/*

* Copyright (c) 1997-1999 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "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:      

*

*/

#pragma warning (disable: 4514) // unreferenced inline/local function has been removed

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <locale.h>

#include <wchar.h>

#if defined(__VC32__)

#include <fcntl.h>

#include <io.h>

#endif

#undef BIG_ENDIAN

const int KVersionNumber=025;

const int KLargeNumber=1000000;

extern int Utf8ToUnicode(wchar_t* aUnicode, const char* aUtf8);

extern int UnicodeToUtf8(char* aUtf8, const wchar_t* aUnicode);

enum TByteOrder

	{

	EByteOrderUnspecified,

	EByteOrderBigEndian,

	EByteOrderLittleEndian,

#if defined(BIG_ENDIAN)

	EByteOrderNative=EByteOrderBigEndian,

	EByteOrderForeign=EByteOrderLittleEndian

#else

	EByteOrderNative=EByteOrderLittleEndian,

	EByteOrderForeign=EByteOrderBigEndian

#endif

	};

struct SBuffer

	{

	int iNumberOfBytes;

	void* iData;

	};

void PrintUsage(const char* aProgramName)

    {

	fprintf(stderr, "\nVersion %03d\n\nCharacter set conversion tool\nCopyright (c) 1999 Symbian Ltd\n\n", KVersionNumber);

	fprintf(stderr, "Usage:\n\n\t%s [<options>] <inputspec> <outputspec>\n\nwhere\n\n\t"

				"options    :=  [-big|-little][-byteordermark]\n\t"

				"inputspec  :=  -input=<format> [<input_file>]\n\t"

				"outputspec :=  -output=<format> [<output_file>]\n\t"

				"format     :=  unicode|1252|utf8|...\n\n", aProgramName);

	const char* localeData=setlocale(LC_ALL, "");

	while (*localeData!='.')

		{

		++localeData;

		}

	fprintf(stderr, "(The default encoding is currently \"%s\")\n\n", localeData+1);

	}

void Assert(int aCondition, const char* aErrorMessageFormat, const void* aExtraParameter1=NULL, const void* aExtraParameter2=NULL)

	{

	if (!aCondition)

		{

		char errorMessage[100];

		sprintf(errorMessage, aErrorMessageFormat, aExtraParameter1, aExtraParameter2);

		fprintf(stderr, "Error: %s\n", errorMessage);

		exit(1);

		}

	}

void PrintWarning(const char* aWarningMessage)

	{

	fprintf(stderr, "Warning: %s\n", aWarningMessage);

	}

int TryFileParameter(int aArgc, char* aArgv[], int& aArgIndex, const char* aInputOrOutput, const char*& aEncoding, FILE*& aFile, const char* aFileMode)

	{

	char prefix[100];

	strcpy(prefix, "-");

	strcat(prefix, aInputOrOutput);

	strcat(prefix, "=");

	int lengthOfPrefix=strlen(prefix);

	if (_strnicmp(aArgv[aArgIndex], prefix, lengthOfPrefix)==0)

		{

		Assert(aEncoding==NULL, "\"%s...\" is specified more than once", prefix);

		aEncoding=aArgv[aArgIndex]+lengthOfPrefix;

		++aArgIndex;

		if ((aArgIndex>=aArgc) || (aArgv[aArgIndex][0]=='-'))

			{

			--aArgIndex;

			}

		else

			{

			aFile=fopen(aArgv[aArgIndex], aFileMode);

			Assert(aFile!=NULL, "opening %s-file failed", aInputOrOutput);

			}

		return 1;

		}

	return 0;

	}

void ReadParameters(int aArgc, char* aArgv[], int& aOutputByteOrderMark, TByteOrder& aUnicodeByteOrder, const char*& aInputEncoding, const char*& aOutputEncoding, FILE*& aInputFile, FILE*& aOutputFile)

	{

	if ((aArgc<=1) || (_stricmp(aArgv[1], "?")==0) || (_stricmp(aArgv[1], "/?")==0))

		{

		PrintUsage(aArgv[0]);

		exit(0);

		}

	for (int i=1; i<aArgc; ++i) // start at index 1 to avoid the program name (which is the first parameter)

		{

		if (_stricmp(aArgv[i], "-byteordermark")==0)

			{

			Assert(!aOutputByteOrderMark, "\"-byteordermark\" is specified more than once");

			aOutputByteOrderMark=1;

			}

		else if (_stricmp(aArgv[i], "-big")==0)

			{

			Assert(aUnicodeByteOrder==EByteOrderUnspecified, "the byte order of unicode text (i.e. \"-big\"/\"-little\") is specified more than once");

			aUnicodeByteOrder=EByteOrderBigEndian;

			}

		else if (_stricmp(aArgv[i], "-little")==0)

			{

			Assert(aUnicodeByteOrder==EByteOrderUnspecified, "the byte order of unicode text (i.e. \"-big\"/\"-little\") is specified more than once");

			aUnicodeByteOrder=EByteOrderLittleEndian;

			}

		else

			{

			Assert(TryFileParameter(aArgc, aArgv, i, "input", aInputEncoding, aInputFile, "r") ||

				   TryFileParameter(aArgc, aArgv, i, "output", aOutputEncoding, aOutputFile, "w"), "bad parameter \"%s\"", aArgv[i]);

			}

		}

	Assert(aInputEncoding!=NULL, "no input encoding is specified");

	Assert(aOutputEncoding!=NULL, "no output encoding is specified");

	}

int ReadFromFileReturningNumberOfBytesRead(void* aBuffer, int aNumberOfBytesToRead, FILE* aInputFile)

	{

	int numberOfBytesRead=0;

	int numberOfBytesToReadThisTime=aNumberOfBytesToRead;

	for (;;)

		{

		for (;;)

			{

			const int remainingNumberOfBytesToRead=aNumberOfBytesToRead-numberOfBytesRead;

			if (numberOfBytesToReadThisTime>remainingNumberOfBytesToRead)

				{

				numberOfBytesToReadThisTime=remainingNumberOfBytesToRead;

				}

			const int numberOfBytesReadThisTime=fread(aBuffer, 1, numberOfBytesToReadThisTime, aInputFile);

			const int error=ferror(aInputFile);

			if (error==0)

				{

				aBuffer=((unsigned char*)aBuffer)+numberOfBytesReadThisTime;

				numberOfBytesRead+=numberOfBytesReadThisTime;

				Assert(numberOfBytesRead<=aNumberOfBytesToRead, "internal error (read too many bytes)");

				if ((numberOfBytesRead>=aNumberOfBytesToRead) || feof(aInputFile))

					{

					return numberOfBytesRead;

					}

				break;

				}

			numberOfBytesToReadThisTime/=2;

			Assert(numberOfBytesToReadThisTime>0, "reading from file failed with error number %d", (const void*)error);

			clearerr(aInputFile);

			}

		}

	}

void WriteToFile(const void* aBuffer, int aNumberOfBytesToWrite, FILE* aOutputFile)

	{

	const int numberOfBytesWritten=fwrite(aBuffer, 1, aNumberOfBytesToWrite, aOutputFile);

	Assert(numberOfBytesWritten==aNumberOfBytesToWrite, "only %d out of %d bytes could be written to file", (const void*)numberOfBytesWritten, (const void*)aNumberOfBytesToWrite);

	const int error=ferror(aOutputFile);

	Assert(error==0, "writing to file failed with error number %d", (const void*)error);

	}

void HandleByteOrderMarks(int aOutputByteOrderMark, TByteOrder& aUnicodeByteOrder, const char* aInputEncoding, const char* aOutputEncoding, FILE* aInputFile, FILE* aOutputFile)

	{

	if (_stricmp(aInputEncoding, "unicode")==0)

		{

		unsigned short firstUnicodeCharacter=0;

		const int numberOfBytesRead=ReadFromFileReturningNumberOfBytesRead((void*)&firstUnicodeCharacter, sizeof(unsigned short), aInputFile);

		TByteOrder byteOrderSpecifiedByByteOrderMark=EByteOrderUnspecified;

		if (numberOfBytesRead==sizeof(unsigned short))

			{

			switch (firstUnicodeCharacter)

				{

			case 0xfeff:

				byteOrderSpecifiedByByteOrderMark=EByteOrderNative;

				break;

			case 0xfffe:

				byteOrderSpecifiedByByteOrderMark=EByteOrderForeign;

				break;

			default:

				const int error=fseek(aInputFile, 0, SEEK_SET); // rewind to the start of the file

				Assert(error==0, "could not rewind to the start of the input file");

				break;

				}

			}

		if (byteOrderSpecifiedByByteOrderMark!=EByteOrderUnspecified)

			{

			if ((aUnicodeByteOrder!=EByteOrderUnspecified) && (byteOrderSpecifiedByByteOrderMark!=aUnicodeByteOrder))

				{

				PrintWarning("the byte order specified by the byte-order mark in the unicode input is different from the byte order specified by the parameter - taking the byte-order specified by the byte-order mark in the unicode input");

				}

			aUnicodeByteOrder=byteOrderSpecifiedByByteOrderMark;

			}

		}

	if (aOutputByteOrderMark)

		{

		if (_stricmp(aOutputEncoding, "unicode")!=0)

			{

			PrintWarning("\"-byteordermark\" is only relevant for unicode output");

			}

		else

			{

			Assert(aUnicodeByteOrder!=EByteOrderUnspecified, "the byte order must be specified if a byte-order mark is to be added to the unicode output");

			unsigned short firstUnicodeCharacter=(unsigned short)((aUnicodeByteOrder==EByteOrderNative)? 0xfeff: 0xfffe);

			WriteToFile((const void*)&firstUnicodeCharacter, sizeof(unsigned short), aOutputFile);

			}

		}

	}

void ObeyRequiredByteOrderIfUnicode(TByteOrder& aUnicodeByteOrder, const char* aEncoding, SBuffer& aBuffer)

	{

	if (_stricmp(aEncoding, "unicode")==0)

		{

		Assert(aBuffer.iNumberOfBytes%sizeof(wchar_t)==0, "internal error (bad number of bytes in unicode buffer)");

		if (aUnicodeByteOrder==EByteOrderUnspecified)

			{

			PrintWarning("the byte order of unicode text is unspecified - defaulting to little endian");

			aUnicodeByteOrder=EByteOrderLittleEndian;

			}

		if (aUnicodeByteOrder==EByteOrderForeign)

			{

			for (unsigned char* bytePointer=((unsigned char*)aBuffer.iData)+(aBuffer.iNumberOfBytes-sizeof(wchar_t)); bytePointer>=aBuffer.iData; bytePointer-=sizeof(wchar_t))

				{

				unsigned char temp=*bytePointer;

				*bytePointer=*(bytePointer+1);

				*(bytePointer+1)=temp;

				}

			}

		}

	}

int OtherToUnicode(const char* aInputEncoding, wchar_t* aUnicode, const char* aOther)

// if the output parameter is NULL, it returns the precise size of the would-be output parameter (in terms of number of "wchar_t"s) excluding any trailing '\0', otherwise it returns 0

	{

	if (_stricmp(aInputEncoding, "utf8")==0)

		{

		return Utf8ToUnicode(aUnicode, aOther);

		}

	char localeData[100];

	strcpy(localeData, ".");

	strcat(localeData, aInputEncoding);

	Assert(setlocale(LC_ALL, localeData)!=NULL, "could not convert from encoding \"%s\"", aInputEncoding);

	return mbstowcs(aUnicode, aOther, KLargeNumber);

	}

int UnicodeToOther(const char* aOutputEncoding, char* aOther, const wchar_t* aUnicode)

// if the output parameter is NULL, it returns the precise size of the would-be output parameter (in terms of number of "char"s) excluding any trailing '\0', otherwise it returns 0

	{

	if (_stricmp(aOutputEncoding, "utf8")==0)

		{

		return UnicodeToUtf8(aOther, aUnicode);

		}

	char localeData[100];

	strcpy(localeData, ".");

	strcat(localeData, aOutputEncoding);

	Assert(setlocale(LC_ALL, localeData)!=NULL, "could not convert to encoding \"%s\"", aOutputEncoding);

	return wcstombs(aOther, aUnicode, KLargeNumber);

	}

void DoConversion(TByteOrder& aUnicodeByteOrder, const char* aInputEncoding, const char* aOutputEncoding, FILE* aInputFile, FILE* aOutputFile)

	{

	SBuffer arrayOfBuffers[3];

	arrayOfBuffers[0].iNumberOfBytes=0;

	arrayOfBuffers[0].iData=malloc(KLargeNumber+2); // +2 for the 2 '\0' bytes appended to the data read from file

	Assert(arrayOfBuffers[0].iData!=NULL, "cannot allocate enough memory");

	arrayOfBuffers[1].iNumberOfBytes=0;

	arrayOfBuffers[1].iData=NULL;

	arrayOfBuffers[2].iNumberOfBytes=0;

	arrayOfBuffers[2].iData=NULL;

	SBuffer* currentBuffer=arrayOfBuffers;

	currentBuffer->iNumberOfBytes=ReadFromFileReturningNumberOfBytesRead(currentBuffer->iData, KLargeNumber, aInputFile);

	// append 2 '\0' bytes at the end of the buffer read from file (2 in case it is unicode)

	((char*)currentBuffer->iData)[currentBuffer->iNumberOfBytes]='\0';

	((char*)currentBuffer->iData)[currentBuffer->iNumberOfBytes+1]='\0';

	ObeyRequiredByteOrderIfUnicode(aUnicodeByteOrder, aInputEncoding, *currentBuffer);

	// if the input and output encodings are different, convert from one to the other (via unicode if neither is itself unicode)

	if (_stricmp(aInputEncoding, aOutputEncoding)!=0)

		{

		if (_stricmp(aInputEncoding, "unicode")!=0)

			{

			SBuffer* nextBuffer=currentBuffer+1;

			nextBuffer->iNumberOfBytes=sizeof(wchar_t)*OtherToUnicode(aInputEncoding, NULL, (const char*)currentBuffer->iData);

			Assert(nextBuffer->iNumberOfBytes>=0, "invalid multi-byte character encountered");

			nextBuffer->iData=malloc(nextBuffer->iNumberOfBytes+sizeof(wchar_t)); // "+sizeof(wchar_t)" for terminating '\0'

			Assert(nextBuffer->iData!=NULL, "cannot allocate enough memory");

			OtherToUnicode(aInputEncoding, (wchar_t*)nextBuffer->iData, (const char*)currentBuffer->iData);

			currentBuffer=nextBuffer;

			}

		if (_stricmp(aOutputEncoding, "unicode")!=0)

			{

			SBuffer* nextBuffer=currentBuffer+1;

			nextBuffer->iNumberOfBytes=sizeof(char)*UnicodeToOther(aOutputEncoding, NULL, (const wchar_t*)currentBuffer->iData);

			Assert(nextBuffer->iNumberOfBytes>=0, "unconvertible unicode character encountered");

			nextBuffer->iData=malloc(nextBuffer->iNumberOfBytes+sizeof(char)); // "+sizeof(char)" for terminating '\0'

			Assert(nextBuffer->iData!=NULL, "cannot allocate enough memory");

			UnicodeToOther(aOutputEncoding, (char*)nextBuffer->iData, (const wchar_t*)currentBuffer->iData);

			currentBuffer=nextBuffer;

			}

		}

	ObeyRequiredByteOrderIfUnicode(aUnicodeByteOrder, aOutputEncoding, *currentBuffer);

	WriteToFile((const void*)currentBuffer->iData, currentBuffer->iNumberOfBytes, aOutputFile);

	free(arrayOfBuffers[0].iData);

	free(arrayOfBuffers[1].iData);

	free(arrayOfBuffers[2].iData);

	}

void FlushAndCloseFiles(FILE* aInputFile, FILE* aOutputFile)

	{

	Assert(fflush(aOutputFile)==0, "flushing output-file failed");

	if (aInputFile!=stdin)

		{

		Assert(fclose(aInputFile)==0, "closing input-file failed");

		}

	if (aOutputFile!=stdout)

		{

		Assert(fclose(aOutputFile)==0, "closing output-file failed");

		}

	}

void main(int aArgc, char* aArgv[])

	{

	int outputByteOrderMark=0;

	TByteOrder unicodeByteOrder=EByteOrderUnspecified;

	const char* inputEncoding=NULL;

	const char* outputEncoding=NULL;

	FILE* inputFile=stdin;

	FILE* outputFile=stdout;

	ReadParameters(aArgc, aArgv, outputByteOrderMark, unicodeByteOrder, inputEncoding, outputEncoding, inputFile, outputFile);

#if defined(__VC32__)

	_setmode(_fileno(inputFile), _O_BINARY);

	_setmode(_fileno(outputFile), _O_BINARY);

#endif

	HandleByteOrderMarks(outputByteOrderMark, unicodeByteOrder, inputEncoding, outputEncoding, inputFile, outputFile);

	DoConversion(unicodeByteOrder, inputEncoding, outputEncoding, inputFile, outputFile);

	FlushAndCloseFiles(inputFile, outputFile);

	exit(0);

	}