Hooking up GUI server & client via web-socket.

Change-Id: If522a5f46de528f28bf09a985af40b140ef5abaa
diff --git a/web/gui/src/main/java/org/onlab/onos/gui/TopologyWebSocket.java b/web/gui/src/main/java/org/onlab/onos/gui/TopologyWebSocket.java
index 7828043..e82303b 100644
--- a/web/gui/src/main/java/org/onlab/onos/gui/TopologyWebSocket.java
+++ b/web/gui/src/main/java/org/onlab/onos/gui/TopologyWebSocket.java
@@ -15,8 +15,18 @@
  */
 package org.onlab.onos.gui;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.eclipse.jetty.websocket.WebSocket;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.net.Annotations;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.device.DeviceEvent;
 import org.onlab.onos.net.device.DeviceService;
+import org.onlab.onos.net.link.LinkEvent;
 import org.onlab.onos.net.topology.Topology;
 import org.onlab.onos.net.topology.TopologyEdge;
 import org.onlab.onos.net.topology.TopologyEvent;
@@ -28,6 +38,11 @@
 
 import java.io.IOException;
 
+import static org.onlab.onos.net.device.DeviceEvent.Type.DEVICE_ADDED;
+import static org.onlab.onos.net.device.DeviceEvent.Type.DEVICE_REMOVED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_ADDED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_REMOVED;
+
 /**
  * Web socket capable of interacting with the GUI topology view.
  */
@@ -37,6 +52,8 @@
     private final TopologyService topologyService;
     private final DeviceService deviceService;
 
+    private final ObjectMapper mapper = new ObjectMapper();
+
     private Connection connection;
 
     /**
@@ -58,22 +75,19 @@
         if (topologyService != null && deviceService != null) {
             topologyService.addListener(this);
 
-            sendMessage("Yo!!!");
-
             Topology topology = topologyService.currentTopology();
             TopologyGraph graph = topologyService.getGraph(topology);
             for (TopologyVertex vertex : graph.getVertexes()) {
-                sendMessage(deviceService.getDevice(vertex.deviceId()).toString());
+                sendMessage(message(new DeviceEvent(DEVICE_ADDED,
+                                                    deviceService.getDevice(vertex.deviceId()))));
             }
 
             for (TopologyEdge edge : graph.getEdges()) {
-                sendMessage(edge.link().toString());
+                sendMessage(message(new LinkEvent(LINK_ADDED, edge.link())));
             }
 
-            sendMessage("That's what we're starting with...");
-
         } else {
-            sendMessage("No topology service!!!");
+            sendMessage(message("error", "No topology service!!!"));
         }
     }
 
@@ -90,7 +104,7 @@
         System.out.println("Received: " + data);
     }
 
-    public void sendMessage(String data) {
+    private void sendMessage(String data) {
         try {
             connection.sendMessage(data);
         } catch (IOException e) {
@@ -98,9 +112,80 @@
         }
     }
 
+    // Produces a link event message to the client.
+    private String message(DeviceEvent event) {
+        Device device = event.subject();
+        ObjectNode payload = mapper.createObjectNode()
+                .put("id", device.id().toString())
+                .put("type", device.type().toString().toLowerCase())
+                .put("online", deviceService.isAvailable(device.id()));
+
+        // Generate labels: id, chassis id, no-label, optional-name
+        ArrayNode labels = mapper.createArrayNode();
+        labels.add(device.id().toString());
+        labels.add(device.chassisId().toString());
+        labels.add(" "); // compact no-label view
+        labels.add(device.annotations().value("name"));
+
+        // Add labels, props and stuff the payload into envelope.
+        payload.set("labels", labels);
+        payload.set("props", props(device.annotations()));
+        payload.set("metaUi", mapper.createObjectNode());
+
+        String type = (event.type() == DEVICE_ADDED) ? "addDevice" :
+                ((event.type() == DEVICE_REMOVED) ? "removeDevice" : "updateDevice");
+        return envelope(type, payload);
+    }
+
+    // Produces a link event message to the client.
+    private String message(LinkEvent event) {
+        Link link = event.subject();
+        ObjectNode payload = mapper.createObjectNode()
+                .put("type", link.type().toString().toLowerCase())
+                .put("linkWidth", 2)
+                .put("src", link.src().deviceId().toString())
+                .put("srcPort", link.src().port().toString())
+                .put("dst", link.dst().deviceId().toString())
+                .put("dstPort", link.dst().port().toString());
+        String type = (event.type() == LINK_ADDED) ? "addLink" :
+                ((event.type() == LINK_REMOVED) ? "removeLink" : "removeLink");
+        return envelope(type, payload);
+    }
+
+    // Produces JSON structure from annotations.
+    private JsonNode props(Annotations annotations) {
+        ObjectNode props = mapper.createObjectNode();
+        for (String key : annotations.keys()) {
+            props.put(key, annotations.value(key));
+        }
+        return props;
+    }
+
+    // Produces a log message event bound to the client.
+    private String message(String severity, String message) {
+        return envelope("message",
+                        mapper.createObjectNode()
+                                .put("severity", severity)
+                                .put("message", message));
+    }
+
+    // Puts the payload into an envelope and returns it.
+    private String envelope(String type, ObjectNode payload) {
+        ObjectNode event = mapper.createObjectNode();
+        event.put("event", type);
+        event.set("payload", payload);
+        return event.toString();
+    }
+
     @Override
     public void event(TopologyEvent event) {
-        sendMessage(event.toString());
+        for (Event reason : event.reasons()) {
+            if (reason instanceof DeviceEvent) {
+                sendMessage(message((DeviceEvent) reason));
+            } else if (reason instanceof LinkEvent) {
+                sendMessage(message((LinkEvent) reason));
+            }
+        }
     }
 }
 
diff --git a/web/gui/src/main/webapp/topo2.js b/web/gui/src/main/webapp/topo2.js
index e7444c9..31d7f7e 100644
--- a/web/gui/src/main/webapp/topo2.js
+++ b/web/gui/src/main/webapp/topo2.js
@@ -604,6 +604,7 @@
             webSock.ws.onmessage = function(m) {
                 if (m.data) {
                     console.log(m.data);
+                    handleServerEvent(JSON.parse(m.data));
                 }
             };