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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.cassandra.config;

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;

import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;

import org.apache.cassandra.OrderedJUnit4ClassRunner;
import org.apache.cassandra.db.Keyspace;
import org.apache.cassandra.exceptions.ConfigurationException;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

@RunWith(OrderedJUnit4ClassRunner.class)
public class DatabaseDescriptorTest
{
    @BeforeClass
    public static void setupDatabaseDescriptor()
    {
        DatabaseDescriptor.daemonInitialization();
    }

    // this came as a result of CASSANDRA-995
    @Test
    public void testConfigurationLoader() throws Exception
    {
        // By default, we should load from the yaml
        Config config = DatabaseDescriptor.loadConfig();
        assertEquals("Test Cluster", config.cluster_name);
        Keyspace.setInitialized();

        // Now try custom loader
        ConfigurationLoader testLoader = new TestLoader();
        System.setProperty("cassandra.config.loader", testLoader.getClass().getName());

        config = DatabaseDescriptor.loadConfig();
        assertEquals("ConfigurationLoader Test", config.cluster_name);
    }

    public static class TestLoader implements ConfigurationLoader
    {
        public Config loadConfig() throws ConfigurationException
        {
            Config testConfig = new Config();
            testConfig.cluster_name = "ConfigurationLoader Test";
            return testConfig;
        }
    }

    static NetworkInterface suitableInterface = null;
    static boolean hasIPv4andIPv6 = false;

    /*
     * Server only accepts interfaces by name if they have a single address
     * OS X seems to always have an ipv4 and ipv6 address on all interfaces which means some tests fail
     * if not checked for and skipped
     */
    @BeforeClass
    public static void selectSuitableInterface() throws Exception {
        Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
        while(interfaces.hasMoreElements()) {
            NetworkInterface intf = interfaces.nextElement();

            System.out.println("Evaluating " + intf.getName());

            if (intf.isLoopback()) {
                suitableInterface = intf;

                boolean hasIPv4 = false;
                boolean hasIPv6 = false;
                Enumeration<InetAddress> addresses = suitableInterface.getInetAddresses();
                while (addresses.hasMoreElements()) {
                    if (addresses.nextElement() instanceof Inet6Address)
                        hasIPv6 = true;
                    else
                        hasIPv4 = true;
                }
                hasIPv4andIPv6 = hasIPv4 && hasIPv6;
                return;
            }
        }
    }

    @Test
    public void testRpcInterface() throws Exception
    {
        Config testConfig = DatabaseDescriptor.loadConfig();
        testConfig.rpc_interface = suitableInterface.getName();
        testConfig.rpc_address = null;
        DatabaseDescriptor.applyAddressConfig(testConfig);

        /*
         * Confirm ability to select between IPv4 and IPv6
         */
        if (hasIPv4andIPv6)
        {
            testConfig = DatabaseDescriptor.loadConfig();
            testConfig.rpc_interface = suitableInterface.getName();
            testConfig.rpc_address = null;
            testConfig.rpc_interface_prefer_ipv6 = true;
            DatabaseDescriptor.applyAddressConfig(testConfig);

            assertEquals(DatabaseDescriptor.getRpcAddress().getClass(), Inet6Address.class);

            testConfig = DatabaseDescriptor.loadConfig();
            testConfig.rpc_interface = suitableInterface.getName();
            testConfig.rpc_address = null;
            testConfig.rpc_interface_prefer_ipv6 = false;
            DatabaseDescriptor.applyAddressConfig(testConfig);

            assertEquals(DatabaseDescriptor.getRpcAddress().getClass(), Inet4Address.class);
        }
        else
        {
            /*
             * Confirm first address of interface is selected
             */
            assertEquals(DatabaseDescriptor.getRpcAddress(), suitableInterface.getInetAddresses().nextElement());
        }
    }

    @Test
    public void testListenInterface() throws Exception
    {
        Config testConfig = DatabaseDescriptor.loadConfig();
        testConfig.listen_interface = suitableInterface.getName();
        testConfig.listen_address = null;
        DatabaseDescriptor.applyAddressConfig(testConfig);

        /*
         * Confirm ability to select between IPv4 and IPv6
         */
        if (hasIPv4andIPv6)
        {
            testConfig = DatabaseDescriptor.loadConfig();
            testConfig.listen_interface = suitableInterface.getName();
            testConfig.listen_address = null;
            testConfig.listen_interface_prefer_ipv6 = true;
            DatabaseDescriptor.applyAddressConfig(testConfig);

            assertEquals(DatabaseDescriptor.getListenAddress().getClass(), Inet6Address.class);

            testConfig = DatabaseDescriptor.loadConfig();
            testConfig.listen_interface = suitableInterface.getName();
            testConfig.listen_address = null;
            testConfig.listen_interface_prefer_ipv6 = false;
            DatabaseDescriptor.applyAddressConfig(testConfig);

            assertEquals(DatabaseDescriptor.getListenAddress().getClass(), Inet4Address.class);
        }
        else
        {
            /*
             * Confirm first address of interface is selected
             */
            assertEquals(DatabaseDescriptor.getRpcAddress(), suitableInterface.getInetAddresses().nextElement());
        }
    }

    @Test
    public void testListenAddress() throws Exception
    {
        Config testConfig = DatabaseDescriptor.loadConfig();
        testConfig.listen_address = suitableInterface.getInterfaceAddresses().get(0).getAddress().getHostAddress();
        testConfig.listen_interface = null;
        DatabaseDescriptor.applyAddressConfig(testConfig);
    }

    @Test
    public void testRpcAddress() throws Exception
    {
        Config testConfig = DatabaseDescriptor.loadConfig();
        testConfig.rpc_address = suitableInterface.getInterfaceAddresses().get(0).getAddress().getHostAddress();
        testConfig.rpc_interface = null;
        DatabaseDescriptor.applyAddressConfig(testConfig);

    }
    
    @Test
    public void testTokensFromString()
    {
        assertTrue(DatabaseDescriptor.tokensFromString(null).isEmpty());
        Collection<String> tokens = DatabaseDescriptor.tokensFromString(" a,b ,c , d, f,g,h");
        assertEquals(7, tokens.size());
        assertTrue(tokens.containsAll(Arrays.asList(new String[]{"a", "b", "c", "d", "f", "g", "h"})));
    }
}