/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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* Redistributions of source code must retain the above
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

/** @file Implementation of the LWO importer class for the older LWOB 
    file formats, including materials */

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

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

using namespace Assimp;


// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWOBFile()
{
	LE_NCONST uint8_t* const end = mFileBuffer + fileSize;
	while (true)
	{
		if (mFileBuffer + sizeof(IFF::ChunkHeader) > end)break;
		LE_NCONST IFF::ChunkHeader* const head = (LE_NCONST IFF::ChunkHeader*)mFileBuffer;
		AI_LSWAP4(head->length);
		AI_LSWAP4(head->type);
		mFileBuffer += sizeof(IFF::ChunkHeader);
		if (mFileBuffer + head->length > end)
		{
			throw new ImportErrorException("LWOB: Invalid file, the size attribute of "
				"a chunk points behind the end of the file");
			break;
		}
		LE_NCONST uint8_t* const next = mFileBuffer+head->length;
		switch (head->type)
		{
			// vertex list
		case AI_LWO_PNTS:
			{
				if (!mCurLayer->mTempPoints.empty())
					DefaultLogger::get()->warn("LWO: PNTS chunk encountered twice");
				else LoadLWOPoints(head->length);
				break;
			}
			// face list
		case AI_LWO_POLS:
			{
				if (!mCurLayer->mFaces.empty())
					DefaultLogger::get()->warn("LWO: POLS chunk encountered twice");
				else LoadLWOPolygons(head->length);
				break;
			}
			// list of tags
		case AI_LWO_SRFS:
			{
				if (!mTags->empty())
					DefaultLogger::get()->warn("LWO: SRFS chunk encountered twice");
				else LoadLWOTags(head->length);
				break;
			}

			// surface chunk
		case AI_LWO_SURF:
			{
				if (!mSurfaces->empty())
					DefaultLogger::get()->warn("LWO: SURF chunk encountered twice");
				else LoadLWOBSurface(head->length);
				break;
			}
		}
		mFileBuffer = next;
	}
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::CountVertsAndFacesLWOB(unsigned int& verts, unsigned int& faces,
	LE_NCONST uint16_t*& cursor, const uint16_t* const end, unsigned int max)
{
	while (cursor < end && max--)
	{
		uint16_t numIndices = *cursor++;
		verts += numIndices;faces++;
		cursor += numIndices;
		int16_t surface = *cursor++;
		if (surface < 0)
		{
			// there are detail polygons
			numIndices = *cursor++;
			CountVertsAndFacesLWOB(verts,faces,cursor,end,numIndices);
		}
	}
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::CopyFaceIndicesLWOB(FaceList::iterator& it,
	LE_NCONST uint16_t*& cursor, 
	const uint16_t* const end,
	unsigned int max)
{
	while (cursor < end && max--)
	{
		LWO::Face& face = *it;++it;
		if(face.mNumIndices = *cursor++)
		{
			if (cursor + face.mNumIndices >= end)break;
			face.mIndices = new unsigned int[face.mNumIndices];
			for (unsigned int i = 0; i < face.mNumIndices;++i)
			{
				unsigned int & mi = face.mIndices[i] = *cursor++;
				if (mi > mCurLayer->mTempPoints.size())
				{
					DefaultLogger::get()->warn("LWOB: face index is out of range");
					mi = (unsigned int)mCurLayer->mTempPoints.size()-1;
				}
			}
		}
		else DefaultLogger::get()->warn("LWOB: Face has 0 indices");
		int16_t surface = *cursor++;
		if (surface < 0)
		{
			surface = -surface;

			// there are detail polygons
			uint16_t numPolygons = *cursor++;
			if (cursor < end)CopyFaceIndicesLWOB(it,cursor,end,numPolygons);
		}
		face.surfaceIndex = surface-1;
	}
}

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

	mSurfaces->push_back( LWO::Surface () );
	LWO::Surface& surf = mSurfaces->back();
	LWO::Texture* pTex = NULL;

	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("LWOB: 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,3);
				surf.mColor.r = *mFileBuffer++ / 255.0f;
				surf.mColor.g = *mFileBuffer++ / 255.0f;
				surf.mColor.b = *mFileBuffer   / 255.0f;
				break;
			}
		// diffuse strength ...
		case AI_LWO_DIFF:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,DIFF,2);
				AI_LSWAP2P(mFileBuffer);
				surf.mDiffuseValue = *((int16_t*)mFileBuffer) / 255.0f;
				break;
			}
		// specular strength ... 
		case AI_LWO_SPEC:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,SPEC,2);
				AI_LSWAP2P(mFileBuffer);
				surf.mSpecularValue = *((int16_t*)mFileBuffer) / 255.0f;
				break;
			}
		// luminosity ... 
		case AI_LWO_LUMI:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,LUMI,2);
				AI_LSWAP2P(mFileBuffer);
				surf.mLuminosity = *((int16_t*)mFileBuffer) / 255.0f;
				break;
			}
		// transparency
		case AI_LWO_TRAN:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,TRAN,2);
				AI_LSWAP2P(mFileBuffer);
				surf.mTransparency = *((int16_t*)mFileBuffer) / 255.0f;
				break;
			}
		// glossiness
		case AI_LWO_GLOS:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,GLOS,2);
				AI_LSWAP2P(mFileBuffer);
				surf.mGlossiness = float(*((int16_t*)mFileBuffer));
				break;
			}
		// color texture
		case AI_LWO_CTEX:
			{
				pTex = &surf.mColorTexture;
				break;
			}
		// diffuse texture
		case AI_LWO_DTEX:
			{
				pTex = &surf.mDiffuseTexture;
				break;
			}
		// specular texture
		case AI_LWO_STEX:
			{
				pTex = &surf.mSpecularTexture;
				break;
			}
		// bump texture
		case AI_LWO_BTEX:
			{
				pTex = &surf.mBumpTexture;
				break;
			}
		// transparency texture
		case AI_LWO_TTEX:
			{
				pTex = &surf.mTransparencyTexture;
				break;
			}
			// texture path
		case AI_LWO_TIMG:
			{
				if (pTex)
				{
					ParseString(pTex->mFileName,head_length);	
					AdjustTexturePath(pTex->mFileName);
					mFileBuffer += pTex->mFileName.length();
				}
				else DefaultLogger::get()->warn("LWOB: TIMG tag was encuntered although "
					"there was no xTEX tag before");
				break;
			}
		// texture strength
		case AI_LWO_TVAL:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head_length,TVAL,1);
				if (pTex)pTex->mStrength = *mFileBuffer / 255.0f;
				else DefaultLogger::get()->warn("LWOB: TVAL tag was encuntered "
					"although there was no xTEX tag before");
				break;
			}
		}
		mFileBuffer = next;
	}
}