using System;
using System.Collections;
using System.Collections.Generic;

namespace DTS.Serialization.IRIGCH10.Packets
{
    /// <summary>
    /// added an analog time format 1 packet for validating exports with EMC
    /// </summary>
    public class TimePacketFormat1 : AbstractDataPacket, IDataPacket
    {
        public enum IRIGTimeSource
        {
            IRIG_TCG_freewheeling,
            IRIG_TCG_freewheeling_from_TIME,
            IRIG_TCG_freewheeling_from_RMM,
            IRIG_TCG_locked_to_external_IRIG,
            IRIG_TCG_locked_to_external_GPS,
            IRIG_TCG_locked_to_external_NetworkTimeProtocol,
            IRIG_TCG_locked_to_external_Precision_Time_Protocol,
            IRIG_TCG_locked_to_external_Embedded,
            RESERVED
        };
        //bits 15-12
        //this is currently not serialized to the CSDW as the EMC validation tool will return errors if the 
        //field is filled in.
        //DTM 2023-10-27
        public IRIGTimeSource ITS
        {
            get; set;
        }

        public enum TimeFormats
        {
            IRIG_B = 0x00,
            IRIG_A = 0x01,
            IRIG_G = 0x02,
            RTC = 0x03,
            UTC = 0x04,
            NativeGPS = 0x05,
            RESERVED = 0x06,
            NONE = 0x0F
        }
        //bits 7-4
        public TimeFormats TimeFormat
        {
            get
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var bits = new BitArray(channelSpecificDataWord);
                var ntf = Utils.Utils.BitArrayToInt32(bits, 4, 7);
                return (TimeFormats)ntf;
            }
            set
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var b = new BitArray(channelSpecificDataWord);
                Utils.Utils.SetBits(b, (uint)value, 4, 7);
                var ret = new byte[sizeof(uint)];
                b.CopyTo(ret, 0);
                ChannelSpecificDataWord = BitConverter.ToUInt32(ret, 0);
            }
        }
        //bits 3-0
        public enum TimeSources
        {
            Internal = 0x00,
            External = 0x01,
            InternalFromRMM = 0x02,
            Reserved = 0x03,
            None = 0x0F
        }
        public TimeSources TimeSource
        {
            get
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var bits = new BitArray(channelSpecificDataWord);
                var ntf = Utils.Utils.BitArrayToInt32(bits, 0, 3);
                return (TimeSources)ntf;
            }
            set
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var b = new BitArray(channelSpecificDataWord);
                Utils.Utils.SetBits(b, (uint)value, 0, 3);
                var ret = new byte[sizeof(uint)];
                b.CopyTo(ret, 0);
                ChannelSpecificDataWord = BitConverter.ToUInt32(ret, 0);
            }
        }

        public enum DateFormats
        {
            IRIGDayAvailable = 0x00,
            MonthAndYearAvailable = 0x01
        }
        //bit 9
        public DateFormats DateFormat
        {
            get
            {
                var csdw = BitConverter.GetBytes(ChannelSpecificDataWord);
                var bits = new BitArray(csdw);
                return bits[9] ? DateFormats.MonthAndYearAvailable : DateFormats.IRIGDayAvailable;
            }
            set
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var b = new BitArray(channelSpecificDataWord);
                b.Set(9, value == DateFormats.MonthAndYearAvailable);
                var ret = new byte[sizeof(uint)];
                b.CopyTo(ret, 0);
                ChannelSpecificDataWord = BitConverter.ToUInt32(ret, 0);
            }
        }
        /// <summary>
        /// the time represented by this packet
        /// </summary>
        public DateTime TimePacketTime { get; set; }
        //bit 8
        public bool IsLeapYear
        {
            get
            {
                var csdw = BitConverter.GetBytes(ChannelSpecificDataWord);
                var bits = new BitArray(csdw);
                return bits[8];
            }
            set
            {
                var channelSpecificDataWord = BitConverter.GetBytes(ChannelSpecificDataWord);
                var b = new BitArray(channelSpecificDataWord);
                b.Set(8, value);
                var ret = new byte[sizeof(uint)];
                b.CopyTo(ret, 0);
                ChannelSpecificDataWord = BitConverter.ToUInt32(ret, 0);
            }
        }

        public TimePacketFormat1(byte sequenceNumber, DateTime packetTime, long rtc, int nanoseconds, int seconds)
            : base(Enums.DataFileDataTypes.TimeDataFormat1, false)
        {
            SetDataVersion(Enums.DataTypeVersion.TG78);
            TimePacketTime = packetTime;
            IsLeapYear = DateTime.IsLeapYear(packetTime.Year);
            DateFormat = DateFormats.MonthAndYearAvailable;
            TimeSource = TimeSources.External;
            ITS = IRIGTimeSource.IRIG_TCG_locked_to_external_Embedded;
            var dataLength = Convert.ToUInt32(4 + sizeof(ushort) + 4);
            var offset = CommonHeaderWork(1, PacketHeader.DataVersion, sequenceNumber, rtc, dataLength, nanoseconds, seconds);

            WriteMonthDayPayload(offset);
        }
        /// <summary>
        /// writes the month day payload portion of the timepacket
        /// </summary>
        /// <param name="offset"></param>
        private void WriteMonthDayPayload(int offset)
        {
            var Line1 = new BitArray(16);
            var digits = GetDigits(TimePacketTime.Second, 2);
            //tens of seconds
            var TSn = digits[0];
            Utils.Utils.SetBits(Line1, (uint)TSn, 12, 14);
            //units of seconds
            var Sn = digits[1];
            Utils.Utils.SetBits(Line1, (uint)Sn, 8, 11);
            digits = GetDigits(TimePacketTime.Millisecond, 3);
            //hundreds of ms
            var Hmn = digits[0];
            Utils.Utils.SetBits(Line1, (uint)Hmn, 4, 7);
            //tens of ms
            var Tmn = digits[1];
            Utils.Utils.SetBits(Line1, (uint)Tmn, 0, 3);

            var temp = new byte[sizeof(ushort)];
            Line1.CopyTo(temp, 0);
            Buffer.BlockCopy(temp, 0, _dataBytes, offset, 2);
            offset += 2;

            var Line2 = new BitArray(16);
            digits = GetDigits(TimePacketTime.Hour, 2);
            //tens of hours
            var THn = digits[0];
            Utils.Utils.SetBits(Line2, (uint)THn, 12, 13);
            //Units of hours
            var Hn = digits[1];
            Utils.Utils.SetBits(Line2, (uint)Hn, 8, 11);
            digits = GetDigits(TimePacketTime.Minute, 2);
            //tens of minutes
            var TMn = digits[0];
            Utils.Utils.SetBits(Line2, (uint)TMn, 4, 6);
            //units of minutes
            var Mn = digits[1];
            Utils.Utils.SetBits(Line2, (uint)Mn, 0, 3);
            temp = new byte[sizeof(ushort)];
            Line2.CopyTo(temp, 0);
            Buffer.BlockCopy(temp, 0, _dataBytes, offset, 2);
            offset += 2;

            var Line3 = new BitArray(16);
            digits = GetDigits(TimePacketTime.Month, 2);
            //tens of months
            var Ton = digits[0];
            Utils.Utils.SetBits(Line3, (uint)Ton, 12, 13);
            //units of months
            var On = digits[1];
            Utils.Utils.SetBits(Line3, (uint)On, 8, 11);
            digits = GetDigits(TimePacketTime.Day, 2);
            //Tens of days
            var TDn = digits[0];
            Utils.Utils.SetBits(Line3, (uint)TDn, 4, 7);
            //units of days
            var Dn = digits[1];
            Utils.Utils.SetBits(Line3, (uint)Dn, 0, 3);
            temp = new byte[sizeof(ushort)];
            Line3.CopyTo(temp, 0);
            Buffer.BlockCopy(temp, 0, _dataBytes, offset, 2);
            offset += 2;

            var line4 = new BitArray(16);
            digits = GetDigits(TimePacketTime.Year, 4);
            var OYn = digits[0];
            //thousands of years
            Utils.Utils.SetBits(line4, (uint)OYn, 12, 13);
            var HYn = digits[1];
            //hundreds of years
            Utils.Utils.SetBits(line4, (uint)HYn, 8, 11);
            var TYn = digits[2];
            //tens of years
            Utils.Utils.SetBits(line4, (uint)TYn, 4, 7);
            var Yn = digits[3];
            //units of years
            Utils.Utils.SetBits(line4, (uint)Yn, 0, 3);
            temp = new byte[sizeof(ushort)];
            line4.CopyTo(temp, 0);
            Buffer.BlockCopy(temp, 0, _dataBytes, offset, 2);
            offset += 2;
        }
        private int[] GetDigits(int number, int expectedDigits)
        {
            var list = new List<int>();
            var res = number;
            while (0 != res)
            {
                var digit = res % 10;
                res /= 10;
                list.Add(digit);
            }
            while (list.Count < expectedDigits)
            {
                list.Add(0);
            }
            list.Reverse();
            return list.ToArray();
        }
    }
}