001/*
002 * Copyright 2015 DuraSpace, Inc.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.fcrepo.kernel.modeshape.rdf.impl;
017
018import static org.fcrepo.kernel.modeshape.identifiers.NodeResourceConverter.nodeConverter;
019import static org.fcrepo.kernel.modeshape.rdf.converters.ValueConverter.nodeForValue;
020import static org.fcrepo.kernel.modeshape.utils.UncheckedFunction.uncheck;
021import static org.fcrepo.kernel.modeshape.utils.StreamUtils.iteratorToStream;
022import static java.util.Arrays.asList;
023import static javax.jcr.PropertyType.PATH;
024import static javax.jcr.PropertyType.REFERENCE;
025import static javax.jcr.PropertyType.WEAKREFERENCE;
026
027import com.hp.hpl.jena.graph.Triple;
028import com.hp.hpl.jena.rdf.model.Resource;
029import org.fcrepo.kernel.api.identifiers.IdentifierConverter;
030import org.fcrepo.kernel.api.models.FedoraResource;
031import org.fcrepo.kernel.modeshape.rdf.impl.mappings.PropertyToTriple;
032import org.fcrepo.kernel.modeshape.rdf.impl.mappings.PropertyValueIterator;
033
034import javax.jcr.Node;
035import javax.jcr.Property;
036import javax.jcr.RepositoryException;
037import javax.jcr.Value;
038
039import java.util.List;
040import java.util.function.Predicate;
041import java.util.stream.Stream;
042
043/**
044 * Accumulate inbound references to a given resource
045 *
046 * @author cabeer
047 * @author escowles
048 */
049public class ReferencesRdfContext extends NodeRdfContext {
050
051    private final PropertyToTriple property2triple;
052
053    public static final List<Integer> REFERENCE_TYPES = asList(PATH, REFERENCE, WEAKREFERENCE);
054
055    /**
056     * Add the inbound references from other nodes to this resource to the stream
057     *
058     * @param resource the resource
059     * @param idTranslator the id translator
060     * @throws RepositoryException if repository exception occurred
061     */
062
063    public ReferencesRdfContext(final FedoraResource resource,
064                                final IdentifierConverter<Resource, FedoraResource> idTranslator)
065        throws RepositoryException {
066        super(resource, idTranslator);
067        property2triple = new PropertyToTriple(resource.getNode().getSession(), idTranslator);
068        concat(putReferencesIntoContext(resource.getNode()));
069    }
070
071    private final Predicate<Triple> INBOUND = t -> {
072        return t.getObject().getURI().equals(uriFor(resource()).getURI());
073    };
074
075    /* References from LDP indirect containers are generated dynamically by LdpContainerRdfContext, so they won't
076       show up in getReferences()/getWeakReferences().  Instead, we should check referencers to see if they are
077       members of an IndirectContainer and generate the appropriate inbound references. */
078    private Stream<Triple> putReferencesIntoContext(final Node node) throws RepositoryException {
079        return Stream.concat(
080            getAllReferences(node).flatMap(property2triple),
081            getAllReferences(node).flatMap(uncheck((final Property x) -> {
082                    return iteratorToStream(new PropertyValueIterator(x.getParent().getProperties()))
083                        .filter((final Value y) -> REFERENCE_TYPES.contains(y.getType()));
084                }))
085                .flatMap(uncheck((final Value x) -> {
086                    return new LdpContainerRdfContext(nodeConverter.convert(nodeForValue(node.getSession(), x)),
087                        translator());
088                }))
089                .filter(INBOUND));
090    }
091
092    @SuppressWarnings("unchecked")
093    private static Stream<Property> getAllReferences(final Node node) throws RepositoryException {
094        return Stream.concat(iteratorToStream(node.getReferences()), iteratorToStream(node.getWeakReferences()));
095    }
096}