/* ====================================================================
   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.hssf.record;

import org.apache.poi.util.LittleEndian;

/**
 * Title:        DBCell Record
 * Description:  Used by Excel and other MS apps to quickly find rows in the sheets.<P>
 * REFERENCE:  PG 299/440 Microsoft Excel 97 Developer's Kit (ISBN: 1-57231-498-2)<P>
 * @author Andrew C. Oliver (acoliver at apache dot org)
 * @author Jason Height
 * @version 2.0-pre
 */

public class DBCellRecord
    extends Record
{
    public final static int BLOCK_SIZE = 32;
    public final static short sid = 0xd7;
    private int               field_1_row_offset;
    private short[]           field_2_cell_offsets;

    public DBCellRecord()
    {
    }

    /**
     * Constructs a DBCellRecord and sets its fields appropriately
     *
     * @param id     id must be 0xd7 or an exception will be throw upon validation
     * @param size  the size of the data area of the record
     * @param data  data of the record (should not contain sid/len)
     */

    public DBCellRecord(RecordInputStream in)
    {
        super(in);
    }

    protected void validateSid(short id)
    {
        if (id != sid)
        {
            throw new RecordFormatException("NOT A valid DBCell RECORD");
        }
    }

    protected void fillFields(RecordInputStream in)
    {
        field_1_row_offset   = in.readUShort();
        int size = in.remaining();        
        field_2_cell_offsets = new short[ size / 2 ];

        for (int i=0;i<field_2_cell_offsets.length;i++)
        {
            field_2_cell_offsets[ i ] = in.readShort();
        }
    }

    /**
     * sets offset from the start of this DBCellRecord to the start of the first cell in
     * the next DBCell block.
     *
     * @param offset    offset to the start of the first cell in the next DBCell block
     */

    public void setRowOffset(int offset)
    {
        field_1_row_offset = offset;
    }

    // need short list impl.
    public void addCellOffset(short offset)
    {
        if (field_2_cell_offsets == null)
        {
            field_2_cell_offsets = new short[ 1 ];
        }
        else
        {
            short[] temp = new short[ field_2_cell_offsets.length + 1 ];

            System.arraycopy(field_2_cell_offsets, 0, temp, 0,
                             field_2_cell_offsets.length);
            field_2_cell_offsets = temp;
        }
        field_2_cell_offsets[ field_2_cell_offsets.length - 1 ] = offset;
    }

    /**
     * gets offset from the start of this DBCellRecord to the start of the first cell in
     * the next DBCell block.
     *
     * @return rowoffset to the start of the first cell in the next DBCell block
     */

    public int getRowOffset()
    {
        return field_1_row_offset;
    }

    /**
     * return the cell offset in the array
     *
     * @param index of the cell offset to retrieve
     * @return celloffset from the celloffset array
     */

    public short getCellOffsetAt(int index)
    {
        return field_2_cell_offsets[ index ];
    }

    /**
     * get the number of cell offsets in the celloffset array
     *
     * @return number of cell offsets
     */

    public int getNumCellOffsets()
    {
        return field_2_cell_offsets.length;
    }

    public String toString()
    {
        StringBuffer buffer = new StringBuffer();

        buffer.append("[DBCELL]\n");
        buffer.append("    .rowoffset       = ")
            .append(Integer.toHexString(getRowOffset())).append("\n");
        for (int k = 0; k < getNumCellOffsets(); k++)
        {
            buffer.append("    .cell_" + k + "          = ")
                .append(Integer.toHexString(getCellOffsetAt(k))).append("\n");
        }
        buffer.append("[/DBCELL]\n");
        return buffer.toString();
    }

    public int serialize(int offset, byte [] data)
    {
        if (field_2_cell_offsets == null)
        {
            field_2_cell_offsets = new short[ 0 ];
        }
        LittleEndian.putShort(data, 0 + offset, sid);
        LittleEndian.putShort(data, 2 + offset,
                              (( short ) (4 + (getNumCellOffsets() * 2))));
        LittleEndian.putInt(data, 4 + offset, getRowOffset());
        for (int k = 0; k < getNumCellOffsets(); k++)
        {
            LittleEndian.putShort(data, 8 + 2*k + offset, getCellOffsetAt(k));
        }
        return getRecordSize();
    }

    public int getRecordSize()
    {
        return 8 + (getNumCellOffsets() * 2);
    }
    
    /** Returns the size of a DBCellRecord when it needs to reference a certain number of rows*/
    public static int getRecordSizeForRows(int rows) {
      return 8 + (rows * 2);
    }

    public short getSid()
    {
        return sid;
    }

    public boolean isInValueSection()
    {
        return true;
    }
}