Aaru/Aaru.Images/CisCopy/Identify.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Identify.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies CisCopy disk images.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library 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
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2021 Natalia Portillo
// ****************************************************************************/

using System.IO;
using Aaru.CommonTypes.Interfaces;

namespace Aaru.DiscImages
{
    public sealed partial class CisCopy
    {
        public bool Identify(IFilter imageFilter)
        {
            Stream stream = imageFilter.GetDataForkStream();
            stream.Seek(0, SeekOrigin.Begin);

            var  type = (DiskType)stream.ReadByte();
            byte tracks;

            switch(type)
            {
                case DiskType.MD1DD8:
                case DiskType.MD1DD:
                case DiskType.MD2DD8:
                case DiskType.MD2DD:
                    tracks = 80;

                    break;
                case DiskType.MF2DD:
                case DiskType.MD2HD:
                case DiskType.MF2HD:
                    tracks = 160;

                    break;
                default: return false;
            }

            byte[] trackBytes = new byte[tracks];
            stream.Read(trackBytes, 0, tracks);

            for(int i = 0; i < tracks; i++)
                if(trackBytes[i] != (byte)TrackType.Copied  &&
                   trackBytes[i] != (byte)TrackType.Omitted &&
                   trackBytes[i] != (byte)TrackType.OmittedAlternate)
                    return false;

            var cmpr = (Compression)stream.ReadByte();

            if(cmpr != Compression.None   &&
               cmpr != Compression.Normal &&
               cmpr != Compression.High)
                return false;

            switch(type)
            {
                case DiskType.MD1DD8:
                    if(stream.Length > (40 * 1 * 8 * 512) + 82)
                        return false;

                    break;
                case DiskType.MD1DD:
                    if(stream.Length > (40 * 1 * 9 * 512) + 82)
                        return false;

                    break;
                case DiskType.MD2DD8:
                    if(stream.Length > (40 * 2 * 8 * 512) + 82)
                        return false;

                    break;
                case DiskType.MD2DD:
                    if(stream.Length > (40 * 2 * 9 * 512) + 82)
                        return false;

                    break;
                case DiskType.MF2DD:
                    if(stream.Length > (80 * 2 * 9 * 512) + 162)
                        return false;

                    break;
                case DiskType.MD2HD:
                    if(stream.Length > (80 * 2 * 15 * 512) + 162)
                        return false;

                    break;
                case DiskType.MF2HD:
                    if(stream.Length > (80 * 2 * 18 * 512) + 162)
                        return false;

                    break;
            }

            return true;
        }
    }
}