package horstmann.ch09_animation2;
import java.util.Comparator;
import java.util.concurrent.BlockingQueue;

/**
   This runnable executes a sort algorithm.
   When two elements are compared, the algorithm
   pauses and updates a panel.
 */
public class Sorter implements Runnable
{
	public Sorter(Double[] values, ArrayComponent panel, BlockingQueue<String> queue)
	{
		this.values = values;
		this.panel = panel;
		this.queue = queue;
	}

	public void run()
	{
		Comparator<Double> comp = (d1, d2) -> {
			try
			{
				String command = queue.take();
				if (command.equals("Run"))
				{
					Thread.sleep(DELAY);
					if (!"Step".equals(queue.peek()))
						queue.add("Run");
				}
			}
			catch (InterruptedException exception)
			{
				Thread.currentThread().interrupt();
			}
			panel.setValues(values, d1, d2);
			return d1.compareTo(d2);
		};
		MergeSorter.sort(values, comp);
		panel.setValues(values, null, null);
	}

	private Double[] values;
	private ArrayComponent panel;
	private BlockingQueue<String> queue;
	private static final int DELAY = 100;
}