/**

  * 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.bck2brwsr.mojo;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.nio.file.Files;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.List;

 import java.util.Map;

 import java.util.jar.Attributes;

 import java.util.jar.JarFile;

 import java.util.jar.Manifest;

 import java.util.zip.ZipEntry;

 import org.apache.maven.artifact.Artifact;

 import org.apache.maven.plugin.AbstractMojo;

 import org.apache.maven.plugin.MojoExecutionException;

 import org.apache.maven.plugin.MojoFailureException;

 import org.apache.maven.plugins.annotations.LifecyclePhase;

 import org.apache.maven.plugins.annotations.Mojo;

 import org.apache.maven.plugins.annotations.Parameter;

 import org.apache.maven.plugins.annotations.ResolutionScope;

 import org.apache.maven.project.MavenProject;

 import org.apidesign.bck2brwsr.aot.Bck2BrwsrJars;

 import org.apidesign.vm4brwsr.Bck2Brwsr;

 import org.apidesign.vm4brwsr.ObfuscationLevel;

 /**

  *

  * @author Jaroslav Tulach

  * @since 0.9

  */

 @Mojo(name = "aot",

     requiresDependencyResolution = ResolutionScope.COMPILE_PLUS_RUNTIME,

     defaultPhase = LifecyclePhase.PACKAGE

 )

 public class AheadOfTime extends AbstractMojo {

     @Parameter(defaultValue = "${project}")

     private MavenProject prj;

     @Parameter(defaultValue = "${project.build.directory}/${project.build.finalName}.jar")

     private File mainJar;

     @Parameter(defaultValue = "${project.build.directory}/${project.build.finalName}.js")

     private File mainJavaScript;

     @Parameter

     private String[] exports;

     /**

      * Directory where to generate ahead-of-time JavaScript files for

      * required libraries.

      */

     @Parameter(defaultValue = "lib")

     private String classPathPrefix;

     /** Root JavaScript file to generate */

     @Parameter(defaultValue="${project.build.directory}/bck2brwsr.js")

     private File vm;

     @Parameter(defaultValue = "true")

     private boolean generateAotLibraries;

     /**

      * The obfuscation level for the generated JavaScript file.

      *

      * @since 0.5

      */

     @Parameter(defaultValue = "NONE")

     private ObfuscationLevel obfuscation;

     @Override

     public void execute() throws MojoExecutionException, MojoFailureException {

         URLClassLoader loader;

         try {

             loader = buildClassLoader(mainJar, prj.getArtifacts());

         } catch (MalformedURLException ex) {

             throw new MojoFailureException("Can't initialize classloader");

         }

         for (Artifact a : prj.getArtifacts()) {

             if (a.getFile() == null) {

                 continue;

             }

             String n = a.getFile().getName();

             if (!n.endsWith(".jar")) {

                 continue;

             }

             if ("provided".equals(a.getScope())) {

                 continue;

             }

             File aot = new File(prj.getBuild().getDirectory(), classPathPrefix);

             aot.mkdirs();

             File js = new File(aot, n.substring(0, n.length() - 4) + ".js");

             if (js.exists()) {

                 getLog().info("Skipping " + js + " as it already exists.");

                 continue;

             }

             try {

                 aotLibrary(a, js , loader);

             } catch (IOException ex) {

                 throw new MojoFailureException("Can't compile " + a.getFile(), ex);

             }

         }

         try {

             if (mainJavaScript.exists()) {

                 getLog().info("Skipping " + mainJavaScript + " as it already exists.");

             } else {

                 getLog().info("Generating " + mainJavaScript);

                 Bck2Brwsr c = Bck2BrwsrJars.configureFrom(null, mainJar, loader);

                 if (exports != null) {

                     for (String e : exports) {

                         c = c.addExported(e.replace('.', '/'));

                     }

                 }

                 FileWriter w = new FileWriter(mainJavaScript);

                 c.

                         obfuscation(obfuscation).

                         generate(w);

                 w.close();

             }

         } catch (IOException ex) {

             throw new MojoFailureException("Cannot generate script for " + mainJar, ex);

         }

         try {

             FileWriter w = new FileWriter(vm);

             Bck2Brwsr.newCompiler().

                     obfuscation(obfuscation).

                     standalone(false).

                     resources(new Bck2Brwsr.Resources() {

                 @Override

                 public InputStream get(String resource) throws IOException {

                     return null;

                 }

             }).

                     generate(w);

             w.close();

         } catch (IOException ex) {

             throw new MojoExecutionException("Can't compile", ex);

         }

     }

     private void aotLibrary(Artifact a, File js, URLClassLoader loader) throws IOException, MojoExecutionException {

         for (Artifact b : prj.getArtifacts()) {

             if ("bck2brwsr".equals(b.getClassifier())) { // NOI18N

                 getLog().debug("Inspecting " + b.getFile());

                 JarFile jf = new JarFile(b.getFile());

                 Manifest man = jf.getManifest();

                 for (Map.Entry<String, Attributes> entrySet : man.getEntries().entrySet()) {

                     String entryName = entrySet.getKey();

                     Attributes attr = entrySet.getValue();

                     if (

                         a.getArtifactId().equals(attr.getValue("Bck2BrwsrArtifactId")) &&

                         a.getGroupId().equals(attr.getValue("Bck2BrwsrGroupId")) &&

                         a.getVersion().equals(attr.getValue("Bck2BrwsrVersion")) &&

                         (

                             obfuscation == ObfuscationLevel.FULL && "true".equals(attr.getValue("Bck2BrwsrMinified"))

                             ||

                             obfuscation != ObfuscationLevel.FULL && "true".equals(attr.getValue("Bck2BrwsrDebug"))

                         )

                     ) {

                         getLog().info("Extracting " + js + " from " + b.getFile());

                         InputStream is = jf.getInputStream(new ZipEntry(entryName));

                         Files.copy(is, js.toPath());

                         is.close();

                         return;

                     }

                 }

             }

         }

         if (!generateAotLibraries) {

             throw new MojoExecutionException("Not generating " + js + " and no precompiled version found!");

         }

         getLog().info("Generating " + js);

         FileWriter w = new FileWriter(js);

         Bck2Brwsr c = Bck2BrwsrJars.configureFrom(null, a.getFile(), loader);

         c.

             obfuscation(obfuscation).

             generate(w);

         w.close();

     }

     private static URLClassLoader buildClassLoader(File root, Collection<Artifact> deps) throws MalformedURLException {

         List<URL> arr = new ArrayList<URL>();

         if (root != null) {

             arr.add(root.toURI().toURL());

         }

         for (Artifact a : deps) {

             if (a.getFile() != null) {

                 arr.add(a.getFile().toURI().toURL());

             }

         }

         return new URLClassLoader(arr.toArray(new URL[0]), Java2JavaScript.class.getClassLoader());

     }

 }