/*
 * Copyright 2007 Wishnu Prasetya.
 *
 * This file is part of T2.
 * T2 is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License (GPL) as published by the
 * Free Software Foundation; either version 3 of the License, or any
 * later version.
 *
 * T2 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.
 *
 * A copy of the GNU General Public License can be found in T2 distribution.
 * If it is missing, see http://www.gnu.org/licenses.
 */

package Sequenic.T2.Seq;

import Sequenic.T2.Pool;
import Sequenic.T2.Msg.T2Error;
import Sequenic.T2.Obj.Cloner;
import Sequenic.T2.export.Visitor;


/**
 * This represents a MkVal-step in which an object is 'created' by picking a
 * 'constant', e.g. from the {@link Sequenic.T2.BaseDomain base domain}.
 * The object used as 'constant' is remembered in this step.
 *
 */
public abstract class CONST extends MkValStep  {
	    
    public abstract Object getObject();
    
    public abstract Class<?> getObjectClass();
        
    public abstract String getObjectClassName();
    
    public abstract boolean isNull();
    
    @Override
    public void visit(Visitor visitor) {
		visitor.visit(this);
	}
    
    public static CONST nonNull(final Object val) {
    	if(val==null)
    		throw new NullPointerException();
    	else return new CONST() {

			@Override
			public Object getObject()
			{
				return val;
			}

			@Override
			public Class<?> getObjectClass()
			{
				return val.getClass();
			}

			@Override
			public String getObjectClassName()
			{
				return val.getClass().getName();
			}

			@Override
			public boolean isNull()
			{
				return false;
			}

			@Override
			public Object exec(Class CUT, Pool pool)
			{
		        try {
		            return Cloner.clone(val);
		        } catch (Exception e) {
		            throw new T2Error("Fail to clone. Perhaps because Base Domain produces unclonable objects.", e);
		        }
			}
			
			@Override
			public String toString()
			{
				if(val instanceof String) {
		        	return "CONST <String>"; // TODO filter unprintable chars and show real value?
		        } else {
		            return "CONST " + val; //StringFormater.indentButFirst(val.toString(),4) ;
		        }
			}
    		
    	};
    }
    
    public static CONST nullConst(final Class<?> type) {
    	return new CONST() {
    		
    		@Override
    		public Object exec(Class CUT, Pool pool)
    		{
    			return null;
    		}

    		@Override
    		public Object getObject()
    		{
    			return null;
    		}

    		@Override
    		public String getObjectClassName()
    		{
    			return type.getName();
    		}

    		@Override
    		public boolean isNull()
    		{
    			return true;
    		}

    		@Override
    		public String toString()
    		{
    			return "CONST null";
    		}

    		@Override
    		public Class getObjectClass()
    		{
    			return type;
    		}
    	};
    }
    
    @Override
	public boolean isObsolete()
	{
		return false;
	}
    
}