/*
 * Copyright (c) 2010, 2022 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.glassfish.jersey.examples.server.async;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.ws.rs.client.Entity;
import javax.ws.rs.client.WebTarget;

import org.glassfish.jersey.internal.guava.ThreadFactoryBuilder;
import org.glassfish.jersey.process.JerseyProcessingUncaughtExceptionHandler;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.test.JerseyTest;
import org.glassfish.jersey.test.TestProperties;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.fail;

public class AsyncResourceTest extends JerseyTest {

    private static final Logger LOGGER = Logger.getLogger(AsyncResourceTest.class.getName());

    @Override
    protected ResourceConfig configure() {
        // mvn test -Djersey.config.test.container.factory=org.glassfish.jersey.test.inmemory.InMemoryTestContainerFactory
        // mvn test -Djersey.config.test.container.factory=org.glassfish.jersey.test.grizzly.GrizzlyTestContainerFactory
        enable(TestProperties.LOG_TRAFFIC);
        enable(TestProperties.DUMP_ENTITY);
        return App.create();
    }

    @Test
    public void testFireAndForgetChatResource() throws InterruptedException {
        executeChatTest(target().path(App.ASYNC_MESSAGING_FIRE_N_FORGET_PATH),
                FireAndForgetChatResource.POST_NOTIFICATION_RESPONSE);
    }

    @Test
    public void testBlockingPostChatResource() throws InterruptedException {
        executeChatTest(target().path(App.ASYNC_MESSAGING_BLOCKING_PATH), BlockingPostChatResource.POST_NOTIFICATION_RESPONSE);
    }

    private void executeChatTest(final WebTarget resourceTarget, final String expectedPostResponse) throws InterruptedException {
        final int MAX_MESSAGES = 100;
        final int LATCH_WAIT_TIMEOUT = 10 * getAsyncTimeoutMultiplier();
        final boolean debugMode = false;
        final boolean sequentialGet = false;
        final boolean sequentialPost = false;
        final Object sequentialGetLock = new Object();
        final Object sequentialPostLock = new Object();

        final ExecutorService executor = Executors.newCachedThreadPool(new ThreadFactoryBuilder()
                .setNameFormat("async-resource-test-%02d")
                .setUncaughtExceptionHandler(new JerseyProcessingUncaughtExceptionHandler())
                .build());

        final Map<Integer, String> postResponses = new ConcurrentHashMap<Integer, String>();
        final Map<Integer, String> getResponses = new ConcurrentHashMap<Integer, String>();

        final CountDownLatch postRequestLatch = new CountDownLatch(MAX_MESSAGES);
        final CountDownLatch getRequestLatch = new CountDownLatch(MAX_MESSAGES);

        try {
            for (int i = 0; i < MAX_MESSAGES; i++) {
                final int requestId = i;
                executor.submit(new Runnable() {

                    @Override
                    public void run() {
                        if (debugMode || sequentialPost) {
                            synchronized (sequentialPostLock) {
                                post();
                            }
                        } else {
                            post();
                        }
                    }

                    private void post() {
                        try {
                            int attemptCounter = 0;
                            while (true) {
                                attemptCounter++;
                                try {
                                    final String response = resourceTarget.request()
                                            .post(Entity.text(String.format("%02d", requestId)), String.class);
                                    postResponses.put(requestId, response);
                                    break;
                                } catch (Throwable t) {
                                    LOGGER.log(Level.WARNING, String.format("Error POSTING message <%s> for %d. time.",
                                            requestId, attemptCounter), t);
                                }
                                if (attemptCounter > 3) {
                                    break;
                                }
                                Thread.sleep(10);
                            }
                        } catch (InterruptedException ignored) {
                            LOGGER.log(Level.WARNING,
                                    String.format("Error POSTING message <%s>: Interrupted", requestId), ignored);
                        } finally {
                            postRequestLatch.countDown();
                        }
                    }
                });
                executor.submit(new Runnable() {

                    @Override
                    public void run() {
                        if (debugMode || sequentialGet) {
                            synchronized (sequentialGetLock) {
                                get();
                            }
                        } else {
                            get();
                        }
                    }

                    private void get() {
                        try {
                            int attemptCounter = 0;
                            while (true) {
                                attemptCounter++;
                                try {
                                    final String response = resourceTarget.queryParam("id", requestId).request()
                                            .get(String.class);
                                    getResponses.put(requestId, response);
                                    break;
                                } catch (Throwable t) {
                                    LOGGER.log(Level.SEVERE, String.format("Error sending GET request <%s> for %d. time.",
                                            requestId, attemptCounter), t);
                                }
                                if (attemptCounter > 3) {
                                    break;
                                }
                                Thread.sleep(10);
                            }
                        } catch (InterruptedException ignored) {
                            LOGGER.log(Level.WARNING,
                                    String.format("Error sending GET message <%s>: Interrupted", requestId), ignored);
                        } finally {
                            getRequestLatch.countDown();
                        }
                    }
                });
            }

            if (debugMode) {
                postRequestLatch.await();
                getRequestLatch.await();
            } else {
                if (!postRequestLatch.await(LATCH_WAIT_TIMEOUT, TimeUnit.SECONDS)) {
                    LOGGER.log(Level.SEVERE, "Waiting for all POST requests to complete has timed out.");
                }
                if (!getRequestLatch.await(LATCH_WAIT_TIMEOUT, TimeUnit.SECONDS)) {
                    LOGGER.log(Level.SEVERE, "Waiting for all GET requests to complete has timed out.");
                }
            }
        } finally {
            executor.shutdownNow();
        }

        StringBuilder messageBuilder = new StringBuilder("POST responses received: ").append(postResponses.size()).append("\n");
        for (Map.Entry<Integer, String> postResponseEntry : postResponses.entrySet()) {
            messageBuilder.append(String.format("POST response for message %02d: ", postResponseEntry.getKey()))
                    .append(postResponseEntry.getValue()).append('\n');
        }
        messageBuilder.append('\n');
        messageBuilder.append("GET responses received: ").append(getResponses.size()).append("\n");
        for (Map.Entry<Integer, String> getResponseEntry : getResponses.entrySet()) {
            messageBuilder.append(String.format("GET response for message %02d: ", getResponseEntry.getKey()))
                    .append(getResponseEntry.getValue()).append('\n');
        }
        LOGGER.info(messageBuilder.toString());

        for (Map.Entry<Integer, String> postResponseEntry : postResponses.entrySet()) {
            assertEquals(expectedPostResponse, postResponseEntry.getValue(),
                    String.format("Unexpected POST notification response for message %02d", postResponseEntry.getKey()));
        }

        final List<Integer> lost = new LinkedList<Integer>();
        final Collection<String> getResponseValues = getResponses.values();
        for (int i = 0; i < MAX_MESSAGES; i++) {
            if (!getResponseValues.contains(String.format("%02d", i))) {
                lost.add(i);
            }
        }
        if (!lost.isEmpty()) {
            fail("Detected a posted message loss(es): " + lost.toString());
        }
        assertEquals(MAX_MESSAGES, postResponses.size());
        assertEquals(MAX_MESSAGES, getResponses.size());
    }

    @Test
    public void testLongRunningResource() throws InterruptedException {
        final WebTarget resourceTarget = target().path(App.ASYNC_LONG_RUNNING_OP_PATH);
        final String expectedResponse = SimpleLongRunningResource.NOTIFICATION_RESPONSE;

        final int MAX_MESSAGES = 100;
        final int LATCH_WAIT_TIMEOUT = 25 * getAsyncTimeoutMultiplier();
        final boolean debugMode = false;
        final boolean sequentialGet = false;
        final Object sequentialGetLock = new Object();

        final ExecutorService executor = Executors.newCachedThreadPool(new ThreadFactoryBuilder()
                .setNameFormat("async-resource-test-%02d")
                .setUncaughtExceptionHandler(new JerseyProcessingUncaughtExceptionHandler())
                .build());

        final Map<Integer, String> getResponses = new ConcurrentHashMap<Integer, String>();

        final CountDownLatch getRequestLatch = new CountDownLatch(MAX_MESSAGES);

        try {
            for (int i = 0; i < MAX_MESSAGES; i++) {
                final int requestId = i;
                executor.submit(new Runnable() {

                    @Override
                    public void run() {
                        if (debugMode || sequentialGet) {
                            synchronized (sequentialGetLock) {
                                get();
                            }
                        } else {
                            get();
                        }
                    }

                    private void get() {
                        try {
                            int attemptCounter = 0;
                            while (true) {
                                attemptCounter++;
                                try {
                                    final String response = resourceTarget.request().get(String.class);
                                    getResponses.put(requestId, response);
                                    break;
                                } catch (Throwable t) {
                                    LOGGER.log(Level.SEVERE, String.format("Error sending GET request <%s> for %d. time.",
                                            requestId, attemptCounter), t);
                                }
                                if (attemptCounter > 3) {
                                    break;
                                }
                                Thread.sleep(10);
                            }
                        } catch (InterruptedException ignored) {
                            LOGGER.log(Level.WARNING,
                                    String.format("Error sending GET message <%s>: Interrupted", requestId), ignored);
                        } finally {
                            getRequestLatch.countDown();
                        }
                    }
                });
            }

            if (debugMode) {
                getRequestLatch.await();
            } else {
                if (!getRequestLatch.await(LATCH_WAIT_TIMEOUT, TimeUnit.SECONDS)) {
                    LOGGER.log(Level.SEVERE, "Waiting for all GET requests to complete has timed out.");
                }
            }
        } finally {
            executor.shutdownNow();
        }

        final ArrayList<Map.Entry<Integer, String>> responseEntryList =
                new ArrayList<Map.Entry<Integer, String>>(getResponses.entrySet());
        Collections.sort(responseEntryList,
                new Comparator<Map.Entry<Integer, String>>() {
                    @Override
                    public int compare(Map.Entry<Integer, String> o1, Map.Entry<Integer, String> o2) {
                        return o1.getKey().compareTo(o2.getKey());
                    }
                });
        StringBuilder messageBuilder = new StringBuilder("GET responses received: ").append(responseEntryList.size())
                .append("\n");
        for (Map.Entry<Integer, String> getResponseEntry : responseEntryList) {
            messageBuilder.append(String.format("GET response for message %02d: ", getResponseEntry.getKey()))
                    .append(getResponseEntry.getValue()).append('\n');
        }
        LOGGER.info(messageBuilder.toString());

        for (Map.Entry<Integer, String> entry : responseEntryList) {
            assertEquals(expectedResponse, entry.getValue(),
                    String.format("Unexpected GET notification response for message %02d", entry.getKey()));
        }
        assertEquals(MAX_MESSAGES, getResponses.size());
    }

}
