/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.hadoop.mapreduce.v2.app2.webapp;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.StringReader;
import java.util.Map;

import javax.ws.rs.core.MediaType;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.v2.api.records.JobId;
import org.apache.hadoop.mapreduce.v2.app2.AppContext;
import org.apache.hadoop.mapreduce.v2.app2.MockJobs;
import org.apache.hadoop.mapreduce.v2.app2.job.Job;
import org.apache.hadoop.mapreduce.v2.app2.rm.container.AMContainerMap;
import org.apache.hadoop.mapreduce.v2.app2.rm.node.AMNodeMap;
import org.apache.hadoop.yarn.Clock;
import org.apache.hadoop.yarn.ClusterInfo;
import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.event.EventHandler;
import org.apache.hadoop.yarn.webapp.GenericExceptionHandler;
import org.apache.hadoop.yarn.webapp.WebServicesTestUtils;
import org.codehaus.jettison.json.JSONException;
import org.codehaus.jettison.json.JSONObject;
import org.junit.Before;
import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.servlet.GuiceServletContextListener;
import com.google.inject.servlet.ServletModule;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.ClientResponse.Status;
import com.sun.jersey.api.client.UniformInterfaceException;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
import com.sun.jersey.test.framework.JerseyTest;
import com.sun.jersey.test.framework.WebAppDescriptor;

/**
 * Test the MapReduce Application master info web services api's. Also test
 * non-existent urls.
 *
 *  /ws/v1/mapreduce
 *  /ws/v1/mapreduce/info
 */
public class TestAMWebServices extends JerseyTest {

  private static Configuration conf = new Configuration();
  private static TestAppContext appContext;

  static class TestAppContext implements AppContext {
    final ApplicationAttemptId appAttemptID;
    final ApplicationId appID;
    final String user = MockJobs.newUserName();
    final Map<JobId, Job> jobs;
    final long startTime = System.currentTimeMillis();

    TestAppContext(int appid, int numJobs, int numTasks, int numAttempts) {
      appID = MockJobs.newAppID(appid);
      appAttemptID = MockJobs.newAppAttemptID(appID, 0);
      jobs = MockJobs.newJobs(appID, numJobs, numTasks, numAttempts);
    }

    TestAppContext() {
      this(0, 1, 1, 1);
    }

    @Override
    public ApplicationAttemptId getApplicationAttemptId() {
      return appAttemptID;
    }

    @Override
    public ApplicationId getApplicationID() {
      return appID;
    }

    @Override
    public CharSequence getUser() {
      return user;
    }

    @Override
    public Job getJob(JobId jobID) {
      return jobs.get(jobID);
    }

    @Override
    public Map<JobId, Job> getAllJobs() {
      return jobs; // OK
    }

    @SuppressWarnings("rawtypes")
    @Override
    public EventHandler getEventHandler() {
      return null;
    }

    @Override
    public Clock getClock() {
      return null;
    }

    @Override
    public String getApplicationName() {
      return "TestApp";
    }

    @Override
    public long getStartTime() {
      return startTime;
    }

    @Override
    public ClusterInfo getClusterInfo() {
      return null;
    }

    @Override
    public Map<ApplicationAccessType, String> getApplicationACLs() {
      return null;
    }

    @Override
    public AMContainerMap getAllContainers() {
      return null;
    }

    @Override
    public AMNodeMap getAllNodes() {
      return null;
    }
  }

  private Injector injector = Guice.createInjector(new ServletModule() {
    @Override
    protected void configureServlets() {

      appContext = new TestAppContext();
      bind(JAXBContextResolver.class);
      bind(AMWebServices.class);
      bind(GenericExceptionHandler.class);
      bind(AppContext.class).toInstance(appContext);
      bind(Configuration.class).toInstance(conf);

      serve("/*").with(GuiceContainer.class);
    }
  });

  public class GuiceServletConfig extends GuiceServletContextListener {

    @Override
    protected Injector getInjector() {
      return injector;
    }
  }

  @Before
  @Override
  public void setUp() throws Exception {
    super.setUp();
  }

  public TestAMWebServices() {
    super(new WebAppDescriptor.Builder(
        "org.apache.hadoop.mapreduce.v2.app2.webapp")
        .contextListenerClass(GuiceServletConfig.class)
        .filterClass(com.google.inject.servlet.GuiceFilter.class)
        .contextPath("jersey-guice-filter").servletPath("/").build());
  }

  @Test
  public void testAM() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .accept(MediaType.APPLICATION_JSON).get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testAMSlash() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce/")
        .accept(MediaType.APPLICATION_JSON).get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testAMDefault() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce/")
        .get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testAMXML() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .accept(MediaType.APPLICATION_XML).get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_XML_TYPE, response.getType());
    String xml = response.getEntity(String.class);
    verifyAMInfoXML(xml, appContext);
  }

  @Test
  public void testInfo() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .path("info").accept(MediaType.APPLICATION_JSON)
        .get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testInfoSlash() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .path("info/").accept(MediaType.APPLICATION_JSON)
        .get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testInfoDefault() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .path("info/").get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
    JSONObject json = response.getEntity(JSONObject.class);
    assertEquals("incorrect number of elements", 1, json.length());
    verifyAMInfo(json.getJSONObject("info"), appContext);
  }

  @Test
  public void testInfoXML() throws JSONException, Exception {
    WebResource r = resource();
    ClientResponse response = r.path("ws").path("v1").path("mapreduce")
        .path("info/").accept(MediaType.APPLICATION_XML)
        .get(ClientResponse.class);
    assertEquals(MediaType.APPLICATION_XML_TYPE, response.getType());
    String xml = response.getEntity(String.class);
    verifyAMInfoXML(xml, appContext);
  }

  @Test
  public void testInvalidUri() throws JSONException, Exception {
    WebResource r = resource();
    String responseStr = "";
    try {
      responseStr = r.path("ws").path("v1").path("mapreduce").path("bogus")
          .accept(MediaType.APPLICATION_JSON).get(String.class);
      fail("should have thrown exception on invalid uri");
    } catch (UniformInterfaceException ue) {
      ClientResponse response = ue.getResponse();
      assertEquals(Status.NOT_FOUND, response.getClientResponseStatus());
      WebServicesTestUtils.checkStringMatch(
          "error string exists and shouldn't", "", responseStr);
    }
  }

  @Test
  public void testInvalidUri2() throws JSONException, Exception {
    WebResource r = resource();
    String responseStr = "";
    try {
      responseStr = r.path("ws").path("v1").path("invalid")
          .accept(MediaType.APPLICATION_JSON).get(String.class);
      fail("should have thrown exception on invalid uri");
    } catch (UniformInterfaceException ue) {
      ClientResponse response = ue.getResponse();
      assertEquals(Status.NOT_FOUND, response.getClientResponseStatus());
      WebServicesTestUtils.checkStringMatch(
          "error string exists and shouldn't", "", responseStr);
    }
  }

  @Test
  public void testInvalidAccept() throws JSONException, Exception {
    WebResource r = resource();
    String responseStr = "";
    try {
      responseStr = r.path("ws").path("v1").path("mapreduce")
          .accept(MediaType.TEXT_PLAIN).get(String.class);
      fail("should have thrown exception on invalid uri");
    } catch (UniformInterfaceException ue) {
      ClientResponse response = ue.getResponse();
      assertEquals(Status.INTERNAL_SERVER_ERROR,
          response.getClientResponseStatus());
      WebServicesTestUtils.checkStringMatch(
          "error string exists and shouldn't", "", responseStr);
    }
  }

  public void verifyAMInfo(JSONObject info, TestAppContext ctx)
      throws JSONException {
    assertEquals("incorrect number of elements", 5, info.length());

    verifyAMInfoGeneric(ctx, info.getString("appId"), info.getString("user"),
        info.getString("name"), info.getLong("startedOn"),
        info.getLong("elapsedTime"));
  }

  public void verifyAMInfoXML(String xml, TestAppContext ctx)
      throws JSONException, Exception {
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    InputSource is = new InputSource();
    is.setCharacterStream(new StringReader(xml));
    Document dom = db.parse(is);
    NodeList nodes = dom.getElementsByTagName("info");
    assertEquals("incorrect number of elements", 1, nodes.getLength());

    for (int i = 0; i < nodes.getLength(); i++) {
      Element element = (Element) nodes.item(i);
      verifyAMInfoGeneric(ctx,
          WebServicesTestUtils.getXmlString(element, "appId"),
          WebServicesTestUtils.getXmlString(element, "user"),
          WebServicesTestUtils.getXmlString(element, "name"),
          WebServicesTestUtils.getXmlLong(element, "startedOn"),
          WebServicesTestUtils.getXmlLong(element, "elapsedTime"));
    }
  }

  public void verifyAMInfoGeneric(TestAppContext ctx, String id, String user,
      String name, long startedOn, long elapsedTime) {

    WebServicesTestUtils.checkStringMatch("id", ctx.getApplicationID()
        .toString(), id);
    WebServicesTestUtils.checkStringMatch("user", ctx.getUser().toString(),
        user);
    WebServicesTestUtils.checkStringMatch("name", ctx.getApplicationName(),
        name);

    assertEquals("startedOn incorrect", ctx.getStartTime(), startedOn);
    assertTrue("elapsedTime not greater then 0", (elapsedTime > 0));

  }
}