/*

* Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include "streamreader.h"

#include "options.h"

#include "ucmp.h"

#include "utf8.h"

StreamReader::StreamReader(istream& aFile)

			:iFileStream(&aFile),

			 iBuf(NULL),

			 iCurrentPos(NULL),

			 iLength(0),

			 iStreamOwnership(false)

	{

	}

StreamReader::StreamReader(const char* aRegFile)

			:iBuf (0) ,

			 iCurrentPos (0),

			 iStreamOwnership(true)

	{

	iFileStream = new ifstream(aRegFile, ios::binary );

	}

bool StreamReader::Initialise()

	{

	// get length of file:

	iFileStream->seekg (0, ios::end);

	iLength = iFileStream->tellg();

	//checks if file is empty

	if(!iLength)

		{

		return true;

		}

	iFileStream->seekg (0, ios::beg);

	// allocate memory:

	iBuf = new char [iLength];

	iCurrentPos = iBuf;

	// read data as a block:

	iFileStream->read (iCurrentPos,iLength);

	return false;

	}

unsigned int StreamReader::ReadInt32()

	{

	int i = 0;

	if ((iLength - (iCurrentPos - iBuf)) < 4)

		{

		throw EInvalidFile;

		}

	unsigned int result = (iCurrentPos[i] & 0x000000FF) + ((iCurrentPos[i+1] << 8) & 0x0000FF00) + 

		((iCurrentPos[i+2] << 16) & 0x00FF0000) + ((iCurrentPos[i+3] << 24) & 0xFF000000) ;

	iCurrentPos += 4;

	return result;

	}

unsigned short int StreamReader::ReadInt16()

	{

	int i = 0;

	if ((iLength - (iCurrentPos - iBuf)) < 2)

		{

		throw EInvalidFile;

		}

	unsigned short int result = (iCurrentPos[i] & 0x00FF) 

		+ ((iCurrentPos[i+1] << 8) & 0xFF00);

	iCurrentPos += 2;

	return result;

	}

unsigned char StreamReader::ReadInt8()

	{

	int i = 0;

	if ((iLength - (iCurrentPos - iBuf)) < 1)

		{

		throw EInvalidFile;

		}

	unsigned char result = iCurrentPos[i];

	iCurrentPos += 1;

	return result;

	}

unsigned char StreamReader::Peek()

	{

	unsigned char result = ReadInt8();

	iCurrentPos -= 1;

	return result;

	}

char* StreamReader::ReadDescriptor() 

	{

	bool isWide = false;

	int len = GetDescriptorInfo(isWide);

	// allocate a buffer big enough to hold this stuff and

	// a null at the end

	char *result = NULL;

	TInt32 bytesRead = 0;

	if(isWide) 

		{

		wchar_t* buffer = new wchar_t[len + 1];

		TMemoryUnicodeSink unicodeTarget(buffer);

		TUnicodeExpander converter;

		converter.Expand(unicodeTarget, (const TUint8*)iCurrentPos, len, KMaxTInt, NULL, &bytesRead);

		buffer[len] = 0;

		// UTF16toUTF8Conversion allocates memory

		// This memory will be freed by the caller of this function

		result = UTF16toUTF8Convert(buffer, len);

		delete []buffer;

		} 

	else 

		{

		// This memory will be freed by the caller of this function

		result = new char[len + 2];

		memcpy(result, iCurrentPos, len);

		bytesRead = len;

		result[len] = 0;

		}

	iCurrentPos += bytesRead;

	return result;

	}

int StreamReader::GetDescriptorInfo(bool& aIsWide, const bool &aConstReadPtr) 

	{

	int len;

	unsigned char cardinality = Peek();

	if ((cardinality & 0x01) == 0)

		{

		// 8 bit cardinality

		len = ReadInt8() & 0xFF;

		// shift of the cardinality bit

		len >>= 1;

		if(aConstReadPtr)

			{

			iCurrentPos -= 1;

			}

		}

	else if ((cardinality & 0x02) == 0)

		{

		// 16 bit cardinality

		len = ReadInt16() & 0xFFFF;

		// shift off the cardinality bits

		len >>= 2;

		if(aConstReadPtr)

			{

			iCurrentPos -= 2;

			}

		}

	else if ((cardinality & 0x04) == 0)	

		{

		// 32 bit cardinality

		len = ReadInt32();

		// shift off the cardinality bits

		len >>= 3;

		if(aConstReadPtr)

			{

			iCurrentPos -= 4;

			}

		}

	else

		{

		// WTF. Unknown cardinality

		throw EInvalidFile;

		}

	// read the wideness of the characters

	aIsWide = ((len & 0x01) == 0);

	// shift off the wideness bit

	len >>= 1;

	// check if we have enough length left in the buffer

	if ((iLength - (iCurrentPos - iBuf)) < len)

		{

		throw EInvalidFile;

		}

	return len;

	}

char* StreamReader::UTF16toUTF8Convert(wchar_t* aSource, int aSrcLength)

{

	int targetLength = 2 * aSrcLength;

	int totalSize = targetLength + 1;

	// This memory will be freed by the caller of this function

	char *ptrUtf8 = new char[targetLength + 1];

	UTF16* sourceStart = static_cast<UTF16*>(aSource);

	UTF16* sourceEnd = sourceStart + aSrcLength; 

	UTF8* targetStart = reinterpret_cast<UTF8*>(ptrUtf8);

	UTF8* targetEnd;

	ConversionResult result = ok;

	do

		{

		targetEnd = targetStart + targetLength;

		result = ConvertUTF16toUTF8(&sourceStart, sourceEnd, &targetStart, targetEnd);

		if(targetExhausted != result)

			{

			break;

			}

		// Memory reallocation

		int endOffset = (char *)targetStart - ptrUtf8;

		char *temp = new char[totalSize + targetLength];

		memcpy(temp, ptrUtf8, totalSize);

		delete[] ptrUtf8;

		ptrUtf8 = temp;

		// New source pointer

		targetStart = reinterpret_cast<UTF8*>(ptrUtf8) + endOffset;

		totalSize += targetLength;

		}while(true);

	// NULL terminating the UTF8 string

	*targetStart = 0;

	return ptrUtf8;

}

StreamReader::~StreamReader()

	{

	if(iStreamOwnership) 

		{

		ifstream* str = static_cast<ifstream *>(iFileStream);

		str->close();

		delete iFileStream;

		}

	delete [] iBuf;

	}