/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package test.apache.skywalking.apm.testcase.jdk.threading;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    @RestController
    static class TestController {
        // Verifies inherited invoke methods dispatch through ThreadPoolExecutor's single enhanced override.
        private static class NestedThreadPoolExecutor extends ThreadPoolExecutor {
            private NestedThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
                                             TimeUnit unit, LinkedBlockingQueue<Runnable> workQueue,
                                             ThreadFactory threadFactory) {
                super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory);
            }
        }

        private final RestTemplate restTemplate;
        private final ExecutorService executorService;
        private final ExecutorService executorService2;
        private final ExecutorService executorService3;

        public TestController(final RestTemplate restTemplate) {
            this.restTemplate = restTemplate;
            this.executorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
                @Override
                public Thread newThread(Runnable r) {
                    Thread thread = new Thread(r);
                    thread.setName("http-get-thread");
                    return thread;
                }
            });
            this.executorService2 = Executors.newSingleThreadExecutor(new ThreadFactory() {
                @Override
                public Thread newThread(Runnable r) {
                    Thread thread = new Thread(r);
                    thread.setName("http-get-thread");
                    return thread;
                }
            });
            this.executorService3 = new NestedThreadPoolExecutor(2, 2, 0L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<Runnable>(), new ThreadFactory() {
                @Override
                public Thread newThread(Runnable r) {
                    Thread thread = new Thread(r);
                    thread.setName("batch-callable-thread");
                    return thread;
                }
            });
        }

        @GetMapping("/healthCheck")
        public String healthCheck() {
            return "Success";
        }

        @GetMapping("/greet/{username}")
        public String testCase(@PathVariable final String username)
            throws ExecutionException, InterruptedException, TimeoutException {
            Runnable runnable = new Runnable() {
                @Override
                public void run() {
                    restTemplate.getForEntity("http://localhost:8080/threadpool", String.class);
                }
            };

            Callable callable = new Callable<String>() {
                @Override
                public String call() {
                    return restTemplate.getForEntity("http://localhost:8080/threadpool", String.class).getBody();
                }
            };

            executorService.execute(runnable);
            executorService.submit(runnable);
            executorService.submit(callable).get();

            executorService2.execute(runnable);
            executorService2.submit(runnable);
            executorService2.submit(callable).get();

            Callable<String> firstCallable = new Callable<String>() {
                @Override
                public String call() {
                    return "first";
                }
            };
            Callable<String> secondCallable = new Callable<String>() {
                @Override
                public String call() {
                    return "second";
                }
            };
            List<Callable<String>> invokeAllCallables = Collections.unmodifiableList(
                Arrays.asList(firstCallable, secondCallable));
            verifyInvokeAllResults(executorService3.invokeAll(invokeAllCallables));
            verifyInvokeAllResults(executorService3.invokeAll(invokeAllCallables, 10, TimeUnit.SECONDS));

            List<Callable<String>> invokeAnyCallables = Collections.singletonList(firstCallable);
            executorService3.invokeAny(invokeAnyCallables);
            executorService3.invokeAny(invokeAnyCallables, 10, TimeUnit.SECONDS);

            return username;
        }

        private void verifyInvokeAllResults(List<Future<String>> results) throws ExecutionException, InterruptedException {
            if (!"first".equals(results.get(0).get()) || !"second".equals(results.get(1).get())) {
                throw new IllegalStateException("invokeAll results do not preserve task iteration order");
            }
        }

        @GetMapping("/threadpool")
        public String threadpool() {
            return "threadpool";
        }

    }
}
