/*******************************************************************************
 *
 * Copyright (c) 2004-2009 Oracle Corporation.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * 
 *    Kohsuke Kawaguchi, Tom Huybrechts
 *
 *
 *******************************************************************************/ 

package hudson;

import hudson.model.Hudson;

import java.io.File;
import java.io.IOException;
import java.util.List;

/**
 * Pluggability point for how to create {@link PluginWrapper}.
 *
 * <p> This extension point was added to allow plugins to be loaded into a
 * different environment (such as loading it in an existing DI container like
 * Plexus.) A plugin strategy is a singleton instance, and as such this feature
 * is primarily meant for OEM.
 *
 * See {@link PluginManager#createPluginStrategy()} for how this instance is
 * created.
 */
public interface PluginStrategy extends ExtensionPoint {

    /**
     * Creates a plugin wrapper, which provides a management interface for the
     * plugin
     *
     * @param archive Either a directory that points to a pre-exploded plugin,
     * or an hpi file, or an hpl file.
     */
    public abstract PluginWrapper createPluginWrapper(File archive)
            throws IOException;

    /**
     * Loads the plugin and starts it.
     *
     * <p> This should be done after all the classloaders are constructed for
     * all the plugins, so that dependencies can be properly loaded by plugins.
     */
    public abstract void load(PluginWrapper wrapper) throws IOException;

    /**
     * Optionally start services provided by the plugin. Should be called when
     * all plugins are loaded.
     *
     * @param plugin
     */
    public abstract void initializeComponents(PluginWrapper plugin);

    /**
     * Find components of the given type using the assigned strategy.
     *
     * @param type The component type
     * @param hudson The Hudson scope
     * @return Sequence of components
     * @since 1.397
     */
    public abstract <T> List<ExtensionComponent<T>> findComponents(Class<T> type, Hudson hudson);
}