///
/// Copyright (c) 2021 Sensus Slovensko a.s.
///
using System;
using System.Globalization;
using System.Text;

namespace Workplace.CheckItems.S640
{
	public class DatastreamFrame
	{
        public const int FrameLength = 49;              /// Including CR,LF
        public const double VolumeScaleFactor = 1000.0; /// Raw volume is in ml
        public const double TimeScaleFactor = 1000.0;   /// Raw time is in ms

		/// Stored values
		public DateTime DateTime;		                /// From PC
        public char[] Data = new char[FrameLength - 2];
		public Int32 VolumeRaw;
        public Int64 VolumeRawExt;
        public Int64 Timestamp;
        public Int64 TimestampExt;
        
		/// Calculated values
        public double Volume() { return (double)VolumeRawExt / VolumeScaleFactor; }
        public double TimestampDbl() { return (double)TimestampExt / TimeScaleFactor; }

		public DatastreamFrame() { }

        /// <summary>
        /// Parses optical telegram and returns OptoTelegramRaw object
        /// </summary>
        /// <description>
        /// Create a configuration structure from a complete byte array
		/// 
		/// Telegram description:
		/// 
        /// AAAAAAAAAAAA[tab]BBBBBBBBBB[tab]CCCCCCCCC[tab]DDDDDDDDDD[tab]EE[cr][lf]  (49 bytes)
		/// 
		/// Data           Comment         Type         Calculate to decimal
		/// ----------------------------------------------------------------
        /// AAAAAAAAAAAA   PCB number      Decimal
        /// BBBBBBBBBB     Radio address   Decimal
        /// CCCCCCCCC      Meter reading   Decimal      Volume in ml
        /// DDDDDDDDDD     Timestamp       Decimal      Time in ms
        /// EE             Checksum        Hexadecimal
		/// ----------------------------------------------------------------
		/// 
		/// Example:
        /// 540210730770	4291524429	000250215	0433411626	4F
        /// 540210730770	4291524429	000250215	0433411876	56
		/// ...
        /// </description>
        /// <param name="data">A complete byte array data</param>
        /// <returns>true = telegram OK, false = telegram NOK</returns>
        public bool UpdateFromString(string frame, ref Int64 volumeRawExtLast, ref Int64 timestampExtLast)
		{
			DateTime = DateTime.Now;

            if (frame == null || frame.Length < FrameLength ||
                frame[FrameLength - 2] != '\r' || frame[FrameLength - 1] != '\n' ||
                frame[12] != '\t' || frame[23] != '\t' || frame[33] != '\t' || frame[44] != '\t')
			{
				return false;
			}

            /// Copy data into the fixed size buffer
            int sum = 0;
            for (int i = 0; i < FrameLength - 4; i++)
            {
                Data[i] = frame[i];
                sum += (int)frame[i];
            }
            Data[FrameLength - 4] = frame[FrameLength - 4];
            Data[FrameLength - 3] = frame[FrameLength - 3];

            byte checkSum;
            bool chksumOk = byte.TryParse(frame.Substring(FrameLength - 4, 2), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out checkSum)
                             && checkSum == (sum & 0xFF);

            bool volumeOk = Int32.TryParse(frame.Substring(24, 9), out VolumeRaw);
            volumeRawExtLast = VolumeRawExt = VolumeRaw;

            bool timeOk = Int64.TryParse(frame.Substring(34, 10), out Timestamp);
            timestampExtLast = TimestampExt = Timestamp;

			bool allOk = volumeOk && timeOk && chksumOk;

            return allOk;
		}

		public override string ToString()
		{
            StringBuilder sb = new StringBuilder(FrameLength - 2);
            for (int i = 0; i < FrameLength - 2; i++)
                sb.Append(Data[i]);

            return string.Format("{0:HH:mm:ss.fff}  {1}  T={2}  V={3}", DateTime, sb.ToString().Replace("\t","~"), TimestampDbl(), Volume());
		}
	}
}