package geniusweb.runserver;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;

import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import geniusweb.deadline.Deadline;
import geniusweb.deadline.DeadlineTime;
import geniusweb.protocol.session.TeamInfo;
import geniusweb.protocol.session.saop.SAOPSettings;
import geniusweb.references.Parameters;
import geniusweb.references.PartyRef;
import geniusweb.references.PartyWithParameters;
import geniusweb.references.PartyWithProfile;
import geniusweb.references.ProfileRef;

/**
 * End to end test starts server, plus partyserver plus profilesserver, and then
 * tries to launch large number of parties and keep them busy. Checks and
 * reports the average CPU loads. Ensure that you have no other background tasks
 * when you run this test, to avoid incorrect CPU measurements (we can't measure
 * java-only CPU loads)
 * 
 * 
 * <h2>Large tests</h2> Tomcat-embed seems very limited in heap space. Best way
 * to test this with {@link #NUMBER_SESSIONS}>20 is to run all services on
 * standard tomcat (not embed). To achieve this, disable the @Before and @After.
 * Additionally, make sure that server.xml has maxThreads="4500" or some large
 * number sufficient for your test.
 */
public class MaxLoadTest {
	private static final int NUMBER_SESSIONS = 5;
	private static final int INTER_LAUNCH_DELAY = 20;
	private static final int PARTY_RESPONSETIME = 1;
    
	// HACK can we get it from maven?
	private static final ObjectMapper jackson = new ObjectMapper();

	/**
	 * Test takes average load of last minute. It may take also a minute or two
	 * to launch all sessions to start with. The average should be taken AFTER
	 * all sessions were launched.
	 */
	private static final long TEST_TIME_MS = 3 * 60 * 1000;

	private static final EmbeddedTomcat tomcat = new EmbeddedTomcat();
	private static final Parameters parameters = new Parameters().with("delay",
			PARTY_RESPONSETIME);
	private static final String PROFILE1 = "ws://localhost:8080/profilesserver/websocket/get/7issues/7issues1";
	private static final String PROFILE2 = "ws://localhost:8080/profilesserver/websocket/get/7issues/7issues2";
	private static final Deadline deadline = new DeadlineTime(TEST_TIME_MS);

	private final URL url;
	private final byte[] startcommand;
	private final String GENIUSWEB_VERSION;
	private final String HARDLINER;
	

	public MaxLoadTest() throws URISyntaxException, FileNotFoundException, IOException, XmlPullParserException {
	    MavenXpp3Reader reader = new MavenXpp3Reader();
	    Model model = reader.read(new FileReader("pom.xml"));
		GENIUSWEB_VERSION = model.getVersion(); // actual geniusweb version in the POM.
		HARDLINER = "http://localhost:8080/partiesserver/run/hardliner-"
				+ GENIUSWEB_VERSION;

		url = new URL("http://localhost:8080/runserver/run");
		String startsession = jackson.writeValueAsString(getSettings());
		startcommand = startsession.toString().getBytes(StandardCharsets.UTF_8);
	}

	/**
	 * Start up embedded tomcat servers (all: parties-, profile- and run-server)
	 * 
	 * @throws InterruptedException
	 * 
	 * @throws Throwable
	 */
	@Before
	public void before() throws InterruptedException {
		tomcat.start();
		tomcat.deploy("runserver");
		tomcat.deployWar("profilesserver", new File(
				"target/jars/profilesserver-" + GENIUSWEB_VERSION + ".war"));
		tomcat.deployWar("partiesserver", new File(
				"target/jars/partiesserver-" + GENIUSWEB_VERSION + ".war"));
		System.out.println("waiting for server start");
		Thread.sleep(1500);// HOW do this properly?
		System.out.println("server started I hope");

	}

	@After
	public void after() throws InterruptedException {
		System.setSecurityManager(null);
		tomcat.stop();
		Thread.sleep(2000);
	}

	@Test
	public void testRunOneSession()
			throws URISyntaxException, IOException, InterruptedException {

		for (int n = 0; n < NUMBER_SESSIONS; n++) {
			startSession();
			Thread.sleep(INTER_LAUNCH_DELAY);
		}

		// wait at least 1minute, becaues getLoadAver averages over 1 minute.
		long testtime = Math.max(TEST_TIME_MS + 100, 60 * 1000);
		System.out.println("Started session. Waiting termination. This should take about "+testtime/1000+"s");
		for (int n=0; n<testtime/1000; n++) {
			System.out.print(n+".");
			Thread.sleep(1000);
		}
		OperatingSystemMXBean operatingSystemMXBean = ManagementFactory
				.getOperatingSystemMXBean();

		System.out.println("average load in last minute was "
				+ operatingSystemMXBean.getSystemLoadAverage());
	}

	/**
	 * 
	 * @return the response received from the startup request
	 * @throws IOException
	 * @throws ProtocolException
	 * @throws IllegalStateException if party can not be launched.
	 */
	private void startSession() throws IOException, ProtocolException {
		URLConnection con = url.openConnection();
		HttpURLConnection http = (HttpURLConnection) con;
		http.setRequestMethod("POST"); // PUT is another valid option
		http.setDoOutput(true);

		http.setFixedLengthStreamingMode(startcommand.length);
		http.setRequestProperty("Content-Type",
				"application/json; charset=UTF-8");
		http.setUseCaches(false);
		http.setDoOutput(true);
		http.connect();
		try (OutputStream os = http.getOutputStream()) {
			os.write(startcommand);
		}

		InputStream is = http.getInputStream();
		BufferedReader rd = new BufferedReader(new InputStreamReader(is));
		String response = "";
		String line;
		while ((line = rd.readLine()) != null) {
			response += line + "\r";
		}
		rd.close();
		System.out.println("sent request. Response=" + response);
		if (!(response.startsWith("SAOP")))
			throw new IllegalStateException(
					"Failed to start party:" + response);
	}

	private SAOPSettings getSettings() throws URISyntaxException {
		PartyRef partyref = new PartyRef(HARDLINER);
		PartyWithParameters party1 = new PartyWithParameters(partyref,
				parameters);
		PartyWithParameters party2 = new PartyWithParameters(partyref,
				parameters);
		PartyWithProfile partyprofile1 = new PartyWithProfile(party1,
				new ProfileRef(PROFILE1));
		PartyWithProfile partyprofile2 = new PartyWithProfile(party2,
				new ProfileRef(PROFILE2));
		TeamInfo team1 = new TeamInfo(Arrays.asList(partyprofile1));
		TeamInfo team2 = new TeamInfo(Arrays.asList(partyprofile2));

		List<TeamInfo> participants = Arrays.asList(team1, team2);
		SAOPSettings settings = new SAOPSettings(participants, deadline);
		return settings;
	}

}