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Common/DTS.Common.Serialization/.svn/pristine/23/23b6334888c9a578fad416b1a7101c46c23eaa11.svn-base

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+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DTS.Serialization.IRIGCH10.Packets
+{
+    /// <summary>
+    /// this class helps encapsulate a secondary time format header, but it's really
+    /// only designed for one type of format currently
+    /// </summary>
+    public class SecondaryTimeFormatHeader : ISecondaryTimeFormatHeader
+    {
+        private byte[] _bytes = new byte[SECONDARY_TIME_HEADER_LENGTH];
+        public int NanoSeconds { get; }
+        public int Seconds { get; }
+        public ushort Reserved { get; }
+        public ushort CheckSum { get; }
+
+        public DateTime LocalTime
+        {
+            get => (new DateTime(1970, 1, 1)).AddSeconds(Seconds).AddTicks(NanoSeconds / 100).ToLocalTime();
+        }
+        public SecondaryTimeFormatHeader(byte[] input)
+        {
+            Array.Copy(input, 0, _bytes, 0, SECONDARY_TIME_HEADER_LENGTH);
+            NanoSeconds = BitConverter.ToInt32(_bytes, 0);
+            Seconds = BitConverter.ToInt32(_bytes, 4);
+            Reserved = BitConverter.ToUInt16(_bytes, 8);
+            CheckSum = BitConverter.ToUInt16(_bytes, 10);
+            byte[] bytesToCompute;
+            using (var ms = new MemoryStream())
+            {
+                using (var bw = new BinaryWriter(ms))
+                {
+                    bw.Write(BitConverter.GetBytes(NanoSeconds));
+                    bw.Write(BitConverter.GetBytes(Seconds));
+                    bw.Write(Reserved);
+                }
+                bytesToCompute = ms.ToArray();
+            }
+            var computedChecksum = Utils.Utils.GetCheckSum8(bytesToCompute);
+            if (computedChecksum != CheckSum)
+            {
+                System.Diagnostics.Trace.WriteLine("Secondary time header CRC does not match expectations");
+            }
+        }
+        public static byte[] GetBytes(int nanoseconds, int seconds)
+        {
+            using (var ms = new MemoryStream())
+            {
+                using (var bw = new BinaryWriter(ms))
+                {
+                    bw.Write(BitConverter.GetBytes(nanoseconds));
+                    bw.Write(BitConverter.GetBytes(seconds));
+                    bw.Write((ushort)0);
+
+                    bw.Write(Utils.Utils.GetCheckSum8(ms.ToArray()));
+                }
+                return ms.ToArray();
+            }
+        }
+        public const int SECONDARY_TIME_HEADER_LENGTH = 12;
+    }
+}