/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
package com.cjs.cms.util.redis.scheduler;

import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.cjs.cms.util.redis.JedisTemplate;

import redis.clients.jedis.Jedis;
import redis.clients.util.Pool;

/**
 * 任务管理，支持任务的安排与取消。
 * 任务分延时任务与立即执行任务两种, 未来或将支持固定间隔循环执行任务.
 */
public class JobProducer {

    private static Logger logger = LoggerFactory.getLogger(JobProducer.class);

    private JedisTemplate jedisTemplate;

    private String        scheduledJobKey;

    private String        readyJobKey;

    public JobProducer(String jobName, Pool<Jedis> jedisPool) {
        jedisTemplate = new JedisTemplate(jedisPool);
        scheduledJobKey = Keys.getScheduledJobKey(jobName);
        readyJobKey = Keys.getReadyJobKey(jobName);
    }

    /**
     * 提交立即执行的任务。
     */
    public void queue(final String job) {
        jedisTemplate.lpush(readyJobKey, job);
    }

    /**
     * 安排延时执行任务.
     */
    public void schedule(final String job, final long delay, final TimeUnit timeUnit) {
        final long delayTimeMillis = System.currentTimeMillis() + timeUnit.toMillis(delay);
        jedisTemplate.zadd(scheduledJobKey, job, delayTimeMillis);
    }

    /**
     * 尝试取消延时任务, 如果任务不存在或已被触发返回false, 否则返回true.
     */
    public boolean cancel(final String job) {
        boolean removed = jedisTemplate.zrem(scheduledJobKey, job);

        if (!removed) {
            logger.warn("Can't cancel scheduld job by value {}", job);
        }

        return removed;
    }
}