From 2fba15f6d99a2c64869dbe23de5bb32303d89684 Mon Sep 17 00:00:00 2001
From: unknown <mort5161@MNPRO3.esri.com>
Date: Thu, 31 Jul 2014 00:59:47 -0700
Subject: [PATCH] Simplified listening to multi part messages

---
 src/NmeaParser.Shared/IMultiPartMessage.cs  |  7 +++-
 src/NmeaParser.Shared/NmeaDevice.cs         | 45 +++++++++++++++++++--
 src/SampleApp.WinDesktop/MainWindow.xaml.cs | 13 ++----
 3 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/src/NmeaParser.Shared/IMultiPartMessage.cs b/src/NmeaParser.Shared/IMultiPartMessage.cs
index 4d68dd0..d586274 100644
--- a/src/NmeaParser.Shared/IMultiPartMessage.cs
+++ b/src/NmeaParser.Shared/IMultiPartMessage.cs
@@ -4,8 +4,8 @@ using System.Text;
 
 namespace NmeaParser
 {
-    interface IMultiPartMessage<T> : IEnumerable<T>
-    {
+	interface IMultiPartMessage : System.Collections.IEnumerable
+	{
 		/// <summary>
 		/// Total number of messages of this type in this cycle
 		/// </summary>
@@ -16,4 +16,7 @@ namespace NmeaParser
 		/// </summary>
 		int MessageNumber { get; }
 	}
+	interface IMultiPartMessage<T> : IMultiPartMessage, IEnumerable<T>
+    {
+	}
 }
diff --git a/src/NmeaParser.Shared/NmeaDevice.cs b/src/NmeaParser.Shared/NmeaDevice.cs
index 9392f2a..5a7f116 100644
--- a/src/NmeaParser.Shared/NmeaDevice.cs
+++ b/src/NmeaParser.Shared/NmeaDevice.cs
@@ -40,6 +40,7 @@ namespace NmeaParser
 			tcs = new System.Threading.CancellationTokenSource();
 			m_stream = await OpenStreamAsync();
 			StartParser();
+			MultiPartMessageCache.Clear();
 		}
 
 		private void StartParser()
@@ -82,6 +83,7 @@ namespace NmeaParser
 			}
 			await closeTask.Task;
 			await CloseStreamAsync(m_stream);
+			MultiPartMessageCache.Clear();
 			m_stream = null;
 		}
 		protected abstract Task CloseStreamAsync(Stream stream);
@@ -98,7 +100,7 @@ namespace NmeaParser
 				if (lineEnd > -1)
 				{
 					line = message.Substring(0, lineEnd).Trim();
-					message = message.Substring(lineEnd);
+					message = message.Substring(lineEnd + 1);
 				}
 			}
 			if (!string.IsNullOrEmpty(line))
@@ -118,10 +120,46 @@ namespace NmeaParser
 
 		private void OnMessageReceived(Nmea.NmeaMessage msg)
 		{
+			var args = new NmeaMessageReceivedEventArgs(msg);
+			if (msg is IMultiPartMessage)
+			{
+				args.IsMultiPart = true;
+				var multi = (IMultiPartMessage)msg;
+				if (MultiPartMessageCache.ContainsKey(msg.MessageType))
+				{
+					var dic = MultiPartMessageCache[msg.MessageType];
+					if (dic.ContainsKey(multi.MessageNumber - 1) && !dic.ContainsKey(multi.MessageNumber))
+					{
+						dic[multi.MessageNumber] = msg;
+					}
+					else //Something is out of order. Clear cache
+						MultiPartMessageCache.Remove(msg.MessageType);
+				}
+				else if (multi.MessageNumber == 1)
+				{
+					MultiPartMessageCache[msg.MessageType] = new Dictionary<int, Nmea.NmeaMessage>(multi.TotalMessages);
+					MultiPartMessageCache[msg.MessageType][1] = msg;
+				}
+				if (MultiPartMessageCache.ContainsKey(msg.MessageType))
+				{
+					var dic = MultiPartMessageCache[msg.MessageType];
+					if (dic.Count == multi.TotalMessages) //We have a full list
+					{
+						MultiPartMessageCache.Remove(msg.MessageType);
+						args.MessageParts = dic.Values.ToArray();
+					}
+				}
+			}
+
 			if (MessageReceived != null)
-				MessageReceived(this, new NmeaMessageReceivedEventArgs(msg));
+			{
+				MessageReceived(this, args);
+			}
 		}
 
+		private Dictionary<string, Dictionary<int, Nmea.NmeaMessage>> MultiPartMessageCache
+			= new Dictionary<string,Dictionary<int,Nmea.NmeaMessage>>();
+
 		public event EventHandler<NmeaMessageReceivedEventArgs> MessageReceived;
 
 		public void Dispose()
@@ -147,10 +185,9 @@ namespace NmeaParser
 	{
 		internal NmeaMessageReceivedEventArgs(Nmea.NmeaMessage message) {
 			Message = message;
-			MessageList = new[] { message };
 		}
 		public Nmea.NmeaMessage Message { get; private set; }
 		public bool IsMultiPart { get; internal set; }
-		public Nmea.NmeaMessage[] MessageList { get; internal set; }
+		public Nmea.NmeaMessage[] MessageParts { get; internal set; }
 	}
 }
diff --git a/src/SampleApp.WinDesktop/MainWindow.xaml.cs b/src/SampleApp.WinDesktop/MainWindow.xaml.cs
index 9c43571..021c0b0 100644
--- a/src/SampleApp.WinDesktop/MainWindow.xaml.cs
+++ b/src/SampleApp.WinDesktop/MainWindow.xaml.cs
@@ -28,25 +28,18 @@ namespace SampleApp.WinDesktop
 			var _ = device.OpenAsync();
 		}
 
-		Dictionary<int, NmeaParser.Nmea.Gps.Gpgsv> gpgsvList = new Dictionary<int,NmeaParser.Nmea.Gps.Gpgsv>();
 		private void device_MessageReceived(object sender, NmeaParser.NmeaMessageReceivedEventArgs args)
 		{
 			Dispatcher.BeginInvoke((Action) delegate()
 			{
-				output.Text += args.Message.MessageType + ": " + args.ToString() + '\n';
+				output.Text += args.Message.MessageType + ": " + args.Message.ToString() + '\n';
 				output.Select(output.Text.Length - 1, 0); //scroll to bottom
 
-				//Merge all gpgsv satellite messages
 				if(args.Message is NmeaParser.Nmea.Gps.Gpgsv)
 				{
 					var gpgsv = (NmeaParser.Nmea.Gps.Gpgsv)args.Message;
-					if(gpgsv.MessageNumber == 1)
-					{
-						gpgsvList = new Dictionary<int,NmeaParser.Nmea.Gps.Gpgsv>(); //first one. Replace list
-					}
-					gpgsvList[gpgsv.MessageNumber] = gpgsv;
-					if(gpgsv.MessageNumber == gpgsv.TotalMessages)
-						satView.GpgsvMessages = gpgsvList.Values;
+					if(args.IsMultiPart && args.MessageParts != null)
+						satView.GpgsvMessages = args.MessageParts.OfType<NmeaParser.Nmea.Gps.Gpgsv>();
 				}
 			});
 		}