/* -*- 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 ***** */
#ifndef nsCharSetProber_h__
#define nsCharSetProber_h__

#include "nscore.h"

//#define DEBUG_chardet // Uncomment this for debug dump.

typedef enum {
  eDetecting = 0,   //We are still detecting, no sure answer yet, but caller can ask for confidence.
  eFoundIt = 1,     //That's a positive answer
  eNotMe = 2        //Negative answer
} nsProbingState;

#define SHORTCUT_THRESHOLD      (float)0.95

class nsCharSetProber {
public:
  virtual ~nsCharSetProber() {}
  virtual const char* GetCharSetName() = 0;
  virtual nsProbingState HandleData(const char* aBuf, PRUint32 aLen) = 0;
  virtual nsProbingState GetState(void) = 0;
  virtual void      Reset(void)  = 0;
  virtual float     GetConfidence(void) = 0;
  virtual void      SetOpion() = 0;

#ifdef DEBUG_chardet
  virtual void  DumpStatus() {}
#endif

  // Helper functions used in the Latin1 and Group probers.
  // both functions Allocate a new buffer for newBuf. This buffer should be 
  // freed by the caller using PR_FREEIF.
  // Both functions return PR_FALSE in case of memory allocation failure.
  static PRBool FilterWithoutEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen);
  static PRBool FilterWithEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen);
};

class nsCharSetProberHelper {
public:
  nsCharSetProberHelper() { mLastChar[0] = mLastChar[1] = 0; }
protected:
  char mLastChar[2];
};
#endif /* nsCharSetProber_h__ */
