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 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * 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
 * "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.elasticsearch.index.reindex;

import org.elasticsearch.Version;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.support.AutoCreateIndex;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.metadata.AliasMetaData;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.test.ESTestCase;

import static org.hamcrest.Matchers.containsString;

/**
 * Tests that indexing from an index back into itself fails the request.
 */
public class ReindexSameIndexTests extends ESTestCase {
    private static final ClusterState STATE = ClusterState.builder(new ClusterName("test")).metaData(MetaData.builder()
                .put(index("target", "target_alias", "target_multi"), true)
                .put(index("target2", "target_multi"), true)
                .put(index("foo"), true)
                .put(index("bar"), true)
                .put(index("baz"), true)
                .put(index("source", "source_multi"), true)
                .put(index("source2", "source_multi"), true)).build();
    private static final IndexNameExpressionResolver INDEX_NAME_EXPRESSION_RESOLVER = new IndexNameExpressionResolver(Settings.EMPTY);
    private static final AutoCreateIndex AUTO_CREATE_INDEX = new AutoCreateIndex(Settings.EMPTY, INDEX_NAME_EXPRESSION_RESOLVER);

    public void testObviousCases() throws Exception {
        fails("target", "target");
        fails("target", "foo", "bar", "target", "baz");
        fails("target", "foo", "bar", "target", "baz", "target");
        succeeds("target", "source");
        succeeds("target", "source", "source2");
    }

    public void testAliasesContainTarget() throws Exception {
        fails("target", "target_alias");
        fails("target_alias", "target");
        fails("target", "foo", "bar", "target_alias", "baz");
        fails("target_alias", "foo", "bar", "target_alias", "baz");
        fails("target_alias", "foo", "bar", "target", "baz");
        fails("target", "foo", "bar", "target_alias", "target_alias");
        fails("target", "target_multi");
        fails("target", "foo", "bar", "target_multi", "baz");
        succeeds("target", "source_multi");
        succeeds("target", "source", "source2", "source_multi");
    }

    public void testTargetIsAlias() throws Exception {
        try {
            succeeds("target_multi", "foo");
            fail("Expected failure");
        } catch (IllegalArgumentException e) {
            assertThat(e.getMessage(), containsString("Alias [target_multi] has more than one indices associated with it [["));
            // The index names can come in either order
            assertThat(e.getMessage(), containsString("target"));
            assertThat(e.getMessage(), containsString("target2"));
        }
    }

    private void fails(String target, String... sources) throws Exception {
        try {
            succeeds(target, sources);
            fail("Expected an exception");
        } catch (ActionRequestValidationException e) {
            assertThat(e.getMessage(),
                    containsString("reindex cannot write into an index its reading from [target]"));
        }
    }

    private void succeeds(String target, String... sources) throws Exception {
        TransportReindexAction.validateAgainstAliases(new SearchRequest(sources), new IndexRequest(target), INDEX_NAME_EXPRESSION_RESOLVER,
                AUTO_CREATE_INDEX, STATE);
    }

    private static IndexMetaData index(String name, String... aliases) {
        IndexMetaData.Builder builder = IndexMetaData.builder(name).settings(Settings.builder()
                .put("index.version.created", Version.CURRENT.id)
                .put("index.number_of_shards", 1)
                .put("index.number_of_replicas", 1));
        for (String alias: aliases) {
            builder.putAlias(AliasMetaData.builder(alias).build());
        }
        return builder.build();
    }
}