// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : FAT.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Microsoft FAT filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies the Microsoft FAT filesystem and shows information.
//
// --[ 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 © 2011-2023 Natalia Portillo
// ****************************************************************************/

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using Aaru.CommonTypes.Interfaces;
using Aaru.CommonTypes.Structs;
using Schemas;

namespace Aaru.Filesystems
{
    // TODO: Differentiate between Atari and X68k FAT, as this one uses a standard BPB.
    // X68K uses cdate/adate from direntry for extending filename
    /// <inheritdoc />
    /// <summary>Implements the File Allocation Table, aka FAT, filesystem (FAT12, FAT16 and FAT32 variants).</summary>
    public sealed partial class FAT : IReadOnlyFilesystem
    {
        uint                                                           _bytesPerCluster;
        byte[]                                                         _cachedEaData;
        CultureInfo                                                    _cultureInfo;
        bool                                                           _debug;
        Dictionary<string, Dictionary<string, CompleteDirectoryEntry>> _directoryCache;
        DirectoryEntry                                                 _eaDirEntry;
        bool                                                           _fat12;
        bool                                                           _fat16;
        bool                                                           _fat32;
        ushort[]                                                       _fatEntries;
        ulong                                                          _fatFirstSector;
        ulong                                                          _firstClusterSector;
        bool                                                           _mounted;
        Namespace                                                      _namespace;
        uint                                                           _reservedSectors;
        Dictionary<string, CompleteDirectoryEntry>                     _rootDirectoryCache;
        uint                                                           _sectorsPerCluster;
        uint                                                           _sectorsPerFat;
        FileSystemInfo                                                 _statfs;
        bool                                                           _useFirstFat;

        /// <inheritdoc />
        public FileSystemType XmlFsType { get; private set; }
        /// <inheritdoc />
        public Encoding Encoding { get; private set; }
        /// <inheritdoc />
        public string Name => "Microsoft File Allocation Table";
        /// <inheritdoc />
        public Guid Id => new Guid("33513B2C-0D26-0D2D-32C3-79D8611158E0");
        /// <inheritdoc />
        public string Author => "Natalia Portillo";

        /// <inheritdoc />
        public IEnumerable<(string name, Type type, string description)> SupportedOptions =>
            new (string name, Type type, string description)[]
                {};

        /// <inheritdoc />
        public Dictionary<string, string> Namespaces => new Dictionary<string, string>
        {
            {
                "dos", "DOS (8.3 all uppercase)"
            },
            {
                "nt", "Windows NT (8.3 mixed case)"
            },
            {
                "os2", "OS/2 .LONGNAME extended attribute"
            },
            {
                "ecs", "Use LFN when available with fallback to .LONGNAME (default)"
            },
            {
                "lfn", "Long file names"
            }
        };

        static Dictionary<string, string> GetDefaultOptions() => new Dictionary<string, string>
        {
            {
                "debug", false.ToString()
            }
        };
    }
}