/*
    * 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.query;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.search.FuzzyQuery;
  import org.apache.lucene.search.Query;
  import org.codelibs.fess.Constants;
  import org.codelibs.fess.entity.QueryContext;
  import org.codelibs.fess.exception.InvalidQueryException;
  import org.codelibs.fess.mylasta.direction.FessConfig;
  import org.codelibs.fess.util.ComponentUtil;
  import org.lastaflute.core.message.UserMessages;
  import org.opensearch.common.unit.Fuzziness;
  import org.opensearch.index.query.QueryBuilder;
  import org.opensearch.index.query.QueryBuilders;
  
  /**
   * Query command implementation for handling fuzzy search queries.
   * This class converts Lucene FuzzyQuery objects into OpenSearch fuzzy query builders,
   * supporting configurable fuzzy matching parameters like edit distance and expansions.
   *
   */
  public class FuzzyQueryCommand extends QueryCommand {
      private static final Logger logger = LogManager.getLogger(FuzzyQueryCommand.class);
  
      /**
       * Default constructor.
       */
      public FuzzyQueryCommand() {
          super();
      }
  
      @Override
      protected String getQueryClassName() {
          return FuzzyQuery.class.getSimpleName();
      }
  
      /**
       * Executes the fuzzy query command to convert a Lucene FuzzyQuery into an OpenSearch QueryBuilder.
       *
       * @param context the query context containing search configuration
       * @param query the Lucene query to convert (must be a FuzzyQuery)
       * @param boost the boost factor to apply to the query
       * @return OpenSearch QueryBuilder for fuzzy matching
       * @throws InvalidQueryException if the query is not a FuzzyQuery
       */
      @Override
      public QueryBuilder execute(final QueryContext context, final Query query, final float boost) {
          if (query instanceof final FuzzyQuery fuzzyQuery) {
              if (logger.isDebugEnabled()) {
                  logger.debug("FuzzyQuery: query={}, boost={}", query, boost);
              }
              return convertFuzzyQuery(context, fuzzyQuery, boost);
          }
          throw new InvalidQueryException(messages -> messages.addErrorsInvalidQueryUnknown(UserMessages.GLOBAL_PROPERTY_KEY),
                  "Unknown q: " + query.getClass() + " => " + query);
      }
  
      /**
       * Converts a Lucene FuzzyQuery into an OpenSearch fuzzy query builder.
       * Applies fuzzy matching configuration including edit distance, expansions, and prefix length.
       *
       * @param context the query context containing field mappings
       * @param fuzzyQuery the Lucene FuzzyQuery to convert
       * @param boost the boost factor to apply
       * @return OpenSearch QueryBuilder configured for fuzzy matching
       */
      protected QueryBuilder convertFuzzyQuery(final QueryContext context, final FuzzyQuery fuzzyQuery, final float boost) {
          final FessConfig fessConfig = ComponentUtil.getFessConfig();
          final Term term = fuzzyQuery.getTerm();
          final String field = getSearchField(context.getDefaultField(), term.field());
  
          if (Constants.DEFAULT_FIELD.equals(field)) {
              final String text = term.text();
              context.addFieldLog(field, text);
              context.addHighlightedQuery(text);
              return buildDefaultQueryBuilder(fessConfig, context,
                      (f, b) -> QueryBuilders.fuzzyQuery(f, text)
                              .fuzziness(Fuzziness.fromEdits(fuzzyQuery.getMaxEdits()))
                              .boost(b * boost)
                              .maxExpansions(fessConfig.getQueryFuzzyExpansionsAsInteger())
                              .prefixLength(fessConfig.getQueryFuzzyPrefixLengthAsInteger())
                              .transpositions(Constants.TRUE.equalsIgnoreCase(fessConfig.getQueryFuzzyTranspositions())));
         }
 
         if (isSearchField(field)) {
             final String text = term.text();
             context.addFieldLog(field, text);
             context.addHighlightedQuery(text);
             return QueryBuilders.fuzzyQuery(field, text)
                     .boost(boost)
                     .fuzziness(Fuzziness.fromEdits(fuzzyQuery.getMaxEdits()))
                     .maxExpansions(fessConfig.getQueryFuzzyExpansionsAsInteger())
                     .prefixLength(fessConfig.getQueryFuzzyPrefixLengthAsInteger())
                     .transpositions(Constants.TRUE.equalsIgnoreCase(fessConfig.getQueryFuzzyTranspositions()));
         }
 
         final String origQuery = term.toString();
         context.addFieldLog(Constants.DEFAULT_FIELD, origQuery);
         context.addHighlightedQuery(origQuery);
         return buildDefaultQueryBuilder(fessConfig, context,
                 (f, b) -> QueryBuilders.fuzzyQuery(f, origQuery)
                         .fuzziness(Fuzziness.fromEdits(fuzzyQuery.getMaxEdits()))
                         .boost(b * boost)
                         .maxExpansions(fessConfig.getQueryFuzzyExpansionsAsInteger())
                         .prefixLength(fessConfig.getQueryFuzzyPrefixLengthAsInteger())
                         .transpositions(Constants.TRUE.equalsIgnoreCase(fessConfig.getQueryFuzzyTranspositions())));
     }
 }