// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : WriteProtect.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MMC write protection 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 © 2011-2020 Natalia Portillo
// ****************************************************************************/

using System;
using System.Diagnostics.CodeAnalysis;
using System.Text;
using Aaru.Helpers;

namespace Aaru.Decoders.SCSI.MMC
{
    // 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
    [SuppressMessage("ReSharper", "InconsistentNaming"), SuppressMessage("ReSharper", "MemberCanBeInternal"),
     SuppressMessage("ReSharper", "MemberCanBePrivate.Global"), SuppressMessage("ReSharper", "NotAccessedField.Global")]
    public static class WriteProtect
    {
        public static WriteProtectionStatus? DecodeWriteProtectionStatus(byte[] WPSResponse)
        {
            if(WPSResponse == null)
                return null;

            var decoded = new WriteProtectionStatus
            {
                DataLength = BigEndianBitConverter.ToUInt16(WPSResponse, 0),
                Reserved1  = WPSResponse[2],
                Reserved2  = WPSResponse[3],
                Reserved3  = (byte)((WPSResponse[4] & 0xF0) >> 4),
                MSWI       = Convert.ToBoolean(WPSResponse[4] & 0x08),
                CWP        = Convert.ToBoolean(WPSResponse[4] & 0x04),
                PWP        = Convert.ToBoolean(WPSResponse[4] & 0x02),
                SWPP       = Convert.ToBoolean(WPSResponse[4] & 0x01),
                Reserved4  = WPSResponse[5],
                Reserved5  = WPSResponse[6],
                Reserved6  = WPSResponse[7]
            };

            return decoded;
        }

        public static string PrettifyWriteProtectionStatus(WriteProtectionStatus? WPSResponse)
        {
            if(WPSResponse == null)
                return null;

            WriteProtectionStatus response = WPSResponse.Value;

            var sb = new StringBuilder();

            if(response.MSWI)
                sb.AppendLine("Writing inhibited by media specific reason");

            if(response.CWP)
                sb.AppendLine("Cartridge sets write protection");

            if(response.PWP)
                sb.AppendLine("Media surface sets write protection");

            if(response.SWPP)
                sb.AppendLine("Software write protection is set until power down");

        #if DEBUG
            if(response.Reserved1 != 0)
                sb.AppendFormat("Reserved1 = 0x{0:X2}", response.Reserved1).AppendLine();

            if(response.Reserved2 != 0)
                sb.AppendFormat("Reserved2 = 0x{0:X2}", response.Reserved2).AppendLine();

            if(response.Reserved3 != 0)
                sb.AppendFormat("Reserved3 = 0x{0:X2}", response.Reserved3).AppendLine();

            if(response.Reserved4 != 0)
                sb.AppendFormat("Reserved4 = 0x{0:X2}", response.Reserved4).AppendLine();

            if(response.Reserved5 != 0)
                sb.AppendFormat("Reserved5 = 0x{0:X2}", response.Reserved5).AppendLine();

            if(response.Reserved6 != 0)
                sb.AppendFormat("Reserved6 = 0x{0:X2}", response.Reserved6).AppendLine();
        #endif

            return sb.ToString();
        }

        public static string PrettifyWriteProtectionStatus(byte[] WPSResponse)
        {
            WriteProtectionStatus? decoded = DecodeWriteProtectionStatus(WPSResponse);

            return PrettifyWriteProtectionStatus(decoded);
        }

        public struct WriteProtectionStatus
        {
            /// <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, bits 7 to 4 Reserved</summary>
            public byte Reserved3;
            /// <summary>Byte 4, bit 3 Writing inhibited by media specific reason</summary>
            public bool MSWI;
            /// <summary>Byte 4, bit 2 Cartridge sets write protection</summary>
            public bool CWP;
            /// <summary>Byte 4, bit 1 Media surface sets write protection</summary>
            public bool PWP;
            /// <summary>Byte 4, bit 0 Software write protection until power down</summary>
            public bool SWPP;
            /// <summary>Byte 5 Reserved</summary>
            public byte Reserved4;
            /// <summary>Byte 6 Reserved</summary>
            public byte Reserved5;
            /// <summary>Byte 7 Reserved</summary>
            public byte Reserved6;
        }
    }
}