/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#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, uint32_t aLen) = 0;
  virtual nsProbingState GetState(void) = 0;
  virtual void      Reset(void)  = 0;
  virtual float     GetConfidence(void) = 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 false in case of memory allocation failure.
  static bool FilterWithoutEnglishLetters(const char* aBuf, uint32_t aLen, char** newBuf, uint32_t& newLen);
  static bool FilterWithEnglishLetters(const char* aBuf, uint32_t aLen, char** newBuf, uint32_t& newLen);

};

#endif /* nsCharSetProber_h__ */
