// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : CDi.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : ISO9660 filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     CD-i extensions structures.
//
// --[ 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
// In the loving memory of Facunda "Tata" Suárez Domínguez, R.I.P. 2019/07/24
// ****************************************************************************/

using System;
using System.Runtime.InteropServices;
using Aaru.Helpers;

namespace Aaru.Filesystems
{
    public sealed partial class ISO9660
    {
        static DecodedVolumeDescriptor DecodeVolumeDescriptor(FileStructureVolumeDescriptor pvd)
        {
            var decodedVd = new DecodedVolumeDescriptor
            {
                SystemIdentifier       = StringHandlers.CToString(pvd.system_id).TrimEnd(),
                VolumeIdentifier       = StringHandlers.CToString(pvd.volume_id).TrimEnd(),
                VolumeSetIdentifier    = StringHandlers.CToString(pvd.volume_set_id).TrimEnd(),
                PublisherIdentifier    = StringHandlers.CToString(pvd.publisher_id).TrimEnd(),
                DataPreparerIdentifier = StringHandlers.CToString(pvd.preparer_id).TrimEnd(),
                ApplicationIdentifier  = StringHandlers.CToString(pvd.application_data).TrimEnd()
            };

            if(pvd.creation_date[0] == '0' ||
               pvd.creation_date[0] == 0x00)
                decodedVd.CreationTime = DateTime.MinValue;
            else
                decodedVd.CreationTime = DateHandlers.HighSierraToDateTime(pvd.creation_date);

            if(pvd.modification_date[0] == '0' ||
               pvd.modification_date[0] == 0x00)
                decodedVd.HasModificationTime = false;
            else
            {
                decodedVd.HasModificationTime = true;
                decodedVd.ModificationTime    = DateHandlers.HighSierraToDateTime(pvd.modification_date);
            }

            if(pvd.expiration_date[0] == '0' ||
               pvd.expiration_date[0] == 0x00)
                decodedVd.HasExpirationTime = false;
            else
            {
                decodedVd.HasExpirationTime = true;
                decodedVd.ExpirationTime    = DateHandlers.HighSierraToDateTime(pvd.expiration_date);
            }

            if(pvd.effective_date[0] == '0' ||
               pvd.effective_date[0] == 0x00)
                decodedVd.HasEffectiveTime = false;
            else
            {
                decodedVd.HasEffectiveTime = true;
                decodedVd.EffectiveTime    = DateHandlers.HighSierraToDateTime(pvd.effective_date);
            }

            decodedVd.Blocks    = pvd.volume_space_size;
            decodedVd.BlockSize = pvd.logical_block_size;

            return decodedVd;
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        readonly struct FileStructureVolumeDescriptor
        {
            public readonly byte type;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
            public readonly byte[] id;
            public readonly byte           version;
            public readonly CdiVolumeFlags flags;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] system_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] volume_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
            public readonly byte[] reserved1;
            public readonly uint volume_space_size;

            // Only used in SVDs
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] escape_sequences;
            public readonly ushort reserved2;
            public readonly ushort volume_set_size;
            public readonly ushort reserved3;
            public readonly ushort volume_sequence_number;
            public readonly ushort reserved4;
            public readonly ushort logical_block_size;
            public readonly uint   reserved5;
            public readonly uint   path_table_size;
            public readonly ulong  reserved6;
            public readonly uint   path_table_addr;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 38)]
            public readonly byte[] reserved7;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]
            public readonly byte[] volume_set_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]
            public readonly byte[] publisher_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]
            public readonly byte[] preparer_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]
            public readonly byte[] application_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] copyright_file_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
            public readonly byte[] reserved8;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] abstract_file_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
            public readonly byte[] reserved9;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public readonly byte[] bibliographic_file_id;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
            public readonly byte[] reserved10;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public readonly byte[] creation_date;
            public readonly byte reserved11;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public readonly byte[] modification_date;
            public readonly byte reserved12;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public readonly byte[] expiration_date;
            public readonly byte reserved13;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public readonly byte[] effective_date;
            public readonly byte reserved14;
            public readonly byte file_structure_version;
            public readonly byte reserved15;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 512)]
            public readonly byte[] application_data;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 653)]
            public readonly byte[] reserved16;
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        readonly struct CdiDirectoryRecord
        {
            public readonly byte                length;
            public readonly byte                xattr_len;
            public readonly uint                reserved1;
            public readonly uint                start_lbn;
            public readonly uint                reserved2;
            public readonly uint                size;
            public readonly HighSierraTimestamp date;
            public readonly byte                reserved3;
            public readonly CdiFileFlags        flags;
            public readonly ushort              file_unit_size;
            public readonly ushort              reserved4;
            public readonly ushort              volume_sequence_number;
            public readonly byte                name_len;

            // Followed by name[name_len] and then CdiSystemArea until length arrives
        }

        // Follows filename on directory record
        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        readonly struct CdiSystemArea
        {
            public readonly ushort        group;
            public readonly ushort        owner;
            public readonly CdiAttributes attributes;
            public readonly ushort        reserved1;
            public readonly byte          file_no;
            public readonly byte          reserved2;
        }
    }
}