// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : CPM.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : CP/M filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Constructors and common variables for the CP/M filesystem plugin.
//
// --[ 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 © 2011-2024 Natalia Portillo
// ****************************************************************************/

using System;
using System.Collections.Generic;
using System.Text;
using Aaru.CommonTypes.AaruMetadata;
using Aaru.CommonTypes.Interfaces;
using Aaru.CommonTypes.Structs;

namespace Aaru.Filesystems;

/// <inheritdoc />
/// <summary>Implements the CP/M filesystem</summary>
public sealed partial class CPM : IReadOnlyFilesystem
{
    const string MODULE_NAME = "CP/M Plugin";
    /// <summary>True if <see cref="Identify" /> thinks this is a CP/M filesystem</summary>
    bool _cpmFound;

    /// <summary>Cached <see cref="FileSystemInfo" /></summary>
    FileSystemInfo _cpmStat;

    /// <summary>Cached file passwords, decoded</summary>
    Dictionary<string, byte[]> _decodedPasswordCache;

    /// <summary>Stores all known CP/M disk definitions</summary>
    CpmDefinitions _definitions;
    IMediaImage _device;
    /// <summary>Cached directory listing</summary>
    List<string> _dirList;
    /// <summary>CP/M disc parameter block (on-memory)</summary>
    DiscParameterBlock _dpb;
    Encoding _encoding;
    /// <summary>Cached file data</summary>
    Dictionary<string, byte[]> _fileCache;
    /// <summary>The volume label, if the CP/M filesystem contains one</summary>
    string _label;
    /// <summary>Timestamp in volume label for creation</summary>
    byte[] _labelCreationDate;
    /// <summary>Timestamp in volume label for update</summary>
    byte[] _labelUpdateDate;
    bool _mounted;
    /// <summary>Cached file passwords</summary>
    Dictionary<string, byte[]> _passwordCache;
    /// <summary>Sector deinterleaving mask</summary>
    int[] _sectorMask;
    /// <summary>True if there are CP/M 3 timestamps</summary>
    bool _standardTimestamps;
    /// <summary>Cached file <see cref="FileEntryInfo" /></summary>
    Dictionary<string, FileEntryInfo> _statCache;
    /// <summary>True if there are timestamps in Z80DOS or DOS+ format</summary>
    bool _thirdPartyTimestamps;
    /// <summary>If <see cref="Identify" /> thinks this is a CP/M filesystem, this is the definition for it</summary>
    CpmDefinition _workingDefinition;

#region IReadOnlyFilesystem Members

    /// <inheritdoc />
    public FileSystem Metadata { get; private set; }

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

    /// <inheritdoc />
    public Guid Id => new("AA2B8585-41DF-4E3B-8A35-D1A935E2F8A1");

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

    /// <inheritdoc />
    public IEnumerable<(string name, Type type, string description)> SupportedOptions =>
        Array.Empty<(string name, Type type, string description)>();

    /// <inheritdoc />
    public Dictionary<string, string> Namespaces => null;

#endregion
}