/**
 * Copyright (c) 2014, the Railo Company Ltd.
 * Copyright (c) 2015, Lucee Assosication Switzerland
 *
 * This library 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 library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package lucee.runtime.util;

import java.util.Enumeration;
import java.util.Iterator;

import lucee.commons.lang.ClassUtil;
import lucee.runtime.exp.PageException;
import lucee.runtime.java.JavaObject;
import lucee.runtime.op.Caster;
import lucee.runtime.op.Decision;
import lucee.runtime.type.Collection;
import lucee.runtime.type.ForEachIteratorable;
import lucee.runtime.type.Iteratorable;
import lucee.runtime.type.ObjectWrap;
import lucee.runtime.type.Resetable;
import lucee.runtime.type.it.EnumAsIt;
import lucee.runtime.type.util.ListUtil;

public class ForEachUtil {
	
	public static Iterator loopCollection(Object o) throws PageException {
		// only components are handled with ForEachIteratorable, because of he magic functions
		if(Decision.isComponent(o)) 
            return Caster.toComponent(o).getIterator();
        
		Iterator it = _toIterator(o);
        if(it!=null) return it;
		
        if(o instanceof ObjectWrap) return loopCollection(((ObjectWrap)o).getEmbededObject());
		return loopCollection(Caster.toCollection(o));
    }

	public static Iterator forEach(Object o) throws PageException {
		if(o instanceof ForEachIteratorable) 
			return ((ForEachIteratorable)o).getIterator();
		
		// every are is handled with ForEachIteratorable
		if(Decision.isArray(o)) 
            return Caster.toArray(o).getIterator();
        
        Iterator it = _toIterator(o);
        if(it!=null) return it;
		
        if(Decision.isWrapped(o))
        	return forEach(Caster.unwrap(o));
        
        return  forEach(Caster.toCollection(o));
	}
	
	
	
	private static Iterator _toIterator(Object o) {
		if(o instanceof Iteratorable) {
            return ((Iteratorable)o).keysAsStringIterator();
        }
		if(o instanceof Iterator) {
            return (Iterator)o;
        }
		if(o instanceof Enumeration) {
			return new EnumAsIt((Enumeration)o);
		}
        if(o instanceof JavaObject) {
        	Collection coll = Caster.toCollection(((JavaObject)o).getEmbededObject(null),null);
        	if(coll!=null) return coll.getIterator();
        	
        	String[] names = ClassUtil.getFieldNames(((JavaObject)o).getClazz());
        	return new ArrayIterator(names);
        }
        else if(o instanceof CharSequence) {
        	return ListUtil.listToArray(o.toString(), ',').getIterator();
        }
		return null;
	}

	public static void reset(Iterator it) throws PageException {
		
		if(it instanceof Resetable) {
			((Resetable)it).reset();
		}
	}

}