/* -*- Mode: C++; tab-width: 2; 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/. */

#include "mozilla/intl/WordBreaker.h"

#include "mozilla/Preferences.h"

using mozilla::intl::WordBreaker;

using mozilla::intl::WordBreakClass;

using mozilla::intl::WordRange;

/*static*/

already_AddRefed<WordBreaker>

WordBreaker::Create()

{

  return RefPtr<WordBreaker>(new WordBreaker()).forget();

}

bool WordBreaker::BreakInBetween(

  const char16_t* aText1 , uint32_t aTextLen1,

  const char16_t* aText2 , uint32_t aTextLen2)

{

  MOZ_ASSERT(nullptr != aText1, "null ptr");

  MOZ_ASSERT(nullptr != aText2, "null ptr");

  if(!aText1 || !aText2 || (0 == aTextLen1) || (0 == aTextLen2))

    return false;

  return GetClass(aText1[aTextLen1-1]) != GetClass(aText2[0]);

}

#define IS_ASCII(c)            (0 == ( 0xFF80 & (c)))

#define ASCII_IS_ALPHA(c)         ((( 'a' <= (c)) && ((c) <= 'z')) || (( 'A' <= (c)) && ((c) <= 'Z')))

#define ASCII_IS_DIGIT(c)         (( '0' <= (c)) && ((c) <= '9'))

#define ASCII_IS_SPACE(c)         (( ' ' == (c)) || ( '\t' == (c)) || ( '\r' == (c)) || ( '\n' == (c)))

#define IS_ALPHABETICAL_SCRIPT(c) ((c) < 0x2E80)

// we change the beginning of IS_HAN from 0x4e00 to 0x3400 to relfect Unicode 3.0

#define IS_HAN(c)              (( 0x3400 <= (c)) && ((c) <= 0x9fff))||(( 0xf900 <= (c)) && ((c) <= 0xfaff))

#define IS_KATAKANA(c)         (( 0x30A0 <= (c)) && ((c) <= 0x30FF))

#define IS_HIRAGANA(c)         (( 0x3040 <= (c)) && ((c) <= 0x309F))

#define IS_HALFWIDTHKATAKANA(c)         (( 0xFF60 <= (c)) && ((c) <= 0xFF9F))

#define IS_THAI(c)         (0x0E00 == (0xFF80 & (c) )) // Look at the higest 9 bits

/* static */ WordBreakClass

WordBreaker::GetClass(char16_t c)

{

  // The pref is cached on first call; changes will require a browser restart.

  static bool sStopAtUnderscore =

    Preferences::GetBool("layout.word_select.stop_at_underscore", false);

  // begin of the hack

  if (IS_ALPHABETICAL_SCRIPT(c))  {

    if(IS_ASCII(c))  {

      if(ASCII_IS_SPACE(c)) {

        return kWbClassSpace;

      } else if(ASCII_IS_ALPHA(c) || ASCII_IS_DIGIT(c) ||

                (c == '_' && !sStopAtUnderscore)) {

        return kWbClassAlphaLetter;

      } else {

        return kWbClassPunct;

      }

    } else if(IS_THAI(c))  {

      return kWbClassThaiLetter;

    } else if (c == 0x00A0/*NBSP*/) {

      return kWbClassSpace;

    } else {

      return kWbClassAlphaLetter;

    }

  }  else {

    if(IS_HAN(c)) {

      return kWbClassHanLetter;

    } else if(IS_KATAKANA(c))   {

      return kWbClassKatakanaLetter;

    } else if(IS_HIRAGANA(c))   {

      return kWbClassHiraganaLetter;

    } else if(IS_HALFWIDTHKATAKANA(c))  {

      return kWbClassHWKatakanaLetter;

    } else  {

      return kWbClassAlphaLetter;

    }

  }

  return static_cast<WordBreakClass>(0);

}

WordRange WordBreaker::FindWord(

  const char16_t* aText , uint32_t aTextLen,

  uint32_t aOffset)

{

  WordRange range;

  MOZ_ASSERT(nullptr != aText, "null ptr");

  MOZ_ASSERT(0 != aTextLen, "len = 0");

  MOZ_ASSERT(aOffset <= aTextLen, "aOffset > aTextLen");

  range.mBegin = aTextLen + 1;

  range.mEnd = aTextLen + 1;

  if(!aText || aOffset > aTextLen)

    return range;

  WordBreakClass c = GetClass(aText[aOffset]);

  uint32_t i;

  // Scan forward

  range.mEnd--;

  for(i = aOffset +1;i <= aTextLen; i++)

  {

     if( c != GetClass(aText[i]))

     {

       range.mEnd = i;

       break;

     }

  }

  // Scan backward

  range.mBegin = 0;

  for(i = aOffset ;i > 0; i--)

  {

     if( c != GetClass(aText[i-1]))

     {

       range.mBegin = i;

       break;

     }

  }

  if(kWbClassThaiLetter == c)

  {

  // need to call Thai word breaker from here

  // we should pass the whole Thai segment to the thai word breaker to find a shorter answer

  }

  return range;

}

int32_t WordBreaker::NextWord(

  const char16_t* aText, uint32_t aLen, uint32_t aPos)

{

  WordBreakClass c1, c2;

  uint32_t cur = aPos;

  if (cur == aLen)

    return NS_WORDBREAKER_NEED_MORE_TEXT;

  c1 = GetClass(aText[cur]);

  for(cur++; cur <aLen; cur++)

  {

     c2 = GetClass(aText[cur]);

     if(c2 != c1)

       break;

  }

  if(kWbClassThaiLetter == c1)

  {

  // need to call Thai word breaker from here

  // we should pass the whole Thai segment to the thai word breaker to find a shorter answer

  }

  if (cur == aLen)

    return NS_WORDBREAKER_NEED_MORE_TEXT;

  return cur;

}