/**
 * 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 jena3.graph.impl;

import java.util.Iterator ;

import jena3.NodeTuple ;
import jena3.graph.Node ;
import jena3.graph.Triple ;
import org.apache.jena.atlas.iterator.IteratorArray ;

public class QuadImpl implements Triple, NodeTuple
{
        private final Node graph, subj, pred, obj;
     
        public QuadImpl(Node g, Node s, Node p, Node o ) {
            if (g == null) throw new UnsupportedOperationException( "graph cannot be null" );
            if (s == null) throw new UnsupportedOperationException( "subject cannot be null" );
            if (p == null) throw new UnsupportedOperationException( "predicate cannot be null" );
            if (o == null) throw new UnsupportedOperationException( "object cannot be null" );
            graph = g ;
            subj = s;
            pred = p;
            obj = o;
        }

        @Override
        public Node get(int i) {
            switch(i) {
                case 0: return graph ; 
                case 1: return subj ;
                case 2: return pred ;
                case 3: return obj ;
                default:
                    throw new IllegalArgumentException("Index out of range for a quad: "+i) ;
            }
        }

        @Override
        public Node getGraph() {
            return graph ;
        }

        @Override
        public Node getSubject() {
            return subj ;
        }

        @Override
        public Node getPredicate() {
            return pred ;
        }

        @Override
        public Node getObject() {
            return obj ;
        }

        @Override
        public int length() {
            return 4 ;
        }
        
        @Override
        public Iterator<Node> iterator() {
            return IteratorArray.create(new Node[]{graph, subj, pred, obj}) ;
        }

        @Override
        public boolean isTriple()   { return false ; }

        @Override
        public boolean isQuad()     { return true ; }
}