package com.huan.study.task.jobs.tasks;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import org.springframework.scheduling.support.CronExpression;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

/**
 * @author huan.fu 2021/7/8 - 下午2:46
 */
@Component
@Slf4j
public class DynamicCronTask implements InitializingBean {

    @Autowired
    private ThreadPoolTaskScheduler taskScheduler;


    private ScheduledFuture<?> scheduledFuture;

    @Override
    public void afterPropertiesSet() throws Exception {
        // 動(dòng)態(tài)啟動(dòng)一個(gè)定時(shí)任務(wù)
        log.info("注冊一個(gè)定時(shí)任務(wù):每隔1秒執(zhí)行一次");
        scheduledFuture = register("* * * * * ?");

        // 取消一個(gè)調(diào)度
        new Thread(() -> {
            try {
                TimeUnit.SECONDS.sleep(5);
                log.info("取消調(diào)度");
                scheduledFuture.cancel(false);
                log.info("取消結(jié)果:" + scheduledFuture.isCancelled());
                log.info("重新注冊一個(gè)定時(shí)任務(wù):每隔2秒執(zhí)行一次");
                register("*/2 * * * * ?");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }).start();
    }

    private ScheduledFuture<?> register(String cron) {

        // 高版本使用 CronExpression，低版本使用 CronSequenceGenerator
        boolean validExpression = CronExpression.isValidExpression(cron);
        log.info("cron:[{}]是合法的嗎:[{}]", cron, validExpression);

        CronExpression expression = CronExpression.parse(cron);
        LocalDateTime nextExecTime = expression.next(LocalDateTime.now());
        if (null != nextExecTime) {
            log.info("定時(shí)任務(wù)下次執(zhí)行的時(shí)間為:[{}]", nextExecTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        }

        return taskScheduler.schedule(new Runnable() {
            @Override
            public void run() {
                log.info("我執(zhí)行了");
            }
        }, new CronTrigger(cron));
    }
}