// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Cartridge.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes DVD cartridge 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 © 2011-2019 Natalia Portillo
// ****************************************************************************/

using System.Diagnostics.CodeAnalysis;
using System.Text;

namespace DiscImageChef.Decoders.DVD
{
    /// <summary>
    ///     Information from the following standards:
    ///     ANSI X3.304-1997
    ///     T10/1048-D revision 9.0
    ///     T10/1048-D revision 10a
    ///     T10/1228-D revision 7.0c
    ///     T10/1228-D revision 11a
    ///     T10/1363-D revision 10g
    ///     T10/1545-D revision 1d
    ///     T10/1545-D revision 5
    ///     T10/1545-D revision 5a
    ///     T10/1675-D revision 2c
    ///     T10/1675-D revision 4
    ///     T10/1836-D revision 2g
    /// </summary>
    [SuppressMessage("ReSharper", "InconsistentNaming")]
    [SuppressMessage("ReSharper", "MemberCanBeInternal")]
    [SuppressMessage("ReSharper", "MemberCanBePrivate.Global")]
    [SuppressMessage("ReSharper", "NotAccessedField.Global")]
    public static class Cartridge
    {
        public struct MediumStatus
        {
            /// <summary>
            ///     Bytes 0 to 1
            ///     Data length
            /// </summary>
            public ushort DataLength;
            /// <summary>
            ///     Byte 2
            ///     Reserved
            /// </summary>
            public byte Reserved1;
            /// <summary>
            ///     Byte 3
            ///     Reserved
            /// </summary>
            public byte Reserved2;
            /// <summary>
            ///     Byte 4, bit 7
            ///     Medium is in a cartridge
            /// </summary>
            public bool Cartridge;
            /// <summary>
            ///     Byte 4, bit 6
            ///     Medium has been taken out/inserted in a cartridge
            /// </summary>
            public bool OUT;
            /// <summary>
            ///     Byte 4, bits 5 to 4
            ///     Reserved
            /// </summary>
            public byte Reserved3;
            /// <summary>
            ///     Byte 4, bit 3
            ///     Media is write protected by reason stablished in RAMSWI
            /// </summary>
            public bool MSWI;
            /// <summary>
            ///     Byte 4, bit 2
            ///     Media is write protected by cartridge
            /// </summary>
            public bool CWP;
            /// <summary>
            ///     Byte 4, bit 1
            ///     Media is persistently write protected
            /// </summary>
            public bool PWP;
            /// <summary>
            ///     Byte 4, bit 0
            ///     Reserved
            /// </summary>
            public bool Reserved4;
            /// <summary>
            ///     Byte 5
            ///     Writable status depending on cartridge
            /// </summary>
            public byte DiscType;
            /// <summary>
            ///     Byte 6
            ///     Reserved
            /// </summary>
            public byte Reserved5;
            /// <summary>
            ///     Byte 7
            ///     Reason of specific write protection, only defined 0x01 as "bare disc wp", and 0xFF as unspecified. Rest reserved.
            /// </summary>
            public byte RAMSWI;
        }

        public static MediumStatus? Decode(byte[] response)
        {
            if(response?.Length != 8) return null;

            return new MediumStatus
            {
                DataLength = (ushort)((response[0] << 8) + response[1]),
                Reserved1  = response[2],
                Reserved2  = response[3],
                Cartridge  = (response[4] & 0x80) == 0x80,
                OUT        = (response[4] & 0x40) == 0x40,
                Reserved3  = (byte)((response[4] & 0x30) >> 4),
                MSWI       = (response[4] & 0x08) == 0x08,
                CWP        = (response[4] & 0x04) == 0x04,
                PWP        = (response[4] & 0x02) == 0x02,
                Reserved4  = (response[4] & 0x01) == 0x01,
                DiscType   = response[5],
                Reserved5  = response[6],
                RAMSWI     = response[7]
            };
        }

        public static string Prettify(MediumStatus? status)
        {
            if(status == null) return null;

            MediumStatus  decoded = status.Value;
            StringBuilder sb      = new StringBuilder();

            if(decoded.PWP) sb.AppendLine("Disc surface is set to write protected status");

            if(decoded.Cartridge)
            {
                sb.AppendLine("Disc comes in a cartridge");
                if(decoded.OUT) sb.AppendLine("Disc has been extracted from the cartridge");
                if(decoded.CWP) sb.AppendLine("Cartridge is set to write protected");
            }

            switch(decoded.DiscType)
            {
                case 0:
                    sb.AppendLine("Disc shall not be written without a cartridge");
                    break;
                case 0x10:
                    sb.AppendLine("Disc may be written without a cartridge");
                    break;
                default:
                    sb.AppendFormat("Unknown disc type id {0}", decoded.DiscType).AppendLine();
                    break;
            }

            if(!decoded.MSWI) return sb.ToString();

            switch(decoded.RAMSWI)
            {
                case 0: break;
                case 1:
                    sb.AppendLine("Disc is write inhibited because it has been extracted from the cartridge");
                    break;
                case 0xFF:
                    sb.AppendLine("Disc is write inhibited for an unspecified reason");
                    break;
                default:
                    sb.AppendFormat("Disc has unknown reason {0} for write inhibition", decoded.RAMSWI).AppendLine();
                    break;
            }

            return sb.ToString();
        }

        public static string Prettify(byte[] response) => Prettify(Decode(response));
    }
}