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 * ownership. Elasticsearch 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
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package org.elasticsearch.cluster.routing.allocation.decider;

import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.test.ESIntegTestCase;

import java.util.Set;

import static org.elasticsearch.common.settings.Settings.settingsBuilder;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
import static org.hamcrest.Matchers.equalTo;

/**
 * Simple integration for {@link EnableAllocationDecider} there is a more exhaustive unittest in
 * {@link EnableAllocationTests} this test is meant to check if the actual update of the settings
 * works as expected.
 */
@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
public class EnableAllocationDeciderIT extends ESIntegTestCase {

    public void testEnableRebalance() throws InterruptedException {
        final String firstNode = internalCluster().startNode();
        client().admin().cluster().prepareUpdateSettings().setTransientSettings(settingsBuilder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE, EnableAllocationDecider.Rebalance.NONE)).get();
        // we test with 2 shards since otherwise it's pretty fragile if there are difference in the num or shards such that
        // all shards are relocated to the second node which is not what we want here. It's solely a test for the settings to take effect
        final int numShards = 2;
        assertAcked(prepareCreate("test").setSettings(settingsBuilder().put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0).put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, numShards)));
        assertAcked(prepareCreate("test_1").setSettings(settingsBuilder().put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0).put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, numShards)));
        ensureGreen();
        assertAllShardsOnNodes("test", firstNode);
        assertAllShardsOnNodes("test_1", firstNode);

        final String secondNode = internalCluster().startNode();
        // prevent via index setting but only on index test
        client().admin().indices().prepareUpdateSettings("test").setSettings(settingsBuilder().put(EnableAllocationDecider.INDEX_ROUTING_REBALANCE_ENABLE, EnableAllocationDecider.Rebalance.NONE)).get();
        client().admin().cluster().prepareReroute().get();
        ensureGreen();
        assertAllShardsOnNodes("test", firstNode);
        assertAllShardsOnNodes("test_1", firstNode);

        // now enable the index test to relocate since index settings override cluster settings
        client().admin().indices().prepareUpdateSettings("test").setSettings(settingsBuilder().put(EnableAllocationDecider.INDEX_ROUTING_REBALANCE_ENABLE, randomBoolean() ? EnableAllocationDecider.Rebalance.PRIMARIES : EnableAllocationDecider.Rebalance.ALL)).get();
        logger.info("--> balance index [test]");
        client().admin().cluster().prepareReroute().get();
        ensureGreen("test");
        Set<String> test = assertAllShardsOnNodes("test", firstNode, secondNode);
        assertThat("index: [test] expected to be rebalanced on both nodes", test.size(), equalTo(2));

        // flip the cluster wide setting such that we can also balance for index test_1 eventually we should have one shard of each index on each node
        client().admin().cluster().prepareUpdateSettings().setTransientSettings(settingsBuilder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE, randomBoolean() ? EnableAllocationDecider.Rebalance.PRIMARIES : EnableAllocationDecider.Rebalance.ALL)).get();
        logger.info("--> balance index [test_1]");
        client().admin().cluster().prepareReroute().get();
        ensureGreen("test_1");
        Set<String> test_1 = assertAllShardsOnNodes("test_1", firstNode, secondNode);
        assertThat("index: [test_1] expected to be rebalanced on both nodes", test_1.size(), equalTo(2));

        test = assertAllShardsOnNodes("test", firstNode, secondNode);
        assertThat("index: [test] expected to be rebalanced on both nodes", test.size(), equalTo(2));
    }
}