/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

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

#include "LETypes.h"
#include "MorphTables.h"
#include "StateTables.h"
#include "MorphStateTables.h"
#include "SubtableProcessor.h"
#include "StateTableProcessor.h"
#include "ContextualGlyphSubstProc.h"
#include "LEGlyphStorage.h"
#include "LESwaps.h"

U_NAMESPACE_BEGIN

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ContextualGlyphSubstitutionProcessor)

ContextualGlyphSubstitutionProcessor::ContextualGlyphSubstitutionProcessor(const MorphSubtableHeader *morphSubtableHeader)
  : StateTableProcessor(morphSubtableHeader)
{
    contextualGlyphSubstitutionHeader = (const ContextualGlyphSubstitutionHeader *) morphSubtableHeader;
    substitutionTableOffset = SWAPW(contextualGlyphSubstitutionHeader->substitutionTableOffset);

    entryTable = (const ContextualGlyphSubstitutionStateEntry *) ((char *) &stateTableHeader->stHeader + entryTableOffset);
}

ContextualGlyphSubstitutionProcessor::~ContextualGlyphSubstitutionProcessor()
{
}

void ContextualGlyphSubstitutionProcessor::beginStateTable()
{
    markGlyph = 0;
}

ByteOffset ContextualGlyphSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)
{
    const ContextualGlyphSubstitutionStateEntry *entry = &entryTable[index];
    ByteOffset newState = SWAPW(entry->newStateOffset);
    le_int16 flags = SWAPW(entry->flags);
    WordOffset markOffset = SWAPW(entry->markOffset);
    WordOffset currOffset = SWAPW(entry->currOffset);

    if (markOffset != 0) {
        const le_int16 *table = (const le_int16 *) ((char *) &stateTableHeader->stHeader + markOffset * 2);
        LEGlyphID mGlyph = glyphStorage[markGlyph];
        TTGlyphID newGlyph = SWAPW(table[LE_GET_GLYPH(mGlyph)]);

         glyphStorage[markGlyph] = LE_SET_GLYPH(mGlyph, newGlyph);
    }

    if (currOffset != 0) {
        const le_int16 *table = (const le_int16 *) ((char *) &stateTableHeader->stHeader + currOffset * 2);
        LEGlyphID thisGlyph = glyphStorage[currGlyph];
        TTGlyphID newGlyph = SWAPW(table[LE_GET_GLYPH(thisGlyph)]);

        glyphStorage[currGlyph] = LE_SET_GLYPH(thisGlyph, newGlyph);
    }

    if (flags & cgsSetMark) {
        markGlyph = currGlyph;
    }

    if (!(flags & cgsDontAdvance)) {
        // should handle reverse too!
        currGlyph += 1;
    }

    return newState;
}

void ContextualGlyphSubstitutionProcessor::endStateTable()
{
}

U_NAMESPACE_END