/*
 * 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.locator;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import org.junit.Assert;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.dht.OrderPreservingPartitioner.StringToken;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.exceptions.ConfigurationException;

public class NetworkTopologyStrategyTest
{
    private String keyspaceName = "Keyspace1";
    private static final Logger logger = LoggerFactory.getLogger(NetworkTopologyStrategyTest.class);

    @Test
    public void testProperties() throws IOException, ConfigurationException
    {
        IEndpointSnitch snitch = new PropertyFileSnitch();
        DatabaseDescriptor.setEndpointSnitch(snitch);
        TokenMetadata metadata = new TokenMetadata();
        createDummyTokens(metadata, true);

        Map<String, String> configOptions = new HashMap<String, String>();
        configOptions.put("DC1", "3");
        configOptions.put("DC2", "2");
        configOptions.put("DC3", "1");

        // Set the localhost to the tokenmetadata. Embedded cassandra way?
        NetworkTopologyStrategy strategy = new NetworkTopologyStrategy(keyspaceName, metadata, snitch, configOptions);
        assert strategy.getReplicationFactor("DC1") == 3;
        assert strategy.getReplicationFactor("DC2") == 2;
        assert strategy.getReplicationFactor("DC3") == 1;
        // Query for the natural hosts
        ArrayList<InetAddress> endpoints = strategy.getNaturalEndpoints(new StringToken("123"));
        assert 6 == endpoints.size();
        assert 6 == new HashSet<InetAddress>(endpoints).size(); // ensure uniqueness
    }

    @Test
    public void testPropertiesWithEmptyDC() throws IOException, ConfigurationException
    {
        IEndpointSnitch snitch = new PropertyFileSnitch();
        DatabaseDescriptor.setEndpointSnitch(snitch);
        TokenMetadata metadata = new TokenMetadata();
        createDummyTokens(metadata, false);

        Map<String, String> configOptions = new HashMap<String, String>();
        configOptions.put("DC1", "3");
        configOptions.put("DC2", "3");
        configOptions.put("DC3", "0");

        // Set the localhost to the tokenmetadata. Embedded cassandra way?
        NetworkTopologyStrategy strategy = new NetworkTopologyStrategy(keyspaceName, metadata, snitch, configOptions);
        assert strategy.getReplicationFactor("DC1") == 3;
        assert strategy.getReplicationFactor("DC2") == 3;
        assert strategy.getReplicationFactor("DC3") == 0;
        // Query for the natural hosts
        ArrayList<InetAddress> endpoints = strategy.getNaturalEndpoints(new StringToken("123"));
        assert 6 == endpoints.size();
        assert 6 == new HashSet<InetAddress>(endpoints).size(); // ensure uniqueness
    }

    @Test
    public void testLargeCluster() throws UnknownHostException, ConfigurationException
    {
        int[] dcRacks = new int[]{2, 4, 8};
        int[] dcEndpoints = new int[]{128, 256, 512};
        int[] dcReplication = new int[]{2, 6, 6};

        IEndpointSnitch snitch = new RackInferringSnitch();
        DatabaseDescriptor.setEndpointSnitch(snitch);
        TokenMetadata metadata = new TokenMetadata();
        Map<String, String> configOptions = new HashMap<String, String>();
        Multimap<InetAddress, Token> tokens = HashMultimap.create();

        int totalRF = 0;
        for (int dc = 0; dc < dcRacks.length; ++dc)
        {
            totalRF += dcReplication[dc];
            configOptions.put(Integer.toString(dc), Integer.toString(dcReplication[dc]));
            for (int rack = 0; rack < dcRacks[dc]; ++rack)
            {
                for (int ep = 1; ep <= dcEndpoints[dc]/dcRacks[dc]; ++ep)
                {
                    byte[] ipBytes = new byte[]{10, (byte)dc, (byte)rack, (byte)ep};
                    InetAddress address = InetAddress.getByAddress(ipBytes);
                    StringToken token = new StringToken(String.format("%02x%02x%02x", ep, rack, dc));
                    logger.debug("adding node {} at {}", address, token);
                    tokens.put(address, token);
                }
            }
        }
        metadata.updateNormalTokens(tokens);

        NetworkTopologyStrategy strategy = new NetworkTopologyStrategy(keyspaceName, metadata, snitch, configOptions);

        for (String testToken : new String[]{"123456", "200000", "000402", "ffffff", "400200"})
        {
            List<InetAddress> endpoints = strategy.calculateNaturalEndpoints(new StringToken(testToken), metadata);
            Set<InetAddress> epSet = new HashSet<InetAddress>(endpoints);

            Assert.assertEquals(totalRF, endpoints.size());
            Assert.assertEquals(totalRF, epSet.size());
            logger.debug("{}: {}", testToken, endpoints);
        }
    }

    public void createDummyTokens(TokenMetadata metadata, boolean populateDC3) throws UnknownHostException
    {
        // DC 1
        tokenFactory(metadata, "123", new byte[]{ 10, 0, 0, 10 });
        tokenFactory(metadata, "234", new byte[]{ 10, 0, 0, 11 });
        tokenFactory(metadata, "345", new byte[]{ 10, 0, 0, 12 });
        // Tokens for DC 2
        tokenFactory(metadata, "789", new byte[]{ 10, 20, 114, 10 });
        tokenFactory(metadata, "890", new byte[]{ 10, 20, 114, 11 });
        //tokens for DC3
        if (populateDC3)
        {
            tokenFactory(metadata, "456", new byte[]{ 10, 21, 119, 13 });
            tokenFactory(metadata, "567", new byte[]{ 10, 21, 119, 10 });
        }
        // Extra Tokens
        tokenFactory(metadata, "90A", new byte[]{ 10, 0, 0, 13 });
        if (populateDC3)
            tokenFactory(metadata, "0AB", new byte[]{ 10, 21, 119, 14 });
        tokenFactory(metadata, "ABC", new byte[]{ 10, 20, 114, 15 });
    }

    public void tokenFactory(TokenMetadata metadata, String token, byte[] bytes) throws UnknownHostException
    {
        Token token1 = new StringToken(token);
        InetAddress add1 = InetAddress.getByAddress(bytes);
        metadata.updateNormalToken(token1, add1);
    }
}