using System;
using System.Globalization;

namespace TBF.BenchControl.WaterMeters.iPerl
{
	public class OptoTelegram
	{
		public static readonly int Length = 42;

		public double EMF;
		public Int16 MagneticField;
		public double Flow;
		public double Volume;
		public Int16 Impedance;
		public UInt32 Timestamp;
		public byte GG;

		string sourceStr;


		public OptoTelegram()
		{
		}

		public override string ToString()
		{
			return sourceStr;
		}

        /// <summary>
        /// Create a configuration structure from a complete byte array
		/// 
		/// Telegram description:
		/// 
		/// AAAAAA[tab]BBBB[tab]CCCC[tab]DDDDDD[tab]EEEE[tab]FFFFFFFF[tab]GG[cr][lf]  (42 bytes)
		/// 
		/// Data     Comment         Type     Calculate to decimal
		/// ----------------------------------------------------------------
		/// AAAAAA   EMF             Int24    Value * 0.000000333
		/// BBBB     Magnetic field  Int16    Value
		/// CCCC     Flow            Int16    Value * 0.225 * Scalig factor
		/// DDDDDD   Volume          Int24    Value / 16000 * Scaling factor
		/// EEEE     Impedance       Int16    Value
		/// FFFFFFFF Timestamp       Uint32   Value / 8192
		/// GG
		/// ----------------------------------------------------------------
		/// 
		/// Example:
		/// FFFFFE	51EA	0000	65324E	0087	F6319DFF	86
		/// FFDD3A	51F9	0000	65324E	0088	F631A60B	45
		/// ...
        /// </summary>
        /// <param name="data">A complete byte array data</param>
        /// <returns>ConfigStruct or null when byte array was not complete</returns>
		public static OptoTelegram FromString(string telegram, MeterType meterType)
		{
			if ((telegram == null) || (telegram.Length < Length) ||
				(telegram[6]  != '\t') || (telegram[11] != '\t') ||
				(telegram[16] != '\t') || (telegram[23] != '\t') ||
				(telegram[28] != '\t') || (telegram[37] != '\t') ||
				(telegram[40] != '\r') || (telegram[41] != '\n'))
			{
				return null;
			}

			OptoTelegram opto = new OptoTelegram();

			Int32 value;
			if (Int32.TryParse(telegram.Substring(0, 6), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
			{
				Int32 svalue = (value >= 0x00800000) ? (value - 0x01000000) : value;
				opto.EMF = 0.000000333 * (double)svalue;
			}
			else return null;

			if (Int32.TryParse(telegram.Substring(7, 4), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
			{
				Int32 svalue = (value >= 0x00008000) ? (value - 0x00010000) : value;
				opto.MagneticField = (Int16)svalue;
			}
			else return null;

			double factor = ScalingFactor(meterType);

			if (Int32.TryParse(telegram.Substring(12, 4), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
			{
				Int32 svalue = (value >= 0x00008000) ? (value - 0x00010000) : value;
				opto.Flow = 0.225 * (double)svalue * factor;
			}
			else return null;

			if (Int32.TryParse(telegram.Substring(17, 6), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
			{
				Int32 svalue = (value >= 0x00800000) ? (value - 0x01000000) : value;
				opto.Volume = (double)svalue / 16000.0 * factor;
			}
			else return null;

			if (Int32.TryParse(telegram.Substring(24, 4), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
			{
				Int32 svalue = (value >= 0x00008000) ? (value - 0x00010000) : value;
				opto.Impedance = (Int16)svalue;
			}
			else return null;

			UInt32 uvalue;
			if (UInt32.TryParse(telegram.Substring(29, 8), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out uvalue))
			{
				opto.Timestamp = uvalue;
			}
			else return null;

			if (UInt32.TryParse(telegram.Substring(38, 2), NumberStyles.HexNumber, CultureInfo.CurrentCulture, out uvalue))
			{
				opto.GG = (byte)uvalue;
			}
			else return null;

			opto.sourceStr = telegram.Substring(0, Length - 2);

			return opto;
		}


		/// <summary>
		/// Scaling factor:
		///   0, 1 (DN15, Coax) . . . .  1
		///   2  (DN20) . . . . . . . .  2
		///   3  (DN25) . . . . . . . .  4
		///   4, 5 (DN26, DN32) . . . .  8
		///   6  (DN40) . . . . . . . . 16
		/// </summary>
		/// <param name="meterType">MeterType (0..6)</param>
		/// <returns>Scaling factor</returns>
		public static double ScalingFactor(MeterType meterType)
		{
			switch (meterType)
			{
				default:
				case MeterType.DN15:
				case MeterType.CoaxManifold: return 1.0;
				case MeterType.DN20: return 2.0;
				case MeterType.DN25: return 4.0;
				case MeterType.DN26:
				case MeterType.DN32: return 8.0;
				case MeterType.DN40: return 16.0;
			}
		}
	}
}