/*
    * Copyright 2008 FatWire Corporation. All Rights Reserved.
    *
    * 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 com.fatwire.gst.foundation.facade.search;
  
  import java.util.Arrays;
  import java.util.List;
  
  import COM.FutureTense.Interfaces.ICS;
  import COM.FutureTense.Util.ftErrors;
  
  import com.fatwire.cs.core.search.data.ResultRow;
  import com.fatwire.cs.core.search.engine.SearchEngine;
  import com.fatwire.cs.core.search.engine.SearchEngineConfig;
  import com.fatwire.cs.core.search.engine.SearchEngineException;
  import com.fatwire.cs.core.search.engine.SearchResult;
  import com.fatwire.cs.core.search.query.Operation;
  import com.fatwire.cs.core.search.query.QueryExpression;
  import com.fatwire.gst.foundation.CSRuntimeException;
  import com.fatwire.gst.foundation.facade.ics.ICSFactory;
  import com.fatwire.search.util.SearchUtils;
  
  /**
   * Simplified SearchEngine class optimized for common use cases
   *
   * @author Tony Field
   * @since Feb 16, 2011
   */
  public class SimpleSearchEngine {
  
      private final SearchEngine searchEngine;
      private final SearchEngineConfig seConfig;
  
      public SimpleSearchEngine(String engineName) {
          try {
              seConfig = SearchUtils.getSearchEngineConfig();
          } catch (SearchEngineException e) {
              throw new CSRuntimeException("Could not get search engine config", ftErrors.exceptionerr, e);
          }
          searchEngine = seConfig.getEngine(engineName);
      }
  
      /**
       * Return an instance of the search engine. This is typically done by passing "lucene" as the engineName
       * parameter because that is the default search engine that ships with Content Server 7.5.
       *
       * @param engineName search engine name as configured in Content Server.  Typically set to "lucene".
       * @return SimpleSearchEngine instance
       */
      public static SimpleSearchEngine getInstance(String engineName) {
          ICS ics = ICSFactory.getOrCreateICS();
          SimpleSearchEngine sse = (SimpleSearchEngine) ics.GetObj(SimpleSearchEngine.class.getName());
          if (sse == null) {
              sse = new SimpleSearchEngine(engineName);
              ics.SetObj(SimpleSearchEngine.class.getName(), sse);
          }
          return sse;
      }
  
      public SearchResultIterable search(QueryExpression query, List<String> indexNames) {
          SearchResult<ResultRow> sr;
          try {
              sr = searchEngine.search(indexNames, query);
          } catch (SearchEngineException e) {
              throw new CSRuntimeException("Search failed with an exception. Index: " + indexNames + ", Query: " + query, ftErrors.exceptionerr, e);
          }
          return new SearchResultIterable(sr);
      }
  
      /**
       * @param query
       * @param indexNames
       * @return search results based on query and indexes provided.
       */
      public SearchResultIterable search(QueryExpression query, String... indexNames) {
          return search(query, Arrays.asList(indexNames));
      }
  
  
      /**
       * @param stringValue
       * @return a new query based on the passed in string.
       * @see SearchUtils#newQuery(String)
       */
      public QueryExpression newQuery(String stringValue) {
          return SearchUtils.newQuery(stringValue);
     }
 
     /**
      * @param fieldName
      * @param op
      * @param values
      * @return a query based on the fields, operation and values.
      */
     public QueryExpression newQuery(String fieldName, Operation op, Object... values) {
         return SearchUtils.newQuery(fieldName, op, Arrays.asList(values));
     }
 
 }