/*
    * #%L
    * prolobjectlink-jpi-tuprolog
    * %%
    * Copyright (C) 2019 Prolobjectlink Project
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as 
    * published by the Free Software Foundation, either version 2.1 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public 
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
   * #L%
   */
  package io.github.prolobjectlink.prolog.tuprolog;
  
  import static io.github.prolobjectlink.prolog.PrologTermType.LIST_TYPE;
  
  import java.util.Iterator;
  
  import alice.tuprolog.Struct;
  import alice.tuprolog.Term;
  import io.github.prolobjectlink.prolog.AbstractIterator;
  import io.github.prolobjectlink.prolog.PrologList;
  import io.github.prolobjectlink.prolog.PrologProvider;
  import io.github.prolobjectlink.prolog.PrologTerm;
  
  /**
   * 
   * @author Jose Zalacain
   * @since 1.0
   */
  class TuPrologList extends TuPrologTerm implements PrologList {
  
  	protected TuPrologList(PrologProvider provider) {
  		super(LIST_TYPE, provider, new Struct());
  	}
  
  	protected TuPrologList(PrologProvider provider, Term[] arguments) {
  		super(LIST_TYPE, provider, new Struct(arguments));
  	}
  
  	protected TuPrologList(PrologProvider provider, PrologTerm[] arguments) {
  		super(LIST_TYPE, provider);
  		Term[] terms = new Term[arguments.length];
  		for (int i = 0; i < arguments.length; i++) {
  			terms[i] = ((TuPrologTerm) arguments[i]).value;
  		}
  		value = new Struct(terms);
  	}
  
  	protected TuPrologList(PrologProvider provider, PrologTerm head, PrologTerm tail) {
  		super(LIST_TYPE, provider);
  		Term h = ((TuPrologTerm) head).value;
  		Term t = ((TuPrologTerm) tail).value;
  		value = new Struct(h, t);
  	}
  
  	protected TuPrologList(PrologProvider provider, PrologTerm[] arguments, PrologTerm tail) {
  		super(LIST_TYPE, provider);
  		value = ((TuPrologTerm) tail).value;
  		for (int i = arguments.length - 1; i >= 0; --i) {
  			value = new Struct(((TuPrologTerm) arguments[i]).value, value);
  		}
  	}
  
  	public int size() {
  		return ((Struct) value).listSize();
  	}
  
  	public void clear() {
  		value = new Struct();
  	}
  
  	public boolean isEmpty() {
  		return ((Struct) value).isEmptyList();
  	}
  
  	public Iterator<PrologTerm> iterator() {
  		Struct list = (Struct) value;
  		return new TuPrologListIter(list);
  	}
  
  	public PrologTerm getHead() {
  		Struct list = (Struct) value;
  		return toTerm(list.listHead(), PrologTerm.class);
  	}
  
  	public PrologTerm getTail() {
  		Struct list = (Struct) value;
  		return toTerm(list.listTail(), PrologTerm.class);
  	}
 
 	public int getArity() {
 		Struct list = (Struct) value;
 		return list.getArity();
 	}
 
 	public String getFunctor() {
 		Struct list = (Struct) value;
 		return list.getName();
 	}
 
 	public PrologTerm[] getArguments() {
 		int index = 0;
 		Struct list = (Struct) value;
 		PrologTerm[] arguments = new PrologTerm[list.listSize()];
 		Iterator<? extends Term> i = list.listIterator();
 		while (i.hasNext()) {
 			Term term = i.next();
 			arguments[index++] = toTerm(term, PrologTerm.class);
 		}
 
 		return arguments;
 	}
 
 	private class TuPrologListIter extends AbstractIterator<PrologTerm> implements Iterator<PrologTerm> {
 
 		private Iterator<? extends Term> i;
 
 		private TuPrologListIter(Struct list) {
 			i = list.listIterator();
 		}
 
 		public boolean hasNext() {
 			return i.hasNext();
 		}
 
 		public PrologTerm next() {
 			return toTerm(i.next(), PrologTerm.class);
 		}
 
 	}
 
 }