/*
    * Copyright (c) 2002-2014, Mairie de Paris
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    *
    *  1. Redistributions of source code must retain the above copyright notice
   *     and the following disclaimer.
   *
   *  2. Redistributions in binary form must reproduce the above copyright notice
   *     and the following disclaimer in the documentation and/or other materials
   *     provided with the distribution.
   *
   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
   *     contributors may be used to endorse or promote products derived from
   *     this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * License 1.0
   */
  package fr.paris.lutece.plugins.digglike.service.digglikesearch;
  
  import fr.paris.lutece.plugins.digglike.business.SubmitFilter;
  import fr.paris.lutece.plugins.digglike.service.search.DigglikeIndexer;
  import fr.paris.lutece.portal.service.search.IndexationService;
  import fr.paris.lutece.portal.service.search.LuceneSearchEngine;
  import fr.paris.lutece.portal.service.util.AppLogService;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.lucene.document.Document;
  import org.apache.lucene.index.DirectoryReader;
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.queryparser.classic.MultiFieldQueryParser;
  import org.apache.lucene.search.BooleanClause;
  import org.apache.lucene.search.IndexSearcher;
  import org.apache.lucene.search.Query;
  import org.apache.lucene.search.ScoreDoc;
  import org.apache.lucene.search.TermQuery;
  import org.apache.lucene.search.TopDocs;
  
  
  /**
   * LuceneSearchEngine
   */
  public class DigglikeLuceneSearchEngine implements DigglikeSearchEngine
  {
      /**
       * Return search results
       * 
       * @param strQuery The search query
       * @param filter the filter
       * @return Results as a collection of SearchResult
       */
      public List<DigglikeSearchItem> getSearchResults( String strQuery, SubmitFilter filter )
      {
          List<DigglikeSearchItem> listResults = new ArrayList<DigglikeSearchItem>( );
          IndexSearcher searcher = null;
  
          try
          {
              IndexReader ir = DirectoryReader.open( IndexationService.getDirectoryIndex( ) );
              searcher = new IndexSearcher( ir );
  
              Collection<String> queries = new ArrayList<String>( );
              Collection<String> fields = new ArrayList<String>( );
              Collection<BooleanClause.Occur> flags = new ArrayList<BooleanClause.Occur>( );
  
              //filter on content
              if ( ( strQuery != null ) && !strQuery.equals( "" ) )
              {
                  Query queryContent = new TermQuery( new Term( DigglikeSearchItem.FIELD_CONTENTS, strQuery ) );
                  queries.add( queryContent.toString( ) );
                  fields.add( DigglikeSearchItem.FIELD_CONTENTS );
                  flags.add( BooleanClause.Occur.MUST );
              }
  
              //filter on content id digg
              if ( filter.containsIdDigg( ) )
              {
                  Query queryIdDigg = new TermQuery( new Term( DigglikeSearchItem.FIELD_ID_DIGG, String.valueOf( filter
                          .getIdDigg( ) ) ) );
                  queries.add( queryIdDigg.toString( ) );
                 fields.add( DigglikeSearchItem.FIELD_ID_DIGG );
                 flags.add( BooleanClause.Occur.MUST );
             }
 
             //filter on digg submit state
             if ( filter.containsIdDiggSubmitState( ) )
             {
                 Query queryState = new TermQuery( new Term( DigglikeSearchItem.FIELD_STATE, String.valueOf( filter
                         .getIdDiggSubmitState( ) ) ) );
                 queries.add( queryState.toString( ) );
                 fields.add( DigglikeSearchItem.FIELD_STATE );
                 flags.add( BooleanClause.Occur.MUST );
             }
 
             //filter on digg type
             Query queryTypeDigg = new TermQuery( new Term( DigglikeSearchItem.FIELD_TYPE,
                     DigglikeIndexer.INDEX_TYPE_DIGG ) );
             queries.add( queryTypeDigg.toString( ) );
             fields.add( DigglikeSearchItem.FIELD_TYPE );
             flags.add( BooleanClause.Occur.MUST );
 
             Query queryMulti = MultiFieldQueryParser.parse( IndexationService.LUCENE_INDEX_VERSION,
                     (String[]) queries.toArray( new String[queries.size( )] ),
                     (String[]) fields.toArray( new String[fields.size( )] ),
                     (BooleanClause.Occur[]) flags.toArray( new BooleanClause.Occur[flags.size( )] ),
                     IndexationService.getAnalyser( ) );
 
             TopDocs topDocs = searcher.search( queryMulti, LuceneSearchEngine.MAX_RESPONSES );
             ScoreDoc[] hits = topDocs.scoreDocs;
 
             for ( int i = 0; i < hits.length; i++ )
             {
                 int docId = hits[i].doc;
                 Document document = searcher.doc( docId );
                 DigglikeSearchItem si = new DigglikeSearchItem( document );
                 listResults.add( si );
             }
         }
         catch ( Exception e )
         {
             AppLogService.error( e.getMessage( ), e );
         }
 
         return listResults;
     }
 }