/*
 * 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;

import java.util.Arrays;
import java.util.Collections;
import java.util.concurrent.CountDownLatch;

import org.elasticsearch.Version;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.admin.cluster.node.stats.NodeStats;
import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
import org.elasticsearch.action.admin.indices.stats.IndicesStatsResponse;
import org.elasticsearch.client.node.NodeClient;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.collect.ImmutableOpenMap;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.monitor.fs.FsInfo;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.threadpool.ThreadPool;

import static java.util.Collections.emptyMap;
import static java.util.Collections.emptySet;

/**
 * Fake ClusterInfoService class that allows updating the nodes stats disk
 * usage with fake values
 */
public class MockInternalClusterInfoService extends InternalClusterInfoService {

    /** This is a marker plugin used to trigger MockNode to use this mock info service. */
    public static class TestPlugin extends Plugin {}

    private final ClusterName clusterName;
    private volatile NodeStats[] stats = new NodeStats[3];

    /** Create a fake NodeStats for the given node and usage */
    public static NodeStats makeStats(String nodeName, DiskUsage usage) {
        FsInfo.Path[] paths = new FsInfo.Path[1];
        FsInfo.Path path = new FsInfo.Path("/dev/null", null,
            usage.getTotalBytes(), usage.getFreeBytes(), usage.getFreeBytes());
        paths[0] = path;
        FsInfo fsInfo = new FsInfo(System.currentTimeMillis(), null, paths);
        return new NodeStats(new DiscoveryNode(nodeName, ESTestCase.buildNewFakeTransportAddress(), emptyMap(), emptySet(), Version.CURRENT),
            System.currentTimeMillis(),
            null, null, null, null, null,
            fsInfo,
            null, null, null,
            null, null, null);
    }

    public MockInternalClusterInfoService(Settings settings, ClusterService clusterService, ThreadPool threadPool, NodeClient client) {
        super(settings, clusterService, threadPool, client);
        this.clusterName = ClusterName.CLUSTER_NAME_SETTING.get(settings);
        stats[0] = makeStats("node_t1", new DiskUsage("node_t1", "n1", "/dev/null", 100, 100));
        stats[1] = makeStats("node_t2", new DiskUsage("node_t2", "n2", "/dev/null", 100, 100));
        stats[2] = makeStats("node_t3", new DiskUsage("node_t3", "n3", "/dev/null", 100, 100));
    }

    public void setN1Usage(String nodeName, DiskUsage newUsage) {
        stats[0] = makeStats(nodeName, newUsage);
    }

    public void setN2Usage(String nodeName, DiskUsage newUsage) {
        stats[1] = makeStats(nodeName, newUsage);
    }

    public void setN3Usage(String nodeName, DiskUsage newUsage) {
        stats[2] = makeStats(nodeName, newUsage);
    }

    @Override
    public CountDownLatch updateNodeStats(final ActionListener<NodesStatsResponse> listener) {
        NodesStatsResponse response = new NodesStatsResponse(clusterName, Arrays.asList(stats), Collections.emptyList());
        listener.onResponse(response);
        return new CountDownLatch(0);
    }

    @Override
    public CountDownLatch updateIndicesStats(final ActionListener<IndicesStatsResponse> listener) {
        // Not used, so noop
        return new CountDownLatch(0);
    }

    @Override
    public ClusterInfo getClusterInfo() {
        ClusterInfo clusterInfo = super.getClusterInfo();
        return new DevNullClusterInfo(clusterInfo.getNodeLeastAvailableDiskUsages(), clusterInfo.getNodeMostAvailableDiskUsages(), clusterInfo.shardSizes);
    }

    /**
     * ClusterInfo that always points to DevNull.
     */
    public static class DevNullClusterInfo extends ClusterInfo {
        public DevNullClusterInfo(ImmutableOpenMap<String, DiskUsage> leastAvailableSpaceUsage,
            ImmutableOpenMap<String, DiskUsage> mostAvailableSpaceUsage, ImmutableOpenMap<String, Long> shardSizes) {
            super(leastAvailableSpaceUsage, mostAvailableSpaceUsage, shardSizes, null);
        }

        @Override
        public String getDataPath(ShardRouting shardRouting) {
            return "/dev/null";
        }
    }

    @Override
    public void setUpdateFrequency(TimeValue updateFrequency) {
        super.setUpdateFrequency(updateFrequency);
    }
}