package com.ruoyi.approve.utils;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.ruoyi.approve.mapper.ApproveProcessMapper;
import com.ruoyi.approve.pojo.ApproveProcess;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.text.SimpleDateFormat;
import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
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;
    }

    @Value("${ruoyi.approvalNumberPrefix}")
    private String approvalNumberPrefix;

    /**查缓存
     * 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;
    }

    @Autowired
    private ApproveProcessMapper approveProcessMapper;

    /**
     * 获取当前时间的  开始日期  ，结束日期
     * @return
     */
    public static StartAndEndDateDto getDateTime(){
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.DATE,1);
        String startDateTime = simpleDateFormat.format(date);
        String endDateTime = simpleDateFormat.format(cal.getTime());
        StartAndEndDateDto startAndEndDateDto = new StartAndEndDateDto();
        startAndEndDateDto.setStartDate(startDateTime);
        startAndEndDateDto.setEndDate(endDateTime);
        return startAndEndDateDto;
    }

    /**查数据库
     * 获取指定计数器在今日的数值，并自增1
     * @return 今日自增后的计数值
     */
    public long incrementAndGetByDb() {
        String today = LocalDate.now().format(DATE_FORMAT);
        String key = approvalNumberPrefix + ":approveNum:" + today;
        String lockKey = "lock:" + key;

        if (Boolean.FALSE.equals(redisTemplate.hasKey(key))) {
            Boolean acquired = redisTemplate.opsForValue().setIfAbsent(lockKey, "1", 10, TimeUnit.SECONDS);
            if (Boolean.TRUE.equals(acquired)) {
                try {
                    if (Boolean.FALSE.equals(redisTemplate.hasKey(key))) {
                        StartAndEndDateDto dateTime = getDateTime();
                        LambdaQueryWrapper<ApproveProcess> approveProcessLambdaQueryWrapper = new LambdaQueryWrapper<>();
                        approveProcessLambdaQueryWrapper
                                .eq(ApproveProcess::getApproveDelete, 0)
                                .gt(ApproveProcess::getCreateTime, dateTime.getStartDate())
                                .lt(ApproveProcess::getCreateTime, dateTime.getEndDate());
                        Long count = approveProcessMapper.selectCount(approveProcessLambdaQueryWrapper);
                        long initialCount = (count == null) ? 0 : count;

                        redisTemplate.opsForValue().set(key, String.valueOf(initialCount), 24, TimeUnit.HOURS);
                    }
                } finally {
                    // 释放锁
                    redisTemplate.delete(lockKey);
                }
            } else {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
                return incrementAndGetByDb(); // 递归重试
            }
        }

        return redisTemplate.opsForValue().increment(key);
    }

    /**
     * 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() {
        LocalDateTime now = LocalDateTime.now();
        LocalDateTime midnight = now.toLocalDate().plusDays(1).atStartOfDay();
        return Duration.between(now, midnight).getSeconds();
    }

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