source: TraumaOntologies/src/main/java/tudelft/healthpsychology/traumaontologies/owltree/OwlOntologyNode.java

package tudelft.healthpsychology.traumaontologies.owltree;

import java.io.File;
import java.util.Collection;
import java.util.List;
import java.util.stream.Collectors;

import org.semanticweb.owlapi.apibinding.OWLManager;
import org.semanticweb.owlapi.model.OWLClass;
import org.semanticweb.owlapi.model.OWLOntologyCreationException;

import tudelft.healthpsychology.traumaontologies.answerstate.OntologyNode;
import tudelft.healthpsychology.traumaontologies.answerstate.Property;
import tudelft.utilities.tree.TreeNode;

/**
 * Default implementation of {@link OntologyNode} that pulls its relations from
 * a owl file. An ontology node points to a {@link OWLClass} object in the
 * ontology.
 * 
 * The OWL Ontology must contain only trees. It is not allowed to have a node
 * with multiple parents (but multiple nodes may have no parents at all).
 */
public class OwlOntologyNode implements OntologyNode {
        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((object == null) ? 0 : object.hashCode());
                result = prime * result
                                + ((reasoner == null) ? 0 : reasoner.hashCode());
                return result;
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                OwlOntologyNode other = (OwlOntologyNode) obj;
                if (object == null) {
                        if (other.object != null)
                                return false;
                } else if (!object.equals(other.object))
                        return false;
                if (reasoner == null) {
                        if (other.reasoner != null)
                                return false;
                } else if (!reasoner.equals(other.reasoner))
                        return false;
                return true;
        }

        private final OwlTreeReasoner reasoner;
        private OWLClass object;

        public OwlOntologyNode(OWLClass object, OwlTreeReasoner reasoner) {
                this.reasoner = reasoner;
                this.object = object;
        }

        public OwlOntologyNode(String nodename, OwlTreeReasoner reas) {
                this(reas.getObject(nodename), reas);
        }

        /**
         * 
         * @param rootname the name of the root {@link OWLClass} in the ontology.
         *                 This is the name after the "#" in the full object iri.
         *                 This does not need to be a root node but usually it will
         *                 be.
         * @param owlfile  the owlfile to read the node from
         * @throws OWLOntologyCreationException
         */
        public static OwlOntologyNode fromFile(String rootname, File owlfile)
                        throws OWLOntologyCreationException {
                OwlTreeReasoner reas = new OwlTreeReasoner(
                                OWLManager.createOWLOntologyManager()
                                                .loadOntologyFromOntologyDocument(owlfile));
                return new OwlOntologyNode(reas.getObject(rootname), reas);
        }

        @Override
        public List<Property> getAttribute() {
                return reasoner.getProperties(object).stream()
                                .map(axiom -> new OwlProperty(axiom, reasoner))
                                .collect(Collectors.toList());
        }

        @Override
        public OwlOntologyNode getChild(String label) {
                for (OWLClass obj : reasoner.getChildren(object)) {
                        if (obj.toStringID().endsWith(label)) // TEST. bit hacky?
                                return new OwlOntologyNode(obj, reasoner);
                }
                return null;
        }

        @Override
        public List<? extends TreeNode<String, Collection<Property>>> getChildren() {
                return reasoner.getChildren(object).stream()
                                .map(owlclass -> new OwlOntologyNode(owlclass, reasoner))
                                .collect(Collectors.toList());
        }

        @Override
        public String getLabel() {
                return object.getIRI().getShortForm();
        }

        @Override
        public List<OntologyNode> getChildren(int depth) {
                return reasoner.getChildren(object, depth).stream()
                                .map(obj -> new OwlOntologyNode(obj, reasoner))
                                .collect(Collectors.toList());
        }

        @Override
        public OntologyNode getParent() {
                OWLClass parent = reasoner.getParent(object);
                if (parent == null)
                        return null;
                return new OwlOntologyNode(parent, reasoner);
        }

        @Override
        public String toString() {
                return "Node[" + object + "]";
        }

}