/*
    * Copyright 2012-2025 CodeLibs Project and the Others.
    *
    * Licensed 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.codelibs.fess.score;
  
  import java.util.Arrays;
  import java.util.Map;
  import java.util.function.Function;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.codelibs.core.lang.StringUtil;
  import org.codelibs.fess.mylasta.direction.FessConfig;
  import org.codelibs.fess.opensearch.client.SearchEngineClient;
  import org.codelibs.fess.util.ComponentUtil;
  import org.opensearch.action.bulk.BulkRequestBuilder;
  import org.opensearch.action.bulk.BulkResponse;
  import org.opensearch.action.search.SearchResponse;
  import org.opensearch.action.update.UpdateRequestBuilder;
  import org.opensearch.index.query.QueryBuilders;
  import org.opensearch.script.Script;
  import org.opensearch.script.ScriptType;
  import org.opensearch.search.SearchHit;
  
  /**
   * This class is a base class for score boosters.
   */
  public abstract class ScoreBooster {
      /**
       * Constructor.
       */
      public ScoreBooster() {
          super();
      }
  
      private static final Logger logger = LogManager.getLogger(ScoreBooster.class);
  
      /**
       * The bulk request builder.
       */
      protected BulkRequestBuilder bulkRequestBuilder = null;
  
      /**
       * The priority of this score booster.
       */
      protected int priority = 1;
  
      /**
       * The request timeout.
       */
      protected String requestTimeout = "1m";
  
      /**
       * The request cache size.
       */
      protected int requestCacheSize = 1000;
  
      /**
       * The script language.
       */
      protected String scriptLang = "painless";
  
      /**
       * The script code.
       */
      protected String scriptCode = null;
  
      /**
       * A function to find document IDs.
       */
      protected Function<Map<String, Object>, String[]> idFinder = params -> {
          final FessConfig fessConfig = ComponentUtil.getFessConfig();
          final SearchEngineClient client = ComponentUtil.getSearchEngineClient();
          final String index = fessConfig.getIndexDocumentUpdateIndex();
          final Object url = params.get("url");
          if (url == null) {
              return StringUtil.EMPTY_STRINGS;
          }
          final SearchResponse response = client.prepareSearch(index)
                  .setQuery(QueryBuilders.termQuery(fessConfig.getIndexFieldUrl(), url))
                  .setFetchSource(false)
                  .setSize(fessConfig.getPageScoreBoosterMaxFetchSizeAsInteger())
                  .execute()
                  .actionGet(requestTimeout);
          return Arrays.stream(response.getHits().getHits()).map(SearchHit::getId).toArray(n -> new String[n]);
      };
  
     /**
      * A function to handle requests.
      */
     protected Function<Map<String, Object>, Long> requestHandler = params -> {
         final FessConfig fessConfig = ComponentUtil.getFessConfig();
         final String[] ids = idFinder.apply(params);
         if (ids.length == 0) {
             return 0L;
         }
         final SearchEngineClient client = ComponentUtil.getSearchEngineClient();
         if (bulkRequestBuilder == null) {
             bulkRequestBuilder = client.prepareBulk();
         }
         final String index = fessConfig.getIndexDocumentUpdateIndex();
         for (final String id : ids) {
             bulkRequestBuilder.add(client.prepareUpdate()
                     .setIndex(index)
                     .setId(id)
                     .setScript(new Script(ScriptType.INLINE, scriptLang, scriptCode, params)));
         }
         if (bulkRequestBuilder.numberOfActions() > requestCacheSize) {
             flush();
         }
         return (long) ids.length;
     };
 
     /**
      * Processes the score boosting.
      * @return The number of processed documents.
      */
     public abstract long process();
 
     /**
      * Enables this score booster.
      */
     protected void enable() {
         final ScoreUpdater scoreUpdater = ComponentUtil.getComponent("scoreUpdater");
         scoreUpdater.addScoreBooster(this);
     }
 
     /**
      * Updates the score of documents.
      * @param params The parameters for the update.
      * @return The number of updated documents.
      */
     protected long updateScore(final Map<String, Object> params) {
         return requestHandler.apply(params);
     }
 
     /**
      * Creates an update request builder.
      * @return The update request builder.
      */
     protected UpdateRequestBuilder createUpdateRequestBuilder() {
         final FessConfig fessConfig = ComponentUtil.getFessConfig();
         return ComponentUtil.getSearchEngineClient().prepareUpdate().setIndex(fessConfig.getIndexDocumentSearchIndex());
     }
 
     /**
      * Flushes the bulk request builder.
      */
     protected void flush() {
         if (bulkRequestBuilder != null) {
             final BulkResponse response = bulkRequestBuilder.execute().actionGet(requestTimeout);
             if (response.hasFailures()) {
                 logger.warn("Failed to update scores: {}", response.buildFailureMessage());
             }
             bulkRequestBuilder = null;
         }
     }
 
     /**
      * Gets the priority of this score booster.
      * @return The priority.
      */
     public int getPriority() {
         return priority;
     }
 
     /**
      * Sets the priority of this score booster.
      * @param priority The priority.
      */
     public void setPriority(final int priority) {
         this.priority = priority;
     }
 
     /**
      * Sets the request timeout.
      * @param bulkRequestTimeout The request timeout.
      */
     public void setRequestTimeout(final String bulkRequestTimeout) {
         requestTimeout = bulkRequestTimeout;
     }
 
     /**
      * Sets the request cache size.
      * @param requestCacheSize The request cache size.
      */
     public void setRequestCacheSize(final int requestCacheSize) {
         this.requestCacheSize = requestCacheSize;
     }
 
     /**
      * Sets the script language.
      * @param scriptLang The script language.
      */
     public void setScriptLang(final String scriptLang) {
         this.scriptLang = scriptLang;
     }
 
     /**
      * Sets the script code.
      * @param scriptCode The script code.
      */
     public void setScriptCode(final String scriptCode) {
         this.scriptCode = scriptCode;
     }
 }