/*

 * 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 6334003 6440786

 * @summary Test ability to write and read zip files that have no entries.

 * @author Dave Bristor

 */

import java.io.*;

import java.util.*;

import java.util.zip.*;

public class TestEmptyZip {

    public static void realMain(String[] args) throws Throwable {

        String zipName = "foo.zip";

        File f = new File(System.getProperty("test.scratch", "."), zipName);

        if (f.exists() && !f.delete()) {

            throw new Exception("failed to delete " + zipName);

        }

        f.createNewFile();

        try {

            // Verify 0-length file cannot be read

            checkCannotRead(f);

            // Verify non-zip file cannot be read

            OutputStream out = new FileOutputStream(f);

            try {

                out.write("class Foo { }".getBytes());

            } finally {

                out.close();

            }

            checkCannotRead(f);

        } finally {

            f.delete();

        }

        // Verify 0-entries file can be written

        write(f);

        // Verify 0-entries file can be read

        readFile(f);

        readStream(f);

        f.delete();

    }

    static void checkCannotRead(File f) throws IOException {

        try {

            new ZipFile(f).close();

            fail();

        } catch (ZipException ze) {

            if (f.length() == 0) {

                check(ze.getMessage().contains("zip file is empty"));

            } else {

                pass();

            }

        }

        try (FileInputStream fis = new FileInputStream(f);

             ZipInputStream zis = new ZipInputStream(fis))

        {

            ZipEntry ze = zis.getNextEntry();

            check(ze == null);

        } catch (IOException ex) {

            unexpected(ex);

        }

    }

    static void write(File f) throws Exception {

        try (FileOutputStream fis = new FileOutputStream(f);

             ZipOutputStream zos = new ZipOutputStream(fis))

        {

            zos.finish();

            pass();

        } catch (Exception ex) {

            unexpected(ex);

        }

    }

    static void readFile(File f) throws Exception {

        try (ZipFile zf = new ZipFile(f)) {

            Enumeration e = zf.entries();

            while (e.hasMoreElements()) {

                ZipEntry entry = (ZipEntry) e.nextElement();

                fail();

            }

            pass();

        } catch (Exception ex) {

            unexpected(ex);

        }

    }

    static void readStream(File f) throws Exception {

        try (FileInputStream fis = new FileInputStream(f);

             ZipInputStream zis = new ZipInputStream(fis))

        {

            ZipEntry ze = zis.getNextEntry();

            check(ze == null);

            byte[] buf = new byte[1024];

            check(zis.read(buf, 0, 1024) == -1);

        }

    }

    //--------------------- Infrastructure ---------------------------

    static volatile int passed = 0, failed = 0;

    static boolean pass() {passed++; return true;}

    static boolean fail() {failed++; Thread.dumpStack(); return false;}

    static boolean fail(String msg) {System.out.println(msg); return fail();}

    static void unexpected(Throwable t) {failed++; t.printStackTrace();}

    static boolean check(boolean cond) {if (cond) pass(); else fail(); return cond;}

    static boolean equal(Object x, Object y) {

        if (x == null ? y == null : x.equals(y)) return pass();

        else return fail(x + " not equal to " + y);}

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

        try {realMain(args);} catch (Throwable t) {unexpected(t);}

        System.out.println("\nPassed = " + passed + " failed = " + failed);

        if (failed > 0) throw new AssertionError("Some tests failed");}

}