point_2;
    if(const Segment_2 *s = CGAL::object_cast<Segment_2>(&o)){
      return this->operator()(*s);
    } else if(const Point_2 *p = CGAL::object_cast<Point_2>(&o)){
      return QLineF(operator()(*p), operator()(*p));
    }
    return QLineF();
  }

  QPolygonF operator()(const CGAL_Triangle_2 &t) const
  {
    QPolygonF qp;
    qp << operator()(t.vertex(0)) << operator()(t.vertex(1)) << operator()(t.vertex(2));
    return qp;
  }


  void operator()(std::list< CGAL_Point_2 >& p, const QPolygonF& qp) const
  {
    for(int i = 0; i < qp.size(); i++){
      p.push_back(operator()(qp[i]));
    }
  }

  template < typename T >
  QPainterPath operator()(const typename CGAL::General_polygon_2< T > &pgn) const
  {
    typedef typename CGAL::General_polygon_2< T > CGAL_Polygon_2;
    typedef typename CGAL_Polygon_2::Curve_const_iterator        CGAL_Curve_const_iterator;
    typedef typename CGAL_Polygon_2::X_monotone_curve_2          CGAL_X_monotone_curve_2;

    QPainterPath result;

    CGAL_Curve_const_iterator current = pgn.curves_begin();
    CGAL_Curve_const_iterator end = pgn.curves_end();

    result.moveTo(QPointF(CGAL::to_double(current->source().x()),
                          CGAL::to_double(current->source().y())));

    do {
      const CGAL_X_monotone_curve_2 &curve = *current;
      const QPointF target = QPointF(CGAL::to_double(curve.target().x()),
                                     CGAL::to_double(curve.target().y()));

      if (curve.is_linear()) {
        result.lineTo(target);
      }
      else if (curve.is_circular()) {
        const bool isClockwise = (curve.supporting_circle().orientation() == CGAL::CLOCKWISE);
        const QRectF rect = operator()(curve.supporting_circle().bbox());
        const QPointF center = QPointF(CGAL::to_double(curve.supporting_circle().center().x()),
                                       CGAL::to_double(curve.supporting_circle().center().y()));
        const QPointF source = QPointF(CGAL::to_double(curve.source().x()),
                                       CGAL::to_double(curve.source().y()));
        const QPointF p1 = source - center;
        const QPointF p2 = target - center;
        const double asource = qAtan2(p1.y(), p1.x());
        const double atarget = qAtan2(p2.y(), p2.x());
        double aspan = atarget - asource;
        if (aspan < -CGAL_PI || (qFuzzyCompare(aspan, -CGAL_PI) && !isClockwise))
            aspan += 2.0*CGAL_PI;
        else if (aspan > CGAL_PI || (qFuzzyCompare(aspan, CGAL_PI) && isClockwise))
            aspan -= 2.0*CGAL_PI;
        result.arcTo(rect.normalized(), qRadiansToDegrees(-asource), qRadiansToDegrees(-aspan));
      }
    } while (++current != end);

    return result;
  }

};

} // namespace Qt
} // namespace CGAL
#endif // CGAL_QT_CONVERTER_H