package org.openslx.imagemaster.serversession;

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.UUID;

import org.apache.log4j.Logger;
import org.openslx.imagemaster.session.SessionManager;
import org.openslx.imagemaster.thrift.iface.ServerSessionData;
import org.openslx.imagemaster.util.Hash;

/**
 * Manages all server sessions and kicks timed out sessions.
 */
public class ServerSessionManager
{
	private static Logger log = Logger.getLogger( SessionManager.class );

	// Map of currently known sessions
	private static final Map<String, ServerSession> serverSessions = new LinkedHashMap<String, ServerSession>();
	private static final Thread gcThread;

	public static ServerSessionData addSession( ServerSession serverSession )
	{
		final String sessionId = Hash.sha256( UUID.randomUUID().toString() );

		synchronized ( serverSessions ) {
			serverSessions.put( sessionId, serverSession );
		}
		return new ServerSessionData( sessionId );
	}

	public static ServerSession getSession( String sessionId )
	{
		final ServerSession serverSession;
		synchronized ( serverSessions ) {
			serverSession = serverSessions.get( sessionId );
		}
		if ( serverSession == null || serverSession.timedOut() ) {
			return null;
		}
		serverSession.refresh();
		return serverSession;
	}

	static {
		gcThread = new Thread( new Runnable() {

			@Override
			public void run()
			{
				for ( ;; ) {
					try {
						Thread.sleep( 1800L * 1000L );
					} catch ( InterruptedException e ) {
					}
					synchronized ( serverSessions ) {
						Iterator<ServerSession> it = serverSessions.values().iterator();
						while ( it.hasNext() ) {
							final ServerSession s = it.next();
							if ( s.timedOut() ) {
								log.debug( "Removing old session of " + s.getOrganization() );
								it.remove();
							}
						}
					}
				}
			}
		} );
		gcThread.start();
	}

}