/* 
 * C# port of Mozilla Character Set Detector
 * 
 * Original Mozilla License Block follows
 * 
 */

#region 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.
#endregion

using System;

namespace Mozilla.CharDet
{
    class nsEscCharSetProber : AbstractCSProber
    {
        const int NUM_OF_ESC_CHARSETS = 4;

  nsEscCharSetProber(void);
  virtual ~nsEscCharSetProber(void);
  nsProbingState HandleData(const char* aBuf, PRUint32 aLen);
  const char* GetCharSetName() {return mDetectedCharset;}
  nsProbingState GetState(void) {return mState;}
  void      Reset(void);
  float     GetConfidence(void){return (float)0.99;}
  void      SetOpion() {}

protected:
  void      GetDistribution(PRUint32 aCharLen, const char* aStr);
  
  nsCodingStateMachine* mCodingSM[NUM_OF_ESC_CHARSETS] ;
  PRUint32    mActiveSM;
  nsProbingState mState;
  const char *  mDetectedCharset;
};


nsEscCharSetProber::nsEscCharSetProber(void)
{
  mCodingSM[0] = new nsCodingStateMachine(&HZSMModel);
  mCodingSM[1] = new nsCodingStateMachine(&ISO2022CNSMModel);
  mCodingSM[2] = new nsCodingStateMachine(&ISO2022JPSMModel);
  mCodingSM[3] = new nsCodingStateMachine(&ISO2022KRSMModel);
  mActiveSM = NUM_OF_ESC_CHARSETS;
  mState = eDetecting;
  mDetectedCharset = nsnull;
}

nsEscCharSetProber::~nsEscCharSetProber(void)
{
  for (PRUint32 i = 0; i < NUM_OF_ESC_CHARSETS; i++)
    delete mCodingSM[i];
}

void nsEscCharSetProber::Reset(void)
{
  mState = eDetecting;
  for (PRUint32 i = 0; i < NUM_OF_ESC_CHARSETS; i++)
    mCodingSM[i]->Reset();
  mActiveSM = NUM_OF_ESC_CHARSETS;
  mDetectedCharset = nsnull;
}

nsProbingState nsEscCharSetProber::HandleData(const char* aBuf, PRUint32 aLen)
{
  nsSMState codingState;
  PRInt32 j;
  PRUint32 i;

  for ( i = 0; i < aLen && mState == eDetecting; i++)
  {
    for (j = mActiveSM-1; j>= 0; j--)
    {
      //byte is feed to all active state machine 
      codingState = mCodingSM[j]->NextState(aBuf[i]);
      if (codingState == eError)
      {
        //got negative answer for this state machine, make it inactive
        mActiveSM--;
        if (mActiveSM == 0)
        {
          mState = eNotMe;
          return mState;
        }
        else if (j != (PRInt32)mActiveSM)
        {
          nsCodingStateMachine* t;
          t = mCodingSM[mActiveSM];
          mCodingSM[mActiveSM] = mCodingSM[j];
          mCodingSM[j] = t;
        }
      }
      else if (codingState == eItsMe)
      {
        mState = eFoundIt;
        mDetectedCharset = mCodingSM[j]->GetCodingStateMachine();
        return mState;
      }
    }
  }

  return mState;
}

