/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* ***** BEGIN LICENSE BLOCK *****

 * Version: MPL 1.1/GPL 2.0/LGPL 2.1

 *

 * The contents of this file are subject to the Mozilla Public License Version

 * 1.1 (the "License"); you may not use this file except in compliance with

 * the License. You may obtain a copy of the License at

 * http://www.mozilla.org/MPL/

 *

 * Software distributed under the License is distributed on an "AS IS" basis,

 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License

 * for the specific language governing rights and limitations under the

 * License.

 *

 * The Original Code is Mozilla Universal charset detector code.

 *

 * The Initial Developer of the Original Code is

 * Netscape Communications Corporation.

 * Portions created by the Initial Developer are Copyright (C) 2001

 * the Initial Developer. All Rights Reserved.

 *

 * Contributor(s):

 *          Shy Shalom <shooshX@gmail.com>

 *

 * Alternatively, the contents of this file may be used under the terms of

 * either the GNU General Public License Version 2 or later (the "GPL"), or

 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),

 * in which case the provisions of the GPL or the LGPL are applicable instead

 * of those above. If you wish to allow use of your version of this file only

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 * decision by deleting the provisions above and replace them with the notice

 * and other provisions required by the GPL or the LGPL. If you do not delete

 * the provisions above, a recipient may use your version of this file under

 * the terms of any one of the MPL, the GPL or the LGPL.

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 * ***** END LICENSE BLOCK ***** */

#include "nsCharSetProber.h"

#include "prmem.h"

//This filter applies to all scripts which do not use English characters

PRBool nsCharSetProber::FilterWithoutEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen)

{

  char *newptr;

  char *prevPtr, *curPtr;

  PRBool meetMSB = PR_FALSE;   

  newptr = *newBuf = (char*)PR_Malloc(aLen);

  if (!newptr)

    return PR_FALSE;

  for (curPtr = prevPtr = (char*)aBuf; curPtr < aBuf+aLen; curPtr++)

  {

    if (*curPtr & 0x80)

    {

      meetMSB = PR_TRUE;

    }

    else if (*curPtr < 'A' || (*curPtr > 'Z' && *curPtr < 'a') || *curPtr > 'z') 

    {

      //current char is a symbol, most likely a punctuation. we treat it as segment delimiter

      if (meetMSB && curPtr > prevPtr) 

      //this segment contains more than single symbol, and it has upper ASCII, we need to keep it

      {

        while (prevPtr < curPtr) *newptr++ = *prevPtr++;  

        prevPtr++;

        *newptr++ = ' ';

        meetMSB = PR_FALSE;

      }

      else //ignore current segment. (either because it is just a symbol or just an English word)

        prevPtr = curPtr+1;

    }

  }

  if (meetMSB && curPtr > prevPtr) 

    while (prevPtr < curPtr) *newptr++ = *prevPtr++;  

  newLen = newptr - *newBuf;

  return PR_TRUE;

}

//This filter applies to all scripts which contain both English characters and upper ASCII characters.

PRBool nsCharSetProber::FilterWithEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen)

{

  //do filtering to reduce load to probers

  char *newptr;

  char *prevPtr, *curPtr;

  PRBool isInTag = PR_FALSE;

  newptr = *newBuf = (char*)PR_Malloc(aLen);

  if (!newptr)

    return PR_FALSE;

  for (curPtr = prevPtr = (char*)aBuf; curPtr < aBuf+aLen; curPtr++)

  {

    if (*curPtr == '>')

      isInTag = PR_FALSE;

    else if (*curPtr == '<')

      isInTag = PR_TRUE;

    if (!(*curPtr & 0x80) &&

        (*curPtr < 'A' || (*curPtr > 'Z' && *curPtr < 'a') || *curPtr > 'z') )

    {

      if (curPtr > prevPtr && !isInTag) // Current segment contains more than just a symbol 

                                        // and it is not inside a tag, keep it.

      {

        while (prevPtr < curPtr) *newptr++ = *prevPtr++;  

        prevPtr++;

        *newptr++ = ' ';

      }

      else

        prevPtr = curPtr+1;

    }

  }

  // If the current segment contains more than just a symbol 

  // and it is not inside a tag then keep it.

  if (!isInTag)

    while (prevPtr < curPtr)

      *newptr++ = *prevPtr++;  

  newLen = newptr - *newBuf;

  return PR_TRUE;

}