/*
   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
 */

#include "md5.h"

#include "iscriplib.h"
#include "imodel.h"

#include "archivelib.h"
#include "stringio.h"

#include "model.h"

#define MD5_RETURN_FALSE_IF_FAIL( expression ) do{ if ( !( expression ) ) { globalErrorStream() << "md5 parse failed: " # expression "\n"; return false; } }while( 0 )

bool MD5_parseToken( Tokeniser& tokeniser, const char* string ){
	const char* token = tokeniser.getToken();
	MD5_RETURN_FALSE_IF_FAIL( token != 0 );
	return string_equal( token, string );
}

bool MD5_parseFloat( Tokeniser& tokeniser, float& f ){
	const char* token = tokeniser.getToken();
	MD5_RETURN_FALSE_IF_FAIL( token != 0 );
	return string_parse_float( token, f );
}

bool MD5_parseString( Tokeniser& tokeniser, const char*& s ){
	const char* token = tokeniser.getToken();
	MD5_RETURN_FALSE_IF_FAIL( token != 0 );
	s = token;
	return true;
}

bool MD5_parseInteger( Tokeniser& tokeniser, int& i ){
	const char* token = tokeniser.getToken();
	MD5_RETURN_FALSE_IF_FAIL( token != 0 );
	return string_parse_int( token, i );
}

bool MD5_parseSize( Tokeniser& tokeniser, std::size_t& i ){
	const char* token = tokeniser.getToken();
	MD5_RETURN_FALSE_IF_FAIL( token != 0 );
	return string_parse_size( token, i );
}

bool MD5_parseVector3( Tokeniser& tokeniser, Vector3& v ){
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "(" ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, v.x() ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, v.y() ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, v.z() ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, ")" ) );
	return true;
}

template<typename Element>
inline Element float_squared( const Element& f ){
	return f * f;
}

class MD5Joint
{
public:
int parent;
Vector3 position;
Vector4 rotation;
};

typedef Array<MD5Joint> MD5Joints;

class MD5Vert
{
public:
std::size_t index;
float u;
float v;
std::size_t weight_index;
std::size_t weight_count;
};

typedef Array<MD5Vert> MD5Verts;

class MD5Tri
{
public:
std::size_t index;
std::size_t a;
std::size_t b;
std::size_t c;
};

typedef Array<MD5Tri> MD5Tris;

class MD5Weight
{
public:
std::size_t index;
std::size_t joint;
float t;
Vector3 v;
};

typedef Array<MD5Weight> MD5Weights;

typedef float MD5Component;
typedef Array<MD5Component> MD5Components;

class MD5Frame
{
public:
MD5Components m_components;
};

typedef Array<MD5Weight> MD5Weights;

bool MD5_parseVersion( Tokeniser& tokeniser ){
	{
		const char* versionKey = tokeniser.getToken();
		if ( versionKey == 0 || !string_equal( versionKey, "MD5Version" ) ) {
			globalErrorStream() << "not a valid md5 file\n";
			return false;
		}
	}
	{
		const char* versionValue = tokeniser.getToken();
		if ( versionValue == 0 || !string_equal( versionValue, "10" ) ) {
			globalErrorStream() << "only md5 version 10 supported\n";
			return false;
		}
	}

	return true;
}

bool MD5Anim_parse( Tokeniser& tokeniser ){
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseVersion( tokeniser ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "commandline" ) );
	const char* commandline;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseString( tokeniser, commandline ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numFrames" ) );
	std::size_t numFrames;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numFrames ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numJoints" ) );
	std::size_t numJoints;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numJoints ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "frameRate" ) );
	std::size_t frameRate;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, frameRate ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numAnimatedComponents" ) );
	std::size_t numAnimatedComponents;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numAnimatedComponents ) );
	tokeniser.nextLine();

	// parse heirarchy
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "hierarchy" ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
	tokeniser.nextLine();

	for ( std::size_t i = 0; i < numJoints; ++i )
	{
		const char* name;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseString( tokeniser, name ) );
		int parent;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseInteger( tokeniser, parent ) );
		std::size_t flags;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, flags ) );
		std::size_t index;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, index ) );
		tokeniser.nextLine();
	}

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
	tokeniser.nextLine();

	// parse bounds
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "bounds" ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
	tokeniser.nextLine();

	for ( std::size_t i = 0; i < numFrames; ++i )
	{
		Vector3 mins;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, mins ) );
		Vector3 maxs;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, maxs ) );
		tokeniser.nextLine();
	}

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
	tokeniser.nextLine();

	// parse baseframe
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "baseframe" ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
	tokeniser.nextLine();

	for ( std::size_t i = 0; i < numJoints; ++i )
	{
		Vector3 position;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, position ) );
		Vector3 rotation;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, rotation ) );
		tokeniser.nextLine();
	}

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
	tokeniser.nextLine();

	// parse frames
	for ( std::size_t i = 0; i < numFrames; ++i )
	{
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "frame" ) );
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
		tokeniser.nextLine();

		for ( std::size_t i = 0; i < numAnimatedComponents; ++i )
		{
			float component;
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, component ) );
			tokeniser.nextLine();
		}

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
		tokeniser.nextLine();
	}

	return true;
}

bool MD5Model_parse( Model& model, Tokeniser& tokeniser ){
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseVersion( tokeniser ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "commandline" ) );
	const char* commandline;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseString( tokeniser, commandline ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numJoints" ) );
	std::size_t numJoints;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numJoints ) );
	tokeniser.nextLine();

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numMeshes" ) );
	std::size_t numMeshes;
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numMeshes ) );
	tokeniser.nextLine();

	MD5Joints joints( numJoints );

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "joints" ) );
	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
	tokeniser.nextLine();

	for ( MD5Joints::iterator i = joints.begin(); i != joints.end(); ++i )
	{
		const char* jointName;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseString( tokeniser, jointName ) );
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseInteger( tokeniser, ( *i ).parent ) );
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, ( *i ).position ) );
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, vector4_to_vector3( ( *i ).rotation ) ) );
		( *i ).rotation.w() = -static_cast<float>( sqrt( 1.0f - ( float_squared( ( *i ).rotation.x() ) + float_squared( ( *i ).rotation.y() ) + float_squared( ( *i ).rotation.z() ) ) ) );
		tokeniser.nextLine();
	}

	MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
	tokeniser.nextLine();

	for ( std::size_t i = 0; i < numMeshes; ++i )
	{
		Surface& surface = model.newSurface();

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "mesh" ) );
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "{" ) );
		tokeniser.nextLine();

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "shader" ) );
		const char* shader;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseString( tokeniser, shader ) );
		surface.setShader( shader );
		tokeniser.nextLine();

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numverts" ) );
		std::size_t numVerts;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numVerts ) );
		tokeniser.nextLine();

		MD5Verts verts( numVerts );

		for ( MD5Verts::iterator j = verts.begin(); j != verts.end(); ++j )
		{
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "vert" ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).index ) );
			MD5_RETURN_FALSE_IF_FAIL( ( *j ).index == std::size_t( j - verts.begin() ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "(" ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, ( *j ).u ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, ( *j ).v ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, ")" ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).weight_index ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).weight_count ) );
			tokeniser.nextLine();
		}

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numtris" ) );
		std::size_t numTris;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numTris ) );
		tokeniser.nextLine();

		MD5Tris tris( numTris );

		for ( MD5Tris::iterator j = tris.begin(); j != tris.end(); ++j )
		{
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "tri" ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).index ) );
			MD5_RETURN_FALSE_IF_FAIL( ( *j ).index == std::size_t( j - tris.begin() ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).a ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).b ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).c ) );
			tokeniser.nextLine();
		}

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "numweights" ) );
		std::size_t numWeights;
		MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, numWeights ) );
		tokeniser.nextLine();

		MD5Weights weights( numWeights );

		for ( MD5Weights::iterator j = weights.begin(); j != weights.end(); ++j )
		{
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "weight" ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).index ) );
			MD5_RETURN_FALSE_IF_FAIL( ( *j ).index == std::size_t( j - weights.begin() ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseSize( tokeniser, ( *j ).joint ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseFloat( tokeniser, ( *j ).t ) );
			MD5_RETURN_FALSE_IF_FAIL( MD5_parseVector3( tokeniser, ( *j ).v ) );
			tokeniser.nextLine();
		}

		MD5_RETURN_FALSE_IF_FAIL( MD5_parseToken( tokeniser, "}" ) );
		tokeniser.nextLine();

		for ( MD5Verts::iterator j = verts.begin(); j != verts.end(); ++j )
		{
			MD5Vert& vert = ( *j );

			Vector3 skinned( 0, 0, 0 );
			for ( std::size_t k = 0; k != vert.weight_count; ++k )
			{
				MD5Weight& weight = weights[vert.weight_index + k];
				MD5Joint& joint = joints[weight.joint];

				skinned += ( quaternion_transformed_point( joint.rotation, weight.v ) + joint.position ) * weight.t;
			}

			surface.vertices().push_back( ArbitraryMeshVertex( vertex3f_for_vector3( skinned ), Normal3f( 0, 0, 0 ), TexCoord2f( vert.u, vert.v ) ) );
		}

		for ( MD5Tris::iterator j = tris.begin(); j != tris.end(); ++j )
		{
			MD5Tri& tri = ( *j );
			surface.indices().insert( RenderIndex( tri.a ) );
			surface.indices().insert( RenderIndex( tri.b ) );
			surface.indices().insert( RenderIndex( tri.c ) );
		}

		for ( Surface::indices_t::iterator j = surface.indices().begin(); j != surface.indices().end(); j += 3 )
		{
			ArbitraryMeshVertex& a = surface.vertices()[*( j + 0 )];
			ArbitraryMeshVertex& b = surface.vertices()[*( j + 1 )];
			ArbitraryMeshVertex& c = surface.vertices()[*( j + 2 )];
			Vector3 weightedNormal(
				vector3_cross(
					reinterpret_cast<const Vector3&>( c.vertex ) - reinterpret_cast<const Vector3&>( a.vertex ),
					reinterpret_cast<const Vector3&>( b.vertex ) - reinterpret_cast<const Vector3&>( a.vertex )
					)
				);
			reinterpret_cast<Vector3&>( a.normal ) += weightedNormal;
			reinterpret_cast<Vector3&>( b.normal ) += weightedNormal;
			reinterpret_cast<Vector3&>( c.normal ) += weightedNormal;
		}

		for ( Surface::vertices_t::iterator j = surface.vertices().begin(); j != surface.vertices().end(); ++j )
		{
			vector3_normalise( reinterpret_cast<Vector3&>( ( *j ).normal ) );
		}

		surface.updateAABB();
	}

	model.updateAABB();

	return true;
}

void MD5Model_construct( Model& model, TextInputStream& inputStream ){
	Tokeniser& tokeniser = GlobalScriptLibrary().m_pfnNewSimpleTokeniser( inputStream );
	MD5Model_parse( model, tokeniser );
	tokeniser.release();
}

scene::Node& MD5Model_new( TextInputStream& inputStream ){
	ModelNode* modelNode = new ModelNode();
	MD5Model_construct( modelNode->model(), inputStream );
	return modelNode->node();
}

scene::Node& loadMD5Model( ArchiveFile& file ){
	BinaryToTextInputStream<InputStream> inputStream( file.getInputStream() );
	return MD5Model_new( inputStream );
}