/* -*- 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 nsCodingStateMachine_h__

#define nsCodingStateMachine_h__

#include "mozilla/ArrayUtils.h"

#include "nsPkgInt.h"

/* Apart from these 3 generic states, machine states are specific to

 * each charset prober.

 */

#define eStart 0

#define eError 1

#define eItsMe 2

#define GETCLASS(c) GETFROMPCK(((unsigned char)(c)), mModel->classTable)

//state machine model

typedef struct

{

  nsPkgInt classTable;

  uint32_t classFactor;

  nsPkgInt stateTable;

  const uint32_t* charLenTable;

#ifdef DEBUG

  const size_t charLenTableLength;

#endif

  const char* name;

} SMModel;

class nsCodingStateMachine {

public:

  explicit nsCodingStateMachine(const SMModel* sm) : mModel(sm) { mCurrentState = eStart; }

  uint32_t NextState(char c){

    //for each byte we get its class , if it is first byte, we also get byte length

    uint32_t byteCls = GETCLASS(c);

    if (mCurrentState == eStart)

    {

      mCurrentBytePos = 0;

      MOZ_ASSERT(byteCls < mModel->charLenTableLength);

      mCurrentCharLen = mModel->charLenTable[byteCls];

    }

    //from byte's class and stateTable, we get its next state

    mCurrentState = GETFROMPCK(mCurrentState * mModel->classFactor + byteCls,

                               mModel->stateTable);

    mCurrentBytePos++;

    return mCurrentState;

  }

  uint32_t  GetCurrentCharLen(void) {return mCurrentCharLen;}

  void      Reset(void) {mCurrentState = eStart;}

  const char * GetCodingStateMachine() {return mModel->name;}

protected:

  uint32_t mCurrentState;

  uint32_t mCurrentCharLen;

  uint32_t mCurrentBytePos;

  const SMModel *mModel;

};

extern const SMModel UTF8SMModel;

extern const SMModel Big5SMModel;

extern const SMModel EUCJPSMModel;

extern const SMModel EUCKRSMModel;

extern const SMModel EUCTWSMModel;

extern const SMModel GB18030SMModel;

extern const SMModel SJISSMModel;

extern const SMModel HZSMModel;

extern const SMModel ISO2022CNSMModel;

extern const SMModel ISO2022JPSMModel;

extern const SMModel ISO2022KRSMModel;

#undef CHAR_LEN_TABLE

#ifdef DEBUG

#define CHAR_LEN_TABLE(x) x, mozilla::ArrayLength(x)

#else

#define CHAR_LEN_TABLE(x) x

#endif

#endif /* nsCodingStateMachine_h__ */