/*
 * 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.jena.sparql.syntax;

import java.util.Iterator;

import org.apache.jena.graph.Triple;
import org.apache.jena.sparql.ARQException;
import org.apache.jena.sparql.core.BasicPattern;
import org.apache.jena.sparql.core.TriplePath;
import org.apache.jena.sparql.util.NodeIsomorphismMap;

/** The syntax element for a SPARQL BasicGraphPattern (SPARQL 1.0)*/
public class ElementTriplesBlock extends Element implements TripleCollector, TripleCollectorMark
{
    private final BasicPattern pattern;

    public ElementTriplesBlock() {
        pattern = new BasicPattern();
    }

    public ElementTriplesBlock(BasicPattern bgp) {
        pattern = bgp;
    }

    public boolean isEmpty() { return pattern.isEmpty(); }

    @Override
    public void addTriple(Triple t)
    { pattern.add(t); }

    @Override
    public int mark() { return pattern.size(); }

    @Override
    public void addTriple(int index, Triple t)
    { pattern.add(index, t); }

    @Override
    public void addTriplePath(TriplePath path)
    { throw new ARQException("Triples-only collector"); }

    @Override
    public void addTriplePath(int index, TriplePath path)
    { throw new ARQException("Triples-only collector"); }

    public BasicPattern getPattern() { return pattern; }
    public Iterator<Triple> patternElts() { return pattern.iterator(); }

    @Override
    public int hashCode() {
        int calcHashCode = Element.HashBasicGraphPattern;
        calcHashCode ^= pattern.hashCode();
        return calcHashCode;
    }

    @Override
    public boolean equalTo(Element el2, NodeIsomorphismMap isoMap) {
        if ( !(el2 instanceof ElementTriplesBlock) )
            return false;
        ElementTriplesBlock eg2 = (ElementTriplesBlock)el2;
        return this.pattern.equiv(eg2.pattern, isoMap);
    }

    @Override
    public void visit(ElementVisitor v) { v.visit(this); }


}
