Adds LogViewerComponent & registers singleton in DI (3rd party devs will have to disable this component & register their own implementation)

Get some more of the basic WebAPI stubs fleshed out to get some data to start using in the UI layer

src/Umbraco.Core/Logging/Viewer/ILogViewer.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using Serilog.Events;
 
 namespace Umbraco.Core.Logging.Viewer
 {
@@ -17,14 +16,14 @@ namespace Umbraco.Core.Logging.Viewer
         LogLevelCounts GetLogLevelCounts();
 
         /// <summary>
-        /// Returns the top 5 common log message templates and their counts
+        /// Returns the top  common log message templates and their counts
         /// </summary>
-        IEnumerable<CommonLogMessage> GetCommonLogMessages();
+        IEnumerable<CommonLogMessage> GetCommonLogMessages(int numberOfResults = 10);
 
         /// <summary>
         /// Returns the collection of logs
         /// </summary>
-        IEnumerable<LogEvent> GetLogs();
+        IEnumerable<LogMessage> GetLogs();
 
     }
 }

src/Umbraco.Core/Logging/Viewer/JsonLogViewer.cs

@@ -7,13 +7,13 @@ using Serilog.Formatting.Compact.Reader;
 
 namespace Umbraco.Core.Logging.Viewer
 {
-    public class LogViewer : ILogViewer
+    public class JsonLogViewer : ILogViewer
     {
-        private List<LogEvent> _logs;
+        private List<LogEvent> _logs = new List<LogEvent>();
 
-        public LogViewer()
+        public JsonLogViewer()
         {
-            var filePath = $@"{AppDomain.CurrentDomain.BaseDirectory}\App_Data\Logs\UmbracoTraceLog.DELLBOOK.20180824.json";
+            var filePath = $@"{AppDomain.CurrentDomain.BaseDirectory}\App_Data\Logs\UmbracoTraceLog.DELLBOOK.20180828.json";
 
             //Open log file
             using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
@@ -48,16 +48,37 @@ namespace Umbraco.Core.Logging.Viewer
             };
         }
 
-        public IEnumerable<CommonLogMessage> GetCommonLogMessages()
+        public IEnumerable<CommonLogMessage> GetCommonLogMessages(int numberOfResults)
         {
-            var messages = new List<CommonLogMessage>();
-            return messages;
+            var templates = _logs.GroupBy(x => x.MessageTemplate.Text)
+                .Select(g => new CommonLogMessage { MessageTemplate = g.Key, Count = g.Count() })
+                .OrderByDescending(x => x.Count)
+                .Take(numberOfResults);
 
+            return templates;
         }
 
-        public IEnumerable<LogEvent> GetLogs()
+        public IEnumerable<LogMessage> GetLogs()
         {
-            throw new NotImplementedException();
+            var messages = new List<LogMessage>();
+            var logs = _logs.Take(20);
+
+            foreach(var log in logs)
+            {
+                var logItem = new LogMessage
+                {
+                    Level = log.Level,
+                    Properties = log.Properties,
+                    Timestamp = log.Timestamp,
+                    MessageTemplateText = log.MessageTemplate.Text, //Not necesarily worried about token position just the message text itself
+                    RenderedMessage = log.RenderMessage(), //Not returning LogEvent itself from Serilog (as we don't get the rendered txt log back)
+                    Exception = log.Exception
+                };
+
+                messages.Add(logItem);
+            }
+
+            return messages;
         }
     }
 }

src/Umbraco.Core/Logging/Viewer/LogMessage.cs

@@ -0,0 +1,42 @@
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Serilog.Events;
+using System;
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Logging.Viewer
+{
+    public class LogMessage
+    {
+        /// <summary>
+        /// The time at which the logevent occurred.
+        /// </summary>
+        public DateTimeOffset Timestamp { get; set; }
+
+        /// <summary>
+        /// The level of the event.
+        /// </summary>
+        [JsonConverter(typeof(StringEnumConverter))]
+        public LogEventLevel Level { get; set; }
+        
+        /// <summary>
+        /// The message template describing the logevent.
+        /// </summary>
+        public string MessageTemplateText { get; set; }
+
+        /// <summary>
+        /// The message template filled with the logevent properties.
+        /// </summary>
+        public string RenderedMessage { get; set; }
+
+        /// <summary>
+        /// Properties associated with the logevent, including those presented in Serilog.Events.LogEvent.MessageTemplate.
+        /// </summary>
+        public IReadOnlyDictionary<string, LogEventPropertyValue> Properties { get; set; }
+        
+        /// <summary>
+        /// An exception associated with the logevent, or null.
+        /// </summary>
+        public Exception Exception { get; set; }
+    }
+}

src/Umbraco.Core/Logging/Viewer/LogViewerComponent.cs

@@ -0,0 +1,14 @@
+using Umbraco.Core.Components;
+using Umbraco.Core.Composing;
+
+namespace Umbraco.Core.Logging.Viewer
+{
+    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
+    public class LogViewerComponent : UmbracoComponentBase, IUmbracoCoreComponent
+    {
+        public override void Compose(Composition composition)
+        {
+            composition.Container.RegisterSingleton<ILogViewer, JsonLogViewer>();
+        }
+    }
+}