/*
Copyright (C) 2001-2006, William Joseph.
All Rights Reserved.

This file is part of GtkRadiant.

GtkRadiant 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 2 of the License, or
(at your option) any later version.

GtkRadiant 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 GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#if !defined(INCLUDED_CURVE_H)
#define INCLUDED_CURVE_H

#include "ientity.h"
#include "selectable.h"
#include "renderable.h"

#include <set>

#include "math/curve.h"
#include "stream/stringstream.h"
#include "selectionlib.h"
#include "render.h"
#include "stringio.h"

class RenderableCurve : public OpenGLRenderable
{
public:
  std::vector<PointVertex> m_vertices;
  void render(RenderStateFlags state) const
  {
    pointvertex_gl_array(&m_vertices.front());
    glDrawArrays(GL_LINE_STRIP, 0, GLsizei(m_vertices.size()));
  }
};

inline void plotBasisFunction(std::size_t numSegments, int point, int degree)
{
  Knots knots;
  KnotVector_openUniform(knots, 4, degree);

  globalOutputStream() << "plotBasisFunction point " << point << " of 4, knot vector:";
  for(Knots::iterator i = knots.begin(); i != knots.end(); ++i)
  {
    globalOutputStream() << " " << *i;
  }
  globalOutputStream() << "\n";
  globalOutputStream() << "t=0 basis=" << BSpline_basis(knots, point, degree, 0.0) << "\n";
  for(std::size_t i = 1; i < numSegments; ++i)
  {
    double t = (1.0 / double(numSegments)) * double(i);
    globalOutputStream() << "t=" << t << " basis=" << BSpline_basis(knots, point, degree, t) << "\n";
  }
  globalOutputStream() << "t=1 basis=" << BSpline_basis(knots, point, degree, 1.0) << "\n";  
}

inline bool ControlPoints_parse(ControlPoints& controlPoints, const char* value)
{
  StringTokeniser tokeniser(value, " ");

  std::size_t size;
  if(!string_parse_size(tokeniser.getToken(), size))
  {
    return false;
  }

  if(size < 3)
  {
    return false;
  }
  controlPoints.resize(size);

  if(!string_equal(tokeniser.getToken(), "("))
  {
    return false;
  }
  for(ControlPoints::iterator i = controlPoints.begin(); i != controlPoints.end(); ++i)
  {
    if(!string_parse_float(tokeniser.getToken(), (*i).x())
      || !string_parse_float(tokeniser.getToken(), (*i).y())
      || !string_parse_float(tokeniser.getToken(), (*i).z()))
    {
      return false;
    }
  }
  if(!string_equal(tokeniser.getToken(), ")"))
  {
    return false;
  }
  return true;
}

inline void ControlPoints_write(const ControlPoints& controlPoints, StringOutputStream& value)
{
  value << Unsigned(controlPoints.size()) << " (";
  for(ControlPoints::const_iterator i = controlPoints.begin(); i != controlPoints.end(); ++i)
  {
    value << " " << (*i).x() << " " << (*i).y() << " " << (*i).z() << " ";
  }
  value << ")";
}

inline void ControlPoint_testSelect(const Vector3& point, ObservedSelectable& selectable, Selector& selector, SelectionTest& test)
{
  SelectionIntersection best;
  test.TestPoint(point, best);
  if(best.valid())
  {
    Selector_add(selector, selectable, best);
  }
}

class ControlPointTransform
{
  const Matrix4& m_matrix;
public:
  ControlPointTransform(const Matrix4& matrix) : m_matrix(matrix)
  {
  }
  void operator()(Vector3& point) const
  {
    matrix4_transform_point(m_matrix, point);
  }
};

class ControlPointSnap
{
  float m_snap;
public:
  ControlPointSnap(float snap) : m_snap(snap)
  {
  }
  void operator()(Vector3& point) const
  {
    vector3_snap(point, m_snap);
  }
};

const Colour4b colour_vertex(0, 255, 0, 255);
const Colour4b colour_selected(0, 0, 255, 255);

class ControlPointAdd
{
  RenderablePointVector& m_points;
public:
  ControlPointAdd(RenderablePointVector& points) : m_points(points)
  {
  }
  void operator()(const Vector3& point) const
  {
    m_points.push_back(PointVertex(vertex3f_for_vector3(point), colour_vertex));
  }
};

class ControlPointAddSelected
{
  RenderablePointVector& m_points;
public:
  ControlPointAddSelected(RenderablePointVector& points) : m_points(points)
  {
  }
  void operator()(const Vector3& point) const
  {
    m_points.push_back(PointVertex(vertex3f_for_vector3(point), colour_selected));
  }
};

class CurveEditType
{
public:
  Shader* m_controlsShader;
  Shader* m_selectedShader;
};

inline void ControlPoints_write(ControlPoints& controlPoints, const char* key, Entity& entity)
{
  StringOutputStream value(256);
  if(!controlPoints.empty())
  {
    ControlPoints_write(controlPoints, value);
  }
  entity.setKeyValue(key, value.c_str());
}

class CurveEdit
{
  SelectionChangeCallback m_selectionChanged;
  ControlPoints& m_controlPoints;
  typedef Array<ObservedSelectable> Selectables;
  Selectables m_selectables;

  RenderablePointVector m_controlsRender;
  mutable RenderablePointVector m_selectedRender;

public:
  typedef Static<CurveEditType> Type;

  CurveEdit(ControlPoints& controlPoints, const SelectionChangeCallback& selectionChanged) :
    m_selectionChanged(selectionChanged),
    m_controlPoints(controlPoints),
    m_controlsRender(GL_POINTS),
    m_selectedRender(GL_POINTS)
  {
  }

  template<typename Functor>
  const Functor& forEachSelected(const Functor& functor)
  {
    ASSERT_MESSAGE(m_controlPoints.size() == m_selectables.size(), "curve instance mismatch");
    ControlPoints::iterator p = m_controlPoints.begin();
    for(Selectables::iterator i = m_selectables.begin(); i != m_selectables.end(); ++i, ++p)
    {
      if((*i).isSelected())
      {
        functor(*p);
      }
    }
    return functor;
  }
  template<typename Functor>
  const Functor& forEachSelected(const Functor& functor) const
  {
    ASSERT_MESSAGE(m_controlPoints.size() == m_selectables.size(), "curve instance mismatch");
    ControlPoints::const_iterator p = m_controlPoints.begin();
    for(Selectables::const_iterator i = m_selectables.begin(); i != m_selectables.end(); ++i, ++p)
    {
      if((*i).isSelected())
      {
        functor(*p);
      }
    }
    return functor;
  }
  template<typename Functor>
  const Functor& forEach(const Functor& functor) const
  {
    for(ControlPoints::const_iterator i = m_controlPoints.begin(); i != m_controlPoints.end(); ++i)
    {
      functor(*i);
    }
    return functor;
  }

  void testSelect(Selector& selector, SelectionTest& test)
  {
    ASSERT_MESSAGE(m_controlPoints.size() == m_selectables.size(), "curve instance mismatch");
    ControlPoints::const_iterator p = m_controlPoints.begin();
    for(Selectables::iterator i = m_selectables.begin(); i != m_selectables.end(); ++i, ++p)
    {
      ControlPoint_testSelect(*p, *i, selector, test);
    }
  }

  bool isSelected() const
  {
    for(Selectables::const_iterator i = m_selectables.begin(); i != m_selectables.end(); ++i)
    {
      if((*i).isSelected())
      {
        return true;
      }
    }
    return false;
  }
  void setSelected(bool selected)
  {
    for(Selectables::iterator i = m_selectables.begin(); i != m_selectables.end(); ++i)
    {
      (*i).setSelected(selected);
    }
  }

  void write(const char* key, Entity& entity)
  {
    ControlPoints_write(m_controlPoints, key, entity);
  }

  void transform(const Matrix4& matrix)
  {
    forEachSelected(ControlPointTransform(matrix));
  }
  void snapto(float snap)
  {
    forEachSelected(ControlPointSnap(snap));
  }

  void updateSelected() const
  {
    m_selectedRender.clear();
    forEachSelected(ControlPointAddSelected(m_selectedRender));
  }
  
  void renderComponents(Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld) const
  {
    renderer.SetState(Type::instance().m_controlsShader, Renderer::eWireframeOnly);
    renderer.SetState(Type::instance().m_controlsShader, Renderer::eFullMaterials);
    renderer.addRenderable(m_controlsRender, localToWorld);
  }

  void renderComponentsSelected(Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld) const
  {
    updateSelected();
    if(!m_selectedRender.empty())
    {
      renderer.Highlight(Renderer::ePrimitive, false);
      renderer.SetState(Type::instance().m_selectedShader, Renderer::eWireframeOnly);
      renderer.SetState(Type::instance().m_selectedShader, Renderer::eFullMaterials);
      renderer.addRenderable(m_selectedRender, localToWorld);
    }
  }

  void curveChanged()
  {
    m_selectables.resize(m_controlPoints.size(), m_selectionChanged);

    m_controlsRender.clear();
    m_controlsRender.reserve(m_controlPoints.size());
    forEach(ControlPointAdd(m_controlsRender));

    m_selectedRender.reserve(m_controlPoints.size());
  }
  typedef MemberCaller<CurveEdit, &CurveEdit::curveChanged> CurveChangedCaller;
};



const int NURBS_degree = 3;

class NURBSCurve
{
  typedef std::set<Callback> Callbacks;
  Callbacks m_curveChanged;
  Callback m_boundsChanged;
public:
  ControlPoints m_controlPoints;
  ControlPoints m_controlPointsTransformed;
  NURBSWeights m_weights;
  Knots m_knots;
  RenderableCurve m_renderCurve;
  AABB m_bounds;

  NURBSCurve(const Callback& boundsChanged) : m_boundsChanged(boundsChanged)
  {
  }

  void attach(const Callback& curveChanged)
  {
    m_curveChanged.insert(curveChanged);
    curveChanged();
  }
  void detach(const Callback& curveChanged)
  {
    m_curveChanged.erase(curveChanged);
  }
  void notify()
  {
    std::for_each(m_curveChanged.begin(), m_curveChanged.end(), CallbackInvoke());
  }

  void tesselate()
  {
    if(!m_controlPointsTransformed.empty())
    {
      const std::size_t numSegments = (m_controlPointsTransformed.size() - 1) * 16;
      m_renderCurve.m_vertices.resize(numSegments + 1);
      m_renderCurve.m_vertices[0].vertex = vertex3f_for_vector3(m_controlPointsTransformed[0]);
      for(std::size_t i = 1; i < numSegments; ++i)
      {
        m_renderCurve.m_vertices[i].vertex = vertex3f_for_vector3(NURBS_evaluate(m_controlPointsTransformed, m_weights, m_knots, NURBS_degree, (1.0 / double(numSegments)) * double(i)));
      }
      m_renderCurve.m_vertices[numSegments].vertex = vertex3f_for_vector3(m_controlPointsTransformed[m_controlPointsTransformed.size() - 1]);
    }
    else
    {
      m_renderCurve.m_vertices.clear();
    }
  }

  void curveChanged()
  {
    tesselate();

    m_bounds = AABB();
    for(ControlPoints::iterator i = m_controlPointsTransformed.begin(); i != m_controlPointsTransformed.end(); ++i)
    {
      aabb_extend_by_point_safe(m_bounds, (*i));
    }

    m_boundsChanged();
    notify();
  }

  bool parseCurve(const char* value)
  {
    if(!ControlPoints_parse(m_controlPoints, value))
    {
      return false;
    }

    m_weights.resize(m_controlPoints.size());
    for(NURBSWeights::iterator i = m_weights.begin(); i != m_weights.end(); ++i)
    {
      (*i) = 1;
    }

    KnotVector_openUniform(m_knots, m_controlPoints.size(), NURBS_degree);

    //plotBasisFunction(8, 0, NURBS_degree);

    return true;
  }

  void curveChanged(const char* value)
  {
    if(string_empty(value) || !parseCurve(value))
    {
      m_controlPoints.resize(0);
      m_knots.resize(0);
      m_weights.resize(0);
    }
    m_controlPointsTransformed = m_controlPoints;
    curveChanged();
  }
  typedef MemberCaller1<NURBSCurve, const char*, &NURBSCurve::curveChanged> CurveChangedCaller;
};

class CatmullRomSpline
{
  typedef std::set<Callback> Callbacks;
  Callbacks m_curveChanged;
  Callback m_boundsChanged;
public:
  ControlPoints m_controlPoints;
  ControlPoints m_controlPointsTransformed;
  RenderableCurve m_renderCurve;
  AABB m_bounds;

  CatmullRomSpline(const Callback& boundsChanged) : m_boundsChanged(boundsChanged)
  {
  }

  void attach(const Callback& curveChanged)
  {
    m_curveChanged.insert(curveChanged);
    curveChanged();
  }
  void detach(const Callback& curveChanged)
  {
    m_curveChanged.erase(curveChanged);
  }
  void notify()
  {
    std::for_each(m_curveChanged.begin(), m_curveChanged.end(), CallbackInvoke());
  }

  void tesselate()
  {
    if(!m_controlPointsTransformed.empty())
    {
      const std::size_t numSegments = (m_controlPointsTransformed.size() - 1) * 16;
      m_renderCurve.m_vertices.resize(numSegments + 1);
      m_renderCurve.m_vertices[0].vertex = vertex3f_for_vector3(m_controlPointsTransformed[0]);
      for(std::size_t i = 1; i < numSegments; ++i)
      {
        m_renderCurve.m_vertices[i].vertex = vertex3f_for_vector3(CatmullRom_evaluate(m_controlPointsTransformed, (1.0 / double(numSegments)) * double(i)));
      }
      m_renderCurve.m_vertices[numSegments].vertex = vertex3f_for_vector3(m_controlPointsTransformed[m_controlPointsTransformed.size() - 1]);
    }
    else
    {
      m_renderCurve.m_vertices.clear();
    }
  }

  bool parseCurve(const char* value)
  {
    return ControlPoints_parse(m_controlPoints, value);
  }

  void curveChanged()
  {
    tesselate();

    m_bounds = AABB();
    for(ControlPoints::iterator i = m_controlPointsTransformed.begin(); i != m_controlPointsTransformed.end(); ++i)
    {
      aabb_extend_by_point_safe(m_bounds, (*i));
    }

    m_boundsChanged();
    notify();
  }

  void curveChanged(const char* value)
  {
    if(string_empty(value) || !parseCurve(value))
    {
      m_controlPoints.resize(0);
    }
    m_controlPointsTransformed = m_controlPoints;
    curveChanged();
  }
  typedef MemberCaller1<CatmullRomSpline, const char*, &CatmullRomSpline::curveChanged> CurveChangedCaller;
};

const char* const curve_Nurbs = "curve_Nurbs";
const char* const curve_CatmullRomSpline = "curve_CatmullRomSpline";


#endif
