package com.monkeylessey.utils;

import javax.validation.constraints.NotNull;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import java.util.stream.Collectors;

/**
 * @author xp
 * @data 2023/11/4
 */
public class ThreadUtil {

    /**
     * 等待所有线程执行完成
     *
     * @throws InterruptedException
     */
    public static void waitAllFinish() throws InterruptedException {
        int threadCount = 5;
        CountDownLatch latch = new CountDownLatch(threadCount);
        for (int i = 0; i < threadCount; i++) {
            Thread thread = new Thread(new WorkThread(latch));
            thread.start();
        }
        latch.await(); // 等待所有线程执行完成

        // 所有线程执行完成后继续执行其他操作
        System.out.println("All threads have finished execution.");
    }



    static class WorkThread implements Runnable {
        private final CountDownLatch latch;

        public WorkThread(CountDownLatch latch) {
            this.latch = latch;
        }

        @Override
        public void run() {
            // 执行相应的任务
            try {
                Thread.sleep(1000); // 模拟任务执行时间
                System.out.println("Thread finished: " + Thread.currentThread().getName());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            latch.countDown(); // 任务完成时将计数器减一
        }
    }

    /**
     * 获取线程执行结果
     *
     * @throws ExecutionException
     * @throws InterruptedException
     */
    public void runThreadAndGetResult() throws ExecutionException, InterruptedException {
        Callable<Integer> callable = new MyCallable();
        FutureTask<Integer> futureTask = new FutureTask<>(callable);

        Thread thread = new Thread(futureTask);
        thread.start();

        // 获取线程的执行结果
        int result = futureTask.get();
        System.out.println("Thread result: " + result);
    }

    static class MyCallable implements Callable<Integer> {
        @Override
        public Integer call() throws Exception {
            // 执行相应的任务，并返回结果
            int result = 0;
            for (int i = 1; i <= 10; i++) {
                result += i;
            }
            return result;
        }
    }

    /**
     * 等待所有任务执行完成，获取执行结果
     *
     * @throws InterruptedException
     * @throws ExecutionException
     */
    public void waitAllFinishAndGetResult() throws InterruptedException, ExecutionException {
        List<FutureTask<Integer>> resultList = new ArrayList<>(5);
        List<Integer> data = new ArrayList<>(5);
        int threadCount = 5;
        for (int i = 0; i < threadCount; i++) {
            Callable<Integer> callable = new MyCallable();
            FutureTask<Integer> futureTask = new FutureTask<>(callable);
            Thread thread = new Thread(futureTask);
            thread.start();
            // 不能直接调用Future的get方法，否则就变成串行执行了，失去多线程意义
            resultList.add(futureTask);
        }
        for (FutureTask<Integer> futureTask : resultList) {
            data.add(futureTask.get());
        }
        // 所有线程执行完成后继续执行其他操作
        System.out.println("All threads have finished execution.");
        System.out.println("执行结果：" + data);
    }

}