/*
 * $Id$
 *
 * Copyright (C) 2003-2015 JNode.org
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; If not, write to the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
package org.jnode.plugin;

import java.util.Iterator;
import java.util.List;

/**
 * Registry of all plugins in the system.
 *
 * @author Ewout Prangsma (epr@users.sourceforge.net)
 */
public interface PluginRegistry extends Iterable<PluginDescriptor> {

    /**
     * Gets the descriptor of the plugin with the given id.
     *
     * @param pluginId
     * @return The plugin descriptor found, or null if not found
     */
    public PluginDescriptor getPluginDescriptor(String pluginId);

    /**
     * Gets the extension point with the given id.
     *
     * @param id
     * @return The extension point found, or null if not found
     */
    public ExtensionPoint getExtensionPoint(String id);

    /**
     * Returns an iterator to iterate over all PluginDescriptor's.
     *
     * @return Iterator<PluginDescriptor>
     */
    public Iterator<PluginDescriptor> iterator();

    /**
     * Load a plugin from a given loader.
     *
     * @param loader
     * @param pluginReference A fully qualified reference to the plugin that should be loaded.
     * @param resolve true to resolve the plugin dependencies, false otherwise
     * @return The descriptor of the loaded plugin.
     * @throws PluginException
     */
    public PluginDescriptor loadPlugin(PluginLoader loader, PluginReference pluginReference, boolean resolve)
        throws PluginException;

    /**
     * Remove the plugin with the given id from this registry.
     * All plugins that depend on the given plugin will also be unloaded.
     *
     * @param pluginId
     * @return The references of the plugins that have been unloaded in order of loading.
     * @throws PluginException
     */
    public List<PluginReference> unloadPlugin(String pluginId) throws PluginException;

    /**
     * Gets the classloader that loads classes from all loaded plugins.
     *
     * @return ClassLoader
     */
    public ClassLoader getPluginsClassLoader();
}