Aaru/Aaru.Images/RayDIM/Read.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Read.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Reads Ray Arachelian's 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 © 2011-2025 Natalia Portillo
// ****************************************************************************/

using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;

namespace Aaru.Images;

public sealed partial class RayDim
{
#region IWritableImage Members

    /// <inheritdoc />
    public ErrorNumber Open(IFilter imageFilter)
    {
        Stream stream = imageFilter.GetDataForkStream();

        if(stream.Length < Marshal.SizeOf<Header>()) return ErrorNumber.InvalidArgument;

        var buffer = new byte[Marshal.SizeOf<Header>()];
        stream.Seek(0, SeekOrigin.Begin);
        stream.EnsureRead(buffer, 0, buffer.Length);

        Header header = Marshal.ByteArrayToStructureLittleEndian<Header>(buffer);

        string signature = StringHandlers.CToString(header.signature);

        Regex sx = SignatureRegex();
        Match sm = sx.Match(signature);

        if(!sm.Success) return ErrorNumber.InvalidArgument;

        _imageInfo.ApplicationVersion = $"{sm.Groups["major"].Value}.{sm.Groups["minor"].Value}";

        _imageInfo.Cylinders       = (uint)(header.cylinders + 1);
        _imageInfo.Heads           = (uint)(header.heads     + 1);
        _imageInfo.SectorsPerTrack = header.sectorsPerTrack;
        _imageInfo.Sectors         = _imageInfo.Cylinders * _imageInfo.Heads * _imageInfo.SectorsPerTrack;
        _imageInfo.SectorSize      = 512;

        var sectors = new byte[_imageInfo.SectorsPerTrack * _imageInfo.SectorSize];
        _disk = new MemoryStream();

        for(var i = 0; i < _imageInfo.SectorsPerTrack * _imageInfo.SectorSize; i++)
        {
            stream.EnsureRead(sectors, 0, sectors.Length);
            stream.Seek(_imageInfo.SectorsPerTrack, SeekOrigin.Current);
            _disk.Write(sectors, 0, sectors.Length);
        }

        _imageInfo.MediaType = Geometry.GetMediaType(((ushort)_imageInfo.Cylinders, (byte)_imageInfo.Heads,
                                                      (ushort)_imageInfo.SectorsPerTrack, 512, MediaEncoding.MFM,
                                                      false));

        switch(_imageInfo.MediaType)
        {
            case MediaType.NEC_525_HD when header.diskType is RayDiskTypes.Mf2hd or RayDiskTypes.Mf2ed:
                _imageInfo.MediaType = MediaType.NEC_35_HD_8;

                break;
            case MediaType.DOS_525_HD when header.diskType is RayDiskTypes.Mf2hd or RayDiskTypes.Mf2ed:
                _imageInfo.MediaType = MediaType.NEC_35_HD_15;

                break;
            case MediaType.RX50 when header.diskType is RayDiskTypes.Md2dd or RayDiskTypes.Md2hd:
                _imageInfo.MediaType = MediaType.ATARI_35_SS_DD;

                break;
        }

        _imageInfo.MetadataMediaType = MetadataMediaType.BlockMedia;

        return ErrorNumber.NoError;
    }

    /// <inheritdoc />
    public ErrorNumber ReadSector(ulong sectorAddress, bool negative, out byte[] buffer, out SectorStatus sectorStatus)
    {
        sectorStatus = SectorStatus.Dumped;

        return ReadSectors(sectorAddress, negative, 1, out buffer, out _);
    }

    /// <inheritdoc />
    public ErrorNumber ReadSectors(ulong              sectorAddress, bool negative, uint length, out byte[] buffer,
                                   out SectorStatus[] sectorStatus)
    {
        buffer       = null;
        sectorStatus = null;

        if(negative) return ErrorNumber.NotSupported;

        if(sectorAddress > _imageInfo.Sectors - 1) return ErrorNumber.OutOfRange;

        if(sectorAddress + length > _imageInfo.Sectors) return ErrorNumber.OutOfRange;

        buffer       = new byte[length * _imageInfo.SectorSize];
        sectorStatus = Enumerable.Repeat(SectorStatus.Dumped, (int)length).ToArray();


        _disk.Seek((long)(sectorAddress          * _imageInfo.SectorSize), SeekOrigin.Begin);
        _disk.EnsureRead(buffer, 0, (int)(length * _imageInfo.SectorSize));

        return ErrorNumber.NoError;
    }

#endregion
}