/**

  * 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 net.java.html.boot;

 import java.io.File;

 import java.io.IOException;

 import java.lang.reflect.Method;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.Arrays;

 import java.util.Collection;

 import java.util.Enumeration;

 import java.util.ServiceLoader;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import net.java.html.js.JavaScriptBody;

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

 import org.netbeans.html.boot.impl.FindResources;

 import org.netbeans.html.boot.impl.FnContext;

 import org.netbeans.html.boot.impl.FnUtils;

 /** Use this builder to launch your Java/HTML based application. Typical

  * usage in a main method of your application looks like this: 

  * <pre>

  * 

  * <b>public static void</b> <em>main</em>(String... args) {

  *     BrowserBuilder.{@link #newBrowser}.

  *          {@link #loadClass(java.lang.Class) loadClass(YourMain.class)}.

  *          {@link #loadPage(java.lang.String) loadPage("index.html")}.

  *          {@link #invoke(java.lang.String, java.lang.String[]) invoke("initialized", args)}.

  *          {@link #showAndWait()};

  *     System.exit(0);

  * }

  * </pre>

  * The above will load <code>YourMain</code> class via

  * a special classloader, it will locate an <code>index.html</code> (relative

  * to <code>YourMain</code> class) and show it in a browser window. When the

  * initialization is over, a <b>public static</b> method <em>initialized</em>

  * in <code>YourMain</code> will be called with provided string parameters.

  * <p>

  * This module provides only API for building browsers. To use it properly one

  * also needs an implementation on the classpath of one's application. For example

  * use: <pre>

  * <dependency>

  *   <groupId>org.netbeans.html</groupId>

  *   <artifactId>net.java.html.boot.fx</artifactId>

  *   <scope>runtime</scope>

  * </dependency>

  * </pre>

  *

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

  */

 public final class BrowserBuilder {

     private static final Logger LOG = Logger.getLogger(BrowserBuilder.class.getName());

     private String resource;

     private Class<?> clazz;

     private Class[] browserClass;

     private Runnable onLoad;

     private String methodName;

     private String[] methodArgs;

     private final Object[] context;

     private BrowserBuilder(Object[] context) {

         this.context = context;

     }

     /** Entry method to obtain a new browser builder. Follow by calling 

      * its instance methods like {@link #loadClass(java.lang.Class)} and

      * {@link #loadPage(java.lang.String)}.

      * 

      * @param context any instances that should be available to the builder -

      *   implementation dependant

      * @return new browser builder

      */

     public static BrowserBuilder newBrowser(Object... context) {

         return new BrowserBuilder(context);

     }

     /** The class to load when the browser is initialized. This class

      * is loaded by a special classloader (that supports {@link JavaScriptBody}

      * and co.). 

      * 

      * @param mainClass the class to load and resolve when the browser is ready

      * @return this builder

      */

     public BrowserBuilder loadClass(Class<?> mainClass) {

         this.clazz = mainClass;

         return this;

     }

     /** Page to load into the browser. If the <code>page</code> represents

      * a {@link URL} known to the Java system, the URL is passed to the browser. 

      * If system property <code>browser.rootdir</code> is specified, then a

      * file <code>page</code> relative to this directory is used as the URL.

      * If no such file exists, the system seeks for the 

      * resource via {@link Class#getResource(java.lang.String)}

      * method (relative to the {@link #loadClass(java.lang.Class) specified class}). 

      * If such resource is not found, a file relative to the location JAR

      * that contains the {@link #loadClass(java.lang.Class) main class} is 

      * searched for.

      * 

      * @param page the location (relative, absolute, or URL) of a page to load

      * @return this browser

      */

     public BrowserBuilder loadPage(String page) {

         this.resource = page;

         return this;

     }

     /** Specifies callback method to notify the application that the browser is ready.

      * There should be a <b>public static</b> method in the class specified

      * by {@link #loadClass(java.lang.Class)} which takes an array of {@link String}

      * argument. The method is called on the browser dispatch thread one

      * the browser finishes loading of the {@link #loadPage(java.lang.String) HTML page}.

      * 

      * @param methodName name of a method to seek for

      * @param args parameters to pass to the method

      * @return this builder

      */

     public BrowserBuilder invoke(String methodName, String... args) {

         this.methodName = methodName;

         this.methodArgs = args;

         return this;

     }

     /** Shows the browser, loads specified page in and executes the 

      * {@link #invoke(java.lang.String, java.lang.String[]) initialization method}.

      * The method returns when the browser is closed.

      * 

      * @throws NullPointerException if some of essential parameters (like {@link #loadPage(java.lang.String) page} or

      *    {@link #loadClass(java.lang.Class) class} have not been specified

      */

     public void showAndWait() {

         if (resource == null) {

             throw new NullPointerException("Need to specify resource via loadPage method");

         }

         URL url = null;

         MalformedURLException mal = null;

         try {

             String baseURL = System.getProperty("browser.rootdir");

             if (baseURL != null) {

                 url = new File(baseURL, resource).toURI().toURL();

             } else {

                 url = new URL(resource);

             }

         } catch (MalformedURLException ex) {

             mal = ex;

         }

         if (url == null) {

             url = clazz.getResource(resource);

         }

         if (url == null) {

             URL jar = clazz.getProtectionDomain().getCodeSource().getLocation();

             try {

                 url = new URL(jar, resource);

             } catch (MalformedURLException ex) {

                 ex.initCause(mal);

                 mal = ex;

             }

         }

         if (url == null) {

             IllegalStateException ise = new IllegalStateException("Can't find resouce: " + resource + " relative to " + clazz);

             if (mal != null) {

                 ise.initCause(mal);

             }

             throw ise;

         }

         Fn.Presenter dfnr = null;

         for (Object o : context) {

             if (o instanceof Fn.Presenter) {

                 dfnr = (Fn.Presenter)o;

                 break;

             }

         }

         if (dfnr == null) for (Fn.Presenter o : ServiceLoader.load(Fn.Presenter.class)) {

             dfnr = o;

             break;

         }

         if (dfnr == null) {

             throw new IllegalStateException("Can't find any Fn.Presenter");

         }

         final ClassLoader loader;

         if (FnUtils.isJavaScriptCapable(clazz.getClassLoader())) {

             loader = clazz.getClassLoader();

         } else {

             FImpl impl = new FImpl(clazz.getClassLoader());

             loader = FnUtils.newLoader(impl, dfnr, clazz.getClassLoader().getParent());

         }

         final Fn.Presenter currentP = dfnr;

         class OnPageLoad implements Runnable {

             @Override

             public void run() {

                 try {

                     Thread.currentThread().setContextClassLoader(loader);

                     Class<?> newClazz = Class.forName(clazz.getName(), true, loader);

                     if (browserClass != null) {

                         browserClass[0] = newClazz;

                     }

                     if (onLoad != null) {

                         onLoad.run();

                     }

                     INIT: if (methodName != null) {

                         Throwable firstError = null;

                         if (methodArgs.length == 0) {

                             try {

                                 Method m = newClazz.getMethod(methodName);

                                 FnContext.currentPresenter(currentP);

                                 m.invoke(null);

                                 break INIT;

                             } catch (Throwable ex) {

                                 firstError = ex;

                             } finally {

                                 FnContext.currentPresenter(null);

                             }

                         }

                         try {

                             Method m = newClazz.getMethod(methodName, String[].class);

                             FnContext.currentPresenter(currentP);

                             m.invoke(m, (Object) methodArgs);

                         } catch (Throwable ex) {

                             if (firstError != null) {

                                 LOG.log(Level.SEVERE, "Can't call " + methodName, firstError);

                             }

                             LOG.log(Level.SEVERE, "Can't call " + methodName + " with args " + Arrays.toString(methodArgs), ex);

                         } finally {

                             FnContext.currentPresenter(null);

                         }

                     }

                 } catch (ClassNotFoundException ex) {

                     LOG.log(Level.SEVERE, "Can't load " + clazz.getName(), ex);

                 }

             }

         }

         dfnr.displayPage(url, new OnPageLoad());

         return;

     }

     private static final class FImpl implements FindResources {

         final ClassLoader l;

         public FImpl(ClassLoader l) {

             this.l = l;

         }

         @Override

         public void findResources(String path, Collection<? super URL> results, boolean oneIsEnough) {

             if (oneIsEnough) {

                 URL u = l.getResource(path);

                 if (u != null) {

                     results.add(u);

                 }

             } else {

                 try {

                     Enumeration<URL> en = l.getResources(path);

                     while (en.hasMoreElements()) {

                         results.add(en.nextElement());

                     }

                 } catch (IOException ex) {

                     // no results

                 }

             }

         }

     }

 }