/*  -*- C++ -*-
*  Copyright (C) 1998 <developer@mozilla.org>
*
*
*  Permission is hereby granted, free of charge, to any person obtaining
*  a copy of this software and associated documentation files (the
*  "Software"), to deal in the Software without restriction, including
*  without limitation the rights to use, copy, modify, merge, publish,
*  distribute, sublicense, and/or sell copies of the Software, and to
*  permit persons to whom the Software is furnished to do so, subject to
*  the following conditions:
*
*  The above copyright notice and this permission notice shall be included
*  in all copies or substantial portions of the Software.
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
*  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
*  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
*  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
*  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
*  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
*  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef __JPCNTX_H__
#define __JPCNTX_H__

#include "kcodecs_export.h"

#define NUM_OF_CATEGORY 6

#define ENOUGH_REL_THRESHOLD  100
#define MAX_REL_THRESHOLD     1000
namespace kencodingprober
{
//hiragana frequency category table
extern const char jp2CharContext[83][83];

class KCODECS_NO_EXPORT JapaneseContextAnalysis
{
public:
    JapaneseContextAnalysis()
    {
        Reset();
    };
    virtual ~JapaneseContextAnalysis() {};

    void HandleData(const char *aBuf, unsigned int aLen);

    void HandleOneChar(const char *aStr, unsigned int aCharLen)
    {
        int order;

        //if we received enough data, stop here
        if (mTotalRel > MAX_REL_THRESHOLD) {
            mDone = true;
        }
        if (mDone) {
            return;
        }

        //Only 2-bytes characters are of our interest
        order = (aCharLen == 2) ? GetOrder(aStr) : -1;
        if (order != -1 && mLastCharOrder != -1) {
            mTotalRel++;
            //count this sequence to its category counter
            mRelSample[(int)jp2CharContext[mLastCharOrder][order]]++;
        }
        mLastCharOrder = order;
    };

    float GetConfidence();
    void      Reset(void);
    void      SetOpion() {};
    bool GotEnoughData()
    {
        return mTotalRel > ENOUGH_REL_THRESHOLD;
    };

protected:
    virtual int GetOrder(const char *str, unsigned int *charLen) = 0;
    virtual int GetOrder(const char *str) = 0;

    //category counters, each interger counts sequence in its category
    unsigned int mRelSample[NUM_OF_CATEGORY];

    //total sequence received
    unsigned int mTotalRel;

    //The order of previous char
    int  mLastCharOrder;

    //if last byte in current buffer is not the last byte of a character, we
    //need to know how many byte to skip in next buffer.
    unsigned int mNeedToSkipCharNum;

    //If this flag is set to true, detection is done and conclusion has been made
    bool   mDone;
};

class KCODECS_NO_EXPORT SJISContextAnalysis : public JapaneseContextAnalysis
{
    //SJISContextAnalysis(){};
protected:
    int GetOrder(const char *str, unsigned int *charLen);

    int GetOrder(const char *str)
    {
        //We only interested in Hiragana, so first byte is '\202'
        if (*str == '\202' &&
                (unsigned char) * (str + 1) >= (unsigned char)0x9f &&
                (unsigned char) * (str + 1) <= (unsigned char)0xf1) {
            return (unsigned char) * (str + 1) - (unsigned char)0x9f;
        }
        return -1;
    };
};

class KCODECS_NO_EXPORT EUCJPContextAnalysis : public JapaneseContextAnalysis
{
protected:
    int GetOrder(const char *str, unsigned int *charLen);
    int GetOrder(const char *str)
    //We only interested in Hiragana, so first byte is '\244'
    {
        if (*str == '\244' &&
                (unsigned char) * (str + 1) >= (unsigned char)0xa1 &&
                (unsigned char) * (str + 1) <= (unsigned char)0xf3) {
            return (unsigned char) * (str + 1) - (unsigned char)0xa1;
        }
        return -1;
    };
};
}
#endif /* __JPCNTX_H__ */

