/* ====================================================================
     Licensed to the Apache Software Foundation (ASF) under one or more
     contributor license agreements.    See the NOTICE file distributed with
     this work for additional information regarding copyright ownership.
     The ASF licenses this file to You under the Apache License, Version 2.0
     (the "License"); you may not use this file except in compliance with
     the License.    You may obtain a copy of the License at

             http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
==================================================================== */

package org.apache.poi.hwpf.model;


import org.apache.poi.hwpf.sprm.ParagraphSprmUncompressor;
import org.apache.poi.hwpf.sprm.SprmBuffer;
import org.apache.poi.hwpf.sprm.SprmOperation;
import org.apache.poi.hwpf.usermodel.ParagraphProperties;
import org.apache.poi.util.Internal;
import org.apache.poi.util.LittleEndian;

/**
 * DANGER - works in bytes!
 *
 * Make sure you call getStart() / getEnd() when you want characters
 *    (normal use), but getStartByte() / getEndByte() when you're
 *    reading in / writing out!
 */
@Internal
@SuppressWarnings( "deprecation" )
public final class PAPX extends BytePropertyNode<PAPX> {

    private ParagraphHeight _phe;

    public PAPX(PAPX other) {
        super(other);
        _phe = (other._phe == null) ? null : other._phe.copy();
    }

    public PAPX( int charStart, int charEnd, byte[] papx, ParagraphHeight phe,
            byte[] dataStream )
    {
        super( charStart, charEnd, new SprmBuffer( papx, 2 ) );
        _phe = phe;
        SprmBuffer buf = findHuge( new SprmBuffer( papx, 2 ), dataStream );
        if ( buf != null )
            _buf = buf;
    }

    public PAPX( int charStart, int charEnd, SprmBuffer buf )
    {
        super( charStart, charEnd, buf );
        _phe = new ParagraphHeight();
    }

    private SprmBuffer findHuge(SprmBuffer buf, byte[] datastream)
    {
        byte[] grpprl = buf.toByteArray();
        if(grpprl.length==8 && datastream!=null) // then check for sprmPHugePapx
        {
            SprmOperation sprm = new SprmOperation(grpprl, 2);
            if ((sprm.getOperation()==0x45 || sprm.getOperation()==0x46)
                    && sprm.getSizeCode() == 3)
            {
                int hugeGrpprlOffset = sprm.getOperand();
                if(hugeGrpprlOffset+1 < datastream.length)
                {
                    int grpprlSize = LittleEndian.getShort(datastream, hugeGrpprlOffset);
                    if( hugeGrpprlOffset+grpprlSize < datastream.length)
                    {
                        byte[] hugeGrpprl = new byte[grpprlSize + 2];
                        // copy original istd into huge Grpprl
                        hugeGrpprl[0] = grpprl[0]; hugeGrpprl[1] = grpprl[1];
                        // copy Grpprl from dataStream
                        System.arraycopy(datastream, hugeGrpprlOffset + 2, hugeGrpprl, 2,
                                                         grpprlSize);
                        return new SprmBuffer(hugeGrpprl, 2);
                    }
                }
            }
        }
        return null;
    }


    public ParagraphHeight getParagraphHeight()
    {
        return _phe;
    }

    public byte[] getGrpprl()
    {
        if (_buf == null)
            return new byte[0];

        return ((SprmBuffer)_buf).toByteArray();
    }

    public short getIstd()
    {
        if ( _buf == null )
            return 0;

        byte[] buf = getGrpprl();
        if (buf.length == 0)
        {
            return 0;
        }
        if (buf.length == 1)
        {
            return LittleEndian.getUByte(buf, 0);
        }
        return LittleEndian.getShort(buf);
    }

    public SprmBuffer getSprmBuf()
    {
        return (SprmBuffer)_buf;
    }

    @Deprecated
    @Internal
    public ParagraphProperties getParagraphProperties(StyleSheet ss)
    {
        if(ss == null) {
            // TODO Fix up for Word 6/95
            return new ParagraphProperties();
        }

        short istd = getIstd();
        ParagraphProperties baseStyle = ss.getParagraphStyle(istd);
        return ParagraphSprmUncompressor.uncompressPAP(baseStyle, getGrpprl(), 2);
    }

    @Override
    public boolean equals(Object o)
    {
        if (super.equals(o))
        {
            return _phe.equals(((PAPX)o)._phe);
        }
        return false;
    }

    @Override
    public int hashCode() {
        assert false : "hashCode not designed";
        return 42; // any arbitrary constant will do
    }

    public String toString()
    {
        return "PAPX from " + getStart() + " to " + getEnd() + " (in bytes "
                            + getStartBytes() + " to " + getEndBytes() + ")";
    }

    @Override
    public PAPX copy() {
        return new PAPX(this);
    }
}