/*

 * otr4j, the open source java otr librar

 *

 * Distributable under LGPL license.

 * See terms of license at gnu.org.

 */

package net.java.otr4j;

import java.security.PublicKey;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Vector;

import net.java.otr4j.session.Session;

import net.java.otr4j.session.SessionID;

import net.java.otr4j.session.SessionImpl;

import net.java.otr4j.session.SessionStatus;

/**

 * 

 * @author George Politis

 * 

 */

public class OtrEngineImpl implements OtrEngine {

	public OtrEngineImpl(OtrEngineHost listener) {

		if (listener == null)

			throw new IllegalArgumentException("OtrEgineHost is required.");

		this.setListener(listener);

	}

	private OtrEngineHost listener;

	private Map<SessionID, Session> sessions;

	private Session getSession(SessionID sessionID) {

		if (sessionID == null || sessionID.equals(SessionID.Empty))

			throw new IllegalArgumentException();

		if (sessions == null)

			sessions = new Hashtable<SessionID, Session>();

		if (!sessions.containsKey(sessionID)) {

			Session session = new SessionImpl(sessionID, getListener());

			sessions.put(sessionID, session);

			session.addOtrEngineListener(new OtrEngineListener() {

				public void sessionStatusChanged(SessionID sessionID) {

					for (OtrEngineListener l : listeners)

						l.sessionStatusChanged(sessionID);

				}

			});

		}

		return sessions.get(sessionID);

	}

	public SessionStatus getSessionStatus(SessionID sessionID) {

		return this.getSession(sessionID).getSessionStatus();

	}

	public String transformReceiving(SessionID sessionID, String msgText) {

		try {

			return this.getSession(sessionID).transformReceiving(msgText);

		} catch (OtrException e) {

			listener.showError(sessionID, e.getMessage());

			return null;

		}

	}

	public String transformSending(SessionID sessionID, String msgText) {

		try {

			return this.getSession(sessionID).transformSending(msgText, null);

		} catch (OtrException e) {

			listener.showError(sessionID, e.getMessage());

			return null;

		}

	}

	public void endSession(SessionID sessionID) {

		try {

			this.getSession(sessionID).endSession();

		} catch (OtrException e) {

			listener.showError(sessionID, e.getMessage());

		}

	}

	public void startSession(SessionID sessionID) {

		try {

			this.getSession(sessionID).startSession();

		} catch (OtrException e) {

			listener.showError(sessionID, e.getMessage());

		}

	}

	private void setListener(OtrEngineHost listener) {

		this.listener = listener;

	}

	private OtrEngineHost getListener() {

		return listener;

	}

	public void refreshSession(SessionID sessionID) {

		try {

			this.getSession(sessionID).refreshSession();

		} catch (OtrException e) {

			listener.showError(sessionID, e.getMessage());

		}

	}

	public PublicKey getRemotePublicKey(SessionID sessionID) {

		return this.getSession(sessionID).getRemotePublicKey();

	}

	private List<OtrEngineListener> listeners = new Vector<OtrEngineListener>();

	public void addOtrEngineListener(OtrEngineListener l) {

		synchronized (listeners) {

			if (!listeners.contains(l))

				listeners.add(l);

		}

	}

	public void removeOtrEngineListener(OtrEngineListener l) {

		synchronized (listeners) {

			listeners.remove(l);

		}

	}

}