package com.ruoyi.approve.utils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.concurrent.TimeUnit;


//基于redis的一个每日计数器
@Component
public class DailyRedisCounter {
    private static final String KEY_PREFIX = "daily_counter:";
    private static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyyMMdd");
    private final StringRedisTemplate redisTemplate;

    public DailyRedisCounter(StringRedisTemplate redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    /**
     * 获取指定计数器在今日的数值，并自增1
     * @param counterName 计数器名称（例如：login_count、order_count）
     * @return 今日自增后的计数值
     */
    public long incrementAndGet(String counterName) {
        String key = getKey(counterName);
        long count = redisTemplate.opsForValue().increment(key, 1);

        // 仅在第一次设置时设置过期时间（避免重复设置）
        if (count == 1) {
            long secondsUntilMidnight = calculateSecondsUntilMidnight();
            redisTemplate.expire(key, secondsUntilMidnight, TimeUnit.SECONDS);
        }

        return count;
    }

    /**
     * 获取指定计数器在今日的当前数值
     * @param counterName 计数器名称
     * @return 今日当前计数值，若不存在则返回0
     */
    public long getCurrentCount(String counterName) {
        String key = getKey(counterName);
        String value = redisTemplate.opsForValue().get(key);
        return value != null ? Long.parseLong(value) : 0;
    }

    /**
     * 计算距离次日凌晨的秒数
     */
    private long calculateSecondsUntilMidnight() {
        LocalDate tomorrow = LocalDate.now().plusDays(1);
        LocalDate midnight = tomorrow.atStartOfDay().toLocalDate();
        return java.time.Duration.between(
                LocalDate.now().atTime(23, 59, 59),
                midnight.atTime(0, 0, 0)
        ).getSeconds() + 1;
    }

    /**
     * 生成Redis键
     */
    private String getKey(String counterName) {
        String today = LocalDate.now().format(DATE_FORMAT);
        return KEY_PREFIX + counterName + ":" + today;
    }
}