ONOS-2315 adding auto-complete to the CLI

Change-Id: I7b3056022188d58ca141bfec2870c7f1b44e37c2

+/*
+ * 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.cli;
+
+import org.onlab.metrics.MetricsService;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Metric name completer.
+ */
+public class MetricNameCompleter extends AbstractChoicesCompleter {
+
+    @Override
+    protected List<String> choices() {
+        MetricsService metricsService = AbstractShellCommand.get(MetricsService.class);
+        return new ArrayList<String>(metricsService.getMetrics().keySet());
+    }
+
+}

@@ -22,6 +22,7 @@ import java.util.Comparator;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
 import org.joda.time.LocalDateTime;
 import org.onlab.metrics.MetricsService;
@@ -45,11 +46,15 @@ import com.google.common.collect.TreeMultimap;
          description = "Prints metrics in the system")
 public class MetricsListCommand extends AbstractShellCommand {
 
+    @Argument(index = 0, name = "metricName", description = "Name of Metric",
+            required = false, multiValued = false)
+    String metricName = null;
+
     @Override
     protected void execute() {
         MetricsService metricsService = get(MetricsService.class);
 
-        MetricFilter filter = MetricFilter.ALL;
+        MetricFilter filter = metricName != null ? (name, metric) -> name.equals(metricName) : MetricFilter.ALL;
 
         TreeMultimap<String, Metric> matched = listMetrics(metricsService, filter);
         matched.asMap().forEach((name, metrics) -> {

@@ -64,6 +64,9 @@
 
         <command>
             <action class="org.onosproject.cli.MetricsListCommand"/>
+            <completers>
+                <ref component-id="metricNameCompleter"/>
+            </completers>
         </command>
 
         <command>
@@ -444,6 +447,7 @@
     <bean id="ExtHeaderCompleter" class="org.onosproject.cli.net.ExtHeaderCompleter"/>
 
     <bean id="startStopCompleter" class="org.onosproject.cli.StartStopCompleter"/>
+    <bean id="metricNameCompleter" class="org.onosproject.cli.MetricNameCompleter"/>
     <bean id="upDownCompleter" class="org.onosproject.cli.UpDownCompleter"/>
 
 </blueprint>

@@ -290,4 +290,15 @@ public class MetricsManager implements MetricsService {
     public void removeMatching(final MetricFilter filter) {
         metricsRegistry.removeMatching(filter);
     }
+
+    /**
+     * Fetches the existing Meters.
+     *
+     *
+     * @return a map of all metrics with the key as the
+     *         name String to the Meter.
+     */
+    public Map<String, Metric> getMetrics() {
+        return metricsRegistry.getMetrics();
+    }
 }

@@ -162,6 +162,14 @@ public interface MetricsService {
      Map<String, Histogram> getHistograms(MetricFilter filter);
 
     /**
+     * Fetches the existing metrics.
+     *
+     * @return a map of the Metrics, with the key as
+     *         the name String to the Histogram.
+     */
+    Map<String, Metric> getMetrics();
+
+    /**
      * Removes all Metrics that match a given filter.
      *
      * @param filter filter to use to select the Metrics to remove.