From 52b402323ae5a7f162aa5b950bc491506e6d180b Mon Sep 17 00:00:00 2001
From: Morten Nielsen <mn@iter.dk>
Date: Mon, 7 Sep 2020 20:01:17 -0700
Subject: [PATCH] Sort ntrip sources by distance

---
 src/SampleApp.WinDesktop/NtripView.xaml    |  4 +++
 src/SampleApp.WinDesktop/NtripView.xaml.cs | 37 +++++++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/SampleApp.WinDesktop/NtripView.xaml b/src/SampleApp.WinDesktop/NtripView.xaml
index 97d31ff..33b76d4 100644
--- a/src/SampleApp.WinDesktop/NtripView.xaml
+++ b/src/SampleApp.WinDesktop/NtripView.xaml
@@ -7,6 +7,9 @@
              mc:Ignorable="d" 
              d:DesignHeight="450" d:DesignWidth="800">
     <Grid >
+        <Grid.Resources>
+            <local:DistanceConverter x:Key="DistanceConverter" />
+        </Grid.Resources>
         <Grid.ColumnDefinitions>
             <ColumnDefinition Width="Auto" MinWidth="80" />
             <ColumnDefinition />
@@ -66,6 +69,7 @@
                 <TextBlock Text="{Binding Mountpoint, StringFormat='Mount point: {0}'}" />
                 <TextBlock Text="{Binding Network, StringFormat='Network: {0}'}" />
                 <TextBlock Text="{Binding SupportsNmea, StringFormat='Supports NMEA: {0}'}" />
+                <TextBlock Text="{Binding Converter={StaticResource DistanceConverter}}" />
                 <Button Content="Connect" Click="Connect_Click" />
             </StackPanel>
         </Grid>
diff --git a/src/SampleApp.WinDesktop/NtripView.xaml.cs b/src/SampleApp.WinDesktop/NtripView.xaml.cs
index 9911533..d955e04 100644
--- a/src/SampleApp.WinDesktop/NtripView.xaml.cs
+++ b/src/SampleApp.WinDesktop/NtripView.xaml.cs
@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -41,13 +42,28 @@ namespace SampleApp.WinDesktop
             try
             {
                 sources = client.GetSourceTable().OfType<NtripStream>().ToList();
+                if(sources.Count == 0)
+                {
+                    MessageBox.Show($"No NTRIP data streams found at {host.Text}:{portNumber}");
+                    return;
+                }
             }
             catch(System.Exception ex)
             {
                 MessageBox.Show("Failed to connect: " + ex.Message);
                 return;
             }
-            sourceList.ItemsSource = sources.OrderBy(s=>s.CountryCode);
+            if (MainWindow.monitor != null && !double.IsNaN(MainWindow.monitor.Latitude) && !double.IsNaN(MainWindow.monitor.Longitude))
+            {
+                var lat = MainWindow.monitor.Latitude;
+                var lon = MainWindow.monitor.Longitude;
+                // Order by closest source
+                sourceList.ItemsSource = sources.OrderBy(s => PointPlotView.Vincenty.GetDistanceVincenty(lat, lon, s.Latitude, s.Longitude));
+            }
+            else
+            {
+                sourceList.ItemsSource = sources.OrderBy(s => s.CountryCode);
+            }
         }
         Stream ntripStream;
         private void Connect_Click(object sender, RoutedEventArgs e)
@@ -89,4 +105,23 @@ namespace SampleApp.WinDesktop
             ntripstatus.Text = $"Connected";
         }
     }
+    public class DistanceConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if(value is NtripStream s && MainWindow.monitor?.IsFixValid == true)
+            {
+                var lat = MainWindow.monitor.Latitude;
+                var lon = MainWindow.monitor.Longitude;
+                var distance = PointPlotView.Vincenty.GetDistanceVincenty(lat, lon, s.Latitude, s.Longitude);
+                return "Distance: " + (distance / 1000).ToString("0.##") + "km";
+            }
+            return "";
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
 }