﻿/* ====================================================================
   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.
==================================================================== */

/* ================================================================
 * About NPOI
 * Author: Tony Qu 
 * Author's email: tonyqus (at) gmail.com 
 * Author's Blog: tonyqus.wordpress.com.cn (wp.tonyqus.cn)
 * HomePage: http://www.codeplex.com/npoi
 * Contributors:
 * 
 * ==============================================================*/

using System;

namespace NPOI.POIFS.Common
{
    /// <summary>
    /// A repository for constants shared by POI classes.
    /// @author Marc Johnson (mjohnson at apache dot org)
    /// </summary>
    internal class POIFSConstants
    {
        /** Most files use 512 bytes as their big block size */
        public const int SMALLER_BIG_BLOCK_SIZE = 0x0200;

        public static POIFSBigBlockSize SMALLER_BIG_BLOCK_SIZE_DETAILS =
       new POIFSBigBlockSize(SMALLER_BIG_BLOCK_SIZE, (short)9);
        /** Some use 4096 bytes */
        public const int LARGER_BIG_BLOCK_SIZE = 0x1000;
        public static POIFSBigBlockSize LARGER_BIG_BLOCK_SIZE_DETAILS =
           new POIFSBigBlockSize(LARGER_BIG_BLOCK_SIZE, (short)12);
        /** Most files use 512 bytes as their big block size */
        //[Obsolete]
        public const int BIG_BLOCK_SIZE = 0x0200;

        /** Most files use 512 bytes as their big block size */
        //[Obsolete]
        public const int MINI_BLOCK_SIZE = 64;
        /** How big a block in the small block stream is. Fixed size */
        public const int SMALL_BLOCK_SIZE = 0x0040;

        /** How big a single property is */
        public const int PROPERTY_SIZE = 0x0080;
        /** 
         * The minimum size of a document before it's stored using 
         *  Big Blocks (normal streams). Smaller documents go in the 
         *  Mini Stream (SBAT / Small Blocks)
         */
        public const int BIG_BLOCK_MINIMUM_DOCUMENT_SIZE = 0x1000;

        /** The highest sector number you're allowed, 0xFFFFFFFA */
        public const int LARGEST_REGULAR_SECTOR_NUMBER = -5;
        /** Indicates the sector holds a FAT block (0xFFFFFFFD) */
        public const int FAT_SECTOR_BLOCK = -3;
        /** Indicates the sector holds a DIFAT block (0xFFFFFFFC) */
        public const int DIFAT_SECTOR_BLOCK = -4;
        /** Indicates the sector is the end of a chain (0xFFFFFFFE) */
        public const int END_OF_CHAIN = -2;
        /** Indicates the sector is not used (0xFFFFFFFF) */
        public const int UNUSED_BLOCK = -1;
        /** The first 4 bytes of an OOXML file, used in detection */
        public static byte[] OOXML_FILE_HEADER =
            new byte[] { 0x50, 0x4b, 0x03, 0x04 };
    }
}
