// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : DragonFlyBSD.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Partitioning scheme plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Manages DragonFly BSD 64-bit disklabels.
//
// --[ 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;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Marshal = Aaru.Helpers.Marshal;

namespace Aaru.Partitions;

/// <inheritdoc />
/// <summary>Implements decoding of DragonFly BSD disklabels</summary>
[SuppressMessage("ReSharper", "UnusedMember.Local")]
public sealed class DragonFlyBSD : IPartition
{
    const uint DISK_MAGIC64 = 0xC4464C59;

#region IPartition Members

    /// <inheritdoc />
    public string Name => Localization.DragonFlyBSD_Name;

    /// <inheritdoc />
    public Guid Id => new("D49E41A6-D952-4760-9D94-03DAE2450C5F");

    /// <inheritdoc />
    public string Author => Authors.NATALIA_PORTILLO;

    /// <inheritdoc />
    public bool GetInformation(IMediaImage imagePlugin, out List<Partition> partitions, ulong sectorOffset)
    {
        partitions = [];
        uint nSectors = 2048 / imagePlugin.Info.SectorSize;

        if(2048 % imagePlugin.Info.SectorSize > 0) nSectors++;

        if(sectorOffset + nSectors >= imagePlugin.Info.Sectors) return false;

        ErrorNumber errno = imagePlugin.ReadSectors(sectorOffset, false, nSectors, out byte[] sectors, out _);

        if(errno != ErrorNumber.NoError || sectors.Length < 2048) return false;

        Disklabel64 disklabel = Marshal.ByteArrayToStructureLittleEndian<Disklabel64>(sectors);

        if(disklabel.d_magic != 0xC4464C59) return false;

        ulong counter = 0;

        foreach(Partition64 entry in disklabel.d_partitions)
        {
            var part = new Partition
            {
                Start    = entry.p_boffset / imagePlugin.Info.SectorSize + sectorOffset,
                Offset   = entry.p_boffset                               + sectorOffset * imagePlugin.Info.SectorSize,
                Size     = entry.p_bsize,
                Length   = entry.p_bsize / imagePlugin.Info.SectorSize,
                Name     = entry.p_stor_uuid.ToString(),
                Sequence = counter,
                Scheme   = Name,
                Type = (BSD.fsType)entry.p_fstype == BSD.fsType.Other
                           ? entry.p_type_uuid.ToString()
                           : BSD.FSTypeToString((BSD.fsType)entry.p_fstype)
            };

            if(entry.p_bsize % imagePlugin.Info.SectorSize > 0) part.Length++;

            if(entry.p_bsize <= 0 || entry.p_boffset <= 0) continue;

            partitions.Add(part);
            counter++;
        }

        return true;
    }

#endregion

#region Nested type: Disklabel64

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    readonly struct Disklabel64
    {
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 512)]
        public readonly byte[] d_reserved0;
        public readonly uint  d_magic;
        public readonly uint  d_crc;
        public readonly uint  d_align;
        public readonly uint  d_npartitions;
        public readonly Guid  d_stor_uuid;
        public readonly ulong d_total_size;
        public readonly ulong d_bbase;
        public readonly ulong d_pbase;
        public readonly ulong d_pstop;
        public readonly ulong d_abase;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 64)]
        public readonly byte[] d_packname;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 64)]
        public readonly byte[] d_reserved;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
        public readonly Partition64[] d_partitions;
    }

#endregion

#region Nested type: Partition64

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    readonly struct Partition64
    {
        public readonly ulong p_boffset;
        public readonly ulong p_bsize;
        public readonly byte  p_fstype;
        public readonly byte  p_unused01;
        public readonly byte  p_unused02;
        public readonly byte  p_unused03;
        public readonly uint  p_unused04;
        public readonly uint  p_unused05;
        public readonly uint  p_unused06;
        public readonly Guid  p_type_uuid;
        public readonly Guid  p_stor_uuid;
    }

#endregion
}