import java.lang.reflect.Field;

import java.util.Hashtable;

import javax.naming.Context;

import javax.naming.NamingException;

import javax.naming.spi.NamingManager;

import com.sun.jndi.dns.DnsContext;

/**

 * @test

 * @bug 6991580

 * @summary IPv6 Nameservers in resolv.conf throws NumberFormatException

 * @run main/manual IPv6NameserverPlatformParsingTest

 *

 * In order to run this test be sure to place, for example, the following

 * snippet into your platform's {@code /etc/resolv.conf}:

 * <pre>

 * nameserver 127.0.0.1

 * nameserver 2001:4860:4860::8888

 * nameserver [::1]:5353

 * nameserver 127.0.0.1:5353

 * </pre>

 *

 * Then, run this test as manual jtreg test.

 *

 * @author Severin Gehwolf

 *

 */

public class IPv6NameserverPlatformParsingTest {

    private static boolean foundIPv6 = false;

    public static void main(String[] args) {

        Hashtable<String, String> env = new Hashtable<>();

        env.put(Context.INITIAL_CONTEXT_FACTORY, com.sun.jndi.dns.DnsContextFactory.class.getName());

        String[] servers;

        try {

            Context ctx = NamingManager.getInitialContext(env);

            if (!com.sun.jndi.dns.DnsContextFactory.platformServersAvailable()) {

                throw new RuntimeException("FAIL: no platform servers available, test does not make sense");

            }

            DnsContext context = (DnsContext)ctx;

            servers = getServersFromContext(context);

        } catch (NamingException e) {

            throw new RuntimeException(e);

        }

        for (String server: servers) {

            System.out.println("DEBUG: 'nameserver = " + server + "'");

            if (server.indexOf(':') >= 0 && server.indexOf('.') < 0) {

                System.out.println("DEBUG: ==> Found IPv6 address in servers list: " + server);

                foundIPv6 = true;

            }

        }

        try {

            new com.sun.jndi.dns.DnsClient(servers, 100, 1);

        } catch (NumberFormatException e) {

            throw new RuntimeException("FAIL: Tried to parse non-[]-encapsulated IPv6 address.", e);

        } catch (Exception e) {

            throw new RuntimeException("ERROR: Something unexpected happened.");

        }

        if (!foundIPv6) {

            // This is a manual test, since it requires changing /etc/resolv.conf on Linux/Unix

            // platforms. See comment as to how to run this test.

            throw new RuntimeException("ERROR: No IPv6 address returned from platform.");

        }

        System.out.println("PASS: Found IPv6 address and DnsClient parsed it correctly.");

    }

    private static String[] getServersFromContext(DnsContext context) {

        try {

            Field serversField = DnsContext.class.getDeclaredField("servers");

            serversField.setAccessible(true);

            return (String[])serversField.get(context);

        } catch (Exception e) {

            throw new RuntimeException(e);

        }

    }

}