// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Hybrid.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MMC's hybrid 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 © 2011-2018 Natalia Portillo
// ****************************************************************************/

using System;
using System.Text;

namespace DiscImageChef.Decoders.SCSI.MMC
{
    /// <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>
    public static class Hybrid
    {
        public struct RecognizedFormatLayers
        {
            /// <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
            /// Number of format layers in hybrid disc identified by drive
            /// </summary>
            public byte NumberOfLayers;
            /// <summary>
            /// Byte 5, bits 7 to 6
            /// Reserved
            /// </summary>
            public byte Reserved3;
            /// <summary>
            /// Byte 5, bits 5 to 4
            /// Layer no. used when disc is inserted
            /// </summary>
            public byte DefaultFormatLayer;
            /// <summary>
            /// Byte 5, bits 3 to 2
            /// Reserved
            /// </summary>
            public byte Reserved4;
            /// <summary>
            /// Byte 5, bits 1 to 0
            /// Layer no. currently in use
            /// </summary>
            public byte OnlineFormatLayer;
            /// <summary>
            /// Bytes 6 to end
            /// Recognized format layers
            /// </summary>
            public ushort[] FormatLayers;
        }

        public static RecognizedFormatLayers? DecodeFormatLayers(byte[] FormatLayersResponse)
        {
            if(FormatLayersResponse == null)
                return null;

            if(FormatLayersResponse.Length < 8)
                return null;

            RecognizedFormatLayers decoded = new RecognizedFormatLayers();

            BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;

            decoded.DataLength = BigEndianBitConverter.ToUInt16(FormatLayersResponse, 0);
            decoded.Reserved1 = FormatLayersResponse[2];
            decoded.Reserved2 = FormatLayersResponse[3];
            decoded.NumberOfLayers = FormatLayersResponse[4];
            decoded.Reserved3 = (byte)((FormatLayersResponse[5] & 0xC0) >> 6);
            decoded.DefaultFormatLayer = (byte)((FormatLayersResponse[5] & 0x30) >> 4);
            decoded.Reserved4 = (byte)((FormatLayersResponse[5] & 0x0C) >> 2);
            decoded.OnlineFormatLayer = (byte)(FormatLayersResponse[5] & 0x03);

            decoded.FormatLayers = new ushort[(FormatLayersResponse.Length - 6) / 2];

            for(int i = 0; i < (FormatLayersResponse.Length - 6) / 2; i++)
            {
                decoded.FormatLayers[i] = BigEndianBitConverter.ToUInt16(FormatLayersResponse, i * 2 + 6);
            }

            return decoded;
        }

        public static string PrettifyFormatLayers(RecognizedFormatLayers? FormatLayersResponse)
        {
            if(FormatLayersResponse == null)
                return null;

            RecognizedFormatLayers response = FormatLayersResponse.Value;

            StringBuilder sb = new StringBuilder();

            sb.AppendFormat("{0} format layers recognized", response.NumberOfLayers);

            for(int i = 0; i < response.FormatLayers.Length; i++)
            {
                switch(response.FormatLayers[i])
                {
                    case (ushort)FormatLayerTypeCodes.BDLayer:
                        {
                            sb.AppendFormat("Layer {0} is of type Blu-ray", i).AppendLine();
                            if(response.DefaultFormatLayer == i)
                                sb.AppendLine("This is the default layer.");
                            if(response.OnlineFormatLayer == i)
                                sb.AppendLine("This is the layer actually in use.");
                            break;
                        }
                    case (ushort)FormatLayerTypeCodes.CDLayer:
                        {
                            sb.AppendFormat("Layer {0} is of type CD", i).AppendLine();
                            if(response.DefaultFormatLayer == i)
                                sb.AppendLine("This is the default layer.");
                            if(response.OnlineFormatLayer == i)
                                sb.AppendLine("This is the layer actually in use.");
                            break;
                        }
                    case (ushort)FormatLayerTypeCodes.DVDLayer:
                        {
                            sb.AppendFormat("Layer {0} is of type DVD", i).AppendLine();
                            if(response.DefaultFormatLayer == i)
                                sb.AppendLine("This is the default layer.");
                            if(response.OnlineFormatLayer == i)
                                sb.AppendLine("This is the layer actually in use.");
                            break;
                        }
                    case (ushort)FormatLayerTypeCodes.HDDVDLayer:
                        {
                            sb.AppendFormat("Layer {0} is of type HD DVD", i).AppendLine();
                            if(response.DefaultFormatLayer == i)
                                sb.AppendLine("This is the default layer.");
                            if(response.OnlineFormatLayer == i)
                                sb.AppendLine("This is the layer actually in use.");
                            break;
                        }
                    default:
                        {
                            sb.AppendFormat("Layer {0} is of unknown type 0x{1:X4}", i, response.FormatLayers[i]).AppendLine();
                            if(response.DefaultFormatLayer == i)
                                sb.AppendLine("This is the default layer.");
                            if(response.OnlineFormatLayer == i)
                                sb.AppendLine("This is the layer actually in use.");
                            break;
                        }
                }
            }

            return sb.ToString();
        }

        public static string PrettifyFormatLayers(byte[] FormatLayersResponse)
        {
            RecognizedFormatLayers? decoded = DecodeFormatLayers(FormatLayersResponse);
            return PrettifyFormatLayers(decoded);
        }
    }
}