/*

 * Copyright (c) 2016, 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.

 *

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 */

/**

 * @test

 * @bug 8016521

 * @library /test/lib

 * @summary InetAddress should not always re-order addresses returned from name

 *          service

 * @run main/othervm -Djava.net.preferIPv6Addresses=false PreferIPv6AddressesTest

 * @run main/othervm -Djava.net.preferIPv6Addresses=true PreferIPv6AddressesTest

 * @run main/othervm -Djava.net.preferIPv6Addresses=system PreferIPv6AddressesTest

 * @run main/othervm PreferIPv6AddressesTest

 */

import java.io.IOException;

import java.net.*;

import java.nio.channels.DatagramChannel;

import java.util.Arrays;

import java.util.stream.IntStream;

import static java.lang.System.out;

import jdk.test.lib.net.IPSupport;

public class PreferIPv6AddressesTest {

    // A name, that if resolves, returns both IPv4 and IPv6 addresses.

    static final String HOST_NAME = "www.google.com";

    static final InetAddress LOOPBACK = InetAddress.getLoopbackAddress();

    static final String preferIPV6Address =

            System.getProperty("java.net.preferIPv6Addresses", "false");

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

        InetAddress addrs[];

        try {

            addrs = InetAddress.getAllByName(HOST_NAME);

        } catch (UnknownHostException e) {

            out.println("Unknown host " + HOST_NAME + ", cannot run test.");

            return;

        }

        int firstIPv4Address = IntStream.range(0, addrs.length)

                .filter(x -> addrs[x] instanceof Inet4Address)

                .findFirst().orElse(-1);

        int firstIPv6Address = IntStream.range(0, addrs.length)

                .filter(x -> addrs[x] instanceof Inet6Address)

                .findFirst().orElse(-1);

        out.println("IPv6 supported: " + IPSupport.hasIPv6());

        out.println("Addresses: " + Arrays.asList(addrs));

        if (preferIPV6Address.equalsIgnoreCase("true") && firstIPv6Address != -1) {

            int off = firstIPv4Address != -1 ? firstIPv4Address : addrs.length;

            assertAllv6Addresses(addrs, 0, off);

            assertAllv4Addresses(addrs, off, addrs.length);

            assertLoopbackAddress(Inet6Address.class);

            assertAnyLocalAddress(Inet6Address.class);

        } else if (preferIPV6Address.equalsIgnoreCase("false") && firstIPv4Address != -1) {

            int off = firstIPv6Address != -1 ? firstIPv6Address : addrs.length;

            assertAllv4Addresses(addrs, 0, off);

            assertAllv6Addresses(addrs, off, addrs.length);

            assertLoopbackAddress(Inet4Address.class);

            assertAnyLocalAddress(Inet4Address.class);

        } else if (preferIPV6Address.equalsIgnoreCase("system") && IPSupport.hasIPv6()) {

            assertLoopbackAddress(Inet6Address.class);

            assertAnyLocalAddress(Inet6Address.class);

        } else if (preferIPV6Address.equalsIgnoreCase("system") && !IPSupport.hasIPv6()) {

            assertLoopbackAddress(Inet4Address.class);

            assertAnyLocalAddress(Inet4Address.class);

        }

    }

    static void assertAllv4Addresses(InetAddress[] addrs, int off, int len) {

        IntStream.range(off, len)

                 .mapToObj(x -> addrs[x])

                 .forEach(x -> {

                     if (!(x instanceof Inet4Address))

                         throw new RuntimeException("Expected IPv4, got " + x);

                 });

    }

    static void assertAllv6Addresses(InetAddress[] addrs, int off, int len) {

        IntStream.range(off, len)

                .mapToObj(x -> addrs[x])

                .forEach(x -> {

                    if (!(x instanceof Inet6Address))

                        throw new RuntimeException("Expected IPv6, got " + x);

                });

    }

    static void assertLoopbackAddress(Class<?> expectedType) {

        if (!LOOPBACK.getClass().isAssignableFrom(expectedType))

            throw new RuntimeException("Expected " + expectedType

                    + ", got " + LOOPBACK.getClass());

    }

    static void assertAnyLocalAddress(Class<?> expectedType) {

        InetAddress anyAddr = (new InetSocketAddress(0)).getAddress();

        if (!anyAddr.getClass().isAssignableFrom(expectedType))

            throw new RuntimeException("Expected " + expectedType

                    + ", got " + anyAddr.getClass());

    }

}