/*
    * 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.syncope.ext.elasticsearch.client;
  
  import co.elastic.clients.elasticsearch.ElasticsearchClient;
  import co.elastic.clients.json.jackson.JacksonJsonpMapper;
  import co.elastic.clients.transport.rest_client.RestClientTransport;
  import com.fasterxml.jackson.databind.SerializationFeature;
  import com.fasterxml.jackson.databind.json.JsonMapper;
  import java.nio.charset.StandardCharsets;
  import java.util.Base64;
  import java.util.List;
  import org.apache.http.Header;
  import org.apache.http.HttpHeaders;
  import org.apache.http.HttpHost;
  import org.apache.http.auth.AuthScope;
  import org.apache.http.auth.UsernamePasswordCredentials;
  import org.apache.http.client.CredentialsProvider;
  import org.apache.http.impl.client.BasicCredentialsProvider;
  import org.apache.http.message.BasicHeader;
  import org.elasticsearch.client.RestClient;
  import org.elasticsearch.client.RestClientBuilder;
  import org.springframework.beans.factory.DisposableBean;
  import org.springframework.beans.factory.FactoryBean;
  
  /**
   * Spring {@link FactoryBean} for getting the {@link ElasticsearchClient} singleton instance.
   */
  public class ElasticsearchClientFactoryBean implements FactoryBean<ElasticsearchClient>, DisposableBean {
  
      private final List<HttpHost> hosts;
  
      private String username;
  
      private String password;
  
      private String serviceToken;
  
      private String apiKeyId;
  
      private String apiKeySecret;
  
      private RestClient restClient;
  
      private ElasticsearchClient client;
  
      public ElasticsearchClientFactoryBean(final List<HttpHost> hosts) {
          this.hosts = hosts;
      }
  
      public void setUsername(final String username) {
          this.username = username;
      }
  
      public void setPassword(final String password) {
          this.password = password;
      }
  
      public String getServiceToken() {
          return serviceToken;
      }
  
      public void setServiceToken(final String serviceToken) {
          this.serviceToken = serviceToken;
      }
  
      public String getApiKeyId() {
          return apiKeyId;
      }
  
      public void setApiKeyId(final String apiKeyId) {
          this.apiKeyId = apiKeyId;
      }
  
      public String getApiKeySecret() {
          return apiKeySecret;
      }
  
      public void setApiKeySecret(final String apiKeySecret) {
          this.apiKeySecret = apiKeySecret;
      }
  
      @Override
     public ElasticsearchClient getObject() throws Exception {
         synchronized (this) {
             if (client == null) {
                 RestClientBuilder builder = RestClient.builder(hosts.toArray(HttpHost[]::new));
                 if (username != null && password != null) {
                     CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
                     credentialsProvider.setCredentials(
                             AuthScope.ANY, new UsernamePasswordCredentials(username, password));
                     builder.setHttpClientConfigCallback(b -> b.setDefaultCredentialsProvider(credentialsProvider));
                 } else if (serviceToken != null) {
                     builder.setDefaultHeaders(
                             new Header[] { new BasicHeader(HttpHeaders.AUTHORIZATION, "Bearer " + serviceToken) });
                 } else if (apiKeyId != null && apiKeySecret != null) {
                     String apiKeyAuth = Base64.getEncoder().encodeToString(
                             (apiKeyId + ":" + apiKeySecret).getBytes(StandardCharsets.UTF_8));
                     builder.setDefaultHeaders(
                             new Header[] { new BasicHeader(HttpHeaders.AUTHORIZATION, "ApiKey " + apiKeyAuth) });
                 }
 
                 restClient = builder.build();
                 client = new ElasticsearchClient(new RestClientTransport(
                         restClient,
                         new JacksonJsonpMapper(JsonMapper.builder().
                                 findAndAddModules().disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS).build())));
             }
         }
         return client;
     }
 
     @Override
     public Class<?> getObjectType() {
         return ElasticsearchClient.class;
     }
 
     @Override
     public void destroy() throws Exception {
         if (restClient != null) {
             restClient.close();
         }
     }
 }