package dk.itu.kasper.Macros;

import java.util.Map;
import java.util.HashMap;

public class MacroDefs extends MacroExpander {
	private final Map<String,String> definitions = new HashMap<String,String>();

	public String def(String[] args){
		if (args.length != 2 )
			return "***def needs two arguments, a name and a macro definition***";
		definitions.put(args[0],args[1]);
		return "";
	}

	public String undefined(String name, final String[] args){
		class ParameterExpander extends MacroExpander {
			public String undefined(String name, String[] dummy){
				int index;
				try{
					index = Integer.parseInt(name);
				}catch(NumberFormatException e){
					return "*** Illegal parameter name ***";
				}
				if ( index >= 0 && index < args.length )
					return args[index];
				else
					return "*** Wrong parameter number ***";
		}};
		if ( definitions.containsKey( name ) )
			return super.process( definitions.get( name ), new ParameterExpander() );
		else
			return "*** undefined macro: " + name + " ***";
	}
}