/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   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
 */

#include "csg.h"

#include "debugging/debugging.h"

#include <list>

#include "map.h"
#include "brushmanip.h"
#include "brushnode.h"
#include "grid.h"

void Face_makeBrush( Face& face, const Brush& brush, brush_vector_t& out, float offset ){
	if ( face.contributes() ) {
		out.push_back( new Brush( brush ) );
		Face* newFace = out.back()->addFace( face );
		if ( newFace != 0 ) {
			newFace->flipWinding();
			newFace->getPlane().offset( offset );
			newFace->planeChanged();
		}
	}
}

void Face_makeRoom( Face &face, const Brush &brush, brush_vector_t &out, float offset ){
	if ( face.contributes() ) {
		face.getPlane().offset( offset );
		out.push_back( new Brush( brush ) );
		face.getPlane().offset( -offset );
		Face* newFace = out.back()->addFace( face );
		if ( newFace != 0 ) {
			newFace->flipWinding();
			newFace->planeChanged();
		}
	}
}

void Brush_makeHollow( const Brush &brush, brush_vector_t &out, float offset ){
	Brush_forEachFace( brush, [&]( Face &face ) {
		Face_makeBrush( face, brush, out, offset );
	} );
}

void Brush_makeRoom( const Brush &brush, brush_vector_t &out, float offset ){
	Brush_forEachFace( brush, [&]( Face &face ) {
		Face_makeRoom( face, brush, out, offset );
	} );
}

class BrushHollowSelectedWalker : public scene::Graph::Walker
{
float m_offset;
bool m_makeRoom;
public:
BrushHollowSelectedWalker( float offset, bool makeRoom )
	: m_offset( offset ), m_makeRoom( makeRoom ){
}

bool pre( const scene::Path& path, scene::Instance& instance ) const {
	if ( path.top().get().visible() ) {
		Brush* brush = Node_getBrush( path.top() );
		if ( brush != 0
			 && Instance_getSelectable( instance )->isSelected()
			 && path.size() > 1 ) {
			brush_vector_t out;

			if ( m_makeRoom ) {
				Brush_makeRoom(* brush, out, m_offset );
			}
			else
			{
				Brush_makeHollow(* brush, out, m_offset );
			}

			for ( brush_vector_t::const_iterator i = out.begin(); i != out.end(); ++i )
			{
				( *i )->removeEmptyFaces();
				NodeSmartReference node( ( new BrushNode() )->node() );
				Node_getBrush( node )->copy( *( *i ) );
				delete ( *i );
				Node_getTraversable( path.parent() )->insert( node );
			}
		}
	}
	return true;
}
};

typedef std::list<Brush*> brushlist_t;

class BrushGatherSelected : public scene::Graph::Walker
{
brush_vector_t& m_brushlist;
public:
BrushGatherSelected( brush_vector_t& brushlist )
	: m_brushlist( brushlist ){
}

bool pre( const scene::Path& path, scene::Instance& instance ) const {
	if ( path.top().get().visible() ) {
		Brush* brush = Node_getBrush( path.top() );
		if ( brush != 0
			 && Instance_getSelectable( instance )->isSelected() ) {
			m_brushlist.push_back( brush );
		}
	}
	return true;
}
};

class BrushDeleteSelected : public scene::Graph::Walker
{
public:
bool pre( const scene::Path& path, scene::Instance& instance ) const {
	return true;
}
void post( const scene::Path& path, scene::Instance& instance ) const {
	if ( path.top().get().visible() ) {
		Brush* brush = Node_getBrush( path.top() );
		if ( brush != 0
			 && Instance_getSelectable( instance )->isSelected()
			 && path.size() > 1 ) {
			Path_deleteTop( path );
		}
	}
}
};

void Scene_BrushMakeHollow_Selected( scene::Graph& graph, bool makeRoom ){
	GlobalSceneGraph().traverse( BrushHollowSelectedWalker( GetGridSize(), makeRoom ) );
	GlobalSceneGraph().traverse( BrushDeleteSelected() );
}

/*
   =============
   CSG_MakeHollow
   =============
 */

void CSG_MakeHollow( void ){
	UndoableCommand undo( "brushHollow" );

	Scene_BrushMakeHollow_Selected( GlobalSceneGraph(), false );

	SceneChangeNotify();
}

void CSG_MakeRoom( void ){
	UndoableCommand undo( "brushRoom" );

	Scene_BrushMakeHollow_Selected( GlobalSceneGraph(), true );

	SceneChangeNotify();
}

template<typename Type>
class RemoveReference
{
public:
typedef Type type;
};

template<typename Type>
class RemoveReference<Type&>
{
public:
typedef Type type;
};

template<typename Functor>
class Dereference
{
const Functor& functor;
public:
Dereference( const Functor& functor ) : functor( functor ){
}
get_result_type<Functor> operator()( typename RemoveReference<get_argument<Functor, 0>>::type *firstArgument ) const {
	return functor( *firstArgument );
}
};

template<typename Functor>
inline Dereference<Functor> makeDereference( const Functor& functor ){
	return Dereference<Functor>( functor );
}

typedef Face* FacePointer;
const FacePointer c_nullFacePointer = 0;

template<typename Predicate>
Face* Brush_findIf( const Brush& brush, const Predicate& predicate ){
	Brush::const_iterator i = std::find_if( brush.begin(), brush.end(), makeDereference( predicate ) );
	return i == brush.end() ? c_nullFacePointer : *i; // uses c_nullFacePointer instead of 0 because otherwise gcc 4.1 attempts conversion to int
}

template<typename Caller>
class BindArguments1
{
typedef get_argument<Caller, 1> FirstBound;
FirstBound firstBound;
public:
BindArguments1( FirstBound firstBound )
	: firstBound( firstBound ){
}

get_result_type<Caller> operator()( get_argument<Caller, 0> firstArgument ) const {
	return Caller::call( firstArgument, firstBound );
}
};

template<typename Caller>
class BindArguments2
{
typedef get_argument<Caller, 1> FirstBound;
typedef get_argument<Caller, 2> SecondBound;
FirstBound firstBound;
SecondBound secondBound;
public:
BindArguments2( FirstBound firstBound, SecondBound secondBound )
	: firstBound( firstBound ), secondBound( secondBound ){
}

get_result_type<Caller> operator()( get_argument<Caller, 0> firstArgument ) const {
	return Caller::call( firstArgument, firstBound, secondBound );
}
};

template<typename Caller, typename FirstBound, typename SecondBound>
BindArguments2<Caller> bindArguments( const Caller& caller, FirstBound firstBound, SecondBound secondBound ){
	return BindArguments2<Caller>( firstBound, secondBound );
}

inline bool Face_testPlane( const Face& face, const Plane3& plane, bool flipped ){
	return face.contributes() && !Winding_TestPlane( face.getWinding(), plane, flipped );
}

typedef Function<bool ( const Face &, const Plane3 &, bool ), Face_testPlane> FaceTestPlane;


/// \brief Returns true if
/// \li !flipped && brush is BACK or ON
/// \li flipped && brush is FRONT or ON
bool Brush_testPlane( const Brush& brush, const Plane3& plane, bool flipped ){
	brush.evaluateBRep();
#if 1
	for ( Brush::const_iterator i( brush.begin() ); i != brush.end(); ++i )
	{
		if ( Face_testPlane( *( *i ), plane, flipped ) ) {
			return false;
		}
	}
	return true;
#else
	return Brush_findIf( brush, bindArguments( FaceTestPlane(), makeReference( plane ), flipped ) ) == 0;
#endif
}

brushsplit_t Brush_classifyPlane( const Brush& brush, const Plane3& plane ){
	brush.evaluateBRep();
	brushsplit_t split;
	for ( Brush::const_iterator i( brush.begin() ); i != brush.end(); ++i )
	{
		if ( ( *i )->contributes() ) {
			split += Winding_ClassifyPlane( ( *i )->getWinding(), plane );
		}
	}
	return split;
}

bool Brush_subtract( const Brush& brush, const Brush& other, brush_vector_t& ret_fragments ){
	if ( aabb_intersects_aabb( brush.localAABB(), other.localAABB() ) ) {
		brush_vector_t fragments;
		fragments.reserve( other.size() );
		Brush back( brush );

		for ( Brush::const_iterator i( other.begin() ); i != other.end(); ++i )
		{
			if ( ( *i )->contributes() ) {
				brushsplit_t split = Brush_classifyPlane( back, ( *i )->plane3() );
				if ( split.counts[ePlaneFront] != 0
					 && split.counts[ePlaneBack] != 0 ) {
					fragments.push_back( new Brush( back ) );
					Face* newFace = fragments.back()->addFace( *( *i ) );
					if ( newFace != 0 ) {
						newFace->flipWinding();
					}
					back.addFace( *( *i ) );
				}
				else if ( split.counts[ePlaneBack] == 0 ) {
					for ( brush_vector_t::iterator i = fragments.begin(); i != fragments.end(); ++i )
					{
						delete( *i );
					}
					return false;
				}
			}
		}
		ret_fragments.insert( ret_fragments.end(), fragments.begin(), fragments.end() );
		return true;
	}
	return false;
}

class SubtractBrushesFromUnselected : public scene::Graph::Walker
{
const brush_vector_t& m_brushlist;
std::size_t& m_before;
std::size_t& m_after;
public:
SubtractBrushesFromUnselected( const brush_vector_t& brushlist, std::size_t& before, std::size_t& after )
	: m_brushlist( brushlist ), m_before( before ), m_after( after ){
}

bool pre( const scene::Path& path, scene::Instance& instance ) const {
	return true;
}

void post( const scene::Path& path, scene::Instance& instance ) const {
	if ( path.top().get().visible() ) {
		Brush* brush = Node_getBrush( path.top() );
		if ( brush != 0
			 && !Instance_getSelectable( instance )->isSelected() ) {
			brush_vector_t buffer[2];
			bool swap = false;
			Brush* original = new Brush( *brush );
			buffer[static_cast<std::size_t>( swap )].push_back( original );

			{
				for ( brush_vector_t::const_iterator i( m_brushlist.begin() ); i != m_brushlist.end(); ++i )
				{
					for ( brush_vector_t::iterator j( buffer[static_cast<std::size_t>( swap )].begin() ); j != buffer[static_cast<std::size_t>( swap )].end(); ++j )
					{
						if ( Brush_subtract( *( *j ), *( *i ), buffer[static_cast<std::size_t>( !swap )] ) ) {
							delete ( *j );
						}
						else
						{
							buffer[static_cast<std::size_t>( !swap )].push_back( ( *j ) );
						}
					}
					buffer[static_cast<std::size_t>( swap )].clear();
					swap = !swap;
				}
			}

			brush_vector_t& out = buffer[static_cast<std::size_t>( swap )];

			if ( out.size() == 1 && out.back() == original ) {
				delete original;
			}
			else
			{
				++m_before;
				for ( brush_vector_t::const_iterator i = out.begin(); i != out.end(); ++i )
				{
					++m_after;
					( *i )->removeEmptyFaces();
					if ( !( *i )->empty() ) {
						NodeSmartReference node( ( new BrushNode() )->node() );
						Node_getBrush( node )->copy( *( *i ) );
						delete ( *i );
						Node_getTraversable( path.parent() )->insert( node );
					}
					else{
						delete ( *i );
					}
				}
				Path_deleteTop( path );
			}
		}
	}
}
};

void CSG_Subtract(){
	brush_vector_t selected_brushes;
	GlobalSceneGraph().traverse( BrushGatherSelected( selected_brushes ) );

	if ( selected_brushes.empty() ) {
		globalOutputStream() << "CSG Subtract: No brushes selected.\n";
	}
	else
	{
		globalOutputStream() << "CSG Subtract: Subtracting " << Unsigned( selected_brushes.size() ) << " brushes.\n";

		UndoableCommand undo( "brushSubtract" );

		// subtract selected from unselected
		std::size_t before = 0;
		std::size_t after = 0;
		GlobalSceneGraph().traverse( SubtractBrushesFromUnselected( selected_brushes, before, after ) );
		globalOutputStream() << "CSG Subtract: Result: "
							 << Unsigned( after ) << " fragment" << ( after == 1 ? "" : "s" )
							 << " from " << Unsigned( before ) << " brush" << ( before == 1 ? "" : "es" ) << ".\n";

		SceneChangeNotify();
	}
}

class BrushSplitByPlaneSelected : public scene::Graph::Walker
{
const Vector3& m_p0;
const Vector3& m_p1;
const Vector3& m_p2;
const char* m_shader;
const TextureProjection& m_projection;
EBrushSplit m_split;
public:
BrushSplitByPlaneSelected( const Vector3& p0, const Vector3& p1, const Vector3& p2, const char* shader, const TextureProjection& projection, EBrushSplit split )
	: m_p0( p0 ), m_p1( p1 ), m_p2( p2 ), m_shader( shader ), m_projection( projection ), m_split( split ){
}

bool pre( const scene::Path& path, scene::Instance& instance ) const {
	return true;
}

void post( const scene::Path& path, scene::Instance& instance ) const {
	if ( path.top().get().visible() ) {
		Brush* brush = Node_getBrush( path.top() );
		if ( brush != 0
			 && Instance_getSelectable( instance )->isSelected() ) {
			Plane3 plane( plane3_for_points( m_p0, m_p1, m_p2 ) );
			if ( plane3_valid( plane ) ) {
				brushsplit_t split = Brush_classifyPlane( *brush, m_split == eFront ? plane3_flipped( plane ) : plane );
				if ( split.counts[ePlaneBack] && split.counts[ePlaneFront] ) {
					// the plane intersects this brush
					if ( m_split == eFrontAndBack ) {
						NodeSmartReference node( ( new BrushNode() )->node() );
						Brush* fragment = Node_getBrush( node );
						fragment->copy( *brush );
						Face* newFace = fragment->addPlane( m_p0, m_p1, m_p2, m_shader, m_projection );
						if ( newFace != 0 && m_split != eFront ) {
							newFace->flipWinding();
						}
						fragment->removeEmptyFaces();
						ASSERT_MESSAGE( !fragment->empty(), "brush left with no faces after split" );

						Node_getTraversable( path.parent() )->insert( node );
						{
							scene::Path fragmentPath = path;
							fragmentPath.top() = makeReference( node.get() );
							selectPath( fragmentPath, true );
						}
					}

					Face* newFace = brush->addPlane( m_p0, m_p1, m_p2, m_shader, m_projection );
					if ( newFace != 0 && m_split == eFront ) {
						newFace->flipWinding();
					}
					brush->removeEmptyFaces();
					ASSERT_MESSAGE( !brush->empty(), "brush left with no faces after split" );
				}
				else
				// the plane does not intersect this brush
				if ( m_split != eFrontAndBack && split.counts[ePlaneBack] != 0 ) {
					// the brush is "behind" the plane
					Path_deleteTop( path );
				}
			}
		}
	}
}
};

void Scene_BrushSplitByPlane( scene::Graph& graph, const Vector3& p0, const Vector3& p1, const Vector3& p2, const char* shader, EBrushSplit split ){
	TextureProjection projection;
	TexDef_Construct_Default( projection );
	graph.traverse( BrushSplitByPlaneSelected( p0, p1, p2, shader, projection, split ) );
	SceneChangeNotify();
}


class BrushInstanceSetClipPlane : public scene::Graph::Walker
{
Plane3 m_plane;
public:
BrushInstanceSetClipPlane( const Plane3& plane )
	: m_plane( plane ){
}

bool pre( const scene::Path& path, scene::Instance& instance ) const {
	BrushInstance* brush = Instance_getBrush( instance );
	if ( brush != 0
		 && path.top().get().visible()
		 && brush->isSelected() ) {
		BrushInstance& brushInstance = *brush;
		brushInstance.setClipPlane( m_plane );
	}
	return true;
}
};

void Scene_BrushSetClipPlane( scene::Graph& graph, const Plane3& plane ){
	graph.traverse( BrushInstanceSetClipPlane( plane ) );
}

/*
   =============
   CSG_Merge
   =============
 */
bool Brush_merge( Brush& brush, const brush_vector_t& in, bool onlyshape ){
	// gather potential outer faces

	{
		typedef std::vector<const Face*> Faces;
		Faces faces;
		for ( brush_vector_t::const_iterator i( in.begin() ); i != in.end(); ++i )
		{
			( *i )->evaluateBRep();
			for ( Brush::const_iterator j( ( *i )->begin() ); j != ( *i )->end(); ++j )
			{
				if ( !( *j )->contributes() ) {
					continue;
				}

				const Face& face1 = *( *j );

				bool skip = false;
				// test faces of all input brushes
				//!\todo SPEEDUP: Flag already-skip faces and only test brushes from i+1 upwards.
				for ( brush_vector_t::const_iterator k( in.begin() ); !skip && k != in.end(); ++k )
				{
					if ( k != i ) { // don't test a brush against itself
						for ( Brush::const_iterator l( ( *k )->begin() ); !skip && l != ( *k )->end(); ++l )
						{
							const Face& face2 = *( *l );

							// face opposes another face
							if ( plane3_opposing( face1.plane3(), face2.plane3() ) ) {
								// skip opposing planes
								skip  = true;
								break;
							}
						}
					}
				}

				// check faces already stored
				for ( Faces::const_iterator m = faces.begin(); !skip && m != faces.end(); ++m )
				{
					const Face& face2 = *( *m );

					// face equals another face
					if ( plane3_equal( face1.plane3(), face2.plane3() ) ) {
						//if the texture/shader references should be the same but are not
						if ( !onlyshape && !shader_equal( face1.getShader().getShader(), face2.getShader().getShader() ) ) {
							return false;
						}
						// skip duplicate planes
						skip = true;
						break;
					}

					// face1 plane intersects face2 winding or vice versa
					if ( Winding_PlanesConcave( face1.getWinding(), face2.getWinding(), face1.plane3(), face2.plane3() ) ) {
						// result would not be convex
						return false;
					}
				}

				if ( !skip ) {
					faces.push_back( &face1 );
				}
			}
		}
		for ( Faces::const_iterator i = faces.begin(); i != faces.end(); ++i )
		{
			if ( !brush.addFace( *( *i ) ) ) {
				// result would have too many sides
				return false;
			}
		}
	}

	brush.removeEmptyFaces();

	return true;
}

void CSG_Merge( void ){
	brush_vector_t selected_brushes;

	// remove selected
	GlobalSceneGraph().traverse( BrushGatherSelected( selected_brushes ) );

	if ( selected_brushes.empty() ) {
		globalOutputStream() << "CSG Merge: No brushes selected.\n";
		return;
	}

	if ( selected_brushes.size() < 2 ) {
		globalOutputStream() << "CSG Merge: At least two brushes have to be selected.\n";
		return;
	}

	globalOutputStream() << "CSG Merge: Merging " << Unsigned( selected_brushes.size() ) << " brushes.\n";

	UndoableCommand undo( "brushMerge" );

	scene::Path merged_path = GlobalSelectionSystem().ultimateSelected().path();

	NodeSmartReference node( ( new BrushNode() )->node() );
	Brush* brush = Node_getBrush( node );
	// if the new brush would not be convex
	if ( !Brush_merge( *brush, selected_brushes, true ) ) {
		globalOutputStream() << "CSG Merge: Failed - result would not be convex.\n";
	}
	else
	{
		ASSERT_MESSAGE( !brush->empty(), "brush left with no faces after merge" );

		// free the original brushes
		GlobalSceneGraph().traverse( BrushDeleteSelected() );

		merged_path.pop();
		Node_getTraversable( merged_path.top() )->insert( node );
		merged_path.push( makeReference( node.get() ) );

		selectPath( merged_path, true );

		globalOutputStream() << "CSG Merge: Succeeded.\n";
		SceneChangeNotify();
	}
}