/*

 * 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.

 */

/* @test

 * @bug 6595866

 * @summary Test java.io.File operations with sym links

 */

import java.io.*;

import java.nio.file.*;

import java.nio.file.attribute.*;

import static java.nio.file.LinkOption.*;

public class SymLinks {

    final static PrintStream out = System.out;

    final static File top = new File(System.getProperty("test.dir", "."));

    // files used by the test

    final static File file              = new File(top, "foofile");

    final static File link2file         = new File(top, "link2file");

    final static File link2link2file    = new File(top, "link2link2file");

    final static File dir               = new File(top, "foodir");

    final static File link2dir          = new File(top, "link2dir");

    final static File link2link2dir     = new File(top, "link2link2dir");

    final static File link2nobody       = new File(top, "link2nobody");

    final static File link2link2nobody  = new File(top, "link2link2nobody");

    /**

     * Setup files, directories, and sym links used by test.

     */

    static void setup() throws IOException {

        // link2link2file -> link2file -> foofile

        FileOutputStream fos = new FileOutputStream(file);

        try {

            fos.write(new byte[16*1024]);

        } finally {

            fos.close();

        }

        mklink(link2file, file);

        mklink(link2link2file, link2file);

        // link2link2dir -> link2dir -> dir

        assertTrue(dir.mkdir());

        mklink(link2dir, dir);

        mklink(link2link2dir, link2dir);

        // link2link2nobody -> link2nobody -> <does-not-exist>

        mklink(link2nobody, new File(top, "DoesNotExist"));

        mklink(link2link2nobody, link2nobody);

    }

    /**

     * Remove files, directories, and sym links used by test.

     */

    static void cleanup() throws IOException {

        if (file != null)

            file.delete();

        if (link2file != null)

            Files.deleteIfExists(link2file.toPath());

        if (link2link2file != null)

            Files.deleteIfExists(link2link2file.toPath());

        if (dir != null)

            dir.delete();

        if (link2dir != null)

            Files.deleteIfExists(link2dir.toPath());

        if (link2link2dir != null)

            Files.deleteIfExists(link2link2dir.toPath());

        if (link2nobody != null)

            Files.deleteIfExists(link2nobody.toPath());

        if (link2link2nobody != null)

            Files.deleteIfExists(link2link2nobody.toPath());

    }

    /**

     * Creates a sym link source->target

     */

    static void mklink(File source, File target) throws IOException {

        Files.createSymbolicLink(source.toPath(), target.toPath());

    }

    /**

     * Returns true if the "link" exists and is a sym link.

     */

    static boolean isSymLink(File link) {

         return Files.isSymbolicLink(link.toPath());

    }

    /**

     * Returns the last modified time of a sym link.

     */

    static long lastModifiedOfSymLink(File link) throws IOException {

        BasicFileAttributes attrs =

            Files.readAttributes(link.toPath(), BasicFileAttributes.class, NOFOLLOW_LINKS);

        assertTrue(attrs.isSymbolicLink());

        return attrs.lastModifiedTime().toMillis();

    }

    /**

     * Returns true if sym links are supported on the file system where

     * "dir" exists.

     */

    static boolean supportsSymLinks(File dir) {

        Path link = dir.toPath().resolve("link");

        Path target = dir.toPath().resolve("target");

        try {

            Files.createSymbolicLink(link, target);

            Files.delete(link);

            return true;

        } catch (UnsupportedOperationException x) {

            return false;

        } catch (IOException x) {

            return false;

        }

    }

    static void assertTrue(boolean v) {

        if (!v) throw new RuntimeException("Test failed");

    }

    static void assertFalse(boolean v) {

        assertTrue(!v);

    }

    static void header(String h) {

        out.println();

        out.println();

        out.println("-- " + h + " --");

    }

    /**

     * Tests go here.

     */

    static void go() throws IOException {

        // check setup

        assertTrue(file.isFile());

        assertTrue(isSymLink(link2file));

        assertTrue(isSymLink(link2link2file));

        assertTrue(dir.isDirectory());

        assertTrue(isSymLink(link2dir));

        assertTrue(isSymLink(link2link2dir));

        assertTrue(isSymLink(link2nobody));

        assertTrue(isSymLink(link2link2nobody));

        header("createNewFile");

        assertFalse(file.createNewFile());

        assertFalse(link2file.createNewFile());

        assertFalse(link2link2file.createNewFile());

        assertFalse(dir.createNewFile());

        assertFalse(link2dir.createNewFile());

        assertFalse(link2link2dir.createNewFile());

        assertFalse(link2nobody.createNewFile());

        assertFalse(link2link2nobody.createNewFile());

        header("mkdir");

        assertFalse(file.mkdir());

        assertFalse(link2file.mkdir());

        assertFalse(link2link2file.mkdir());

        assertFalse(dir.mkdir());

        assertFalse(link2dir.mkdir());

        assertFalse(link2link2dir.mkdir());

        assertFalse(link2nobody.mkdir());

        assertFalse(link2link2nobody.mkdir());

        header("delete");

        File link = new File(top, "mylink");

        try {

            mklink(link, file);

            assertTrue(link.delete());

            assertTrue(!isSymLink(link));

            assertTrue(file.exists());

            mklink(link, link2file);

            assertTrue(link.delete());

            assertTrue(!isSymLink(link));

            assertTrue(link2file.exists());

            mklink(link, dir);

            assertTrue(link.delete());

            assertTrue(!isSymLink(link));

            assertTrue(dir.exists());

            mklink(link, link2dir);

            assertTrue(link.delete());

            assertTrue(!isSymLink(link));

            assertTrue(link2dir.exists());

            mklink(link, link2nobody);

            assertTrue(link.delete());

            assertTrue(!isSymLink(link));

            assertTrue(isSymLink(link2nobody));

        } finally {

            Files.deleteIfExists(link.toPath());

        }

        header("renameTo");

        File newlink = new File(top, "newlink");

        assertTrue(link2file.renameTo(newlink));

        try {

            assertTrue(file.exists());

            assertTrue(isSymLink(newlink));

            assertTrue(!isSymLink(link2file));

        } finally {

            newlink.renameTo(link2file);  // restore link

        }

        assertTrue(link2dir.renameTo(newlink));

        try {

            assertTrue(dir.exists());

            assertTrue(isSymLink(newlink));

            assertTrue(!isSymLink(link2dir));

        } finally {

            newlink.renameTo(link2dir);  // restore link

        }

        header("list");

        final String name = "entry";

        File entry = new File(dir, name);

        try {

            assertTrue(dir.list().length == 0);   // directory should be empty

            assertTrue(link2dir.list().length == 0);

            assertTrue(link2link2dir.list().length == 0);

            assertTrue(entry.createNewFile());

            assertTrue(dir.list().length == 1);

            assertTrue(dir.list()[0].equals(name));

            // access directory by following links

            assertTrue(link2dir.list().length == 1);

            assertTrue(link2dir.list()[0].equals(name));

            assertTrue(link2link2dir.list().length == 1);

            assertTrue(link2link2dir.list()[0].equals(name));

            // files that are not directories

            assertTrue(link2file.list() == null);

            assertTrue(link2nobody.list() == null);

        } finally {

            entry.delete();

        }

        header("isXXX");

        assertTrue(file.isFile());

        assertTrue(link2file.isFile());

        assertTrue(link2link2file.isFile());

        assertTrue(dir.isDirectory());

        assertTrue(link2dir.isDirectory());

        assertTrue(link2link2dir.isDirectory());

        // on Windows we test with the DOS hidden attribute set

        if (System.getProperty("os.name").startsWith("Windows")) {

            DosFileAttributeView view = Files

                .getFileAttributeView(file.toPath(), DosFileAttributeView.class);

            view.setHidden(true);

            try {

                assertTrue(file.isHidden());

                assertTrue(link2file.isHidden());

                assertTrue(link2link2file.isHidden());

            } finally {

                view.setHidden(false);

            }

            assertFalse(file.isHidden());

            assertFalse(link2file.isHidden());

            assertFalse(link2link2file.isHidden());

        }

        header("length");

        long len = file.length();

        assertTrue(len > 0L);

        // these tests should follow links

        assertTrue(link2file.length() == len);

        assertTrue(link2link2file.length() == len);

        assertTrue(link2nobody.length() == 0L);

        header("lastModified / setLastModified");

        // need time to diff between link and file

        long origLastModified = file.lastModified();

        assertTrue(origLastModified != 0L);

        try { Thread.sleep(2000); } catch (InterruptedException x) { }

        file.setLastModified(System.currentTimeMillis());

        long lastModified = file.lastModified();

        assertTrue(lastModified != origLastModified);

        assertTrue(lastModifiedOfSymLink(link2file) != lastModified);

        assertTrue(lastModifiedOfSymLink(link2link2file) != lastModified);

        assertTrue(link2file.lastModified() == lastModified);

        assertTrue(link2link2file.lastModified() == lastModified);

        assertTrue(link2nobody.lastModified() == 0L);

        origLastModified = dir.lastModified();

        assertTrue(origLastModified != 0L);

        dir.setLastModified(0L);

        assertTrue(dir.lastModified() == 0L);

        assertTrue(link2dir.lastModified() == 0L);

        assertTrue(link2link2dir.lastModified() == 0L);

        dir.setLastModified(origLastModified);

        header("setXXX / canXXX");

        assertTrue(file.canRead());

        assertTrue(file.canWrite());

        assertTrue(link2file.canRead());

        assertTrue(link2file.canWrite());

        assertTrue(link2link2file.canRead());

        assertTrue(link2link2file.canWrite());

        if (file.setReadOnly()) {

            assertFalse(file.canWrite());

            assertFalse(link2file.canWrite());

            assertFalse(link2link2file.canWrite());

            assertTrue(file.setWritable(true));             // make writable

            assertTrue(file.canWrite());

            assertTrue(link2file.canWrite());

            assertTrue(link2link2file.canWrite());

            assertTrue(link2file.setReadOnly());            // make read only

            assertFalse(file.canWrite());

            assertFalse(link2file.canWrite());

            assertFalse(link2link2file.canWrite());

            assertTrue(link2link2file.setWritable(true));   // make writable

            assertTrue(file.canWrite());

            assertTrue(link2file.canWrite());

            assertTrue(link2link2file.canWrite());

        }

    }

    public static void main(String[] args) throws IOException {

        if (supportsSymLinks(top)) {

            try {

                setup();

                go();

            } finally {

                cleanup();

            }

        }

    }

}