/* -*- 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

 * under the terms of either the GPL or the LGPL, and not to allow others to

 * use your version of this file under the terms of the MPL, indicate your

 * 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.

 *

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

#include <stdio.h>

#include "nsSBCharSetProber.h"

nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32 aLen)

{

  unsigned char order;

  for (PRUint32 i = 0; i < aLen; i++)

  {

    order = mModel->charToOrderMap[(unsigned char)aBuf[i]];

    if (order < SYMBOL_CAT_ORDER)

      mTotalChar++;

    if (order < SAMPLE_SIZE)

    {

        mFreqChar++;

      if (mLastOrder < SAMPLE_SIZE)

      {

        mTotalSeqs++;

        if (!mReversed)

          ++(mSeqCounters[mModel->precedenceMatrix[mLastOrder*SAMPLE_SIZE+order]]);

        else // reverse the order of the letters in the lookup

          ++(mSeqCounters[mModel->precedenceMatrix[order*SAMPLE_SIZE+mLastOrder]]);

      }

    }

    mLastOrder = order;

  }

  if (mState == eDetecting)

    if (mTotalSeqs > SB_ENOUGH_REL_THRESHOLD)

    {

      float cf = GetConfidence();

      if (cf > POSITIVE_SHORTCUT_THRESHOLD)

        mState = eFoundIt;

      else if (cf < NEGATIVE_SHORTCUT_THRESHOLD)

        mState = eNotMe;

    }

  return mState;

}

void  nsSingleByteCharSetProber::Reset(void)

{

  mState = eDetecting;

  mLastOrder = 255;

  for (PRUint32 i = 0; i < NUMBER_OF_SEQ_CAT; i++)

    mSeqCounters[i] = 0;

  mTotalSeqs = 0;

  mTotalChar = 0;

  mFreqChar = 0;

}

//#define NEGATIVE_APPROACH 1

float nsSingleByteCharSetProber::GetConfidence(void)

{

#ifdef NEGATIVE_APPROACH

  if (mTotalSeqs > 0)

    if (mTotalSeqs > mSeqCounters[NEGATIVE_CAT]*10 )

      return ((float)(mTotalSeqs - mSeqCounters[NEGATIVE_CAT]*10))/mTotalSeqs * mFreqChar / mTotalChar;

  return (float)0.01;

#else  //POSITIVE_APPROACH

  float r;

  if (mTotalSeqs > 0) {

    r = ((float)1.0) * mSeqCounters[POSITIVE_CAT] / mTotalSeqs / mModel->mTypicalPositiveRatio;

    r = r*mFreqChar/mTotalChar;

    if (r >= (float)1.00)

      r = (float)0.99;

    return r;

  }

  return (float)0.01;

#endif

}

const char* nsSingleByteCharSetProber::GetCharSetName() 

{

  if (!mNameProber)

    return mModel->charsetName;

  return mNameProber->GetCharSetName();

}

#ifdef DEBUG_chardet

void nsSingleByteCharSetProber::DumpStatus()

{

  printf("  SBCS: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());

}

#endif