Implement REST APIs for link flow statistics

Change-Id: I65ca3cec9dd1771a70811afd319619827f7b9010
diff --git a/web/api/src/test/java/org/onosproject/rest/StatisticsResourceTest.java b/web/api/src/test/java/org/onosproject/rest/StatisticsResourceTest.java
new file mode 100644
index 0000000..af64224
--- /dev/null
+++ b/web/api/src/test/java/org/onosproject/rest/StatisticsResourceTest.java
@@ -0,0 +1,179 @@
+/*
+ * 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.rest;
+
+import java.util.HashMap;
+import java.util.stream.IntStream;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.osgi.ServiceDirectory;
+import org.onlab.osgi.TestServiceDirectory;
+import org.onlab.rest.BaseResource;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.impl.CodecManager;
+import org.onosproject.net.Link;
+import org.onosproject.net.link.LinkService;
+import org.onosproject.net.statistic.DefaultLoad;
+import org.onosproject.net.statistic.StatisticService;
+
+import com.eclipsesource.json.JsonArray;
+import com.eclipsesource.json.JsonObject;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.sun.jersey.api.client.WebResource;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.lessThanOrEqualTo;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.net.NetTestTools.connectPoint;
+import static org.onosproject.net.NetTestTools.link;
+
+/**
+ * Unit tests for statistics REST APIs.
+ */
+public class StatisticsResourceTest extends ResourceTest {
+
+    Link link1 = link("src1", 1, "dst1", 1);
+    Link link2 = link("src2", 2, "dst2", 2);
+    Link link3 = link("src3", 3, "dst3", 3);
+
+    LinkService mockLinkService;
+    StatisticService mockStatisticService;
+
+    /**
+     * Initializes test mocks and environment.
+     */
+    @Before
+    public void setUpTest() {
+        mockLinkService = createMock(LinkService.class);
+        expect(mockLinkService.getLinks())
+                .andReturn(ImmutableList.of(link1, link2, link3));
+        expect(mockLinkService.getLinks(connectPoint("0000000000000001", 2)))
+                .andReturn(ImmutableSet.of(link3));
+
+        mockStatisticService = createMock(StatisticService.class);
+        expect(mockStatisticService.load(link1))
+                .andReturn(new DefaultLoad(2, 1, 1));
+        expect(mockStatisticService.load(link2))
+                .andReturn(new DefaultLoad(22, 11, 1));
+        expect(mockStatisticService.load(link3))
+                .andReturn(new DefaultLoad(222, 111, 1));
+
+        replay(mockLinkService, mockStatisticService);
+
+        // Register the services needed for the test
+        CodecManager codecService = new CodecManager();
+        codecService.activate();
+        ServiceDirectory testDirectory =
+                new TestServiceDirectory()
+                        .add(LinkService.class, mockLinkService)
+                        .add(StatisticService.class, mockStatisticService)
+                        .add(CodecService.class, codecService);
+
+        BaseResource.setServiceDirectory(testDirectory);
+    }
+
+    /**
+     * Checks that the values in a JSON representation of a Load are
+     * correct.
+     *
+     * @param load JSON for the Loan object
+     * @param rate expected vale fo rate
+     * @param latest expected value for latest
+     * @param valid expected value for valid flag
+     * @param device expected device ID
+     */
+    private void checkValues(JsonObject load, int rate, int latest,
+                             boolean valid, String device) {
+        assertThat(load, notNullValue());
+        assertThat(load.get("rate").asInt(), is(rate));
+        assertThat(load.get("latest").asInt(), is(latest));
+        assertThat(load.get("valid").asBoolean(), is(valid));
+        assertThat(load.get("time").asLong(),
+                lessThanOrEqualTo((System.currentTimeMillis())));
+        assertThat(load.get("link").asString(),
+                containsString("device=of:" + device));
+    }
+
+    /**
+     * Tests GET of a single Load statistics object.
+     */
+    @Test
+    public void testSingleLoadGet() {
+        final WebResource rs = resource();
+        final String response = rs.path("statistics/flows/link")
+                .queryParam("device", "of:0000000000000001")
+                .queryParam("port", "2")
+                .get(String.class);
+
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("loads"));
+
+        final JsonArray jsonLoads = result.get("loads").asArray();
+        assertThat(jsonLoads, notNullValue());
+        assertThat(jsonLoads.size(), is(1));
+
+        JsonObject load1 = jsonLoads.get(0).asObject();
+        checkValues(load1, 111, 222, true, "src3");
+    }
+
+    /**
+     * Tests GET of all Load statistics objects.
+     */
+    @Test
+    public void testLoadsGet() {
+        final WebResource rs = resource();
+        final String response = rs.path("statistics/flows/link/").get(String.class);
+
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("loads"));
+
+        final JsonArray jsonLoads = result.get("loads").asArray();
+        assertThat(jsonLoads, notNullValue());
+        assertThat(jsonLoads.size(), is(3));
+
+        // Hash the loads by the current field to allow easy lookup if the
+        // order changes.
+        HashMap<Integer, JsonObject> currentMap = new HashMap<>();
+        IntStream.range(0, jsonLoads.size())
+                .forEach(index -> currentMap.put(
+                        jsonLoads.get(index).asObject().get("latest").asInt(),
+                        jsonLoads.get(index).asObject()));
+
+        JsonObject load1 = currentMap.get(2);
+        checkValues(load1, 1, 2, true, "src1");
+
+        JsonObject load2 = currentMap.get(22);
+        checkValues(load2, 11, 22, true, "src2");
+
+        JsonObject load3 = currentMap.get(222);
+        checkValues(load3, 111, 222, true, "src3");
+
+    }
+}