/**

 * 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

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

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

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

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 *

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

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

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

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 * 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

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package org.netbeans.html.mojo;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStream;

import java.lang.reflect.Method;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLClassLoader;

import java.util.ArrayList;

import java.util.List;

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.Component;

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.objectweb.asm.ClassReader;

@Mojo(

    name="process-js-annotations",

    requiresDependencyResolution = ResolutionScope.COMPILE,

    defaultPhase= LifecyclePhase.PROCESS_CLASSES

)

public final class ProcessJsAnnotationsMojo extends AbstractMojo {

    @Component

    private MavenProject prj;

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

    private File classes;

    public ProcessJsAnnotationsMojo() {

    }

    @Override

    public void execute() throws MojoExecutionException, MojoFailureException {

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

        boolean foundAsm = false;

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

            final File f = a.getFile();

            if (f != null) {

                if (a.getArtifactId().equals("asm")) {

                    foundAsm = true;

                }

                try {

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

                } catch (MalformedURLException ex) {

                    throw new IllegalStateException(ex);

                }

            }

        }

        if (!foundAsm) {

            URL loc = ClassReader.class.getProtectionDomain().getCodeSource().getLocation();

            arr.add(loc);

        }

        URLClassLoader l = new URLClassLoader(arr.toArray(new URL[arr.size()]));

        try {

            File master = new File(new File(classes, "META-INF"), "net.java.html.js.classes");

            processClasses(l, master, classes);

        } catch (IOException ex) {

            throw new MojoExecutionException("Problem converting JavaScriptXXX annotations", ex);

        }

    }

    private void processClasses(ClassLoader l, File master, File f) throws IOException, MojoExecutionException {

        if (!f.exists()) {

            return;

        }

        if (f.isDirectory()) {

            boolean classes = new File(f, "net.java.html.js.classes").exists();

            File[] arr = f.listFiles();

            if (arr != null) {

                for (File file : arr) {

                    if (classes || file.isDirectory()) {

                        processClasses(l, master, file);

                    }

                }

            }

            return;

        }

        if (!f.getName().endsWith(".class")) {

            return;

        }

        byte[] arr = new byte[(int)f.length()];

        FileInputStream is = new FileInputStream(f);

        try {

            readArr(arr, is);

        } finally {

            is.close();

        }

        byte[] newArr = null;

        try {

            Class<?> fnUtils = l.loadClass("org.netbeans.html.boot.impl.FnUtils");

            Method transform = fnUtils.getMethod("transform", byte[].class, ClassLoader.class);

            newArr = (byte[]) transform.invoke(null, arr, l);

            if (newArr == null || newArr == arr) {

                return;

            }

            filterClass(new File(f.getParentFile(), "net.java.html.js.classes"), f.getName());

            filterClass(master, f.getName());

        } catch (Exception ex) {

            throw new MojoExecutionException("Can't process " + f, ex);

        }

        getLog().info("Processing " + f);

        writeArr(f, newArr);        

    }

    private void writeArr(File f, byte[] newArr) throws IOException, FileNotFoundException {

        FileOutputStream os = new FileOutputStream(f);

        try {

            os.write(newArr);

        } finally {

            os.close();

        }

    }

    private static void readArr(byte[] arr, InputStream is) throws IOException {

        int off = 0;

        while (off< arr.length) {

            int read = is.read(arr, off, arr.length - off);

            if (read == -1) {

                break;

            }

            off += read;

        }

    }

    private static void filterClass(File f, String className) throws IOException {

        if (!f.exists()) {

            return;

        }

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

            className = className.substring(0, className.length() - 6);

        }

        BufferedReader r = new BufferedReader(new FileReader(f));

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

        boolean modified = false;

        for (;;) {

            String line = r.readLine();

            if (line == null) {

                break;

            }

            if (line.endsWith(className)) {

                modified = true;

                continue;

            }

            arr.add(line);

        }

        r.close();

        if (modified) {

            if (arr.isEmpty()) {

                f.delete();

            } else {

                FileWriter w = new FileWriter(f);

                for (String l : arr) {

                    w.write(l);

                    w.write("\n");

                }

                w.close();

            }

        }

    }

}