//**************************************************************************************
// Filename:	CUTextFileStream.cp
// Copyright © 1999 Tomasz Kukielka. All rights reserved.
//
// Description:	
//
//**************************************************************************************
// Revision History:
// Tuesday, May 4, 1999 - Original
//**************************************************************************************

#include "CUTextFileStream.h"

CUTextFileStream::CUTextFileStream(const FSRef& inFileRef, SInt8 inPermissions) : ARefFork(inFileRef, inPermissions)
{
	mByteOrder = kByteOrderUndefined;
}

CUTextFileStream::~CUTextFileStream()
{
}


//the fork is already opened in constructor
//this is a legacy logic, but still we need to interpret and skip BOM

void
CUTextFileStream::OpenDataForkForReading(Boolean isUnicode /*= kTextIsUnicode*/)
{
	SetPosition(0);

	if(isUnicode == kTextIsNOTUnicode)
	{
		mByteOrder = kByteOrderUndefined;
		return;
	}

//read BOM, take care not to invert it
//	ByteCount byteCount = ARefFork::Read( sizeof(UniChar), (void*)&mByteOrder, fsFromStart, 0)	;
	
	ByteCount byteCount = 0;	
	OSStatus err = ::FSReadFork(mForkRefNum, fsFromStart, 0, sizeof(UniChar), (void*)&mByteOrder, &byteCount);

	if( (err == noErr) && (byteCount == sizeof(UniChar)) && (mByteOrder == kMacByteOrderChar) || (mByteOrder == kPCByteOrderChar) )
	{
		;//OK
	}
	else
	{//move back and start over - there is no byte-order char, we default to mac
		mByteOrder = kMacByteOrderChar;
		SetPosition(0);
	}
}

//the fork is already opened in constructor
//this is a legacy logic, but still we need to put BOM

void
CUTextFileStream::OpenDataForkForWriting(Boolean isUnicode /*= kTextIsUnicode*/)
{
	SetPosition(0);

	if(isUnicode == kTextIsNOTUnicode)
	{
		mByteOrder = kByteOrderUndefined;
		return;
	}

	//add byte order char at the begining	
	mByteOrder = kMacByteOrderChar;
	ARefFork::Write( sizeof(UniChar), &mByteOrder, fsFromStart, 0);
}

//does not throw
OSStatus
CUTextFileStream::ReadData(
						SInt32 &ioCount, void *inBuffer,
						UInt16 inPosMode, SInt64 inOffset)
{
	ByteCount readCount = 0;	
	OSStatus err = ::FSReadFork(mForkRefNum, inPosMode, inOffset, ioCount, inBuffer, &readCount);
	ioCount = readCount;

//	ByteCount outCount = ARefFork::Read( inCount, inBuffer, inPosMode, inOffset);

	if( (err == noErr) && (ioCount > 0) && (mByteOrder == kPCByteOrderChar) )
	{
		InvertByteOrder( (UniCharPtr)inBuffer, ioCount/sizeof(UniChar) );
	}

	return err;
}


void
CUTextFileStream::InvertByteOrder(UniCharPtr uniTextPtr, UniCharCount uniTextLen)
{
	for(UInt32 i = 0; i< uniTextLen; i++)
	{
		uniTextPtr[i] = SwapHiLoBytes( uniTextPtr[i] );
	}
}