/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program 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 General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.vm4brwsr;

 import java.io.BufferedWriter;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.io.Writer;

 import java.net.URI;

 import java.net.URISyntaxException;

 import java.net.URL;

 import java.util.Enumeration;

 import java.util.jar.JarEntry;

 import java.util.jar.JarFile;

 /** Generator of JavaScript from bytecode of classes on classpath of the VM

  * with a Main method.

  *

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

  */

 final class Main {

     private Main() {}

     public static void main(String... args) throws IOException, URISyntaxException {

         final String obfuscate = "--obfuscatelevel";

         final String extension = "--createextension";

         if (args.length < 2) {

             System.err.println("Bck2Brwsr Translator from Java(tm) to JavaScript, (c) Jaroslav Tulach 2012");

             System.err.print("Usage: java -cp ... -jar ... [");

             System.err.print(obfuscate);

             System.err.print(" [");

             boolean first = true;

             for (ObfuscationLevel l : ObfuscationLevel.values()) {

                 if (!first) {

                     System.err.print('|');

                 }

                 System.err.print(l.name());

                 first = false;

             }

             System.err.print("]] [");

             System.err.print(extension);

             System.err.println("] <file_to_generate_js_code_to> java/lang/Class org/your/App ...");

             System.exit(9);

         }

         final ClassLoader mainClassLoader = Main.class.getClassLoader();

         ObfuscationLevel obfLevel = ObfuscationLevel.NONE;

         boolean createExtension = false;

         StringArray classes = new StringArray();

         String generateTo = null;

         for (int i = 0; i < args.length; i++) {

             if (obfuscate.equals(args[i])) { // NOI18N

                 i++;

                 try {

                     obfLevel = ObfuscationLevel.valueOf(args[i]);

                 } catch (Exception e) {

                     System.err.print(obfuscate);

                     System.err.print(" parameter needs to be followed by one of ");

                     boolean first = true;

                     for (ObfuscationLevel l : ObfuscationLevel.values()) {

                         if (!first) {

                             System.err.print(", ");

                         }

                         System.err.print(l.name());

                         first = false;

                     }

                     System.err.println();

                     System.exit(1);

                 }

                 continue;

             }

             if (extension.equals(args[i])) { // NOI18N

                 createExtension = true;

                 continue;

             }

             if (generateTo == null) {

                 generateTo = args[i];

             } else {

                 collectClasses(classes, mainClassLoader, args[i]);

             }

         }

         File gt = new File(generateTo);

         if (Boolean.getBoolean("skip.if.exists") && gt.isFile()) {

             System.err.println("Skipping as " + gt + " exists.");

             System.exit(0);

         }

         try (Writer w = new BufferedWriter(new FileWriter(gt))) {

             Bck2Brwsr.newCompiler().

                 extension(createExtension).

                 obfuscation(obfLevel).

                 addRootClasses(classes.toArray()).

                 resources(new LdrRsrcs(mainClassLoader)).

                 generate(w);

         }

     }

     private static void collectClasses(

             final StringArray dest,

             final ClassLoader cl, final String relativePath)

                 throws IOException, URISyntaxException {

         final Enumeration<URL> urls = cl.getResources(relativePath);

         if (!urls.hasMoreElements()) {

             dest.add(relativePath);

             return;

         }

         do {

             final URL url = urls.nextElement();

             switch (url.getProtocol()) {

                 case "file":

                     collectClasses(dest, relativePath,

                                    new File(new URI(url.toString())));

                     continue;

                 case "jar":

                     final String fullPath = url.getPath();

                     final int sepIndex = fullPath.indexOf('!');

                     final String jarFilePath =

                             (sepIndex != -1) ? fullPath.substring(0, sepIndex)

                                              : fullPath;

                     final URI jarUri = new URI(jarFilePath);

                     if (jarUri.getScheme().equals("file")) {

                         try (JarFile jarFile = new JarFile(new File(jarUri))) {

                             collectClasses(dest, relativePath, jarFile);

                             continue;

                         }

                     }

                     break;

             }

             dest.add(relativePath);

         } while (urls.hasMoreElements());

     }

     private static void collectClasses(final StringArray dest,

                                        final String relativePath,

                                        final File file) {

         if (file.isDirectory()) {

             final File[] subFiles = file.listFiles();

             for (final File subFile: subFiles) {

                 collectClasses(dest,

                                extendPath(relativePath, subFile.getName()),

                                subFile);

             }

             return;

         }

         final String filePath = file.getPath();

         if (filePath.endsWith(".class")) {

             validateAndAddClass(dest, relativePath);

         }

     }

     private static void collectClasses(final StringArray dest,

                                        final String relativePath,

                                        final JarFile jarFile) {

         if (relativePath.endsWith(".class")) {

             if (jarFile.getJarEntry(relativePath) != null) {

                 validateAndAddClass(dest, relativePath);

             }

             return;

         }

         final String expectedPrefix =

                 relativePath.endsWith("/") ? relativePath

                                            : relativePath + '/';

         final Enumeration<JarEntry> entries = jarFile.entries();

         while (entries.hasMoreElements()) {

             final JarEntry entry = entries.nextElement();

             if (!entry.isDirectory()) {

                 final String entryName = entry.getName();

                 if (entryName.startsWith(expectedPrefix)

                         && entryName.endsWith(".class")) {

                     validateAndAddClass(dest, entryName);

                 }

             }

         }

     }

     private static String extendPath(final String relativePath,

                                      final String fileName) {

         return relativePath.endsWith("/") ? relativePath + fileName

                                           : relativePath + '/' + fileName;

     }

     private static void validateAndAddClass(final StringArray dest,

                                             final String relativePath) {

         final String className =

                 relativePath.substring(0, relativePath.length() - 6);

         if (!className.endsWith("package-info")) {

             dest.add(className);

         }

     }

 }