/*
 * 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.cluster.routing.allocation;

import org.apache.logging.log4j.Logger;
import org.elasticsearch.Version;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ESAllocationTestCase;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.cluster.routing.RoutingNode;
import org.elasticsearch.cluster.routing.RoutingNodes;
import org.elasticsearch.cluster.routing.RoutingTable;
import org.elasticsearch.cluster.routing.allocation.decider.ClusterRebalanceAllocationDecider;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.settings.Settings;

import static org.elasticsearch.cluster.routing.ShardRoutingState.INITIALIZING;
import static org.elasticsearch.cluster.routing.ShardRoutingState.STARTED;
import static org.hamcrest.Matchers.equalTo;

public class FailedNodeRoutingTests extends ESAllocationTestCase {
    private final Logger logger = Loggers.getLogger(FailedNodeRoutingTests.class);

    public void testSimpleFailedNodeTest() {
        AllocationService strategy = createAllocationService(Settings.builder().put(ClusterRebalanceAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING.getKey(),
                ClusterRebalanceAllocationDecider.ClusterRebalanceType.ALWAYS.toString()).build());

        MetaData metaData = MetaData.builder()
                .put(IndexMetaData.builder("test1").settings(settings(Version.CURRENT)).numberOfShards(1).numberOfReplicas(1))
                .put(IndexMetaData.builder("test2").settings(settings(Version.CURRENT)).numberOfShards(1).numberOfReplicas(1))
                .build();

        RoutingTable initialRoutingTable = RoutingTable.builder()
                .addAsNew(metaData.index("test1"))
                .addAsNew(metaData.index("test2"))
                .build();

        ClusterState clusterState = ClusterState.builder(org.elasticsearch.cluster.ClusterName.CLUSTER_NAME_SETTING.getDefault(Settings.EMPTY)).metaData(metaData).routingTable(initialRoutingTable).build();

        logger.info("start 4 nodes");
        clusterState = ClusterState.builder(clusterState).nodes(DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")).add(newNode("node3")).add(newNode("node4"))).build();
        clusterState = strategy.reroute(clusterState, "reroute");

        logger.info("start all the primary shards, replicas will start initializing");
        RoutingNodes routingNodes = clusterState.getRoutingNodes();
        clusterState = strategy.applyStartedShards(clusterState, routingNodes.shardsWithState(INITIALIZING));
        routingNodes = clusterState.getRoutingNodes();

        logger.info("start the replica shards");
        routingNodes = clusterState.getRoutingNodes();
        clusterState = strategy.applyStartedShards(clusterState, routingNodes.shardsWithState(INITIALIZING));
        routingNodes = clusterState.getRoutingNodes();

        assertThat(routingNodes.node("node1").numberOfShardsWithState(STARTED), equalTo(1));
        assertThat(routingNodes.node("node2").numberOfShardsWithState(STARTED), equalTo(1));
        assertThat(routingNodes.node("node3").numberOfShardsWithState(STARTED), equalTo(1));
        assertThat(routingNodes.node("node4").numberOfShardsWithState(STARTED), equalTo(1));


        logger.info("remove 2 nodes where primaries are allocated, reroute");

        clusterState = ClusterState.builder(clusterState).nodes(DiscoveryNodes.builder(clusterState.nodes())
                .remove(clusterState.routingTable().index("test1").shard(0).primaryShard().currentNodeId())
                .remove(clusterState.routingTable().index("test2").shard(0).primaryShard().currentNodeId())
        )
                .build();
        clusterState = strategy.deassociateDeadNodes(clusterState, true, "reroute");
        routingNodes = clusterState.getRoutingNodes();

        for (RoutingNode routingNode : routingNodes) {
            assertThat(routingNode.numberOfShardsWithState(STARTED), equalTo(1));
            assertThat(routingNode.numberOfShardsWithState(INITIALIZING), equalTo(1));
        }
    }
}
