/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2011, Red Hat, Inc. and/or its affiliates or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat, Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.search.query.engine.impl;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryWrapperFilter;
import org.hibernate.search.query.dsl.impl.FacetingRequestImpl;
import org.hibernate.search.query.engine.spi.DocumentExtractor;
import org.hibernate.search.query.engine.spi.FacetManager;
import org.hibernate.search.query.facet.Facet;
import org.hibernate.search.query.facet.FacetSelection;
import org.hibernate.search.query.facet.FacetingRequest;
import static org.hibernate.search.util.impl.CollectionHelper.newArrayList;
import static org.hibernate.search.util.impl.CollectionHelper.newHashMap;
/**
* Default implementation of the {@link FacetManager} implementation.
*
* @author Hardy Ferentschik
*/
public class FacetManagerImpl implements FacetManager {
/**
* The map of currently active/enabled facet requests.
*/
private final Map<String, FacetingRequestImpl> facetRequests = newHashMap();
/**
* Keep track of the current facet selection groups.
*/
private final Map<String, FacetSelectionImpl> facetSelection = newHashMap();
/**
* Keeps track of faceting results. This map gets populated once the query gets executed and needs to be
* reset on any query changing call.
*/
private Map<String, List<Facet>> facetResults;
/**
* The combined filter for all selected facets which needs to be applied on the current query
*/
private Filter facetFilter;
/**
* The query from which this manager was retrieved
*/
private final HSQueryImpl query;
FacetManagerImpl(HSQueryImpl query) {
this.query = query;
}
public FacetManager enableFaceting(FacetingRequest facetingRequest) {
facetRequests.put( facetingRequest.getFacetingName(), (FacetingRequestImpl) facetingRequest );
queryHasChanged();
return this;
}
public void disableFaceting(String facetingName) {
facetRequests.remove( facetingName );
if ( facetResults != null ) {
facetResults.remove( facetingName );
}
queryHasChanged();
}
public List<Facet> getFacets(String facetingName) {
// if there are no facet requests we don't have to do anything
if ( facetRequests.isEmpty() || !facetRequests.containsKey( facetingName ) ) {
return Collections.emptyList();
}
List<Facet> facets = null;
if ( facetResults != null ) {
facets = facetResults.get( facetingName );
}
if ( facets != null ) {
return facets;
}
DocumentExtractor queryDocumentExtractor = query.queryDocumentExtractor();
queryDocumentExtractor.close();
//handle edge case of an empty index
if (facetResults == null) {
return Collections.emptyList();
}
List<Facet> results = facetResults.get( facetingName );
if (results != null) {
return results;
}
else {
return Collections.emptyList();
}
}
public FacetSelection getFacetGroup(String groupName) {
if ( groupName == null ) {
throw new IllegalArgumentException( "null is not a valid facet selection group name" );
}
FacetSelectionImpl selection = facetSelection.get( groupName );
if ( selection == null ) {
selection = new FacetSelectionImpl();
facetSelection.put( groupName, selection );
}
return selection;
}
Map<String, FacetingRequestImpl> getFacetRequests() {
return facetRequests;
}
void setFacetResults(Map<String, List<Facet>> facetResults) {
this.facetResults = facetResults;
}
void queryHasChanged() {
facetFilter = null;
this.facetResults = null;
query.clearCachedResults();
}
Filter getFacetFilter() {
if ( facetFilter == null ) {
BooleanQuery boolQuery = new BooleanQuery();
for ( FacetSelectionImpl selection : facetSelection.values() ) {
if ( !selection.getFacetList().isEmpty() ) {
Query selectionGroupQuery = createSelectionGroupQuery( selection );
boolQuery.add( selectionGroupQuery, BooleanClause.Occur.MUST );
}
}
if ( boolQuery.getClauses().length > 0 ) {
this.facetFilter = new QueryWrapperFilter( boolQuery );
}
}
return facetFilter;
}
private Query createSelectionGroupQuery(FacetSelectionImpl selection) {
BooleanQuery orQuery = new BooleanQuery();
for ( Facet facet : selection.getFacetList() ) {
orQuery.add( facet.getFacetQuery(), BooleanClause.Occur.SHOULD );
}
return orQuery;
}
class FacetSelectionImpl implements FacetSelection {
private final List<Facet> facetList = newArrayList();
public List<Facet> getFacetList() {
return facetList;
}
public void selectFacets(Facet... facets) {
if ( facets == null ) {
return;
}
facetList.addAll( Arrays.asList( facets ) );
queryHasChanged();
}
public List<Facet> getSelectedFacets() {
return Collections.unmodifiableList( facetList );
}
public void deselectFacets(Facet... facets) {
boolean hasChanged = facetList.removeAll( Arrays.asList( facets ) );
if ( hasChanged ) {
queryHasChanged();
}
}
public void clearSelectedFacets() {
facetList.clear();
queryHasChanged();
}
}
}