/**

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.

 *

 * Oracle and Java are registered trademarks of Oracle and/or its affiliates.

 * Other names may be trademarks of their respective owners.

 *

 * The contents of this file are subject to the terms of either the GNU

 * General Public License Version 2 only ("GPL") or the Common

 * Development and Distribution License("CDDL") (collectively, the

 * "License"). You may not use this file except in compliance with the

 * License. You can obtain a copy of the License at

 * http://www.netbeans.org/cddl-gplv2.html

 * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

 * specific language governing permissions and limitations under the

 * License.  When distributing the software, include this License Header

 * Notice in each file and include the License file at

 * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the GPL Version 2 section of the License file that

 * accompanied this code. If applicable, add the following below the

 * License Header, with the fields enclosed by brackets [] replaced by

 * your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * Contributor(s):

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.

 *

 * If you wish your version of this file to be governed by only the CDDL

 * or only the GPL Version 2, indicate your decision by adding

 * "[Contributor] elects to include this software in this distribution

 * under the [CDDL or GPL Version 2] license." If you do not indicate a

 * single choice of license, a recipient has the option to distribute

 * your version of this file under either the CDDL, the GPL Version 2 or

 * to extend the choice of license to its licensees as provided above.

 * However, if you add GPL Version 2 code and therefore, elected the GPL

 * Version 2 license, then the option applies only if the new code is

 * made subject to such option by the copyright holder.

 */

package org.netbeans.html.ko4j;

import net.java.html.json.Model;

import org.apidesign.html.boot.spi.Fn;

import org.apidesign.html.context.spi.Contexts;

import org.apidesign.html.context.spi.Contexts.Provider;

import org.apidesign.html.json.spi.Technology;

import org.apidesign.html.json.spi.Transfer;

import org.apidesign.html.json.spi.WSTransfer;

import org.openide.util.lookup.ServiceProvider;

/** Support for <a href="http://knockoutjs.com">knockout.js</a>

 * and its Java binding via {@link Model model classes}.

 * Registers {@link Provider}, so {@link java.util.ServiceLoader} can find it.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 * @since 0.7

 */

@ServiceProvider(service = Provider.class)

public final class KO4J implements Provider {

    private final Fn.Presenter presenter;

    private FXContext c;

    public KO4J() {

        this(null);

    }

    public KO4J(Fn.Presenter presenter) {

        this.presenter = presenter;

    }

    private FXContext getKO() {

        if (c == null) {

            c = new FXContext(presenter == null ? Fn.activePresenter() : presenter);

        }

        return c;

    }

    /** Return instance of the knockout.js for Java technology.

     * @return non-null instance

     */

    public Technology knockout() {

        return getKO();

    }

    /** Browser based implementation of transfer interface. Uses

     * browser method to convert string to JSON.

     * 

     * @return non-null instance

     */

    public Transfer transfer() {

        return getKO();

    }

    /** Returns browser based implementation of websocket transfer.

     * If available (for example JavaFX WebView on JDK7 does not have

     * this implementation).

     * 

     * @return an instance or <code>null</code>, if there is no

     *   <code>WebSocket</code> object in the browser

     */

    public WSTransfer<?> websockets() {

        return getKO().areWebSocketsSupported() ? getKO() : null;

    }

    /** Registers technologies at position 100:

     * <ul>

     *   <li>{@link #knockout()}</li>

     *   <li>{@link #transfer()}</li>

     *   <li>{@link #websockets()()} - if browser supports web sockets</li>

     * </ul>

     * @param context the context to register to

     * @param requestor the class requesting the registration

     */

    @Override

    public void fillContext(Contexts.Builder context, Class<?> requestor) {

        if (FXContext.isJavaScriptEnabled()) {

            context.register(Technology.class, knockout(), 100);

            context.register(Transfer.class, transfer(), 100);

            if (c.areWebSocketsSupported()) {

                context.register(WSTransfer.class, websockets(), 100);

            }

        }

    }

}