/*

 *

 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved

 *

 */

#include "LETypes.h"

#include "LEGlyphFilter.h"

#include "OpenTypeTables.h"

#include "LEGlyphStorage.h"

#include "ThaiShaping.h"

U_NAMESPACE_BEGIN

enum {

    CH_SPACE        = 0x0020,

    CH_YAMAKKAN     = 0x0E4E,

    CH_MAI_HANAKAT  = 0x0E31,

    CH_SARA_AA      = 0x0E32,

    CH_SARA_AM      = 0x0E33,

    CH_SARA_UEE     = 0x0E37,

    CH_MAITAIKHU    = 0x0E47,

    CH_NIKHAHIT     = 0x0E4D,

    CH_SARA_U       = 0x0E38,

    CH_PHINTHU      = 0x0E3A,

    CH_YO_YING      = 0x0E0D,

    CH_THO_THAN     = 0x0E10,

    CH_DOTTED_CIRCLE = 0x25CC

};

    le_uint8 ThaiShaping::getCharClass(LEUnicode ch)

{

    le_uint8 charClass = NON;

    if (ch >= 0x0E00 && ch <= 0x0E5B) {

        charClass = classTable[ch - 0x0E00];

    }

    return charClass;

}

LEUnicode ThaiShaping::leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet)

{

    static const LEUnicode leftAboveVowels[][7] = {

        {0x0E61, 0x0E32, 0x0E33, 0x0E64, 0x0E65, 0x0E66, 0x0E67},

        {0xF710, 0x0E32, 0x0E33, 0xF701, 0xF702, 0xF703, 0xF704},

        {0xF884, 0x0E32, 0x0E33, 0xF885, 0xF886, 0xF887, 0xF788},

        {0x0E31, 0x0E32, 0x0E33, 0x0E34, 0x0E35, 0x0E36, 0x0E37}

    };

    if (vowel >= CH_MAI_HANAKAT && vowel <= CH_SARA_UEE) {

        return leftAboveVowels[glyphSet][vowel - CH_MAI_HANAKAT];

    }

    if (vowel == CH_YAMAKKAN && glyphSet == 0) {

        return 0x0E7E;

    }

    return vowel;

}

LEUnicode ThaiShaping::lowerRightTone(LEUnicode tone, le_uint8 glyphSet)

{

    static const LEUnicode lowerRightTones[][7] = {

        {0x0E68, 0x0E69, 0x0E6A, 0x0E6B, 0x0E6C, 0x0E6D, 0x0E6E},

        {0x0E47, 0xF70A, 0xF70B, 0xF70C, 0xF70D, 0xF70E, 0x0E4D},

        {0x0E47, 0xF88B, 0xF88E, 0xF891, 0xF894, 0xF897, 0x0E4D},

        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

    };

    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

        return lowerRightTones[glyphSet][tone - CH_MAITAIKHU];

    }

    return tone;

}

LEUnicode ThaiShaping::lowerLeftTone(LEUnicode tone, le_uint8 glyphSet)

{

    static const LEUnicode lowerLeftTones[][7] = {

        {0x0E76, 0x0E77, 0x0E78, 0x0E79, 0x0E7A, 0x0E7B, 0x0E7C},

        {0xF712, 0xF705, 0xF706, 0xF707, 0xF708, 0xF709, 0xF711},

        {0xF889, 0xF88C, 0xF88F, 0xF892, 0xF895, 0xF898, 0xF899},

        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

    };

    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

        return lowerLeftTones[glyphSet][tone - CH_MAITAIKHU];

    }

    return tone;

}

LEUnicode ThaiShaping::upperLeftTone(LEUnicode tone, le_uint8 glyphSet)

{

    static const LEUnicode upperLeftTones[][7] = {

        {0x0E6F, 0x0E70, 0x0E71, 0x0E72, 0x0E73, 0x0E74, 0x0E75},

        {0xF712, 0xF713, 0xF714, 0xF715, 0xF716, 0xF717, 0xF711},

        {0xF889, 0xF88A, 0xF88D, 0xF890, 0xF893, 0xF896, 0xF899},

        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

    };

    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

        return upperLeftTones[glyphSet][tone - CH_MAITAIKHU];

    }

    return tone;

}

LEUnicode ThaiShaping::lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet)

{

    static const LEUnicode lowerBelowVowels[][3] = {

        {0x0E3C, 0x0E3D, 0x0E3E},

        {0xF718, 0xF719, 0xF71A},

        {0x0E38, 0x0E39, 0x0E3A},

        {0x0E38, 0x0E39, 0x0E3A}

    };

    if (vowel >= CH_SARA_U && vowel <= CH_PHINTHU) {

        return lowerBelowVowels[glyphSet][vowel - CH_SARA_U];

    }

    return vowel;

}

LEUnicode ThaiShaping::noDescenderCOD(LEUnicode cod, le_uint8 glyphSet)

{

    static const LEUnicode noDescenderCODs[][4] = {

        {0x0E60, 0x0E0E, 0x0E0F, 0x0E63},

        {0xF70F, 0x0E0E, 0x0E0F, 0xF700},

        {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10},

        {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10}

    };

    if (cod >= CH_YO_YING && cod <= CH_THO_THAN) {

        return noDescenderCODs[glyphSet][cod - CH_YO_YING];

    }

    return cod;

}

le_uint8 ThaiShaping::doTransition (StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,

        LEUnicode errorChar, LEUnicode *outputBuffer, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)

{

    LEErrorCode success = LE_NO_ERROR;

    switch (transition.action) {

    case tA:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = currChar;

        break;

    case tC:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = currChar;

        break;

    case tD:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = leftAboveVowel(currChar, glyphSet);

        break;

    case tE:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = lowerRightTone(currChar, glyphSet);

        break;

    case tF:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = lowerLeftTone(currChar, glyphSet);

        break;

    case tG:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = upperLeftTone(currChar, glyphSet);

        break;

    case tH:

    {

        LEUnicode cod = outputBuffer[outputIndex - 1];

        LEUnicode coa = noDescenderCOD(cod, glyphSet);

        if (cod != coa) {

            outputBuffer[outputIndex - 1] = coa;

            glyphStorage.setCharIndex(outputIndex, inputIndex, success);

            outputBuffer[outputIndex++] = currChar;

            break;

        }

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = lowerBelowVowel(currChar, glyphSet);

        break;

    }

    case tR:

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = errorChar;

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = currChar;

        break;

    case tS:

        if (currChar == CH_SARA_AM) {

            glyphStorage.setCharIndex(outputIndex, inputIndex, success);

            outputBuffer[outputIndex++] = errorChar;

        }

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = currChar;

        break;

    default:

        // FIXME: if we get here, there's an error

        // in the state table!

        glyphStorage.setCharIndex(outputIndex, inputIndex, success);

        outputBuffer[outputIndex++] = currChar;

        break;

     }

     return transition.nextState;

}

le_uint8 ThaiShaping::getNextState(LEUnicode ch, le_uint8 prevState, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,

                              le_uint8 &charClass, LEUnicode *output, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)

{

    StateTransition transition;

    charClass = getCharClass(ch);

    transition = getTransition(prevState, charClass);

    return doTransition(transition, ch, inputIndex, glyphSet, errorChar, output, glyphStorage, outputIndex);

}

le_bool ThaiShaping::isLegalHere(LEUnicode ch, le_uint8 prevState)

{

    le_uint8 charClass = getCharClass(ch);

    StateTransition transition = getTransition(prevState, charClass);

    switch (transition.action) {

    case tA:

    case tC:

    case tD:

    case tE:

    case tF:

    case tG:

    case tH:

        return TRUE;

    case tR:

    case tS:

        return FALSE;

    default:

        // FIXME: if we get here, there's an error

        // in the state table!

        return FALSE;

    }

}

le_int32 ThaiShaping::compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,

                          LEUnicode errorChar, LEUnicode *output, LEGlyphStorage &glyphStorage)

{

    le_uint8 state = 0;

    le_int32 inputIndex;

    le_int32 outputIndex = 0;

    le_uint8 conState = 0xFF;

    le_int32 conInput = -1;

    le_int32 conOutput = -1;

    for (inputIndex = 0; inputIndex < charCount; inputIndex += 1) {

        LEUnicode ch = input[inputIndex + offset];

        le_uint8 charClass;

        // Decompose SARA AM into NIKHAHIT + SARA AA

        if (ch == CH_SARA_AM && isLegalHere(ch, state)) {

            outputIndex = conOutput;

            state = getNextState(CH_NIKHAHIT, conState, inputIndex, glyphSet, errorChar, charClass,

                output, glyphStorage, outputIndex);

            for (int j = conInput + 1; j < inputIndex; j += 1) {

                ch = input[j + offset];

                state = getNextState(ch, state, j, glyphSet, errorChar, charClass,

                    output, glyphStorage, outputIndex);

            }

            ch = CH_SARA_AA;

        }

        state = getNextState(ch, state, inputIndex, glyphSet, errorChar, charClass,

            output, glyphStorage, outputIndex);

        if (charClass >= CON && charClass <= COD) {

            conState = state;

            conInput = inputIndex;

            conOutput = outputIndex;

        }

    }

    return outputIndex;

}

U_NAMESPACE_END