/*
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Open Asset Import Library (ASSIMP)
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*/

/** @file Implementation of the material oart of the LWO importer class */

// internal headers
#include "LWOLoader.h"
#include "MaterialSystem.h"
#include "ByteSwap.h"

// public assimp headers
#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"
#include "../include/DefaultLogger.h"

// boost headers
#include <boost/scoped_ptr.hpp>

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
void LWOImporter::ConvertMaterial(const LWO::Surface& surf,MaterialHelper* pcMat)
{
	// copy the name of the surface
	aiString st;
	st.Set(surf.mName);
	pcMat->AddProperty(&st,AI_MATKEY_NAME);

	int i = surf.bDoubleSided ? 1 : 0;
	pcMat->AddProperty<int>(&i,1,AI_MATKEY_TWOSIDED);
	
	if (surf.mSpecularValue && surf.mGlossiness)
	{
		// this is only an assumption, needs to be confirmed.
		// the values have been tweaked by hand and seem to be correct.
		float fGloss;
		if (mIsLWO2)fGloss = surf.mGlossiness * 0.8f;
		else
		{
			if (16.0f >= surf.mGlossiness)fGloss = 6.0f;
			else if (64.0f >= surf.mGlossiness)fGloss = 20.0f;
			else if (256.0f >= surf.mGlossiness)fGloss = 50.0f;
			else fGloss = 80.0f;
		}

		pcMat->AddProperty<float>(&surf.mSpecularValue,1,AI_MATKEY_SHININESS_STRENGTH);
		pcMat->AddProperty<float>(&fGloss,1,AI_MATKEY_SHININESS);
	}

	// (the diffuse value is just a scaling factor)
	aiColor3D clr = surf.mColor;
	clr.r *= surf.mDiffuseValue;
	clr.g *= surf.mDiffuseValue;
	clr.b *= surf.mDiffuseValue;
	pcMat->AddProperty<aiColor3D>(&clr,1,AI_MATKEY_COLOR_DIFFUSE);

	// specular color
	clr.b = clr.g  = clr.r = surf.mSpecularValue;
	pcMat->AddProperty<aiColor3D>(&clr,1,AI_MATKEY_COLOR_SPECULAR);

	// emissive color
	// (luminosity is not really the same but it affects the surface in 
	//  a similar way. However, some scalings seems to be necessary)
	clr.g = clr.b = clr.r = surf.mLuminosity*0.8f;
	pcMat->AddProperty<aiColor3D>(&clr,1,AI_MATKEY_COLOR_EMISSIVE);

	// opacity
	float f = 1.0f-surf.mTransparency;
	pcMat->AddProperty<float>(&f,1,AI_MATKEY_OPACITY);

	// now handle all textures ...
	// TODO
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::FindUVChannels(const LWO::Surface& surf, const LWO::Layer& layer,
	unsigned int out[AI_MAX_NUMBER_OF_TEXTURECOORDS])
{
	out[0] = 0xffffffff;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::FindVCChannels(const LWO::Surface& surf, const LWO::Layer& layer,
	unsigned int out[AI_MAX_NUMBER_OF_COLOR_SETS])
{
	out[0] = 0xffffffff;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2ImageMap(unsigned int size, LWO::Texture& tex )
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2Procedural(unsigned int size, LWO::Texture& tex )
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2Gradient(unsigned int size, LWO::Texture& tex  )
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2TextureHeader(unsigned int size, LWO::Texture& tex )
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2TextureBlock(uint32_t type, unsigned int size )
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;

	LWO::Surface& surf = mSurfaces->back();
	LWO::Texture tex;

	// now get the exact type of the texture
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWO2Surface(unsigned int size)
{
	LE_NCONST uint8_t* const end = mFileBuffer + size;

	mSurfaces->push_back( LWO::Surface () );
	LWO::Surface& surf = mSurfaces->back();

	ParseString(surf.mName,size);
	mFileBuffer+=surf.mName.length()+1;
	 // skip one byte if the length of the surface name is odd
	if (!(surf.mName.length() & 1))++mFileBuffer;
	while (true)
	{
		if (mFileBuffer + 6 > end)break;

		// no proper IFF header here - the chunk length is specified as int16
		uint32_t head_type		= *((LE_NCONST uint32_t*)mFileBuffer);mFileBuffer+=4;
		uint16_t head_length	= *((LE_NCONST uint16_t*)mFileBuffer);mFileBuffer+=2;
		AI_LSWAP4(head_type);
		AI_LSWAP2(head_length);
		if (mFileBuffer + head_length > end)
		{
			throw new ImportErrorException("LWO2: Invalid file, the size attribute of "
				"a surface sub chunk points behind the end of the file");
		}
		LE_NCONST uint8_t* const next = mFileBuffer+head_length;
		switch (head_type)
		{
			// diffuse color
		case AI_LWO_COLR:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,COLR,12);
				surf.mColor.r = ((float*)mFileBuffer)[0];
				surf.mColor.g = ((float*)mFileBuffer)[1];
				surf.mColor.b = ((float*)mFileBuffer)[2];
				AI_LSWAP4(surf.mColor.r);
				AI_LSWAP4(surf.mColor.g);
				AI_LSWAP4(surf.mColor.b);
				break;
			}
			// diffuse strength ... hopefully
		case AI_LWO_DIFF:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,DIFF,4);
				surf.mDiffuseValue = *((float*)mFileBuffer);
				AI_LSWAP4(surf.mDiffuseValue);
				break;
			}
			// specular strength ... hopefully
		case AI_LWO_SPEC:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,SPEC,4);
				surf.mSpecularValue = *((float*)mFileBuffer);
				AI_LSWAP4(surf.mSpecularValue);
				break;
			}
			// transparency
		case AI_LWO_TRAN:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,TRAN,4);
				surf.mTransparency = *((float*)mFileBuffer);
				AI_LSWAP4(surf.mTransparency);
				break;
			}
			// glossiness
		case AI_LWO_GLOS:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,GLOS,4);
				surf.mGlossiness = *((float*)mFileBuffer);
				AI_LSWAP4(surf.mGlossiness);
				break;
			}
			// surface bock entry
		case AI_LWO_BLOK:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,BLOK,4);
				uint32_t type = *((uint32_t*)mFileBuffer);
				AI_LSWAP4(type);

				switch (type)
				{
				case AI_LWO_IMAP:
				case AI_LWO_PROC:
				case AI_LWO_GRAD:
					mFileBuffer+=4;
					LoadLWO2TextureBlock(type,head_length-4);
					break;
				};

				break;
			}
		}
		mFileBuffer = next;
	}
}

// ------------------------------------------------------------------------------------------------
bool LWOImporter::ComputeGradientTexture(LWO::GradientInfo& grad,
	std::vector<aiTexture*>& out)
{
	aiTexture* tex = new aiTexture();

	tex->mHeight = configGradientResY;
	tex->mWidth = configGradientResX;
	unsigned int numPixels;
	tex->pcData = new aiTexel[numPixels = tex->mHeight * tex->mWidth];

	// to be implemented ...

	out.push_back(tex);
	return true;
}