From 317fc97652c5a9e18152b7a15c686d35a4625c57 Mon Sep 17 00:00:00 2001
From: "Frank A. Krueger" <fak@praeclarum.org>
Date: Mon, 12 Jun 2017 16:24:40 -0700
Subject: [PATCH] Add publishing to the server

---
 Ooui/Server.cs     | 67 +++++++++++++++++++++++++++++++++++++++-------
 Samples/Program.cs |  2 ++
 2 files changed, 60 insertions(+), 9 deletions(-)

diff --git a/Ooui/Server.cs b/Ooui/Server.cs
index 0bf534d..510e1f1 100644
--- a/Ooui/Server.cs
+++ b/Ooui/Server.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.IO;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -9,6 +11,9 @@ namespace Ooui
 {
     public class Server
     {
+        readonly Dictionary<string, Func<Element>> publishedPaths =
+            new Dictionary<string, Func<Element>> ();
+
         public Task RunAsync (string listenerPrefix)
         {
             return RunAsync (listenerPrefix, CancellationToken.None);
@@ -22,22 +27,66 @@ namespace Ooui
             Console.WriteLine ($"Listening at {listenerPrefix}...");
 
             while (!token.IsCancellationRequested) {
-                var listenerContext = await listener.GetContextAsync ();
+                var listenerContext = await listener.GetContextAsync ().ConfigureAwait (false);
                 if (listenerContext.Request.IsWebSocketRequest) {
                     ProcessWebSocketRequest (listenerContext, token);
                 }
                 else {
-                    listenerContext.Response.StatusCode = 400;
-                    listenerContext.Response.Close ();
+                    ProcessRequest (listenerContext, token);
                 }
             }
         }
 
+        public void Publish (string path, Func<Element> elementCtor)
+        {
+            System.Console.WriteLine($"PUBLISH {path}");
+            publishedPaths[path] = elementCtor;
+        }
+
+        public void Publish (string path, Element element)
+        {
+            Publish (path, () => element);
+        }
+
+        void ProcessRequest (HttpListenerContext listenerContext, CancellationToken token)
+        {
+            var url = listenerContext.Request.Url;
+            var path = url.LocalPath;
+
+            Console.WriteLine ($"{listenerContext.Request.HttpMethod} {url.LocalPath}");
+
+            Func<Element> ctor;
+            if (publishedPaths.TryGetValue (path, out ctor)) {
+                var element = ctor ();
+                RegisterElement (element);
+                WriteElementHtml (element, listenerContext.Response);
+            }
+            else {
+                listenerContext.Response.StatusCode = 404;
+                listenerContext.Response.Close ();
+            }
+        }
+
+        void RegisterElement (Element element)
+        {
+        }
+
+        void WriteElementHtml (Element element, HttpListenerResponse response)
+        {
+            response.StatusCode = 200;
+            using (var s = response.OutputStream) {
+                using (var w = new StreamWriter (s, Encoding.UTF8)) {
+                    w.WriteLine ($"Hello {element}");
+                }
+            }
+            response.Close ();
+        }
+
         async void ProcessWebSocketRequest (HttpListenerContext listenerContext, CancellationToken token)
         {
             WebSocketContext webSocketContext = null;
             try {
-                webSocketContext = await listenerContext.AcceptWebSocketAsync(subProtocol: null);
+                webSocketContext = await listenerContext.AcceptWebSocketAsync(subProtocol: null).ConfigureAwait (false);
                 Console.WriteLine ("Accepted WebSocket: {0}", webSocketContext);
             }
             catch (Exception e) {
@@ -58,26 +107,26 @@ namespace Ooui
                     var receiveResult = await webSocket.ReceiveAsync(new ArraySegment<byte>(receiveBuffer), token);
 
                     if (receiveResult.MessageType == WebSocketMessageType.Close) {
-                        await webSocket.CloseAsync (WebSocketCloseStatus.NormalClosure, "", token);
+                        await webSocket.CloseAsync (WebSocketCloseStatus.NormalClosure, "", token).ConfigureAwait (false);
                     }
                     else if (receiveResult.MessageType == WebSocketMessageType.Binary) {
-                        await webSocket.CloseAsync (WebSocketCloseStatus.InvalidMessageType, "Cannot accept binary frame", token);
+                        await webSocket.CloseAsync (WebSocketCloseStatus.InvalidMessageType, "Cannot accept binary frame", token).ConfigureAwait (false);
                     }
                     else {
                         var size = receiveResult.Count;
                         while (!receiveResult.EndOfMessage) {
                             if (size >= receiveBuffer.Length) {
-                                await webSocket.CloseAsync (WebSocketCloseStatus.MessageTooBig, "Message too big", token);
+                                await webSocket.CloseAsync (WebSocketCloseStatus.MessageTooBig, "Message too big", token).ConfigureAwait (false);
                                 return;
                             }
-                            receiveResult = await webSocket.ReceiveAsync (new ArraySegment<byte>(receiveBuffer, size, receiveBuffer.Length - size), token);
+                            receiveResult = await webSocket.ReceiveAsync (new ArraySegment<byte>(receiveBuffer, size, receiveBuffer.Length - size), token).ConfigureAwait (false);
                             size += receiveResult.Count;
                         }
                         var receivedString = Encoding.UTF8.GetString (receiveBuffer, 0, size);
                         Console.WriteLine ("RECEIVED: {0}", receivedString);
 
                         var outputBuffer = new ArraySegment<byte> (Encoding.UTF8.GetBytes ($"You said: {receivedString}"));
-                        await webSocket.SendAsync (outputBuffer, WebSocketMessageType.Text, true, token);
+                        await webSocket.SendAsync (outputBuffer, WebSocketMessageType.Text, true, token).ConfigureAwait (false);
                     }
                 }
             }
diff --git a/Samples/Program.cs b/Samples/Program.cs
index 537ad19..ea4862e 100644
--- a/Samples/Program.cs
+++ b/Samples/Program.cs
@@ -9,6 +9,8 @@ namespace Samples
         {
             Console.WriteLine ("Hello World!");
             var server = new Server ();
+            var button = new Button();
+            server.Publish ("/button", button);
             server.RunAsync ("http://*:8080/").Wait ();
             return 0;
         }