/*
 * 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.test;

import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
import org.elasticsearch.action.admin.cluster.node.info.NodesInfoResponse;
import org.elasticsearch.action.admin.cluster.node.stats.NodeStats;
import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.breaker.CircuitBreaker;
import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.node.internal.InternalSettingsPreparer;
import org.elasticsearch.plugins.Plugin;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.file.Path;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.concurrent.atomic.AtomicInteger;

import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertThat;

/**
 * External cluster to run the tests against.
 * It is a pure immutable test cluster that allows to send requests to a pre-existing cluster
 * and supports by nature all the needed test operations like wipeIndices etc.
 */
public final class ExternalTestCluster extends TestCluster {

    private static final ESLogger logger = Loggers.getLogger(ExternalTestCluster.class);

    private static final AtomicInteger counter = new AtomicInteger();
    public static final String EXTERNAL_CLUSTER_PREFIX = "external_";

    private final Client client;

    private final InetSocketAddress[] httpAddresses;

    private final String clusterName;

    private final int numDataNodes;
    private final int numMasterAndDataNodes;

    public ExternalTestCluster(Path tempDir, Settings additionalSettings, Collection<Class<? extends Plugin>> pluginClasses, TransportAddress... transportAddresses) {
        super(0);
        Settings clientSettings = Settings.settingsBuilder()
                .put(additionalSettings)
                .put("name", InternalTestCluster.TRANSPORT_CLIENT_PREFIX + EXTERNAL_CLUSTER_PREFIX + counter.getAndIncrement())
                .put(InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING, true) // prevents any settings to be replaced by system properties.
                .put("client.transport.ignore_cluster_name", true)
                .put("path.home", tempDir)
                .put("node.mode", "network").build(); // we require network here!

        TransportClient.Builder transportClientBuilder = TransportClient.builder().settings(clientSettings);
        for (Class<? extends Plugin> pluginClass : pluginClasses) {
            transportClientBuilder.addPlugin(pluginClass);
        }
        this.client = transportClientBuilder.build().addTransportAddresses(transportAddresses);

        NodesInfoResponse nodeInfos = this.client.admin().cluster().prepareNodesInfo().clear().setSettings(true).setHttp(true).get();
        httpAddresses = new InetSocketAddress[nodeInfos.getNodes().length];
        this.clusterName = nodeInfos.getClusterName().value();
        int dataNodes = 0;
        int masterAndDataNodes = 0;
        for (int i = 0; i < nodeInfos.getNodes().length; i++) {
            NodeInfo nodeInfo = nodeInfos.getNodes()[i];
            httpAddresses[i] = ((InetSocketTransportAddress) nodeInfo.getHttp().address().publishAddress()).address();
            if (DiscoveryNode.dataNode(nodeInfo.getSettings())) {
                dataNodes++;
                masterAndDataNodes++;
            } else if (DiscoveryNode.masterNode(nodeInfo.getSettings())) {
                masterAndDataNodes++;
            }
        }
        this.numDataNodes = dataNodes;
        this.numMasterAndDataNodes = masterAndDataNodes;
        logger.info("Setup ExternalTestCluster [{}] made of [{}] nodes", nodeInfos.getClusterName().value(), size());
    }

    @Override
    public void afterTest() {

    }

    @Override
    public Client client() {
        return client;
    }

    @Override
    public int size() {
        return httpAddresses.length;
    }

    @Override
    public int numDataNodes() {
        return numDataNodes;
    }

    @Override
    public int numDataAndMasterNodes() {
        return numMasterAndDataNodes;
    }

    @Override
    public InetSocketAddress[] httpAddresses() {
        return httpAddresses;
    }

    @Override
    public void close() throws IOException {
        client.close();
    }

    @Override
    public void ensureEstimatedStats() {
        if (size() > 0) {
            NodesStatsResponse nodeStats = client().admin().cluster().prepareNodesStats()
                    .clear().setBreaker(true).setIndices(true).execute().actionGet();
            for (NodeStats stats : nodeStats.getNodes()) {
                assertThat("Fielddata breaker not reset to 0 on node: " + stats.getNode(),
                        stats.getBreaker().getStats(CircuitBreaker.FIELDDATA).getEstimated(), equalTo(0L));
                // ExternalTestCluster does not check the request breaker,
                // because checking it requires a network request, which in
                // turn increments the breaker, making it non-0

                assertThat("Fielddata size must be 0 on node: " + stats.getNode(), stats.getIndices().getFieldData().getMemorySizeInBytes(), equalTo(0l));
                assertThat("Query cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getQueryCache().getMemorySizeInBytes(), equalTo(0l));
                assertThat("FixedBitSet cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
            }
        }
    }

    @Override
    public Iterator<Client> iterator() {
        return Collections.singleton(client).iterator();
    }

    @Override
    public String getClusterName() {
        return clusterName;
    }
}