//**************************************************************************************
// Filename:	AStdMalloc.h
//				Part of Contextual Menu Workshop by Abracode Inc.
//				http://free.abracode.com/cmworkshop/
// Copyright © 2003 Abracode, Inc.  All rights reserved.
//
// Description:	Extension to David Catmull's ACCELA Mac toolbox C++ wrapper library
//**************************************************************************************

#pragma once

#include "AMemoryCommon.h"
#include "CThrownResult.h"
#include <cstdlib>
#include <string>

template <class T>
class AStdMalloc
{
public:
		AStdMalloc()
			: mObject(NULL), mIsOwner( kMemObj_NotOwned) {}
		
		//memory allocation constructor
		//CAUTION: the size is interpreted as a count of T objects
		AStdMalloc(SInt32 inSize, EMemObjClearOption inClearOption = kMemObj_DontClearMemory)
			: mObject(NULL), mIsOwner(kMemObj_NotOwned)
		{
			AllocateAndCopy(NULL, inSize, inClearOption);
		}

		//plain assignment with optional ownership taking, no copy.
		//inMallocPtr must be allocated with malloc or calloc
		AStdMalloc(
				void * inMallocPtr,
				EMemObjOwnershipType inIsOwner = kMemObj_Owned)
			: mObject(static_cast<T*>(inMallocPtr)), mIsOwner(inIsOwner) {}
		
		//pointer and size constructor 
		//the input pointer may not be allocated by malloc, so we allocate private copy
		//CAUTION: the size is interpreted as a count of T objects
		AStdMalloc(
				const T *inPtr,
				SInt32 inSize)
			: mObject(NULL), mIsOwner(kMemObj_NotOwned)
		{
			AllocateAndCopy(inPtr,inSize);
		}
		
		//copy constructor - only shallow is allowed here
		//becaue we do not keep the size of the block so we cannot copy it
		//the object is detached from the original
		AStdMalloc(const AStdMalloc& inOrig)
			: mObject(NULL), mIsOwner(kMemObj_NotOwned)
		{
			EMemObjOwnershipType isOwner = inOrig.mIsOwner;
			Reset(inOrig.Detach(), isOwner );
		}

	virtual
		~AStdMalloc() { Dispose(); }

		//object assignment as a shallow copy with ownership change
	AStdMalloc&
		operator=(
				const AStdMalloc& inMallocPtr)
		{
			EMemObjOwnershipType isOwner = inMallocPtr.mIsOwner;
			Reset(inMallocPtr.Detach(), isOwner );
			return *this;
		}

		//plain pointer assignment with ownership taking, no copy
		//inMallocPtr must be allocated with  malloc or calloc
	AStdMalloc&
		operator=(
				const void * inMallocPtr)
		{
			Reset(static_cast<T*>(const_cast<void*>(inMallocPtr)), kMemObj_Owned);
			return *this;
		}

		operator T*() const
		{
			return mObject;
		}

	T&
		operator * () const
		{
			return *mObject;
		}

	T*
		operator -> () const
		{
			return mObject;
		}

	T&
		operator [] (UInt32 index) const
		{
			return mObject[index];
		}

	//CAUTION: potentially costly
	//CAUTION: you cannot reallocate not owned pointer so resize will fail
	//CAUTION: the size is interpreted as a count of T objects
	void
		Resize(SInt32 inNewSize)
		{
			if(mObject != NULL)
			{
				if(mIsOwner == kMemObj_Owned)
				{//reallocate ONLY if we own the pointer
					T *newPtr = static_cast<T*>(std::realloc(mObject, inNewSize*sizeof(T)));
					if(newPtr == NULL)
						CThrownOSErr throwErr = memFullErr;
					mObject = newPtr;
				}
				else
					CThrownOSErr throwErr = -1;
			}
			else
				AllocateAndCopy(NULL, inNewSize);
		}

	static void
		CopyData(const T *inSource, T *inDest, SInt32 inSize)
		{
			std::memmove(inDest, inSource, inSize *sizeof(T));
		}

	static void
		ClearData(void *inPtr, SInt32 inSize)
		{
			std::memset(inPtr, 0, inSize*sizeof(T) );
		}

	T *
		Get() const
		{
			return mObject;
		}

	T *
		Detach() const
		{
			mIsOwner = kMemObj_NotOwned;
			return mObject;
		}

	void
		Reset(
				T *inObject,
				EMemObjOwnershipType inIsOwner = kMemObj_Owned)
		{
			if ((mIsOwner == kMemObj_Owned) && (mObject != NULL) && (inObject != mObject)) DisposeSelf();
			mObject = inObject;
			mIsOwner = inIsOwner;
		}

	void
		Dispose()
		{
			if (mObject != NULL)
			{
				if(mIsOwner == kMemObj_Owned) DisposeSelf();
				mObject = NULL;
			}
			mIsOwner = kMemObj_NotOwned;
		}

	static void
		DisposeProc(void *inObj)
		{
			if(inObj != NULL)
			{
				void **objPtr = reinterpret_cast<void **>(inObj);
				if(*objPtr != NULL)
					std::free(*objPtr);
				*objPtr = NULL;
			}	
		}

protected:

	void
		AllocateAndCopy(
				const T *inSrcPtr,
				SInt32 inSize,
				EMemObjClearOption inClearOption = kMemObj_DontClearMemory)
		{
			if(inSize != 0)
			{
				if(	(inClearOption == kMemObj_ClearMemory) && (inSrcPtr == NULL) )
					mObject = static_cast<T*>(std::calloc(inSize, sizeof(T)));
				else
					mObject = static_cast<T*>(std::malloc(inSize*sizeof(T)));
				
				if(mObject == NULL) 
					CThrownOSErr throwErr = memFullErr;
				
				mIsOwner = kMemObj_Owned;
				
				if( (inSrcPtr != NULL) && (mObject != NULL) )
					CopyData(inSrcPtr, mObject, inSize);
			}
		}

	void
		DisposeSelf()
		{
			std::free(mObject);
		}

protected:
	T *mObject;
	mutable EMemObjOwnershipType mIsOwner;
};

typedef AStdMalloc<char> AMalloc;