code: package it.unibz.inf.ontop.spec.ontology.impl;
  
  /*
   * #%L
   * ontop-obdalib-core
   * %%
   * Copyright (C) 2009 - 2014 Free University of Bozen-Bolzano
   * %%
   * 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.
   * #L%
   */
  
  import it.unibz.inf.ontop.model.vocabulary.OWL;
  import it.unibz.inf.ontop.spec.ontology.DataPropertyExpression;
  import it.unibz.inf.ontop.spec.ontology.DataPropertyRangeExpression;
  import it.unibz.inf.ontop.spec.ontology.DataSomeValuesFrom;
  import it.unibz.inf.ontop.spec.ontology.Datatype;
  import org.apache.commons.rdf.api.IRI;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Represents DataPropertyExpression from the OWL 2 QL Specification
   * 
   * DataPropertyExpression := DataProperty
   * 
   * Support for owl:topDataProperty and owl:bottomDataProperty
   * 
   * @author Roman Kontchakov
   *
   */
  
  public class DataPropertyExpressionImpl implements DataPropertyExpression {
  
  	private final IRI iri;
  	private final boolean isTop, isBottom;
  	
  	private final Map<Datatype, DataSomeValuesFrom> domains = new HashMap<>();
  	private final DataPropertyRangeExpressionImpl range;
  	
      public static final DataPropertyExpression owlTopDataProperty = new DataPropertyExpressionImpl(OWL.TOP_DATA_PROPERTY);
      public static final DataPropertyExpression owlBottomDataProperty = new DataPropertyExpressionImpl(OWL.BOTTOM_DATA_PROPERTY);
  
  	DataPropertyExpressionImpl(IRI iri) {
  		this.iri = iri;
  		this.isTop = iri.equals(OWL.TOP_DATA_PROPERTY);
  		this.isBottom = iri.equals(OWL.BOTTOM_DATA_PROPERTY);
  
  		this.domains.put(DatatypeImpl.rdfsLiteral, new DataSomeValuesFromImpl(this, DatatypeImpl.rdfsLiteral));
  		this.range = new DataPropertyRangeExpressionImpl(this);
  	}
  
  	@Override
  	public IRI getIRI() {
  		return iri;
  	}
  
  	@Override
  	public DataSomeValuesFrom getDomainRestriction(Datatype datatype) {
  		DataSomeValuesFrom domain = domains.get(datatype);
  		if (domain == null) {
  			domain = new DataSomeValuesFromImpl(this, datatype);
  			domains.put(datatype, domain);
  		}
  		return domain;
  	}
  
  	@Override
  	public Collection<DataSomeValuesFrom> getAllDomainRestrictions() {
  		return domains.values();
  	}
  
  	
  	@Override
  	public DataPropertyRangeExpression getRange() {
  		return range;
  	}
  	
  	@Override
  	public boolean isBottom() {
  		return isBottom;
  	}
  	
  	@Override
  	public boolean isTop() {
  		return isTop;
  	}
  	
  	@Override
  	public boolean equals(Object obj) {
  		if (obj == this)
  			return true;
  		
  		if (obj instanceof DataPropertyExpressionImpl) {
  			DataPropertyExpressionImpl other = (DataPropertyExpressionImpl) obj;
  			return iri.equals(other.iri);
  		}
  		
  		// object and data properties share the same name space	
  		if (obj instanceof ObjectPropertyExpressionImpl) {
  			ObjectPropertyExpressionImpl other = (ObjectPropertyExpressionImpl) obj;
  			return !other.isInverse() && iri.equals(other.getIRI());
  		}
  		return false;
  	}
  
  	@Override
  	public int hashCode() {
  		return iri.hashCode();
  	}
  	
  	@Override
  	public String toString() {
  		return iri.getIRIString();
  	}
  }
  