package org.argeo.eclipse.ui.jetty;
   
   import java.io.IOException;
   import java.lang.management.ManagementFactory;
   import java.nio.file.Files;
   import java.nio.file.Path;
   
   import javax.servlet.ServletContextEvent;
   import javax.servlet.ServletContextListener;
  
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.server.ServerConnector;
  import org.eclipse.jetty.servlet.DefaultServlet;
  import org.eclipse.jetty.servlet.ServletContextHandler;
  import org.eclipse.jetty.servlet.ServletHolder;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.util.thread.QueuedThreadPool;
  import org.eclipse.rap.rwt.application.AbstractEntryPoint;
  import org.eclipse.rap.rwt.application.ApplicationRunner;
  import org.eclipse.rap.rwt.engine.RWTServlet;
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Control;
  import org.eclipse.swt.widgets.Label;
  
  /** A minimal RWT runner based on embedded Jetty. */
  public class RwtRunner {
  
  	private final Server server;
  	private final ServerConnector serverConnector;
  	private Path tempDir;
  
  	public RwtRunner() {
  		server = new Server(new QueuedThreadPool(10, 1));
  		serverConnector = new ServerConnector(server);
  		serverConnector.setPort(0);
  		server.setConnectors(new Connector[] { serverConnector });
  	}
  
  	protected Control createUi(Composite parent, Object context) {
  		return new Label(parent, SWT.NONE);
  	}
  
  	public void init() {
  		ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
  		context.setContextPath("/");
  		server.setHandler(context);
  
  		String entryPoint = "app";
  
  		// rwt-resources requires a file system
  		try {
  			tempDir = Files.createTempDirectory("argeo-rwtRunner");
  			context.setBaseResource(Resource.newResource(tempDir.resolve("www").toString()));
  		} catch (IOException e) {
  			throw new IllegalStateException("Cannot create temporary directory", e);
  		}
  		context.addEventListener(new ServletContextListener() {
  			ApplicationRunner applicationRunner;
  
  			@Override
  			public void contextInitialized(ServletContextEvent sce) {
  				applicationRunner = new ApplicationRunner(
  						(application) -> application.addEntryPoint("/" + entryPoint, () -> new AbstractEntryPoint() {
  							private static final long serialVersionUID = 5678385921969090733L;
  
  							@Override
  							protected void createContents(Composite parent) {
  								createUi(parent, null);
  							}
  						}, null), sce.getServletContext());
  				applicationRunner.start();
  			}
  
  			@Override
  			public void contextDestroyed(ServletContextEvent sce) {
  				applicationRunner.stop();
  			}
  		});
  
  		context.addServlet(new ServletHolder(new RWTServlet()), "/" + entryPoint);
  
  		// Required to serve rwt-resources. It is important that this is last.
  		ServletHolder holderPwd = new ServletHolder("default", DefaultServlet.class);
  		context.addServlet(holderPwd, "/");
  
  		try {
  			server.start();
  		} catch (Exception e) {
  			throw new IllegalStateException("Cannot start Jetty server", e);
  		}
  	}
  
  	public void destroy() {
  		try {
  			serverConnector.close();
  			server.stop();
  			// TODO delete temp dir
 		} catch (Exception e) {
 			e.printStackTrace();
 		}
 	}
 
 	public Integer getEffectivePort() {
 		return serverConnector.getLocalPort();
 	}
 
 	public void waitFor() throws InterruptedException {
 		server.join();
 	}
 
 	public static void main(String[] args) throws Exception {
 		RwtRunner rwtRunner = new RwtRunner() {
 
 			@Override
 			protected Control createUi(Composite parent, Object context) {
 				Label label = new Label(parent, SWT.NONE);
 				label.setText("Hello world!");
 				return label;
 			}
 		};
 		rwtRunner.init();
 		Runtime.getRuntime().addShutdownHook(new Thread(() -> rwtRunner.destroy(), "Jetty shutdown"));
 
 		long jvmUptime = ManagementFactory.getRuntimeMXBean().getUptime();
 		System.out.println("App available in " + jvmUptime + " ms, on port " + rwtRunner.getEffectivePort());
 
 		// open browser in app mode
 		Thread.sleep(2000);// wait for RWT to be ready
 		Runtime.getRuntime().exec("google-chrome --app=http://localhost:" + rwtRunner.getEffectivePort() + "/app");
 
 		rwtRunner.waitFor();
 	}
 }