package cn.besteam.common.job;

import cn.besteam.common.util.RedisUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.StopWatch;

/**
 * @author chenbo@guworks.cc
 * @title redis分布式锁/任务, 子类负责初始化ICacheService
 * @date 2018年07月17日
 * @since v1.0.0
 */
public abstract class AbstractRedisLockJob {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    protected RedisUtil redisUtil;

    /**
     * 锁的键值
     */
    protected String lockKey = "medical-common-lock-key";

    /**
     * 锁的过期时间，单位：秒
     * 在锁过期时间内完成任务, 并须配合重复任务的时间间隔
     */
    protected int expireSeconds = 60 * 60;

    /**
     * setNx 获取锁
     */
    public void doJob() {

        logger.info("job开始，尝试获取分布式锁: {}", lockKey);
        boolean locked = false;
        try {
            //
            locked = redisUtil.lock(lockKey, expireSeconds);
            if (locked) {
                logger.info("分布式锁获取成功: {}, 锁过期时间: {}秒", lockKey, expireSeconds);
                doProcess();
            } else {
                logger.info("分布式锁获取失败, key={}, 表示有其他实例正在执行该任务", lockKey);
            }
        } catch (Exception e) {
            logger.error("job执行异常", e);
            // 如果异常发生在异步任务启动前，需要释放锁
            if (locked) {
                try {
                    redisUtil.del(lockKey);
                    logger.info("异常情况下分布式锁释放成功: {}", lockKey);
                } catch (Exception ex) {
                    logger.error("异常情况下分布式锁释放异常: {}", lockKey, ex);
                }
            }
        }
    }

    private void doProcess() {
        logger.info("获取到锁后，开始异步执行任务: {}, 线程ID: {}", lockKey, Thread.currentThread().getId());
        StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        try {
            process();
        } catch (Exception e) {
            logger.error("任务执行异常", e);
        } finally {
            // 任务执行完成后释放锁
            try {
                redisUtil.del(lockKey);
                logger.info("任务完成，分布式锁释放成功: {}", lockKey);
            } catch (Exception e) {
                logger.error("任务完成，分布式锁释放异常: {}", lockKey, e);
            }
        }
        stopWatch.stop();
        logger.info("job耗时: {} 毫秒", stopWatch.getTotalTimeMillis());
    }

    protected abstract void process();

}