package org.argeo.cms.swt.rap.cli;

import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Objects;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.argeo.minidesktop.MiniDesktopManager;
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.ApplicationConfiguration;
import org.eclipse.rap.rwt.application.ApplicationRunner;
import org.eclipse.rap.rwt.application.EntryPoint;
import org.eclipse.rap.rwt.application.Application.OperationMode;
import org.eclipse.rap.rwt.engine.RWTServlet;
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;

	private ApplicationConfiguration applicationConfiguration;

	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, 0);
	}

	public void init() {
		Objects.requireNonNull(applicationConfiguration);

		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(applicationConfiguration, 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);
		}
		Runtime.getRuntime().addShutdownHook(new Thread(() -> destroy(), "Jetty shutdown"));

		long jvmUptime = ManagementFactory.getRuntimeMXBean().getUptime();
		System.out.println("RWT App available in " + jvmUptime + " ms, on port " + getEffectivePort());
	}

	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 void setApplicationConfiguration(ApplicationConfiguration applicationConfiguration) {
		this.applicationConfiguration = applicationConfiguration;
	}

	public static void main(String[] args) throws Exception {
		RwtRunner rwtRunner = new RwtRunner();

		String entryPoint = "app";
		ApplicationConfiguration applicationConfiguration = (application) -> {
			application.setOperationMode(OperationMode.SWT_COMPATIBILITY);
			application.addEntryPoint("/" + entryPoint, () -> new EntryPoint() {
				@Override
				public int createUI() {
					MiniDesktopManager miniDesktopManager = new MiniDesktopManager(false, false);
					miniDesktopManager.init();
					miniDesktopManager.run();
					return 0;
				}
			}, null);
		};

		rwtRunner.setApplicationConfiguration(applicationConfiguration);
		rwtRunner.init();

		// 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();
	}
}