package org.apidesign.openfixed;

import java.util.List;

import java.util.concurrent.CountDownLatch;

/** Test the Calculator.createPending() behavior.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

public class PendingTest extends CalculatorBase {

    public PendingTest(String testName) {

        super(testName);

    }

    @Override

    protected Calculator create() {

        return Calculator.createPending();

    }

    public void testPendingEvents() throws Exception {

        BlockingListener bl = new BlockingListener();

        Calculator calc = create();

        calc.addModificationListener(bl);

        calc.add(10);

        bl.first.await();

        calc.add(1);

        calc.add(2);

        calc.add(3);

        bl.cdl.countDown();

        List<ModificationEvent> events = bl.assertEvents("Four changes together", 4);

        assertEquals("No pending events for first event", 0, events.get(0).getPending());

        assertEquals("Group of three, two remaining", 2, events.get(1).getPending());

        assertEquals("Group of three, one remaining", 1, events.get(2).getPending());

        assertEquals("Group of three, last one", 0, events.get(3).getPending());

    }

    static class BlockingListener extends MockListener {

        CountDownLatch first = new CountDownLatch(1);

        CountDownLatch cdl = new CountDownLatch(1);

        @Override

        public synchronized void modification(ModificationEvent ev) {

            try {

                first.countDown();

                cdl.await();

            } catch (InterruptedException ex) {

                throw new IllegalStateException(ex);

            }

            super.modification(ev);

        }

    }

}