package sorting;

import java.util.Comparator;
import java.util.Random;
import java.util.Vector;
import rebelsky.io.Pen;

/**
 * Test a particular sorter.
 *
 * @author CSC152 2004F.
 */
public class SorterTester
{
	/**
	 * The sorter we are to test.
	 */
	Sorter s;
		
	/**
	 * Our friendly integer comparator.
	 */
	Comparator iic;

	/**
	 * Create a new tester for a particular sorter.
	 */
	public SorterTester(Sorter _s)
	{
		this.s = _s;
		this.iic = new IncreasingIntegerComparator();
	} // SorterTester(Sorter)

	/**
	 * For those who want to see results, show a test of sorting
	 * n randomly selected integers.
	 */
	public void printedTest(Pen p, int n)
	{
		Vector v = new Vector(n);
		Random r = new Random();
		for (int i = 0; i < n; i++) 
			v.add(i, new Integer(r.nextInt(199)-99));
		p.println("Original random vector: " + v);
		this.s.sort(v, this.iic);
		p.println("Sorted vector: "  + v);
	} // printedTest()

	/** 
	 * Perform a simple test on the sorter.
	 */
	public boolean simpleTest()
	{
		// Create a vector
		Vector v = new Vector(6);
		v.setSize(6);
		v.set(0, new Integer(22));
		v.set(1, new Integer(6));
		v.set(2, new Integer(6));
		v.set(3, new Integer(7));
		v.set(4, new Integer(1));
		v.set(5, new Integer(2));
	
		// Sort it using the sorter
		this.s.sort(v, this.iic);
		
		// Verify that it is now in order
		for (int i = 1; i < v.size(); i++) {
			if (this.iic.compare(v.get(i-1),v.get(i)) > 0)
				return false;
		} // for
		
		return true;
	} // simpleTest(Sorter)
	
	/**
	 * Test a vector that is exactly backwards.
	 */
	public boolean backwardsTest(int n)
	{
		Vector v = new Vector(n);
		v.setSize(n);
		// Create the vector of odds in decreasing order [....,5,3,1]
		for (int i = 0; i < n; i++) 
			v.set(n-i-1, new Integer(2*i+1));
		// Sort the vector
		this.s.sort(v,this.iic);
		// Check that it contains the right values
		for (int i = 0; i < n; i++) {
			if (((Integer) v.get(i)).intValue() != 2*i+1)
				return false;
		}
		return true;
	} // backwardsTest(int)
	
} // class SorterTester