/*
   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 "signal/signal.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 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([&](Vector3 &point) {
		matrix4_transform_point(matrix, point);
	});
}
void snapto( float snap ){
	forEachSelected([&](Vector3 &point) {
		vector3_snap(point, snap);
	});
}

void updateSelected() const {
	m_selectedRender.clear();
	forEachSelected([&](const Vector3 &point) {
		m_selectedRender.push_back(PointVertex(vertex3f_for_vector3(point), colour_selected));
	});
}

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([&](const Vector3 &point) {
		m_controlsRender.push_back(PointVertex(vertex3f_for_vector3(point), colour_vertex));
	});

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



const int NURBS_degree = 3;

class NURBSCurve
{
Signal0 m_curveChanged;
Callback<void()> m_boundsChanged;
public:
ControlPoints m_controlPoints;
ControlPoints m_controlPointsTransformed;
NURBSWeights m_weights;
Knots m_knots;
RenderableCurve m_renderCurve;
AABB m_bounds;

NURBSCurve( const Callback<void()>& boundsChanged ) : m_boundsChanged( boundsChanged ){
}

SignalHandlerId connect( const SignalHandler& curveChanged ){
	curveChanged();
	return m_curveChanged.connectLast( curveChanged );
}
void disconnect( SignalHandlerId id ){
	m_curveChanged.disconnect( id );
}
void notify(){
	m_curveChanged();
}

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 MemberCaller<NURBSCurve, void(const char*), &NURBSCurve::curveChanged> CurveChangedCaller;
};

class CatmullRomSpline
{
Signal0 m_curveChanged;
Callback<void()> m_boundsChanged;
public:
ControlPoints m_controlPoints;
ControlPoints m_controlPointsTransformed;
RenderableCurve m_renderCurve;
AABB m_bounds;

CatmullRomSpline( const Callback<void()>& boundsChanged ) : m_boundsChanged( boundsChanged ){
}

SignalHandlerId connect( const SignalHandler& curveChanged ){
	curveChanged();
	return m_curveChanged.connectLast( curveChanged );
}
void disconnect( SignalHandlerId id ){
	m_curveChanged.disconnect( id );
}
void notify(){
	m_curveChanged();
}

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 MemberCaller<CatmullRomSpline, void(const char*), &CatmullRomSpline::curveChanged> CurveChangedCaller;
};

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


#endif