/*
    * #%L
    * prolobjectlink-jpi-jlog
    * %%
    * Copyright (C) 2019 Prolobjectlink Project
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as
    * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   * 
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/gpl-3.0.html>.
   * #L%
   */
  package io.github.prolobjectlink.prolog.jlog;
  
  import static io.github.prolobjectlink.prolog.PrologTermType.LIST_TYPE;
  
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import io.github.prolobjectlink.prolog.AbstractIterator;
  import io.github.prolobjectlink.prolog.PrologList;
  import io.github.prolobjectlink.prolog.PrologProvider;
  import io.github.prolobjectlink.prolog.PrologTerm;
  import ubc.cs.JLog.Terms.jList;
  import ubc.cs.JLog.Terms.jListPair;
  import ubc.cs.JLog.Terms.jNullList;
  import ubc.cs.JLog.Terms.jTerm;
  
  /**
   * 
   * @author Jose Zalacain
   * @since 1.0
   */
  class JLogList extends JLogTerm implements PrologList {
  
  	protected JLogList(PrologProvider provider) {
  		super(LIST_TYPE, provider, jNullList.NULL_LIST);
  	}
  
  	protected JLogList(PrologProvider provider, PrologTerm[] arguments) {
  		super(LIST_TYPE, provider);
  		value = adaptList(arguments);
  	}
  
  	protected JLogList(PrologProvider provider, jTerm[] arguments) {
  		super(LIST_TYPE, provider);
  		value = jNullList.NULL_LIST;
  		for (int i = arguments.length - 1; i >= 0; --i) {
  			value = new jListPair(arguments[i], value);
  		}
  	}
  
  	protected JLogList(PrologProvider provider, PrologTerm[] arguments, PrologTerm tail) {
  		super(LIST_TYPE, provider);
  		value = fromTerm(tail, jTerm.class);
  		for (int i = arguments.length - 1; i >= 0; --i) {
  			value = new jListPair(fromTerm(arguments[i], jTerm.class), value);
  		}
  	}
  
  	protected JLogList(PrologProvider provider, PrologTerm head, PrologTerm tail) {
  		super(LIST_TYPE, provider);
  		value = new jListPair(fromTerm(head, jTerm.class), fromTerm(tail, jTerm.class));
  	}
  
  	public int size() {
  		int size = 0;
  		jList list = ((jList) value);
  		Iterator<?> i = new JLogIterator(list);
  		while (i.hasNext()) {
  			i.next();
  			size++;
  		}
  		return size;
  	}
  
  	public void clear() {
  		value = jNullList.NULL_LIST;
  	}
  
  	public boolean isEmpty() {
  		return size() == 0;
  	}
  
  	public Iterator<PrologTerm> iterator() {
  		jListPair list = (jListPair) value;
  		return new JLogListIter(list);
  	}
  
  	public PrologTerm getHead() {
 		jListPair list = (jListPair) value;
 		return toTerm(list.getHead(), PrologTerm.class);
 	}
 
 	public PrologTerm getTail() {
 		jListPair list = (jListPair) value;
 		return toTerm(list.getTail(), PrologTerm.class);
 	}
 
 	public int getArity() {
 		return 2;
 	}
 
 	public String getFunctor() {
 		jListPair list = (jListPair) value;
 		return list.getName();
 	}
 
 	public PrologTerm[] getArguments() {
 		int index = 0;
 		PrologTerm[] arguments = new PrologTerm[size()];
 		Iterator<PrologTerm> i = iterator();
 		while (i.hasNext()) {
 			arguments[index++] = i.next();
 		}
 		return arguments;
 	}
 
 	private final class JLogListIter extends AbstractIterator<PrologTerm> implements Iterator<PrologTerm> {
 
 		private final Iterator<? extends jTerm> e;
 
 		private JLogListIter(jListPair list) {
 			e = new JLogIterator(list);
 		}
 
 		public boolean hasNext() {
 			return e.hasNext();
 		}
 
 		public PrologTerm next() {
 			if (!hasNext()) {
 				throw new NoSuchElementException();
 			}
 			return toTerm(e.next(), PrologTerm.class);
 		}
 
 	}
 
 }