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/***
 * Reflex-Fractal
 *
 * Copyright (C) 2007 : INRIA - Domaine de Voluceau, Rocquencourt, B.P. 105, 
 * 78153 Le Chesnay Cedex - France 
 *
 * 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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact: jade  inrialpes  fr
 *
 * Author: SARDES project - http://sardes.inrialpes.fr
 *
 */
 
package org.ow2.jasmine.jade.reflex.api;

import java.util.Map;

import org.objectweb.fractal.api.Component;
import org.objectweb.fractal.api.factory.Factory;
import org.objectweb.fractal.api.factory.GenericFactory;
import org.objectweb.fractal.api.factory.InstantiationException;

/**
 * Provides a static method to get a Fractal bootstrap component which operates in 
 * reflexive mode (the components created by this bootstrap are reflexive components, 
 * which means that they are associated to a dual component created by a dual bootstrap).
 * 
 * The fractal.provider system property should be defined, as it specifies
 * which Fractal implementation to use. 
 *  
 * The reflex-fractal.name and reflex-fractal.level system properties
 * respectively indicate the name and the reflexive level (execution / meta) of the 
 * returned Fractal bootstrap component.
 * 
 * @author Fabienne Boyer
 */
public class ReflexFractal {

    static Component bootstrapComponent = null;

    /**
     * Private constructor (uninstantiable class).
     */

    private ReflexFractal() {
    }

    /**
     * Returns a reflexive bootstrap component (i.e. a component which allows to
     * create other components in reflexive mode). This method more precisely
     * creates an instance of the class whose name is prefixed by
     * "org.ow2.jasmine.jade.reflex.util.Reflex" followed by the fractal.provider
     * system property. For instance, if the fractal.provider system
     * property is equal to org.objectweb.fractal.julia.Julia, this method
     * instanciate the class org.ow2.jasmine.jade.reflex.util.ReflexJulia. This class must
     * implement the {@link Factory} interface.
     * 
     * @return a bootstrap component to create other components. This component
     *         provides at least two interfaces named type-factory
     *         and generic-factory to create component types and
     *         components. The type of the generic-factory interface
     *         is {@link org.objectweb.fractal.api.factory.GenericFactory}, or
     *         a sub type of this type, but the type of the
     *         type-factory interface is not necessarily
     *         {@link org.objectweb.fractal.api.type.TypeFactory} (or a sub type
     *         of this type).
     * @throws InstantiationException
     *             if the bootstrap component cannot be created.
     */

    public static Component getBootstrapComponent()
            throws InstantiationException {
        if (bootstrapComponent != null)
            return bootstrapComponent;

        String bootTmplClassName = System.getProperty("fractal.provider");
        if (bootTmplClassName == null) {
            throw new InstantiationException(
                    "The fractal.provider system property is not defined");
        }
        Factory bootTmpl;
        try {
            /*
             * TODO build the bootTmpClassName from configuration file Class
             * bootTmplClass = Class.forName("Reflex" + bootTmplClassName);
             */
            Class bootTmplClass = Class
                    .forName("org.ow2.jasmine.jade.reflex.util.ReflexJulia");
            bootTmpl = (Factory) bootTmplClass.newInstance();

        } catch (Exception e) {
            throw new InstantiationException(
                    "Cannot find or instantiate the 'Reflex"
                            + bootTmplClassName
                            + "' class specified in the fractal.provider system property");
        }
        bootstrapComponent = bootTmpl.newFcInstance();
        return bootstrapComponent;
    }

    /**
     * Returns a bootstrap component to create other components. This method
     * creates an instance of the class whose name is associated to the
     * "fractal.provider" key, which much implement the {@link Factory} or
     * {@link GenericFactory} interface, and returns the component instantiated
     * by this factory.
     * 
     * @param hints
     *            a map which must associate a value to the "fractal.provider"
     *            key, and which may associate a ClassLoader to the
     *            "classloader" key. This class loader will be used to load the
     *            bootstrap component.
     * @return a bootstrap component to create other components.
     * @throws InstantiationException
     *             if the bootstrap component cannot be created.
     */

    public static Component getBootstrapComponent(final Map hints)
            throws InstantiationException {
        String bootTmplClassName = (String) hints.get("fractal.provider");
        if (bootTmplClassName == null) {
            bootTmplClassName = System.getProperty("fractal.provider");
        }
        // TODO build the bootTmpClassName from configuration file
        System.out
                .println("ReflexFractal.getBootstrapComponent(hints) NOT YET IMPLEMENTED");

        if (bootTmplClassName == null) {
            throw new InstantiationException(
                    "The fractal.provider value is not defined");
        }
        Object bootTmpl;
        try {
            ClassLoader cl = (ClassLoader) hints.get("classloader");
            if (cl == null) {
                cl = new ReflexFractal().getClass().getClassLoader();
            }
            Class bootTmplClass = cl.loadClass(bootTmplClassName);
            bootTmpl = bootTmplClass.newInstance();
        } catch (Exception e) {
            throw new InstantiationException("Cannot find or instantiate the '"
                    + bootTmplClassName
                    + "' class associated to the fractal.provider key");
        }
        if (bootTmpl instanceof GenericFactory) {
            return ((GenericFactory) bootTmpl).newFcInstance(null, null, hints);
        } else {
            return ((Factory) bootTmpl).newFcInstance();
        }
    }
}