/*
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Open Asset Import Library (assimp)
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*/

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

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_LWO_IMPORTER

// Internal headers
#include "LWOLoader.h"
using namespace Assimp;


// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWOBFile()
{
	LE_NCONST uint8_t* const end = mFileBuffer + fileSize;
	bool running = true;
	while (running)
	{
		if (mFileBuffer + sizeof(IFF::ChunkHeader) > end)break;
		LE_NCONST IFF::ChunkHeader* const head = IFF::LoadChunk(mFileBuffer);

		if (mFileBuffer + head->length > end)
		{
			throw DeadlyImportError("LWOB: Invalid chunk length");
			break;
		}
		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 LoadLWOBPolygons(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:
			{
				LoadLWOBSurface(head->length);
				break;
			}
		}
		mFileBuffer = next;
	}
}

// ------------------------------------------------------------------------------------------------
void LWOImporter::LoadLWOBPolygons(unsigned int length)
{
	// first find out how many faces and vertices we'll finally need
	LE_NCONST uint16_t* const end	= (LE_NCONST uint16_t*)(mFileBuffer+length);
	LE_NCONST uint16_t* cursor		= (LE_NCONST uint16_t*)mFileBuffer;

	// perform endianess conversions
#ifndef AI_BUILD_BIG_ENDIAN
	while (cursor < end)ByteSwap::Swap2(cursor++);
	cursor = (LE_NCONST uint16_t*)mFileBuffer;
#endif

	unsigned int iNumFaces = 0,iNumVertices = 0;
	CountVertsAndFacesLWOB(iNumVertices,iNumFaces,cursor,end);

	// allocate the output array and copy face indices
	if (iNumFaces)
	{
		cursor = (LE_NCONST uint16_t*)mFileBuffer;

		mCurLayer->mFaces.resize(iNumFaces);
		FaceList::iterator it = mCurLayer->mFaces.begin();
		CopyFaceIndicesLWOB(it,cursor,end);
	}
}

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

// ------------------------------------------------------------------------------------------------
LWO::Texture* LWOImporter::SetupNewTextureLWOB(LWO::TextureList& list,unsigned int size)
{
	list.push_back(LWO::Texture());
	LWO::Texture* tex = &list.back();

	std::string type;
	GetS0(type,size);
	const char* s = type.c_str();

	if(strstr(s, "Image Map"))
	{
		// Determine mapping type
		if(strstr(s, "Planar"))
			tex->mapMode = LWO::Texture::Planar;
		else if(strstr(s, "Cylindrical"))
			tex->mapMode = LWO::Texture::Cylindrical;
		else if(strstr(s, "Spherical"))
			tex->mapMode = LWO::Texture::Spherical;
		else if(strstr(s, "Cubic"))
			tex->mapMode = LWO::Texture::Cubic;
		else if(strstr(s, "Front"))
			tex->mapMode = LWO::Texture::FrontProjection;
	}
	else
	{
		// procedural or gradient, not supported
		DefaultLogger::get()->error("LWOB: Unsupported legacy texture: " + type);
	}

	return tex;
}

// ------------------------------------------------------------------------------------------------
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;

	GetS0(surf.mName,size);
	bool runnning = true;
	while (runnning)	{
		if (mFileBuffer + 6 >= end)
			break;

		IFF::SubChunkHeader* const head = IFF::LoadSubChunk(mFileBuffer);

		/*  A single test file (sonycam.lwo) seems to have invalid surface chunks.
		 *  I'm assuming it's the fault of a single, unknown exporter so there are
		 *  probably THOUSANDS of them. Here's a dirty workaround:
		 *
		 *  We don't break if the chunk limit is exceeded. Instead, we're computing 
		 *  how much storage is actually left and work with this value from now on.
		 */
		if (mFileBuffer + head->length > end) {
			DefaultLogger::get()->error("LWOB: Invalid surface chunk length. Trying to continue.");
			head->length = (uint16_t) (end - mFileBuffer);
		}

		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 = GetU1() / 255.0f;
				surf.mColor.g = GetU1() / 255.0f;
				surf.mColor.b = GetU1() / 255.0f;
				break;
			}
		// diffuse strength ...
		case AI_LWO_DIFF:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,DIFF,2);
				surf.mDiffuseValue = GetU2() / 255.0f;
				break;
			}
		// specular strength ... 
		case AI_LWO_SPEC:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,SPEC,2);
				surf.mSpecularValue = GetU2() / 255.0f;
				break;
			}
		// luminosity ... 
		case AI_LWO_LUMI:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,LUMI,2);
				surf.mLuminosity = GetU2() / 255.0f;
				break;
			}
		// transparency
		case AI_LWO_TRAN:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,TRAN,2);
				surf.mTransparency = GetU2() / 255.0f;
				break;
			}
		// surface flags
		case AI_LWO_FLAG:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,FLAG,2);
				uint16_t flag = GetU2();
				if (flag & 0x4 )   surf.mMaximumSmoothAngle = 1.56207f;
				if (flag & 0x8 )   surf.mColorHighlights = 1.f;
				if (flag & 0x100)  surf.bDoubleSided = true;
				break;
			}
		// maximum smoothing angle
		case AI_LWO_SMAN:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,SMAN,4);
				surf.mMaximumSmoothAngle = std::fabs( GetF4() );
				break;
			}
		// glossiness
		case AI_LWO_GLOS:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,GLOS,2);
				surf.mGlossiness = (float)GetU2();
				break;
			}
		// color texture
		case AI_LWO_CTEX:
			{
				pTex = SetupNewTextureLWOB(surf.mColorTextures,
					head->length);
				break;
			}
		// diffuse texture
		case AI_LWO_DTEX:
			{
				pTex = SetupNewTextureLWOB(surf.mDiffuseTextures,
					head->length);
				break;
			}
		// specular texture
		case AI_LWO_STEX:
			{
				pTex = SetupNewTextureLWOB(surf.mSpecularTextures,
					head->length);
				break;
			}
		// bump texture
		case AI_LWO_BTEX:
			{
				pTex = SetupNewTextureLWOB(surf.mBumpTextures,
					head->length);
				break;
			}
		// transparency texture
		case AI_LWO_TTEX:
			{
				pTex = SetupNewTextureLWOB(surf.mOpacityTextures,
					head->length);
				break;
			}
		// texture path
		case AI_LWO_TIMG:
			{
				if (pTex)	{
					GetS0(pTex->mFileName,head->length);	
				}
				else DefaultLogger::get()->warn("LWOB: Unexpected TIMG chunk");
				break;
			}
		// texture strength
		case AI_LWO_TVAL:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,TVAL,1);
				if (pTex)	{
					pTex->mStrength = (float)GetU1()/ 255.f;
				}
				else DefaultLogger::get()->warn("LWOB: Unexpected TVAL chunk");
				break;
			}
		// texture flags
		case AI_LWO_TFLG:
			{
				AI_LWO_VALIDATE_CHUNK_LENGTH(head->length,TFLG,2);

				if (pTex) 
				{
					const uint16_t s = GetU2();
					if (s & 1)
						pTex->majorAxis = LWO::Texture::AXIS_X;
					else if (s & 2)
						pTex->majorAxis = LWO::Texture::AXIS_Y;
					else if (s & 4)
						pTex->majorAxis = LWO::Texture::AXIS_Z;

					if (s & 16)
						DefaultLogger::get()->warn("LWOB: Ignoring \'negate\' flag on texture");
				} 
				else DefaultLogger::get()->warn("LWOB: Unexpected TFLG chunk");
				break;
			}
		}
		mFileBuffer = next;
	}
}

#endif // !! ASSIMP_BUILD_NO_LWO_IMPORTER
