/*
 * Copyright The WildFly Authors
 * SPDX-License-Identifier: Apache-2.0
 */

package org.wildfly.event.logger;

import java.io.StringReader;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonReader;

import org.junit.Assert;
import org.junit.Test;

/**
 * @author <a href="mailto:jperkins@redhat.com">James R. Perkins</a>
 */
@SuppressWarnings("MagicNumber")
public class AsyncEventLoggerTestCase extends AbstractEventLoggerTestCase {

    @Test
    public void testLogger() throws Exception {
        final ExecutorService executor = Executors.newSingleThreadExecutor();
        try {
            final QueuedJsonWriter writer = new QueuedJsonWriter();
            final EventLogger logger = EventLogger.createAsyncLogger("test-async-logger", writer, executor);
            testLogger(logger, writer);
        } finally {
            executor.shutdown();
            Assert.assertTrue(String.format("Executed did not complete within %d seconds", TIMEOUT),
                    executor.awaitTermination(TIMEOUT, TimeUnit.SECONDS));
        }
    }

    @Test
    public void testMultiLogger() throws Exception {
        final ExecutorService executor = createExecutor();
        try {
            final QueuedJsonWriter writer = new QueuedJsonWriter();
            final EventLogger logger = EventLogger.createAsyncLogger("test=multi-async-logger", writer, executor);
            testMultiLogger(logger, writer, 100, true);
        } finally {
            executor.shutdown();
            Assert.assertTrue(String.format("Executed did not complete within %d seconds", TIMEOUT),
                    executor.awaitTermination(TIMEOUT, TimeUnit.SECONDS));
        }
    }

    @Test
    public void testMultiFloodLogger() throws Exception {
        final ExecutorService executor = createExecutor();
        try {
            final QueuedJsonWriter writer = new QueuedJsonWriter();
            final EventLogger logger = EventLogger.createAsyncLogger("test=multi-async-logger", writer, executor);
            testMultiLogger(logger, writer, 10000, false);
        } finally {
            executor.shutdown();
            Assert.assertTrue(String.format("Executed did not complete within %d seconds", TIMEOUT),
                    executor.awaitTermination(TIMEOUT, TimeUnit.SECONDS));
        }
    }

    private static void testMultiLogger(final EventLogger logger, final QueuedJsonWriter writer, final int logCount,
                                        final boolean sleep) throws Exception {
        final Random r = new Random();
        final ExecutorService executor = createExecutor();
        try {
            final Map<Integer, TestValues> createValues = new HashMap<>();
            for (int i = 0; i < logCount; i++) {
                final TestValues values = new TestValues()
                        .add("eventSource", logger.getEventSource(), JsonObject::getString)
                        .add("count", i, JsonObject::getInt);
                createValues.put(i, values);
                // Use a supplier for every 5th event
                final boolean useSupplier = (i % 5 == 0);
                executor.submit(() -> {
                    if (useSupplier) {
                        logger.log(values::asMap);
                    } else {
                        logger.log(values.asMap());
                    }
                    if (sleep) {
                        // Add a short sleep to ensure slower messages still make it through and aren't lost
                        try {
                            TimeUnit.MILLISECONDS.sleep(r.nextInt(150));
                        } catch (InterruptedException e) {
                            Assert.fail("Interrupted running thread " + Thread.currentThread().getName() + ": " + e.getMessage());
                        }
                    }
                });
            }

            for (int i = 0; i < logCount; i++) {
                final String jsonString = writer.events.poll(TIMEOUT, TimeUnit.SECONDS);
                Assert.assertNotNull("Expected value written, but was null", jsonString);

                try (JsonReader reader = Json.createReader(new StringReader(jsonString))) {
                    final JsonObject jsonObject = reader.readObject();
                    final int count = jsonObject.getInt("count");
                    final TestValues values = createValues.remove(count);
                    Assert.assertNotNull("Failed to find value for entry " + count, values);
                    for (TestValue<?> testValue : values) {
                        testValue.compare(jsonObject);
                    }
                }
            }
            Assert.assertTrue("Values were created that were not logged: " + createValues, createValues.isEmpty());
        } finally {
            executor.shutdown();
            Assert.assertTrue(String.format("Executed did not complete within %d seconds", TIMEOUT),
                    executor.awaitTermination(TIMEOUT, TimeUnit.SECONDS));
        }
    }
}
