GUI -- Simpler version of DeviceGuiResource for the UI.

 D'Oh -- has to have public-no-args constructor!

Change-Id: Ib586f74bdd109385fd1772e53122e096bdd7e8d5

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.gui;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onlab.rest.BaseResource;
+import org.onosproject.net.Annotations;
+import org.onosproject.net.Device;
+import org.onosproject.net.device.DeviceService;
+import org.slf4j.Logger;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Response;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * UI REST resource for interacting with the inventory of infrastructure devices.
+ */
+@Path("device")
+public class DeviceGuiResource extends BaseResource {
+
+    private static final String ICON_ID_ONLINE = "deviceOnline";
+    private static final String ICON_ID_OFFLINE = "deviceOffline";
+
+    private static final Logger log = getLogger(DeviceGuiResource.class);
+
+    private final ObjectMapper mapper = new ObjectMapper();
+
+
+    // return list of devices
+    @GET
+    @Produces("application/json")
+    public Response getDevices() {
+        ObjectNode rootNode = mapper.createObjectNode();
+        ArrayNode devices = mapper.createArrayNode();
+        DeviceService service = get(DeviceService.class);
+
+        for (Device dev: service.getDevices()) {
+            devices.add(deviceJson(service, dev));
+        }
+
+        rootNode.set("devices", devices);
+        return Response.ok(rootNode.toString()).build();
+    }
+
+    /**
+     * Returns a JSON node representing the specified device.
+     *
+     * @param device infrastructure device
+     * @return JSON node
+     */
+    private ObjectNode deviceJson(DeviceService service, Device device) {
+        boolean available = service.isAvailable(device.id());
+        String iconId = available ? ICON_ID_ONLINE : ICON_ID_OFFLINE;
+
+        ObjectNode result = mapper.createObjectNode();
+        result.put("id", device.id().toString())
+                .put("available", service.isAvailable(device.id()))
+                .put("_iconid_available", iconId)
+                .put("type", device.type().toString())
+                .put("role", service.getRole(device.id()).toString())
+                .put("mfr", device.manufacturer())
+                .put("hw", device.hwVersion())
+                .put("sw", device.swVersion())
+                .put("serial", device.serialNumber())
+                .set("annotations", annotations(mapper, device.annotations()));
+        return result;
+    }
+
+    /**
+     * Produces a JSON object from the specified key/value annotations.
+     *
+     * @param mapper ObjectMapper to use while converting to JSON
+     * @param annotations key/value annotations
+     * @return JSON object
+     */
+    private static ObjectNode annotations(ObjectMapper mapper, Annotations annotations) {
+        ObjectNode result = mapper.createObjectNode();
+        for (String key : annotations.keys()) {
+            result.put(key, annotations.value(key));
+        }
+        return result;
+    }
+
+}