/*

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

* All rights reserved.

* This component and the accompanying materials are made available

* 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: 

*

*/

#if !defined(WEAVEPATH_CPP)

#define WEAVEPATH_CPP

/***

 *

 *  Previously, each <OS>PlatformUtils.cpp has its onw copy of the

 *  method weavePaths(), and almost of them implemented the same logic,

 *  with few platform specific difference, and unfortunately that 

 *  implementation was wrong.

 *  

 *  The only platform specific issue is slash character.

 *  On all platforms other than Windows, chForwardSlash and chBackSlash 

 *  are considered slash, while on Windows, two additional characters, 

 *  chYenSign and chWonSign are slash as well.

 *

 *  The idea is to maintain a SINGLE copy of this method rather than

 *  each <OS>PlatformUtils.cpp has its own copy, we introduce a new

 *  method, XMLPlatformUtils::isAnySlash(), to replace the direct checking

 *  code ( if ( c == chForwardSlash || c == chBackSlash).

 *

 *  With this approach, we might have a performance hit since isAnySlash() 

 *  is so frequently used in this implementation, so we intend to make it 

 *  inline. Then we face a complier issue.

 *

 *  There are two compilation units involved, one is PlatformUtils.cpp and 

 *  the other <OS>PlatformUtils.cpp. When PlatformUtils.cp get compiled,

 *  the weavePath(), remove**Slash() have dependency upon isAnySlash() which

 *  is in <OS>PlatformUtils.cpp (and what is worse, it is inlined), so we have

 *  undefined/unresolved symbol: isAnySlash() on AIX/xlc_r, Solaris/cc and 

 *  Linux/gcc, while MSVC and HP/aCC are fine with this.

 *  

 *  That means we can not place these new methods in PlatformUtils.cpp with

 *  inlined XMLPlatformUtils::isAnySlash() in <OS>PlatformUtils.cpp.

 *

 *  The solution to this is <os>PlatformUtils.cpp will include this file so that

 *  we have only one copy of these methods while get compiled in <os>PlatformUtils

 *  inlined isAnySlash().

 *

 ***/

XMLCh* XMLPlatformUtils::weavePaths(const XMLCh* const    basePath

                                  , const XMLCh* const    relativePath

                                  , MemoryManager* const  manager)

{

    // Create a buffer as large as both parts and empty it

    XMLCh* tmpBuf = (XMLCh*) manager->allocate

    (

        (XMLString::stringLen(basePath)

         + XMLString::stringLen(relativePath) + 2) * sizeof(XMLCh)

    );//new XMLCh[XMLString::stringLen(basePath) + XMLString::stringLen(relativePath) + 2];

    *tmpBuf = 0;

    //

    //  If we have no base path, then just take the relative path as is.

    //

    if ((!basePath) || (!*basePath))

    {

        XMLString::copyString(tmpBuf, relativePath);

        return tmpBuf;

    }

    //

    // Remove anything after the last slash

    //

    const XMLCh* basePtr = basePath + (XMLString::stringLen(basePath) - 1);

    while ((basePtr >= basePath)  &&  ((isAnySlash(*basePtr) == false)))

    {

        basePtr--;

    }

    // There is no relevant base path, so just take the relative part

    if (basePtr < basePath)

    {

        XMLString::copyString(tmpBuf, relativePath);

        return tmpBuf;

    }

    //

    // 1. concatenate the base and relative

    // 2. remove all occurences of "/./"

    // 3. remove all occurences of segment/../ where segment is not ../

	// 

    XMLString::subString(tmpBuf, basePath, 0, (basePtr - basePath + 1), manager);

    tmpBuf[basePtr - basePath + 1] = 0;

    XMLString::catString(tmpBuf, relativePath);

    removeDotSlash(tmpBuf, manager);

    removeDotDotSlash(tmpBuf, manager);

    return tmpBuf;

}

//

// Remove all occurences of './' when it is part of '/./'

//

// Since it could be '.\' or other combination on windows ( eg, '.'+chYanSign)

// we can't make use of patterMatch().

//

//

void XMLPlatformUtils::removeDotSlash(XMLCh* const path

                                      , MemoryManager* const manager)

{

    if ((!path) || (!*path))

        return;

    XMLCh* srcPtr = XMLString::replicate(path, manager);

    int    srcLen = XMLString::stringLen(srcPtr);

    ArrayJanitor<XMLCh>   janName(srcPtr, manager);   

    XMLCh* tarPtr = path;

    while (*srcPtr)

    {

        if ( 3 <= srcLen )

        {

            if ( (isAnySlash(*srcPtr))     &&

                (chPeriod == *(srcPtr+1)) &&

                (isAnySlash(*(srcPtr+2)))  )

            {

                // "\.\x" seen

                // skip the first two, and start from the 3rd,

                // since "\x" could be another "\."

                srcPtr+=2;              

                srcLen-=2;

            }

            else

            {

                *tarPtr++ = *srcPtr++;  // eat the current char

                srcLen--;

            }

        }

        else if ( 1 == srcLen )

        {

            *tarPtr++ = *srcPtr++;

        }

        else if ( 2 == srcLen)

        {

            *tarPtr++ = *srcPtr++;

            *tarPtr++ = *srcPtr++;

        }

    }

    *tarPtr = 0;

    return;

}

//

// Remove all occurences of '/segment/../' when segment is not '..'

//

// Cases with extra /../ is left to the underlying file system.

//

void XMLPlatformUtils::removeDotDotSlash(XMLCh* const path

                                         , MemoryManager* const manager)

{

    int pathLen = XMLString::stringLen(path);

    XMLCh* tmp1 = (XMLCh*) manager->allocate

    (

        (pathLen+1) * sizeof(XMLCh)

    );//new XMLCh [pathLen+1];

    ArrayJanitor<XMLCh>   tmp1Name(tmp1, manager);

    XMLCh* tmp2 = (XMLCh*) manager->allocate

    (

        (pathLen+1) * sizeof(XMLCh)

    );//new XMLCh [pathLen+1];

    ArrayJanitor<XMLCh>   tmp2Name(tmp2, manager);

    // remove all "<segment>/../" where "<segment>" is a complete

    // path segment not equal to ".."

    int index = -1;

    int segIndex = -1;

    int offset = 1;

    while ((index = searchSlashDotDotSlash(&(path[offset]))) != -1)

    {

        // Undo offset

        index += offset;

        // Find start of <segment> within substring ending at found point.

        XMLString::subString(tmp1, path, 0, index-1, manager);

        segIndex = index - 1;

        while ((segIndex >= 0) && (!isAnySlash(tmp1[segIndex])))

        {

            segIndex--;

        }

        // Ensure <segment> exists and != ".."

        if (segIndex >= 0                 &&

            (path[segIndex+1] != chPeriod ||

             path[segIndex+2] != chPeriod ||

             segIndex + 3 != index))

        {

            XMLString::subString(tmp1, path, 0, segIndex, manager);

            XMLString::subString(tmp2, path, index+3, XMLString::stringLen(path), manager);

            path[0] = 0;

            XMLString::catString(path, tmp1);

            XMLString::catString(path, tmp2);

            offset = (segIndex == 0 ? 1 : segIndex);

        }

        else

        {

            offset += 4;

        }

    }// while

}

int XMLPlatformUtils::searchSlashDotDotSlash(XMLCh* const srcPath)

{

    if ((!srcPath) || (!*srcPath))

        return -1;

    XMLCh* srcPtr = srcPath;

    int    srcLen = XMLString::stringLen(srcPath);

    int    retVal = -1;

    while (*srcPtr)

    {

        if ( 4 <= srcLen )

        {

            if ( (isAnySlash(*srcPtr))     &&

                 (chPeriod == *(srcPtr+1)) &&

                 (chPeriod == *(srcPtr+2)) &&

                 (isAnySlash(*(srcPtr+3)))  )

            {

                retVal = (srcPtr - srcPath);

                break;

            }

            else

            {

                srcPtr++;

                srcLen--;

            }

        }

        else 

        {

            break;

        }

    } // while

    return retVal;

}

#endif