/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#ifndef BT_SERIALIZER_H
#define BT_SERIALIZER_H

#include "btScalar.h" // has definitions like SIMD_FORCE_INLINE
#include "btStackAlloc.h"
#include "btHashMap.h"

#if !defined( __CELLOS_LV2__) && !defined(__MWERKS__)
#include <memory.h>
#endif
#include <string.h>



///only the 32bit versions for now
extern unsigned char sBulletDNAstr[];
extern int sBulletDNAlen;
extern unsigned char sBulletDNAstr64[];
extern int sBulletDNAlen64;

SIMD_FORCE_INLINE	int btStrLen(const char* str) 
{
    if (!str) 
		return(0);
	int len = 0;
    
	while (*str != 0)
	{
        str++;
        len++;
    }

    return len;
}


class btChunk
{
public:
	int		m_chunkCode;
	int		m_length;
	void	*m_oldPtr;
	int		m_dna_nr;
	int		m_number;
};

class	btSerializer
{

public:

	virtual ~btSerializer() {}

	virtual	const unsigned char*		getBufferPointer() const = 0;

	virtual	int		getCurrentBufferSize() const = 0;

	virtual	btChunk*	allocate(size_t size, int numElements) = 0;

	virtual	void	finalizeChunk(btChunk* chunk, const char* structType, int chunkCode,void* oldPtr)= 0;

	virtual	 void*	findPointer(void* oldPtr)  = 0;

	virtual	void	startSerialization() = 0;
	
	virtual	void	finishSerialization() = 0;

	virtual	const char*	findNameForPointer(const void* ptr) const = 0;

	virtual	void	registerNameForPointer(const void* ptr, const char* name) = 0;

	virtual void	serializeName(const char* ptr) = 0;

};



#define BT_HEADER_LENGTH 12
#if defined(__sgi) || defined (__sparc) || defined (__sparc__) || defined (__PPC__) || defined (__ppc__) || defined (__BIG_ENDIAN__)
#	define MAKE_ID(a,b,c,d) ( (int)(a)<<24 | (int)(b)<<16 | (c)<<8 | (d) )
#else
#	define MAKE_ID(a,b,c,d) ( (int)(d)<<24 | (int)(c)<<16 | (b)<<8 | (a) )
#endif

#define BT_COLLISIONOBJECT_CODE MAKE_ID('C','O','B','J')
#define BT_RIGIDBODY_CODE		MAKE_ID('R','B','D','Y')
#define BT_CONSTRAINT_CODE		MAKE_ID('C','O','N','S')
#define BT_BOXSHAPE_CODE		MAKE_ID('B','O','X','S')
#define BT_SHAPE_CODE			MAKE_ID('S','H','A','P')
#define BT_ARRAY_CODE			MAKE_ID('A','R','A','Y')



class btDefaultSerializer	:	public btSerializer
{


	btAlignedObjectArray<char*>			mTypes;
	btAlignedObjectArray<short*>			mStructs;
	btAlignedObjectArray<short>			mTlens;
	btHashMap<btHashInt, int>			mStructReverse;
	btHashMap<btHashString,int>	mTypeLookup;

	
	btHashMap<btHashPtr,void*>	m_chunkP;
	
	btHashMap<btHashPtr,const char*>	m_nameMap;


	int					m_totalSize;
	unsigned char*		m_buffer;
	int					m_currentSize;
	void*				m_dna;
	int					m_dnaLength;


	btAlignedObjectArray<btChunk*>	m_chunkPtrs;
	
protected:

	virtual	void*	findPointer(void* oldPtr) 
	{
		void** ptr = m_chunkP.find(oldPtr);
		if (ptr && *ptr)
			return *ptr;
		return 0;
	}



		void	writeDNA()
		{
			unsigned char* dnaTarget = m_buffer+m_currentSize;
			memcpy(dnaTarget,m_dna,m_dnaLength);
			m_currentSize += m_dnaLength;
		}

		int getReverseType(const char *type) const
		{

			btHashString key(type);
			const int* valuePtr = mTypeLookup.find(key);
			if (valuePtr)
				return *valuePtr;
			
			return -1;
		}

		void initDNA(const char* bdnaOrg,int dnalen)
		{
			///was already initialized
			if (m_dna)
				return;

			int littleEndian= 1;
			littleEndian= ((char*)&littleEndian)[0];
			

			m_dna = btAlignedAlloc(dnalen,16);
			memcpy(m_dna,bdnaOrg,dnalen);
			m_dnaLength = dnalen;

			int *intPtr=0;
			short *shtPtr=0;
			char *cp = 0;int dataLen =0;long nr=0;
			intPtr = (int*)m_dna;

			/*
				SDNA (4 bytes) (magic number)
				NAME (4 bytes)
				<nr> (4 bytes) amount of names (int)
				<string>
				<string>
			*/

			if (strncmp((const char*)m_dna, "SDNA", 4)==0)
			{
				// skip ++ NAME
				intPtr++; intPtr++;
			}

			// Parse names
			if (!littleEndian)
				*intPtr = btSwapEndian(*intPtr);
				
			dataLen = *intPtr;
			
			intPtr++;

			cp = (char*)intPtr;
			int i;
			for ( i=0; i<dataLen; i++)
			{
				
				while (*cp)cp++;
				cp++;
			}
			{
				nr= (long)cp;
			//	long mask=3;
				nr= ((nr+3)&~3)-nr;
				while (nr--)
				{
					cp++;
				}
			}

			/*
				TYPE (4 bytes)
				<nr> amount of types (int)
				<string>
				<string>
			*/

			intPtr = (int*)cp;
			assert(strncmp(cp, "TYPE", 4)==0); intPtr++;

			if (!littleEndian)
				*intPtr =  btSwapEndian(*intPtr);
			
			dataLen = *intPtr;
			intPtr++;

			
			cp = (char*)intPtr;
			for (i=0; i<dataLen; i++)
			{
				mTypes.push_back(cp);
				while (*cp)cp++;
				cp++;
			}

		{
				nr= (long)cp;
			//	long mask=3;
				nr= ((nr+3)&~3)-nr;
				while (nr--)
				{
					cp++;
				}
			}


			/*
				TLEN (4 bytes)
				<len> (short) the lengths of types
				<len>
			*/

			// Parse type lens
			intPtr = (int*)cp;
			assert(strncmp(cp, "TLEN", 4)==0); intPtr++;

			dataLen = (int)mTypes.size();

			shtPtr = (short*)intPtr;
			for (i=0; i<dataLen; i++, shtPtr++)
			{
				if (!littleEndian)
					shtPtr[0] = btSwapEndian(shtPtr[0]);
				mTlens.push_back(shtPtr[0]);
			}

			if (dataLen & 1) shtPtr++;

			/*
				STRC (4 bytes)
				<nr> amount of structs (int)
				<typenr>
				<nr_of_elems>
				<typenr>
				<namenr>
				<typenr>
				<namenr>
			*/

			intPtr = (int*)shtPtr;
			cp = (char*)intPtr;
			assert(strncmp(cp, "STRC", 4)==0); intPtr++;

			if (!littleEndian)
				*intPtr = btSwapEndian(*intPtr);
			dataLen = *intPtr ; 
			intPtr++;


			shtPtr = (short*)intPtr;
			for (i=0; i<dataLen; i++)
			{
				mStructs.push_back (shtPtr);
				
				if (!littleEndian)
				{
					shtPtr[0]= btSwapEndian(shtPtr[0]);
					shtPtr[1]= btSwapEndian(shtPtr[1]);

					int len = shtPtr[1];
					shtPtr+= 2;

					for (int a=0; a<len; a++, shtPtr+=2)
					{
							shtPtr[0]= btSwapEndian(shtPtr[0]);
							shtPtr[1]= btSwapEndian(shtPtr[1]);
					}

				} else
				{
					shtPtr+= (2*shtPtr[1])+2;
				}
			}

			// build reverse lookups
			for (i=0; i<(int)mStructs.size(); i++)
			{
				short *strc = mStructs.at(i);
				mStructReverse.insert(strc[0], i);
				mTypeLookup.insert(btHashString(mTypes[strc[0]]),i);
			}
		}

public:	
	

	

		btDefaultSerializer(int totalSize)
			:m_totalSize(totalSize),
			m_currentSize(0),
			m_dna(0),
			m_dnaLength(0)
		{
			m_buffer = (unsigned char*)btAlignedAlloc(totalSize, 16);
			
			const bool VOID_IS_8 = ((sizeof(void*)==8));

#ifdef BT_INTERNAL_UPDATE_SERIALIZATION_STRUCTURES
			if (VOID_IS_8)
			{
#if _WIN64
				initDNA((const char*)sBulletDNAstr64,sBulletDNAlen64);
#else
				btAssert(0);
#endif
			} else
			{
#ifndef _WIN64
				initDNA((const char*)sBulletDNAstr,sBulletDNAlen);
#else
				btAssert(0);
#endif
			}
	
#else //BT_INTERNAL_UPDATE_SERIALIZATION_STRUCTURES
			if (VOID_IS_8)
			{
				initDNA((const char*)sBulletDNAstr64,sBulletDNAlen64);
			} else
			{
				initDNA((const char*)sBulletDNAstr,sBulletDNAlen);
			}
#endif //BT_INTERNAL_UPDATE_SERIALIZATION_STRUCTURES
	
		}

		virtual ~btDefaultSerializer() 
		{
			if (m_buffer)
				btAlignedFree(m_buffer);
			if (m_dna)
				btAlignedFree(m_dna);
		}

		virtual	void	startSerialization()
		{
			m_currentSize = BT_HEADER_LENGTH;

#ifdef  BT_USE_DOUBLE_PRECISION
			memcpy(m_buffer, "BULLETd", 7);
#else
			memcpy(m_buffer, "BULLETf", 7);
#endif //BT_USE_DOUBLE_PRECISION
	
			int littleEndian= 1;
			littleEndian= ((char*)&littleEndian)[0];

			if (sizeof(void*)==8)
			{
				m_buffer[7] = '-';
			} else
			{
				m_buffer[7] = '_';
			}

			if (littleEndian)
			{
				m_buffer[8]='v';				
			} else
			{
				m_buffer[8]='V';
			}


			m_buffer[9] = '2';
			m_buffer[10] = '7';
			m_buffer[11] = '6';

			
		}

		virtual	void	finishSerialization()
		{
			writeDNA();
		}


		virtual	const unsigned char*		getBufferPointer() const
		{
			return m_buffer;
		}

		virtual	int					getCurrentBufferSize() const
		{
			return	m_currentSize;
		}

		virtual	void	finalizeChunk(btChunk* chunk, const char* structType, int chunkCode,void* oldPtr)
		{
			btAssert(!findPointer(oldPtr));

			chunk->m_dna_nr = getReverseType(structType);
			
			chunk->m_chunkCode = chunkCode;
			m_chunkP.insert(oldPtr,chunk->m_oldPtr);
			chunk->m_oldPtr = oldPtr;
			
		}

		

		

		virtual	btChunk*	allocate(size_t size, int numElements)
		{

			unsigned char* ptr = m_buffer+m_currentSize;
			m_currentSize += int(size)*numElements+sizeof(btChunk);
			btAssert(m_currentSize<m_totalSize);

			unsigned char* data = ptr + sizeof(btChunk);
			
			btChunk* chunk = (btChunk*)ptr;
			chunk->m_chunkCode = 0;
			chunk->m_oldPtr = data;
			chunk->m_length = int(size)*numElements;
			chunk->m_number = numElements;
			
			m_chunkPtrs.push_back(chunk);
			

			return chunk;
		}

		virtual	const char*	findNameForPointer(const void* ptr) const
		{
			const char*const * namePtr = m_nameMap.find(ptr);
			if (namePtr && *namePtr)
				return *namePtr;
			return 0;

		}

		virtual	void	registerNameForPointer(const void* ptr, const char* name)
		{
			m_nameMap.insert(ptr,name);
		}

		virtual void	serializeName(const char* name)
		{
			if (name)
			{
				int len = btStrLen(name);
				if (len)
				{

					int newLen = len+1;
					int padding = ((newLen+3)&~3)-newLen;
					newLen += padding;

					//serialize name string now
					btChunk* chunk = allocate(sizeof(char),newLen);
					char* destinationName = (char*)chunk->m_oldPtr;
					for (int i=0;i<len;i++)
					{
						destinationName[i] = name[i];
					}
					destinationName[len] = 0;
					finalizeChunk(chunk,"char",BT_ARRAY_CODE,(void*)name);
				}
			}
		}
};


#endif //BT_SERIALIZER_H

