using DTS.Serialization.IRIGCH10.Enums;
using DTS.Serialization.IRIGCH10.Packets;
using System;
using System.Collections;
using System.Text;

namespace DTS.Serialization.IRIGCH10
{
    /// <summary>
    /// the TMATS packet in the ch10 file is
    /// a packet containing the setup file, a description of
    /// what channels, das, time formats, etc are used in the file
    /// </summary>
    public class TMATSPacket : AbstractDataPacket, IDataPacket
    {
        /// <summary>
        /// whether the TMATS is in XML or ASCII format
        /// </summary>
        public bool XMLFormat
        {
            get
            {
                var b = new BitArray(BitConverter.GetBytes(ChannelSpecificDataWord));
                return b.Get(9);
            }
        }
        /// <summary>
        /// whether the setup record has changed or not
        /// </summary>
        public bool SetupRecordConfigurationChange
        {
            get
            {
                var b = new BitArray(BitConverter.GetBytes(ChannelSpecificDataWord));
                return b.Get(8);
            }
        }
        /// <summary>
        /// the chapter 10 version of the TMATS file
        /// </summary>
        public RCCChapter10Versions Chapter10Version
        {
            get
            {
                var b = new BitArray(BitConverter.GetBytes(ChannelSpecificDataWord));
                var ver = Utils.Utils.BitArrayToInt32(b, 0, 7);
                switch (ver)
                {
                    case 0x07: return RCCChapter10Versions.RCC_106_07;
                    case 0x08: return RCCChapter10Versions.RCC_106_09;
                    case 0x09: return RCCChapter10Versions.RCC_106_11;
                    case 0x0A: return RCCChapter10Versions.RCC_106_13;
                    case 0x0B: return RCCChapter10Versions.RCC_106_15;
                    default: return RCCChapter10Versions.RESERVED;
                }
            }
        }
        public enum RCCChapter10Versions
        {
            RESERVED,
            RCC_106_07,
            RCC_106_09,
            RCC_106_11,
            RCC_106_13,
            RCC_106_15
        }
        private const byte DataVersionNoSecondaryHeader = 0x01;
        private const byte DataVersionSecondaryHeader = 0x09;
        public TMATSPacket(int nanoseconds, int seconds, string tmatsDoc, bool secondaryHeaderPresent)
            : base(DataFileDataTypes.ComputerGeneratedDataFormat1, secondaryHeaderPresent)
        {
            var tmatsBytes = Encoding.ASCII.GetBytes(tmatsDoc);
            var dataLength = Convert.ToUInt32(4 + tmatsBytes.Length); ;
            var offset = CommonHeaderWork(0, secondaryHeaderPresent ? DataVersionSecondaryHeader : DataVersionNoSecondaryHeader,
                1, BASE_RTC, dataLength, nanoseconds, seconds);
            Buffer.BlockCopy(tmatsBytes, 0, _dataBytes, offset, tmatsBytes.Length);
        }

        public TMATSPacket(byte[] bytes) : base(bytes)
        {
        }
        /// <summary>
        /// the TMATS document
        /// </summary>
        public string TMATSDocument
        {
            get
            {
                //the document is prepended by a ChannelSpecificDataWord and potentially a time header
                var prepend = 4; //CSDW
                if (PacketHeader.SecondaryHeaderPresent) { prepend += SecondaryTimeFormatHeader.SECONDARY_TIME_HEADER_LENGTH; }
                var length = PacketHeader.DataLength - prepend;
                var bytes = new byte[length];
                Buffer.BlockCopy(_dataBytes, prepend, bytes, 0, bytes.Length);
                return Encoding.ASCII.GetString(bytes);
            }
        }
    }
}