/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.metron.elasticsearch.integration.components;

import org.apache.commons.io.FileUtils;
import org.apache.metron.elasticsearch.dao.ElasticsearchDao;
import org.apache.metron.indexing.dao.AccessConfig;
import org.apache.metron.indexing.dao.IndexDao;
import org.apache.metron.indexing.dao.update.Document;
import org.apache.metron.integration.InMemoryComponent;
import org.apache.metron.integration.UnableToStartException;
import org.apache.metron.stellar.common.utils.ConversionUtils;
import org.elasticsearch.ElasticsearchTimeoutException;
import org.elasticsearch.action.admin.cluster.health.ClusterHealthAction;
import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.admin.indices.refresh.RefreshRequest;
import org.elasticsearch.action.admin.indices.stats.IndicesStatsRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.support.WriteRequest;
import org.elasticsearch.client.Client;
import org.elasticsearch.cluster.health.ClusterHealthStatus;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.node.InternalSettingsPreparer;
import org.elasticsearch.node.Node;
import org.elasticsearch.node.NodeValidationException;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.transport.Netty4Plugin;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;

import static java.util.Arrays.asList;

public class ElasticSearchComponent implements InMemoryComponent {

  private static class Mapping {
    String index;
    String docType;
    String mapping;

    public Mapping(String index, String docType, String mapping) {
      this.index = index;
      this.docType = docType;
      this.mapping = mapping;
    }
  }

  public static class Builder {

    private int httpPort;
    private File indexDir;
    private Map<String, String> extraElasticSearchSettings = null;
    private List<Mapping> mappings = new ArrayList<>();
    private AccessConfig accessConfig = new AccessConfig();

    public Builder withMapping(String index, String docType, String mapping) {
      mappings.add(new Mapping(index, docType, mapping));
      return this;
    }

    public Builder withHttpPort(int httpPort) {
      this.httpPort = httpPort;
      return this;
    }

    public Builder withIndexDir(File indexDir) {
      this.indexDir = indexDir;
      return this;
    }

    public Builder withExtraElasticSearchSettings(
        Map<String, String> extraElasticSearchSettings) {
      this.extraElasticSearchSettings = extraElasticSearchSettings;
      return this;
    }

    public Builder withAccessConfig(AccessConfig accessConfig) {
      this.accessConfig = accessConfig;
      return this;
    }

    public ElasticSearchComponent build() {
      return new ElasticSearchComponent(httpPort, indexDir, extraElasticSearchSettings, mappings, accessConfig);
    }
  }

  private static final String STARTUP_TIMEOUT = "60s";
  private Client client;
  private Node node;
  private int httpPort;
  private File indexDir;
  private Map<String, String> extraElasticSearchSettings;
  private List<Mapping> mappings;
  private AccessConfig accessConfig;
  private IndexDao indexDao;

  public ElasticSearchComponent(int httpPort, File indexDir,
      Map<String, String> extraElasticSearchSettings, List<Mapping> mappings, AccessConfig accessConfig) {
    this.httpPort = httpPort;
    this.indexDir = indexDir;
    this.extraElasticSearchSettings = extraElasticSearchSettings;
    this.mappings = mappings;
    this.accessConfig = accessConfig;
  }

  @Override
  public void start() throws UnableToStartException {
    File logDir = new File(indexDir, "/logs");
    File dataDir = new File(indexDir, "/data");
    try {
      cleanDir(logDir);
      cleanDir(dataDir);
    } catch (IOException e) {
      throw new UnableToStartException("Unable to clean log or data directories", e);
    }

    Settings.Builder settingsBuilder = Settings.builder()
        .put("cluster.name", "metron")
        .put("path.logs",logDir.getAbsolutePath())
        .put("path.data",dataDir.getAbsolutePath())
        .put("path.home", indexDir.getAbsoluteFile())
        .put("transport.type", "netty4")
        .put("http.enabled", "true");

    if (extraElasticSearchSettings != null) {
      settingsBuilder = settingsBuilder.put(extraElasticSearchSettings);
    }

    node = new TestNode(settingsBuilder.build(), asList(Netty4Plugin.class));
    client = node.client();
    try {
      node.start();
    } catch (NodeValidationException e) {
      throw new UnableToStartException("Error starting ES node.", e);
    }
    waitForCluster(client, ClusterHealthStatus.YELLOW, STARTUP_TIMEOUT);
    for(Mapping m : Optional.ofNullable(mappings).orElse(new ArrayList<>())) {
          client.admin().indices().prepareCreate(m.index)
            .addMapping(m.docType, m.mapping).get();
    }

    indexDao = new ElasticsearchDao()
            .withRefreshPolicy(WriteRequest.RefreshPolicy.WAIT_UNTIL);
    indexDao.init(accessConfig);
  }

  private void cleanDir(File dir) throws IOException {
    if (dir.exists()) {
      FileUtils.deleteDirectory(dir);
    }
    dir.mkdirs();
  }

  // ES 5.x+ needs this to startup a node without using their test framework
  private static class TestNode extends Node {

    private TestNode(Settings preparedSettings,
        Collection<Class<? extends Plugin>> classpathPlugins) {
      super(InternalSettingsPreparer.prepareEnvironment(preparedSettings, null), classpathPlugins);
    }

  }

  public static void waitForCluster(Client client, ClusterHealthStatus statusThreshold,
      String timeout) throws UnableToStartException {
    try {
      ClusterHealthResponse healthResponse = (ClusterHealthResponse) client
          .execute(ClusterHealthAction.INSTANCE,
              new ClusterHealthRequest().waitForStatus(statusThreshold).timeout(timeout))
          .actionGet();
      if (healthResponse != null && healthResponse.isTimedOut()) {
        throw new UnableToStartException("cluster state is " + healthResponse.getStatus().name()
            + " and not " + statusThreshold.name()
            + ", from here on, everything will fail!");
      }
    } catch (ElasticsearchTimeoutException e) {
      throw new UnableToStartException(
          "timeout, cluster does not respond to health request, cowardly refusing to continue with operations");
    }
  }

  public Client getClient() {
    return client;
  }

  public void add(String indexName, String sensorType, String... docs)
          throws IOException, ParseException {
    List<String> d = new ArrayList<>();
    Collections.addAll(d, docs);
    add(indexName, sensorType, d, false);
  }

  public void add(String indexName, String sensorType, Iterable<String> docs) throws IOException, ParseException {
    add(indexName, sensorType, docs, false);
  }

  public void add(String indexName, String sensorType, Iterable<String> docs, boolean setDocumentId)
          throws IOException, ParseException {

    // create a collection of indexable documents
    JSONParser parser = new JSONParser();
    Map<Document, Optional<String>> documents = new HashMap<>();
    for(String json: docs) {
      JSONObject message = (JSONObject) parser.parse(json);
      documents.put(createDocument(message, sensorType, setDocumentId), Optional.of(indexName));
    }

    // write the documents
    indexDao.batchUpdate(documents);
  }

  /**
   * Create an indexable Document from a JSON message.
   *
   * @param message The JSON message that needs indexed.
   * @param docType The document type to write.
   * @return The {@link Document} that was written.
   * @throws IOException
   */
  private static Document createDocument(JSONObject message, String docType, boolean setDocumentId) throws IOException {
    Long timestamp = ConversionUtils.convert(message.get("timestamp"), Long.class);
    String source = message.toJSONString();
    String guid = (String) message.get("guid");
    Document document = new Document(source, guid, docType, timestamp);
    if (setDocumentId) {
      document.setDocumentID(guid);
    }
    return document;
  }

  public void createIndexWithMapping(String indexName, String mappingType, String mappingSource)
      throws IOException {
    CreateIndexResponse cir = client.admin().indices().prepareCreate(indexName)
        .addMapping(mappingType, mappingSource)
        .get();

    if (!cir.isAcknowledged()) {
      throw new IOException("Create index was not acknowledged");
    }
  }

  public List<Map<String, Object>> getAllIndexedDocs(String index, String sourceType)
      throws IOException {
    return getAllIndexedDocs(index, sourceType, null);
  }

  public List<Map<String, Object>> getAllIndexedDocs(String index, String sourceType,
      String subMessage) throws IOException {
    getClient().admin().indices().refresh(new RefreshRequest());
    SearchResponse response = getClient().prepareSearch(index)
        .setTypes(sourceType)
        .setFrom(0)
        .setSize(1000)
        .execute().actionGet();
    List<Map<String, Object>> ret = new ArrayList<Map<String, Object>>();
    for (SearchHit hit : response.getHits()) {
      Object o = null;
      if (subMessage == null) {
        o = hit.getSource();
      } else {
        o = hit.getSource().get(subMessage);
      }
      ret.add((Map<String, Object>) (o));
    }
    return ret;
  }

  public boolean hasIndex(String indexName) {
    Set<String> indices = getClient().admin()
        .indices()
        .stats(new IndicesStatsRequest())
        .actionGet()
        .getIndices()
        .keySet();
    return indices.contains(indexName);

  }

  @Override
  public void stop() {
    try {
      if(node != null) {
        node.close();
      }
    } catch (IOException e) {
      throw new RuntimeException("Unable to stop node." , e);
    }
    node = null;
    client = null;
  }

  @Override
  public void reset() {
      client.admin().indices().delete(new DeleteIndexRequest("*")).actionGet();
  }
}