--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MetroWpf/FxRates.UI/ViewModels/FxRatesViewModel.cs	Tue Mar 20 20:18:35 2012 +0000
@@ -0,0 +1,109 @@
+using System;
+using System.ComponentModel;
+using System.Linq;
+using System.Reactive;
+using System.Reactive.Linq;
+using System.Windows.Input;
+using FxRates.Common;
+using FxRates.UI.Models;
+using GalaSoft.MvvmLight;
+using GalaSoft.MvvmLight.Command;
+
+namespace FxRates.UI.ViewModels
+{
+  public class FxRatesViewModel : ViewModelBase
+  {
+    private IPricingService pricingService;
+    
+    public BindingList<DisplayFxRate> DisplayFxRates { get; set; }
+    public ICommand ServiceRunningCommand { get; set; }
+    public ICommand SubscriptionCommand { get; set; }
+    
+    public FxRatesViewModel(IPricingService service)
+    {
+      pricingService = service;
+      GetLatestPrices();
+
+      SubscriptionCommand = new RelayCommand(SubscriptionCommand_Execute);
+      ServiceRunningCommand = new RelayCommand(ServiceRunningCommand_Execute);
+
+      var priceUpdates = Observable.FromEventPattern<PriceUpdateEventArgs>(
+        pricingService, "PriceUpdate");
+
+      priceUpdates.Where(e => (Subscribed)
+         // && (e.EventArgs.LatestPrice.Ccy == Ccy.EURtoGBP) example of filter
+          )
+                  //.Throttle(TimeSpan.FromSeconds(1))  example of throttling
+                  .Subscribe(PriceUpdate);
+    }
+
+    public void PriceUpdate(EventPattern<PriceUpdateEventArgs> e)
+    {
+        var displayRate = DisplayFxRates.First(rate => rate.Ccy == e.EventArgs.LatestPrice.Ccy);
+        
+        if (displayRate != null)
+          displayRate.Update(e.EventArgs.LatestPrice);
+    }
+
+
+    private void GetLatestPrices()
+    {
+      DisplayFxRates = new BindingList<DisplayFxRate>();
+      var currentRates = pricingService.GetFullCurrentPrices();
+      foreach (var latestRate in currentRates)
+      {
+        var displayRate = DisplayFxRate.Create(latestRate);
+        DisplayFxRates.Add(displayRate);
+      }
+    }
+
+    private const string SubscribedPropertyName = "Subscribed";
+    private bool _subscribed = false;
+    public bool Subscribed
+    {
+      get { return _subscribed; }
+      set
+      {
+        if (_subscribed == value) return;
+        _subscribed = value;
+        RaisePropertyChanged(SubscribedPropertyName);
+      }
+    }
+
+    private const string ServiceRunningPropertyName = "ServiceRunning";
+    private bool _serviceRunning;
+    public bool ServiceRunning
+    {
+      get 
+      {
+        return _serviceRunning;
+      }
+      set
+      {
+        if (_serviceRunning == value) return;
+        _serviceRunning = value;
+        RaisePropertyChanged(ServiceRunningPropertyName);
+      }
+    }
+
+    void ServiceRunningCommand_Execute()
+    {
+      if (pricingService.IsRunning)
+      {
+        pricingService.Stop();
+        ServiceRunning = false;
+      }
+      else
+      {
+        pricingService.Start();
+        ServiceRunning = true;
+      }
+    }
+
+    void SubscriptionCommand_Execute()
+    {
+      //toggle subscribed
+      Subscribed = !Subscribed;
+    }
+  }
+}