/*

 * Copyright (c) 2006-2009 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: 

 *

 */

 #include <e32std.h>

 #include <e32def.h>

 #include <e32des8.h> 

 #include "unicodeconv.h"

 //replacement character to be used when unicode cannot be converted

 const TUint8 KForeignReplacement = 0x5F;

 //This function converts from Unicoded characters, to foreign characters and adds them into a descriptor

 EXPORT_C void UnicodeConv::ConvertFromUnicodeL(TDes8& aForeign, const TDesC16& aUnicode)

     {

     UnicodeConv::ConvertFromUnicodeL(aForeign, aUnicode, ETrue);

     }

 //This function converts from Unicoded characters, to foreign characters and adds them into a descriptor

 EXPORT_C TInt UnicodeConv::ConvertFromUnicodeL(TDes8& aForeign, const TDesC16& aUnicode, TBool leaveWhenOverflow)

 	{

 	const TInt unicodeLength = aUnicode.Length();

 	//loop going through the character of the unicode descriptor

 	for(TInt i=0; i<unicodeLength; i++)

 		{

 		const TUint16 unicodeChar = aUnicode[i];

 		// if the output buffer is already full, leave with KErrOverflow

 		if ( aForeign.Length() >= aForeign.MaxLength() )

 		    {

 		    if (leaveWhenOverflow)

 		        User::Leave(KErrOverflow);

 		    else

 		        return KErrOverflow;

 		    }			

 		//charcters from 0x0000 to 0x007F, can be mapped directly

 		if(unicodeChar<0x0080)

 			{

 			aForeign.Append(static_cast<TUint8>(unicodeChar));

 			}

 		else

 			{

 			TInt trailByte = KErrNotFound;

 			TInt returnValue = TConvDataStruct::ConvertSingleUnicode(unicodeChar,trailByte);

 			if(returnValue!=KErrNotFound)

 				{

 				if(trailByte!=KErrNotFound)		

 					{					

 					// as two bytes are being added check enough space for second

 					if ( aForeign.Length() + 2 <= aForeign.MaxLength() )

 					    {

 					    aForeign.Append(static_cast<TUint8>(returnValue));

 					    aForeign.Append(static_cast<TUint8>(trailByte));

 					    }

 					else

 					    {

 			            if (leaveWhenOverflow)

 			                User::Leave(KErrOverflow);

 			            else

 			                return KErrOverflow;

 					    }					

 					}

 				else

 					aForeign.Append(static_cast<TUint8>(returnValue));

 				}		

 			else

 				aForeign.Append(KForeignReplacement);

 			}

 		}

 	return KErrNone;

 	}

 //This function converts from foreign characters into unicode and adds them into a descriptor

 EXPORT_C void UnicodeConv::ConvertToUnicodeL(TDes16& aUnicode, const TDesC8& aForeign)

     {

     UnicodeConv::ConvertToUnicodeL(aUnicode, aForeign, ETrue);

     }

 //This function converts from foreign characters into unicode and adds them into a descriptor

 EXPORT_C TInt UnicodeConv::ConvertToUnicodeL(TDes16& aUnicode, const TDesC8& aForeign, TBool leaveWhenOverflow)

 	{

 	const TInt foreignLength = aForeign.Length();

 	//loop going through the characters of the foreign descriptor

 	for(TInt i = 0; i<foreignLength; i++)

 		{

 		const TUint8 leadForeign = aForeign[i];

 		TUint8 tailForeign = 0x00;

 		// Check there is enough space in the output buffer, and leave with KErrOverflow if not

 		if ( aUnicode.Length() == aUnicode.MaxLength() )

             {

             if (leaveWhenOverflow)

                 User::Leave(KErrOverflow);

             else

                 return KErrOverflow;

             }

 		//charcters from 0x00 to 0x7F, can be mapped directly

 		if(leadForeign < 0x80)

 			aUnicode.Append(static_cast<TUint16>(leadForeign));

 		else

 			{

 			if((i+1)<foreignLength)

 				tailForeign = aForeign[i+1];

 			const TLeadOrSingle* structPtr = TConvDataStruct::KFirstByteConversions + (leadForeign-0x80);

 			if(structPtr->iUnicodeIfSingle)

 				aUnicode.Append(structPtr->iUnicodeIfSingle);

 			else

 				{

 				if(TConvDataStruct::KMinTrailByte<=tailForeign && tailForeign<=TConvDataStruct::KMaxTrailByte)

 					aUnicode.Append(TConvDataStruct::KDoubleByteConversions[structPtr->iDoubleByteIndex+

 						(tailForeign - TConvDataStruct::KMinTrailByte)]);

 				else

 					aUnicode.Append(0xFFFD);

 				i++;

 				}

 			}

 		}

 	return KErrNone;

 	}

 EXPORT_C TBool UnicodeConv::IsLegalShortNameCharacter (TUint aCharacter)

 	{

 	//1. aCharacter >= 0x0080 

 	if (aCharacter>=0x0080)

 		{

 		if (aCharacter>0xFFFF)

 			return EFalse;

 		TInt trailByte = KErrNotFound;

 		TInt returnValue = TConvDataStruct::ConvertSingleUnicode(aCharacter,trailByte);

 		if(returnValue!=KErrNotFound)

 			return ETrue;

 		else

 			return EFalse;

 		}

     // For most common cases: 

     // Note: lower case characters are considered legal DOS char here. 

 	if ((aCharacter>='a' && aCharacter<='z') || 

 	    (aCharacter>='A' && aCharacter<='Z') || 

 	    (aCharacter>='0' && aCharacter<='9'))

 			{

 			return ETrue;

 			}

     // Checking for illegal chars: 

     // 2. aCharacter <= 0x20 

     // Note: leading 0x05 byte should be guarded by callers of this function 

     //  as the information of the position of the character is required. 

 	if (aCharacter < 0x20)

 		return EFalse;

 	// Space (' ') is not considered as a legal DOS char here.

 	if (aCharacter == 0x20)

 		return EFalse;

 	// 3. 0x20 < aCharacter < 0x80 

     // According to FAT Spec, "following characters are not legal in any bytes of DIR_Name": 

     switch (aCharacter) 

             { 

             case 0x22:        // '"' 

             case 0x2A:        // '*' 

             case 0x2B:        // '+' 

             case 0x2C:        // ',' 

             //case 0x2E:        // '.'   // Although '.' is not allowed in any bytes of DIR_Name, it 

                                          // is a valid character in short file names. 

             case 0x2F:        // '/' 

             case 0x3A:        // ':' 

             case 0x3B:        // ';' 

             case 0x3C:        // '<' 

             case 0x3D:        // '=' 

             case 0x3E:        // '>' 

             case 0x3F:        // '?' 

             case 0x5B:        // '[' 

             case 0x5C:        // '\' 

             case 0x5D:        // ']' 

             case 0x7C:        // '|' 

             	return EFalse; 

             default: 

             	return ETrue; 

             } 

 	}