/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.testlibrary;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;

/**
 * Common library for various test jar file utility functions.
 */
public final class JarUtils {

    private static final int BUF_SIZE = 1024;

    /**
     * Create jar file with specified files.
     */
    public static void createJar(String jarFilename, String... files)
            throws IOException {
        try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(
                jarFilename), new Manifest())) {
            for (String file : files) {
                System.out.println(String.format("Adding %s to %s",
                        new Object[] {file, jarFilename}));

                String filename = new File(file).getName();

                // add archive entry
                JarEntry entry = new JarEntry(filename);
                jos.putNextEntry(entry);

                // write file
                try (FileInputStream fis = new FileInputStream(file)) {
                    byte[] buffer = new byte[BUF_SIZE];
                    while (true) {
                        int read = fis.read(buffer, 0, buffer.length);
                        if (read <= 0) {
                            break;
                        }
                        jos.write(buffer, 0, read);
                    }
                }
            }
        }
        System.out.println();
    }

    /**
     * Add specified files to existing jar file.
     */
    public static void updateJar(String srcJarFilename, String destJarFilename,
            String... files) throws IOException {
        try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(
                destJarFilename))) {
            byte[] buffer = new byte[BUF_SIZE];
            int read;

            for (String file : files) {
                System.out.println(String.format("Updating %s with %s",
                        new Object[] {destJarFilename, file}));
                String filename = new File(file).getName();
                try (FileInputStream fis = new FileInputStream(file)) {
                    JarEntry entry = new JarEntry(filename);
                    jos.putNextEntry(entry);

                    while ((read = fis.read(buffer)) != -1) {
                        jos.write(buffer, 0, read);
                    }
                }
                try (JarFile srcJarFile = new JarFile(srcJarFilename)) {
                    for (Enumeration entries = srcJarFile.entries(); entries.
                            hasMoreElements();) {
                        JarEntry entry = (JarEntry) entries.nextElement();

                        if (!entry.getName().equals(file)) {
                            InputStream entryStream = srcJarFile.getInputStream(
                                    entry);
                            jos.putNextEntry(entry);

                            while ((read = entryStream.read(buffer)) != -1) {
                                jos.write(buffer, 0, read);
                            }
                        }
                    }
                }
            }
        }
        System.out.println();
    }

}