/*
 * (c) Copyright 2009 Hewlett-Packard Development Company, LP
 * All rights reserved.
 * [See end of file]
 */

package dev.g2;

import org.openjena.atlas.iterator.IteratorConcat;

import java.util.Collection;
import java.util.Iterator;


import org.openjena.atlas.lib.DS;

public class TupleIndex<T> //extends Index<T, Index<T, Collection<T>>>
{
    // Top : Hash of T -> (T, T*) 
    private Index<T, IndexImpl<T, Collection<T>>> map = new IndexImpl<T, IndexImpl<T, Collection<T>>>() ;
    
    public TupleIndex() {}
    
    public Index<T, Collection<T>> get(T key1) { return map.get(key1) ; }
    
    public Collection<T> get(T key1, T key2) { return map.get(key1).get(key2) ; }
    
    public Iterator<T> keys() { return map.keys() ; }
    
    public void put(T key1, T key2, T value)
    { 
        IndexImpl<T, Collection<T>> x = map.get(key1) ;
        if ( x == null )
        {
            x = new IndexImpl<T, Collection<T>>() ;
            map.put(key1, x) ;
        }
        
        Collection<T> z = x.get(key2) ;
        if ( z == null )
        {
            z = DS.list() ;
            x.put(key2, z) ;
        }
        z.add(value) ;
    }
    
    public void remove(T key1, T key2)
    {
        Index<T, Collection<T>> x = map.get(key1) ;
        if ( x == null )
            return ;
        x.remove(key2) ;
        if ( x.size() == 0 )
            map.remove(key1) ;
    }
    
    public Iterator<T> flatten()
    {
        // Accumulating iterator.
        IteratorConcat<T> all = new IteratorConcat<T>() ;
        for ( Iterator<T> iter = map.keys() ; iter.hasNext() ; )
        {
            T k1 = iter.next();
            Index<T, Collection<T>> x =  map.get(k1) ;
            for (Iterator<T> iter2 = x.keys() ; iter.hasNext() ; )
            {
                T k2 = iter2.next();
                Collection<T> y = x.get(k2) ;
                all.add(y.iterator()) ;
            }
        }
        return all ;
    }
    
    public int size() { return map.size() ; }
    public boolean isEmpty() { return map.isEmpty() ; }
}

/*
 * (c) Copyright 2009 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.
 */