Observable logs (#51)

* observable log entries

* event test

src/WireMock.Net/Owin/WireMockMiddleware.cs

@@ -1,5 +1,6 @@
-using System;
+using System;
 using System.Collections;
+using System.Collections.ObjectModel;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Threading.Tasks;
@@ -161,13 +162,20 @@ namespace WireMock.Owin
 
                 if (_options.MaxRequestLogCount != null)
                 {
-                    _options.LogEntries = _options.LogEntries.Skip(_options.LogEntries.Count - _options.MaxRequestLogCount.Value).ToList();
+                    var amount = _options.LogEntries.Count - _options.MaxRequestLogCount.Value;
+                    for (var i = 0; i < amount; i++, _options.LogEntries.RemoveAt(0)) ;
                 }
 
                 if (_options.RequestLogExpirationDuration != null)
                 {
                     var checkTime = DateTime.Now.AddHours(-_options.RequestLogExpirationDuration.Value);
-                    _options.LogEntries = _options.LogEntries.Where(le => le.RequestMessage.DateTime > checkTime).ToList();
+
+                    for (var i = _options.LogEntries.Count - 1; i >= 0; i--)
+                    {
+                        var le = _options.LogEntries[i];
+                        if (le.RequestMessage.DateTime <= checkTime)
+                            _options.LogEntries.RemoveAt(i);
+                    }
                 }
             }
         }

src/WireMock.Net/Owin/WireMockMiddlewareOptions.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using WireMock.Logging;
 using WireMock.Matchers;
 
@@ -15,7 +16,7 @@ namespace WireMock.Owin
 
         public IList<Mapping> Mappings { get; set; }
 
-        public IList<LogEntry> LogEntries { get; set; }
+        public ObservableCollection<LogEntry> LogEntries { get; set; }
         
         public int? RequestLogExpirationDuration { get; set; }
 
@@ -24,7 +25,7 @@ namespace WireMock.Owin
         public WireMockMiddlewareOptions()
         {
             Mappings = new List<Mapping>();
-            LogEntries = new List<LogEntry>();
+            LogEntries = new ObservableCollection<LogEntry>();
         }
     }
 }

src/WireMock.Net/Server/FluentMockServer.LogEntries.cs

@@ -2,6 +2,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.Collections.Specialized;
 using JetBrains.Annotations;
 using WireMock.Logging;
 using WireMock.Matchers.Request;
@@ -11,6 +12,28 @@ namespace WireMock.Server
 {
     public partial class FluentMockServer
     {
+        /// <summary>
+        /// Log entries notification handler
+        /// </summary>
+        [PublicAPI]
+        public event NotifyCollectionChangedEventHandler LogEntriesChanged
+        {
+            add
+            {
+                lock (((ICollection) _options.LogEntries).SyncRoot)
+                {
+                    _options.LogEntries.CollectionChanged += value;
+                }
+            }
+            remove
+            {
+                lock (((ICollection)_options.LogEntries).SyncRoot)
+                {
+                    _options.LogEntries.CollectionChanged -= value;
+                }
+            }
+        }
+
         /// <summary>
         /// Gets the request logs.
         /// </summary>

test/WireMock.Net.Tests/ObservableLogEntriesTest.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Threading.Tasks;
+using NFluent;
+using RestEase;
+using WireMock.RequestBuilders;
+using WireMock.ResponseBuilders;
+using WireMock.Server;
+using Xunit;
+
+namespace WireMock.Net.Tests
+{
+    public class ObservableLogEntriesTest: IDisposable
+    {
+        private FluentMockServer _server;
+
+        [Fact]
+        public async void Test()
+        {
+            // given
+            _server = FluentMockServer.Start();
+
+            _server
+                .Given(Request.Create()
+                    .WithPath("/foo")
+                    .UsingGet())
+                .RespondWith(Response.Create()
+                    .WithStatusCode(200)
+                    .WithBody(@"{ msg: ""Hello world!""}"));
+
+            var count = 0;
+            _server.LogEntriesChanged += (sender, args) => count++;
+
+            // when
+            var response = await new HttpClient().GetAsync("http://localhost:" + _server.Ports[0] + "/foo");
+
+            // then
+            Check.That(count).Equals(1);
+        }
+
+        public void Dispose()
+        {
+            _server?.Dispose();
+        }
+    }
+}