package geniusweb.simplerunner;

import java.util.List;
import java.util.logging.Level;

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

import geniusweb.events.ProtocolEvent;
import geniusweb.protocol.CurrentNegoState;
import geniusweb.protocol.NegoProtocol;
import geniusweb.protocol.NegoSettings;
import geniusweb.protocol.NegoState;
import geniusweb.protocol.partyconnection.ProtocolToPartyConnFactory;
import tudelft.utilities.logging.Reporter;

/**
 * A simple tool to run a negotiation stand-alone, without starting the servers.
 * All referred files and classes need to be stored locally (or be in the
 * dependency list if you use maven).
 * <p>
 * <em>IMPORTANT</em> SimpleRunner has a number of restrictions, compared to a
 * run using a runserver and partyserver
 * <ul>
 * <li>With stand-alone runner, your parties are run together in a single
 * classloader. The main implication is that there may arise version conflicts
 * between parties.
 * <li>Stand-alone runner does NOT enforce the time deadline. Parties may
 * continue running indefinitely and thus bog down the JVM and stalling
 * tournaments.
 * </ul>
 */
public class Runner implements Runnable {
	private final static ObjectMapper jackson = new ObjectMapper();

	private final NegoSettings settings;
	private final NegoProtocol protocol;
	private final ClassPathConnectionFactory connectionfactory;
	protected final Reporter log;
	private boolean properlyStopped = false;
	private final int LOOPTIME = 200;// ms
	private final int FINALWAITTIME = 5000;// ms
	private long maxruntime;

	/**
	 * 
	 * @param settings          the {@link NegoSettings}
	 * @param connectionfactory the {@link ProtocolToPartyConnFactory}
	 * @param logger            the {@link Reporter} to log problems
	 * @param maxruntime        limit in millisecs. Ignored if 0
	 */
	public Runner(NegoSettings settings,
			ClassPathConnectionFactory connectionfactory, Reporter logger,
			long maxruntime) {
		if (settings == null || connectionfactory == null) {
			throw new NullPointerException("Arguments must be not null");
		}
		this.settings = settings;
		this.log = logger;
		this.protocol = settings.getProtocol(log);
		this.connectionfactory = connectionfactory;
		this.maxruntime = maxruntime;
	}

	/**
	 * 
	 * @return true if the runner has finished
	 */
	public boolean isProperlyStopped() {
		return properlyStopped;
	}

	@Override
	public void run() {
		protocol.addListener(evt -> handle(evt));
		protocol.start(connectionfactory);
		long remainingtime = maxruntime;
		while (!properlyStopped && (maxruntime == 0 || remainingtime > 0)) {
			try {
				Thread.sleep(LOOPTIME);
				remainingtime -= LOOPTIME;
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		log.log(Level.INFO, "Waiting for connection closure");

		remainingtime = FINALWAITTIME;
		while (remainingtime > 0
				&& !connectionfactory.getOpenConnections().isEmpty()) {
			try {
				Thread.sleep(LOOPTIME);
				remainingtime -= LOOPTIME;
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		List<BasicConnection> openconn = connectionfactory.getOpenConnections();
		if (!openconn.isEmpty())
			log.log(Level.WARNING, "Connections " + openconn
					+ " did not close properly at end of run");
		log.log(Level.INFO, "end run");
	}

	private void handle(ProtocolEvent evt) {
		if (evt instanceof CurrentNegoState && ((CurrentNegoState) evt)
				.getState().isFinal(System.currentTimeMillis())) {
			stop();
		}
	}

	protected void stop() {
		logFinal(Level.INFO, protocol.getState());
		properlyStopped = true;
	}

	/**
	 * Separate so that we can intercept this when mocking, as this will crash
	 * on mocks because {@link #jackson} can not handle mocks.
	 * 
	 * @param level the log {@link Level}
	 * @param state the {@link NegoState} to log
	 */
	protected void logFinal(Level level, NegoState state) {
		try {
			log.log(level, "protocol ended normally: "
					+ jackson.writeValueAsString(protocol.getState()));
		} catch (JsonProcessingException e) {
			e.printStackTrace();
		}
	}

	/**
	 * @return protocol that runs/ran the session.
	 */
	public NegoProtocol getProtocol() {
		return protocol;
	}
}