/*
 *  ====================================================================
 * 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 java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import org.apache.poi.util.Internal;

/**
 * This class provides access to all the fields Plex.
 */
@Internal
public class FieldsTables
{
    // The size in bytes of the FLD data structure
    private static final int FLD_SIZE = 2;

    /**
     * annotation subdocument
     */
    @Deprecated
    public static final int PLCFFLDATN = 0;

    /**
     * endnote subdocument
     */
    @Deprecated
    public static final int PLCFFLDEDN = 1;
    /**
     * footnote subdocument
     */
    @Deprecated
    public static final int PLCFFLDFTN = 2;
    /**
     * header subdocument
     */
    @Deprecated
    public static final int PLCFFLDHDR = 3;
    /**
     * header textbox subdoc
     */
    @Deprecated
    public static final int PLCFFLDHDRTXBX = 4;
    /**
     * main document
     */
    @Deprecated
    public static final int PLCFFLDMOM = 5;
    /**
     * textbox subdoc
     */
    @Deprecated
    public static final int PLCFFLDTXBX = 6;

    private static ArrayList<PlexOfField> toArrayList( PlexOfCps plexOfCps )
    {
        if ( plexOfCps == null )
            return new ArrayList<>();

        ArrayList<PlexOfField> fields = new ArrayList<>(
                plexOfCps.length());
        for ( int i = 0; i < plexOfCps.length(); i++ )
        {
            GenericPropertyNode propNode = plexOfCps.getProperty( i );
            PlexOfField plex = new PlexOfField( propNode );
            fields.add( plex );
        }

        return fields;
    }

    private Map<FieldsDocumentPart, PlexOfCps> _tables;

    public FieldsTables( byte[] tableStream, FileInformationBlock fib )
    {
        _tables = new HashMap<>(
                FieldsDocumentPart.values().length);

        for ( FieldsDocumentPart part : FieldsDocumentPart.values() )
        {
            final PlexOfCps plexOfCps = readPLCF( tableStream, fib, part );
            _tables.put( part, plexOfCps );
        }
    }

    public ArrayList<PlexOfField> getFieldsPLCF( FieldsDocumentPart part )
    {
        return toArrayList( _tables.get( part ) );
    }

    @Deprecated
    public ArrayList<PlexOfField> getFieldsPLCF( int partIndex )
    {
        return getFieldsPLCF( FieldsDocumentPart.values()[partIndex] );
    }

    private PlexOfCps readPLCF( byte[] tableStream, FileInformationBlock fib,
            FieldsDocumentPart documentPart )
    {
        int start = fib.getFieldsPlcfOffset( documentPart );
        int length = fib.getFieldsPlcfLength( documentPart );

        if ( start <= 0 || length <= 0 )
            return null;

        return new PlexOfCps( tableStream, start, length, FLD_SIZE );
    }

    private int savePlex( FileInformationBlock fib, FieldsDocumentPart part,
            PlexOfCps plexOfCps, ByteArrayOutputStream outputStream )
            throws IOException
    {
        if ( plexOfCps == null || plexOfCps.length() == 0 )
        {
            fib.setFieldsPlcfOffset( part, outputStream.size() );
            fib.setFieldsPlcfLength( part, 0 );
            return 0;
        }

        byte[] data = plexOfCps.toByteArray();

        int start = outputStream.size();
        int length = data.length;

        outputStream.write( data );

        fib.setFieldsPlcfOffset( part, start );
        fib.setFieldsPlcfLength( part, length );

        return length;
    }

    public void write( FileInformationBlock fib, ByteArrayOutputStream tableStream )
            throws IOException
    {
        for ( FieldsDocumentPart part : FieldsDocumentPart.values() )
        {
            PlexOfCps plexOfCps = _tables.get( part );
            savePlex( fib, part, plexOfCps, tableStream );
        }
    }

}