/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.common.util.concurrent;

import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.test.ReachabilityChecker;

import java.util.concurrent.atomic.AtomicInteger;

public class RunOnceTests extends ESTestCase {

    public void testRunOnce() {
        final AtomicInteger counter = new AtomicInteger(0);
        final RunOnce runOnce = new RunOnce(counter::incrementAndGet);
        assertFalse(runOnce.hasRun());

        runOnce.run();
        assertTrue(runOnce.hasRun());
        assertEquals(1, counter.get());

        runOnce.run();
        assertTrue(runOnce.hasRun());
        assertEquals(1, counter.get());
    }

    public void testRunOnceConcurrently() throws InterruptedException {
        final AtomicInteger counter = new AtomicInteger(0);
        final RunOnce runOnce = new RunOnce(counter::incrementAndGet);
        startInParallel(between(3, 10), i -> runOnce.run());
        assertTrue(runOnce.hasRun());
        assertEquals(1, counter.get());
    }

    public void testRunOnceWithAbstractRunnable() {
        final AtomicInteger onRun = new AtomicInteger(0);
        final AtomicInteger onFailure = new AtomicInteger(0);
        final AtomicInteger onAfter = new AtomicInteger(0);

        final RunOnce runOnce = new RunOnce(new AbstractRunnable() {
            @Override
            protected void doRun() throws Exception {
                onRun.incrementAndGet();
                throw new RuntimeException("failure");
            }

            @Override
            public void onFailure(Exception e) {
                onFailure.incrementAndGet();
            }

            @Override
            public void onAfter() {
                onAfter.incrementAndGet();
            }
        });

        final int iterations = randomIntBetween(1, 10);
        for (int i = 0; i < iterations; i++) {
            runOnce.run();
            assertEquals(1, onRun.get());
            assertEquals(1, onFailure.get());
            assertEquals(1, onAfter.get());
            assertTrue(runOnce.hasRun());
        }
    }

    public void testReleasesDelegate() {
        final var reachabilityChecker = new ReachabilityChecker();
        final var runOnce = new RunOnce(reachabilityChecker.register(this::noop));
        reachabilityChecker.checkReachable();
        runOnce.run();
        reachabilityChecker.ensureUnreachable();
        assertEquals("RunOnce[null]", runOnce.toString());
    }

    private void noop() {}
}