// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Session.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes CD session 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 © 2011-2016 Natalia Portillo
// ****************************************************************************/

using System;
using DiscImageChef.Console;
using System.Text;

namespace DiscImageChef.Decoders.CD
{
    /// <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 Session
    {
        public struct CDSessionInfo
        {
            /// <summary>
            /// Total size of returned session information minus this field
            /// </summary>
            public UInt16 DataLength;
            /// <summary>
            /// First track number in hex
            /// </summary>
            public byte FirstCompleteSession;
            /// <summary>
            /// Last track number in hex
            /// </summary>
            public byte LastCompleteSession;
            /// <summary>
            /// Track descriptors
            /// </summary>
            public TrackDataDescriptor[] TrackDescriptors;
        }

        public struct TrackDataDescriptor
        {
            /// <summary>
            /// Byte 0
            /// Reserved
            /// </summary>
            public byte Reserved1;
            /// <summary>
            /// Byte 1, bits 7 to 4
            /// Type of information in Q subchannel of block where this TOC entry was found
            /// </summary>
            public byte ADR;
            /// <summary>
            /// Byte 1, bits 3 to 0
            /// Track attributes
            /// </summary>
            public byte CONTROL;
            /// <summary>
            /// Byte 2
            /// First track number in last complete session
            /// </summary>
            public byte TrackNumber;
            /// <summary>
            /// Byte 3
            /// Reserved
            /// </summary>
            public byte Reserved2;
            /// <summary>
            /// Bytes 4 to 7
            /// First track number in last complete session start address in LBA or in MSF
            /// </summary>
            public UInt32 TrackStartAddress;
        }

        public static CDSessionInfo? Decode(byte[] CDSessionInfoResponse)
        {
            if(CDSessionInfoResponse == null)
                return null;

            CDSessionInfo decoded = new CDSessionInfo();

            BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;

            decoded.DataLength = BigEndianBitConverter.ToUInt16(CDSessionInfoResponse, 0);
            decoded.FirstCompleteSession = CDSessionInfoResponse[2];
            decoded.LastCompleteSession = CDSessionInfoResponse[3];
            decoded.TrackDescriptors = new TrackDataDescriptor[(decoded.DataLength - 2) / 8];

            if(decoded.DataLength + 2 != CDSessionInfoResponse.Length)
            {
                DicConsole.DebugWriteLine("CD Session Info decoder", "Expected CDSessionInfo size ({0} bytes) is not received size ({1} bytes), not decoding", decoded.DataLength + 2, CDSessionInfoResponse.Length);
                return null;
            }

            for(int i = 0; i < ((decoded.DataLength - 2) / 8); i++)
            {
                decoded.TrackDescriptors[i].Reserved1 = CDSessionInfoResponse[0 + i * 8 + 4];
                decoded.TrackDescriptors[i].ADR = (byte)((CDSessionInfoResponse[1 + i * 8 + 4] & 0xF0) >> 4);
                decoded.TrackDescriptors[i].CONTROL = (byte)(CDSessionInfoResponse[1 + i * 8 + 4] & 0x0F);
                decoded.TrackDescriptors[i].TrackNumber = CDSessionInfoResponse[2 + i * 8 + 4];
                decoded.TrackDescriptors[i].Reserved2 = CDSessionInfoResponse[3 + i * 8 + 4];
                decoded.TrackDescriptors[i].TrackStartAddress = BigEndianBitConverter.ToUInt32(CDSessionInfoResponse, 4 + i * 8 + 4);
            }

            return decoded;
        }

        public static string Prettify(CDSessionInfo? CDSessionInfoResponse)
        {
            if(CDSessionInfoResponse == null)
                return null;

            CDSessionInfo response = CDSessionInfoResponse.Value;

            StringBuilder sb = new StringBuilder();

            sb.AppendFormat("First complete session number: {0}", response.FirstCompleteSession).AppendLine();
            sb.AppendFormat("Last complete session number: {0}", response.LastCompleteSession).AppendLine();
            foreach(TrackDataDescriptor descriptor in response.TrackDescriptors)
            {
                sb.AppendFormat("First track number in last complete session: {0}", descriptor.TrackNumber).AppendLine();
                sb.AppendFormat("Track starts at LBA {0}, or MSF {1:X2}:{2:X2}:{3:X2}", descriptor.TrackStartAddress,
                    (descriptor.TrackStartAddress & 0x0000FF00) >> 8,
                    (descriptor.TrackStartAddress & 0x00FF0000) >> 16,
                    (descriptor.TrackStartAddress & 0xFF000000) >> 24).AppendLine();

                switch((TOC_ADR)descriptor.ADR)
                {
                    case TOC_ADR.NoInformation:
                        sb.AppendLine("Q subchannel mode not given");
                        break;
                    case TOC_ADR.CurrentPosition:
                        sb.AppendLine("Q subchannel stores current position");
                        break;
                    case TOC_ADR.ISRC:
                        sb.AppendLine("Q subchannel stores ISRC");
                        break;
                    case TOC_ADR.MediaCatalogNumber:
                        sb.AppendLine("Q subchannel stores media catalog number");
                        break;
                }

                if((descriptor.CONTROL & (byte)TOC_CONTROL.ReservedMask) == (byte)TOC_CONTROL.ReservedMask)
                    sb.AppendFormat("Reserved flags 0x{0:X2} set", descriptor.CONTROL).AppendLine();
                else
                {
                    switch((TOC_CONTROL)(descriptor.CONTROL & 0x0D))
                    {
                        case TOC_CONTROL.TwoChanNoPreEmph:
                            sb.AppendLine("Stereo audio track with no pre-emphasis");
                            break;
                        case TOC_CONTROL.TwoChanPreEmph:
                            sb.AppendLine("Stereo audio track with 50/15 μs pre-emphasis");
                            break;
                        case TOC_CONTROL.FourChanNoPreEmph:
                            sb.AppendLine("Quadraphonic audio track with no pre-emphasis");
                            break;
                        case TOC_CONTROL.FourChanPreEmph:
                            sb.AppendLine("Stereo audio track with 50/15 μs pre-emphasis");
                            break;
                        case TOC_CONTROL.DataTrack:
                            sb.AppendLine("Data track, recorded uninterrupted");
                            break;
                        case TOC_CONTROL.DataTrackIncremental:
                            sb.AppendLine("Data track, recorded incrementally");
                            break;
                    }

                    if((descriptor.CONTROL & (byte)TOC_CONTROL.CopyPermissionMask) == (byte)TOC_CONTROL.CopyPermissionMask)
                        sb.AppendLine("Digital copy of track is permitted");
                    else
                        sb.AppendLine("Digital copy of track is prohibited");

#if DEBUG
                    if(descriptor.Reserved1 != 0)
                        sb.AppendFormat("Reserved1 = 0x{0:X2}", descriptor.Reserved1).AppendLine();
                    if(descriptor.Reserved2 != 0)
                        sb.AppendFormat("Reserved2 = 0x{0:X2}", descriptor.Reserved2).AppendLine();
#endif

                    sb.AppendLine();
                }
            }

            return sb.ToString();
        }

        public static string Prettify(byte[] CDSessionInfoResponse)
        {
            CDSessionInfo? decoded = Decode(CDSessionInfoResponse);
            return Prettify(decoded);
        }
    }
}