import list.*;
import list.visitor.*;

/**
* A simple test program for AList and its subclasses.
*
* @author Dung X. Nguyen
*/
public class ListClient
{
    public static void main (String[] args)
    {
	AList pc0 = ListFactory.Singleton.makeEmptyList();
	AList pc1 = ListFactory.Singleton.makeNEList (new Integer(-1), pc0);
	AList p1  = ListFactory.Singleton.makeNEList ("-5", pc0); // NOTE: "-5" is a String, not an Integer!
	AList p2  = ListFactory.Singleton.makeNEList (new Integer(2), p1);
	AList p3  = ListFactory.Singleton.makeNEList (new Integer(-4), p2);
	AList p4  = ListFactory.Singleton.makeNEList (new Integer(3), pc1);
	
	ListClient client = new ListClient ();  // uses default constructor!

	System.out.println ("\nTesting toString(): \n");
	System.out.println ("EmptyList = " + pc0);
	System.out.println ("(-1) = " + pc1);
	System.out.println ("(3 -1) = " + p4);
	System.out.println ("(-5) = " + p1);
	System.out.println ("(2 -5) = " + p2);
	System.out.println ("(-4 2 -5) = " + p3);

	System.out.println ("\nTesting reverse(): \n");
	client.testVisitor (pc0, Reverse.Singleton, null);
	client.testVisitor (pc1, Reverse.Singleton, null);
	client.testVisitor (p1, Reverse.Singleton, null);
	client.testVisitor (p2, Reverse.Singleton, null);
	client.testVisitor (p3, Reverse.Singleton, null);
	client.testVisitor (p4, Reverse.Singleton, null);
      
	System.out.println ("\nTesting makeClone(): \n");
	client.testVisitor (pc0, MakeClone.Singleton, null);
	client.testVisitor (pc1, MakeClone.Singleton, null);
	client.testVisitor (p1, MakeClone.Singleton, null);
	client.testVisitor (p2, MakeClone.Singleton, null);
	client.testVisitor (p3, MakeClone.Singleton, null);
	client.testVisitor (p4, MakeClone.Singleton, null);
      
	System.out.println ("\nTesting NthElement(): \n");
	client.testVisitor (pc0, NthElement.Singleton, new Integer(2));
	client.testVisitor (pc1, NthElement.Singleton, new Integer(0));
	client.testVisitor (p4, NthElement.Singleton, new Integer(1));
	client.testVisitor (p3, NthElement.Singleton, new Integer(0));
	client.testVisitor (p3, NthElement.Singleton, new Integer(1));
	client.testVisitor (p3, NthElement.Singleton, new Integer(2));
	client.testVisitor (p3, NthElement.Singleton, new Integer(3));

	System.out.println ("\nTesting lastElement(): \n");
	client.testVisitor (pc0, LastElement.Singleton, null);
	client.testVisitor (pc1, LastElement.Singleton, null);
	client.testVisitor (p1, LastElement.Singleton, null);
	client.testVisitor (p2, LastElement.Singleton, null);
	client.testVisitor (p3, LastElement.Singleton, null);
	client.testVisitor (p4, LastElement.Singleton, null);

	System.out.println ("\nTesting firstNElements(): \n");
	client.testVisitor (pc0, FirstElements.Singleton, new Integer(2));
	client.testVisitor (pc1, FirstElements.Singleton, new Integer(0));
	client.testVisitor (p4, FirstElements.Singleton, new Integer(1));
	client.testVisitor (p3, FirstElements.Singleton, new Integer(0));
	client.testVisitor (p3, FirstElements.Singleton, new Integer(1));
	client.testVisitor (p3, FirstElements.Singleton, new Integer(2));
	client.testVisitor (p3, FirstElements.Singleton, new Integer(3));
	client.testVisitor (p3, FirstElements.Singleton, new Integer(4));

	System.out.println ("\nTesting Append(): \n");
	client.testVisitor (pc0, Append.Singleton, p4);
	client.testVisitor (pc1, Append.Singleton, pc0);
	client.testVisitor (p4, Append.Singleton, p3);
	client.testVisitor (p3, Append.Singleton, p2);
    }

    private void testVisitor(AList p, IListAlgo algo, Object input)
    {
	// NOTE the use of Object.getClass ()!!!
	// Also watch what happens when input == null!!!
	try {
	    System.out.println (p + " execute " + algo.getClass () + ", " +
				input + "...");
	    System.out.println ("   ---> " + p.execute (algo, input));
	}
	catch (Exception e) {
	    System.out.println (e);
	}
    }
}