/**
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements. See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership. The ASF licenses this file
    * to you 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.
   */
  package org.apache.commons.rdf.rdf4j.impl;
  
  import java.util.Objects;
  import java.util.Optional;
  import java.util.UUID;
  
  import org.apache.commons.rdf.api.BlankNodeOrIRI;
  import org.apache.commons.rdf.api.Quad;
  import org.apache.commons.rdf.api.RDFTerm;
  import org.apache.commons.rdf.api.Triple;
  import org.apache.commons.rdf.rdf4j.RDF4J;
  import org.apache.commons.rdf.rdf4j.RDF4JQuad;
  import org.eclipse.rdf4j.model.Statement;
  
  final class QuadImpl implements RDF4JQuad {
      private transient int hashCode = 0;
      private final UUID salt;
      private final Statement statement;
  
      QuadImpl(final Statement statement, final UUID salt) {
          this.statement = statement;
          this.salt = salt;
      }
  
      @Override
      public Statement asStatement() {
          return statement;
      }
  
      @Override
      public Triple asTriple() {
          return new TripleImpl(statement, salt);
      }
  
      @Override
      public boolean equals(final Object obj) {
          if (obj instanceof Quad) {
              final Quad quad = (Quad) obj;
              return getGraphName().equals(quad.getGraphName()) &&
                      getSubject().equals(quad.getSubject()) &&
                      getPredicate().equals(quad.getPredicate()) &&
                      getObject().equals(quad.getObject());
          }
          return false;
      }
  
      @Override
      public Optional<BlankNodeOrIRI> getGraphName() {
          if (statement.getContext() == null) {
              return Optional.empty();
          }
          final BlankNodeOrIRI g = (BlankNodeOrIRI) RDF4J.asRDFTerm(statement.getContext(), salt);
          return Optional.of(g);
      }
  
      @Override
      public RDFTerm getObject() {
          return RDF4J.asRDFTerm(statement.getObject(), salt);
      }
  
      @Override
      public org.apache.commons.rdf.api.IRI getPredicate() {
          return (org.apache.commons.rdf.api.IRI) RDF4J.asRDFTerm(statement.getPredicate(), null);
      }
  
      @Override
      public BlankNodeOrIRI getSubject() {
          return (BlankNodeOrIRI) RDF4J.asRDFTerm(statement.getSubject(), salt);
      }
  
      @Override
      public int hashCode() {
          if (hashCode != 0) {
              return hashCode;
          }
          return hashCode = Objects.hash(getSubject(), getPredicate(), getObject(), getGraphName());
      }
  
      @Override
      public String toString() {
          return statement.toString();
      }
 }