/*
 * (c) Copyright 2008 Hewlett-Packard Development Company, LP
 * All rights reserved.
 * [See end of file]
 */

package dev.g2;

import java.util.Iterator ;

import org.openjena.atlas.iterator.Iter ;
import org.openjena.atlas.iterator.Transform ;
import org.openjena.atlas.lib.ColumnMap ;
import org.openjena.atlas.lib.Tuple ;

import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.graph.Triple ;
import com.hp.hpl.jena.graph.TripleMatch ;
import com.hp.hpl.jena.graph.query.QueryHandler ;
import com.hp.hpl.jena.shared.PrefixMapping ;
import com.hp.hpl.jena.shared.impl.PrefixMappingImpl ;
import com.hp.hpl.jena.sparql.graph.GraphBase2 ;
import com.hp.hpl.jena.util.iterator.ExtendedIterator ;
import com.hp.hpl.jena.util.iterator.NiceIterator ;

public class Graph2 extends GraphBase2
{
    //TupleDex  
    TupleDex indexes[] = { new TupleDex(new ColumnMap("SPO", "SPO")) , 
                           new TupleDex(new ColumnMap("SPO", "POS")) ,
                           new TupleDex(new ColumnMap("SPO", "OSP")) } ; 
    @Override
    protected PrefixMapping createPrefixMapping()
    {
        return new PrefixMappingImpl() ;
    }

    @Override
    protected ExtendedIterator<Triple> graphBaseFind(TripleMatch m)
    {
        Node s = m.getMatchSubject() ;
        Node p = m.getMatchPredicate() ;
        Node o = m.getMatchObject() ;
        
        // A bit mixed between tuples and S,P,O - solve with Tuple>Triple
        Tuple<Node> tuple = Tuple.create(s,p,o) ;
        int indexNumSlots = -1 ;
        int index = -1 ;
        TupleDex tupleIndex = null ;
        
        for ( int i = 0 ; i < indexes.length ; i++ )
        {
            TupleDex idx = indexes[i] ;
            if ( idx != null )
            {
                int w = idx.weight(tuple) ;
                if ( w > indexNumSlots )
                {
                    indexNumSlots = w ;
                    tupleIndex = idx ;
                }
            }
        }
        
        if ( tupleIndex == null )
            // Scan
            tupleIndex = indexes[0] ;

        Iterator<Triple> iter = Iter.map(tupleIndex.find(tuple), transform) ;
        return new MapperIteratorTriples(iter) ;
    }

    // Convert from Iterator<Triple> to ExtendedIterator
    static class MapperIteratorTriples extends NiceIterator<Triple>
    {
        private final Iterator<Triple> iter ;
        MapperIteratorTriples(Iterator<Triple> iter) { this.iter = iter ; }
        @Override public boolean hasNext() { return iter.hasNext() ; } 
        @Override public Triple next() { return iter.next(); }
        @Override public void remove() { iter.remove(); }
    }
    
    @Override
    public QueryHandler queryHandler()
    {
        return null ;
    }
    
    @Override
    public void performAdd( Triple t )
    {
        Tuple<Node> tuple = Tuple.create(t.getSubject(), t.getPredicate(), t.getObject()) ;
        for ( TupleDex index : indexes )
            index.add(tuple) ;
    }
    
    @Override
    public void performDelete( Triple t )
    {
        Tuple<Node> tuple = Tuple.create(t.getSubject(), t.getPredicate(), t.getObject()) ;
        for ( TupleDex index : indexes )
            index.remove(tuple) ;
    }
    
    static Transform<Tuple<Node>, Triple> transform = new Transform<Tuple<Node>, Triple>() {

        @Override
        public Triple convert(Tuple<Node> tuple)
        {
            return new Triple(tuple.get(0), tuple.get(1), tuple.get(2)) ;
        }} ;

}

/*
 * (c) Copyright 2008 Hewlett-Packard Development Company, LP
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */