/*
 *
 *    OPEN-XCHANGE legal information
 *
 *    All intellectual property rights in the Software are protected by
 *    international copyright laws.
 *
 *
 *    In some countries OX, OX Open-Xchange, open xchange and OXtender
 *    as well as the corresponding Logos OX Open-Xchange and OX are registered
 *    trademarks of the Open-Xchange, Inc. group of companies.
 *    The use of the Logos is not covered by the GNU General Public License.
 *    Instead, you are allowed to use these Logos according to the terms and
 *    conditions of the Creative Commons License, Version 2.5, Attribution,
 *    Non-commercial, ShareAlike, and the interpretation of the term
 *    Non-commercial applicable to the aforementioned license is published
 *    on the web site http://www.open-xchange.com/EN/legal/index.html.
 *
 *    Please make sure that third-party modules and libraries are used
 *    according to their respective licenses.
 *
 *    Any modifications to this package must retain all copyright notices
 *    of the original copyright holder(s) for the original code used.
 *
 *    After any such modifications, the original and derivative code shall remain
 *    under the copyright of the copyright holder(s) and/or original author(s)per
 *    the Attribution and Assignment Agreement that can be located at
 *    http://www.open-xchange.com/EN/developer/. The contributing author shall be
 *    given Attribution for the derivative code and a license granting use.
 *
 *     Copyright (C) 2004-2010 Open-Xchange, Inc.
 *     Mail: info@open-xchange.com
 *
 *
 *     This program is free software; you can redistribute it and/or modify it
 *     under the terms of the GNU General Public License, Version 2 as published
 *     by the Free Software Foundation.
 *
 *     This program is distributed in the hope that it will be useful, but
 *     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 *     or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 *     for more details.
 *
 *     You should have received a copy of the GNU General Public License along
 *     with this program; if not, write to the Free Software Foundation, Inc., 59
 *     Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

package com.openexchange.ajax.login.osgi;

import java.util.Dictionary;
import java.util.Hashtable;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import javax.servlet.ServletException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.service.http.HttpService;
import org.osgi.service.http.NamespaceException;
import org.osgi.util.tracker.ServiceTrackerCustomizer;
import com.openexchange.ajax.Login;
import com.openexchange.config.ConfigurationService;
import com.openexchange.configuration.ServerConfig.Property;
import com.openexchange.login.ConfigurationProperty;

/**
 * {@link LoginServletRegisterer}
 *
 * @author <a href="mailto:marcus.klein@open-xchange.com">Marcus Klein</a>
 */
public class LoginServletRegisterer implements ServiceTrackerCustomizer {

    private static final Log LOG = LogFactory.getLog(LoginServletRegisterer.class);
    private static final String SERVLET_PATH = "/ajax/login";
    
    private final BundleContext context;
    private final Lock lock = new ReentrantLock();

    private ConfigurationService configService;
    private HttpService httpService;
    private Login login;

    public LoginServletRegisterer(BundleContext context) {
        super();
        this.context = context;
    }

    public Object addingService(ServiceReference reference) {
        final Object obj = context.getService(reference);
        final boolean needsRegistration;
        lock.lock();
        try {
            if (obj instanceof ConfigurationService) {
                configService = (ConfigurationService) obj;
            }
            if (obj instanceof HttpService) {
                httpService = (HttpService) obj;
            }
            needsRegistration = null != configService && null != httpService && login == null;
            if (needsRegistration) {
                login = new Login();
            }
        } finally {
            lock.unlock();
        }
        if (needsRegistration) {
            Dictionary<String, String> params = new Hashtable<String, String>();
            addProperty(params, Property.UI_WEB_PATH);
            addProperty(params, Property.COOKIE_HASH);
            addProperty(params, ConfigurationProperty.HTTP_AUTH_AUTOLOGIN);
            addProperty(params, ConfigurationProperty.HTTP_AUTH_CLIENT);
            addProperty(params, ConfigurationProperty.HTTP_AUTH_VERSION);
            addProperty(params, ConfigurationProperty.ERROR_PAGE_TEMPLATE);
            try {
                LOG.info("Registering login servlet.");
                httpService.registerServlet(SERVLET_PATH, new Login(), params, null);
            } catch (ServletException e) {
                LOG.error("Registering login servlet failed.", e);
            } catch (NamespaceException e) {
                LOG.error("Registering login servlet failed.", e);
            }
        }
        return obj;
    }

    private void addProperty(Dictionary<String, String> params, Property property) {
        String propertyName = property.getPropertyName();
        params.put(propertyName, configService.getProperty(propertyName, property.getDefaultValue()));
    }

    private void addProperty(Dictionary<String, String> params, com.openexchange.login.ConfigurationProperty property) {
        String propertyName = property.getPropertyName();
        String value = configService.getProperty(propertyName, property.getDefaultValue());
        if (null != value) {
            params.put(propertyName, value);
        }
    }

    public void modifiedService(ServiceReference reference, Object service) {
        // Nothing to do.
    }

    public void removedService(ServiceReference reference, Object service) {
        HttpService unregister = null;
        lock.lock();
        try {
            if (service instanceof ConfigurationService) {
                configService = null;
            }
            if (service instanceof HttpService) {
                if (login != null) {
                    unregister = httpService;
                    login = null;
                }
                httpService = null;
            }
        } finally {
            lock.unlock();
        }
        if (null != unregister) {
            LOG.info("Unregistering login servlet.");
            unregister.unregister(SERVLET_PATH);
        }
        context.ungetService(reference);
    }
}
