/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.test.rest;
  
  import static org.opencastproject.util.data.functions.Misc.chuck;
  
  import org.opencastproject.util.UrlSupport;
  
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.servlet.ServletContextHandler;
  import org.eclipse.jetty.servlet.ServletHolder;
  import org.glassfish.jersey.server.ResourceConfig;
  import org.glassfish.jersey.servlet.ServletContainer;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.net.URL;
  import java.util.concurrent.ThreadLocalRandom;
  
  /**
   * Helper environment for creating REST service unit tests.
   * <p>
   * The REST endpoint to test needs a no-arg constructor in order to be created by the framework.
   * <p>
   * Write REST unit tests using <a href="http://code.google.com/p/rest-assured/">rest assured</a>.
   * <h2>Example Usage</h2>
   * 
   * <pre>
   *   import static com.jayway.restassured.RestAssured.*;
   *   import static com.jayway.restassured.matcher.RestAssuredMatchers.*;
   *   import static org.hamcrest.Matchers.*;
   *   import static org.opencastproject.rest.RestServiceTestEnv.*
   *
   *   public class RestEndpointTest {
   *   // create a local environment running on some random port
   *   // use rt.host("/path/to/service") to wrap all URL creations for HTTP request methods
   *   private static final RestServiceTestEnv rt = testEnvScanAllPackages(localhostRandomPort());
   *
   *   \@BeforeClass public static void oneTimeSetUp() {
   *   env.setUpServer();
   *   }
   *
   *   \@AfterClass public static void oneTimeTearDown() {
   *   env.tearDownServer();
   *   }
   *   }
   * </pre>
   * 
   * Add the following dependencies to your pom
   * 
   * <pre>
   * &lt;dependency&gt;
   *   &lt;groupId&gt;com.jayway.restassured&lt;/groupId&gt;
   *   &lt;artifactId&gt;rest-assured&lt;/artifactId&gt;
   *   &lt;version&gt;1.7.2&lt;/version&gt;
   *   &lt;scope&gt;test&lt;/scope&gt;
   * &lt;/dependency&gt;
   * &lt;dependency&gt;
   *   &lt;groupId&gt;org.apache.httpcomponents&lt;/groupId&gt;
   *   &lt;artifactId&gt;httpcore&lt;/artifactId&gt;
   *   &lt;version&gt;4.2.4&lt;/version&gt;
   *   &lt;scope&gt;test&lt;/scope&gt;
   * &lt;/dependency&gt;
   * </pre>
   */
  public final class RestServiceTestEnv {
    private Server server;
  
    private URL baseUrl = null;
    private final ResourceConfig cfg;
  
    private static final Logger logger = LoggerFactory.getLogger(RestServiceTestEnv.class);
  
    /**
     * Create an environment for <code>baseUrl</code>. The base URL should be the URL where the service to test is
     * mounted, e.g. http://localhost:8090/test
     */
    private RestServiceTestEnv(ResourceConfig cfg) {
      this.cfg = cfg;
   }
 
   public static RestServiceTestEnv testEnvForClasses(Class<?>... restServices) {
     return new RestServiceTestEnv(new ResourceConfig(restServices));
   }
 
   /** Create a URL suitable for rest-assured's post(), get() e.al. methods. */
   public String host(String path) {
     if (baseUrl == null) {
       throw new RuntimeException("Server not yet started");
     }
     return UrlSupport.url(baseUrl, path).toString();
   }
 
   /**
    * Return the base URL of the HTTP server. <code>http://host:port</code> public URL getBaseUrl() { return baseUrl; }
    *
    * Call in @BeforeClass annotated method.
    */
   public void setUpServer() {
     int port = -1;
     int maxRetries = 100;
     try {
       ServletContainer servletContainer = new ServletContainer(cfg);
       ServletHolder jerseyServlet = new ServletHolder(servletContainer);
       for (int tries = maxRetries; tries > 0; tries--) {
         try {
           port = 3000 + tries + ThreadLocalRandom.current().nextInt(62000);
           logger.info("Starting http server at port {}", port);
           server = new Server(port);
           ServletContextHandler context = new ServletContextHandler(server, "/");
           context.addServlet(jerseyServlet, "/*");
           server.start();
           baseUrl = UrlSupport.url("http", "127.0.0.1", port);
           return;
         } catch (IOException e) {
           logger.error("Couldn't bind server to port {}. Retrying with new port...", port, e);
           // Rethrow exception after last try
           if (tries == 1) {
             logger.error("Couldn't start server after {} tries.", maxRetries);
             throw e;
           }
           Thread.sleep(100);
         }
       }
     } catch (Exception e) {
       logger.error("Unexpected Exception occurred while setting up http server");
       chuck(e);
     }
   }
 
   /** Call in @AfterClass annotated method. */
   public void tearDownServer() {
     if (server != null) {
       logger.info("Stop http server");
       try {
         server.stop();
       } catch (Exception e) {
         logger.warn("Stop http server - failed {}", e.getMessage());
       }
     }
   }
 
 }