server/src/main/java/com/qmth/exam/reserve/cache/impl/ApplyTaskCacheService.java

package com.qmth.exam.reserve.cache.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.qmth.boot.core.concurrent.service.ConcurrentService;
import com.qmth.exam.reserve.bean.apply.ApplyRecordCacheBean;
import com.qmth.exam.reserve.bean.applytask.CurrentApplyTaskVO;
import com.qmth.exam.reserve.bean.examsite.ExamSiteCapacityInfo;
import com.qmth.exam.reserve.cache.CacheConstants;
import com.qmth.exam.reserve.cache.RedisClient;
import com.qmth.exam.reserve.entity.StudentApplyEntity;
import com.qmth.exam.reserve.entity.TimePeriodEntity;
import com.qmth.exam.reserve.service.*;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.collections4.MapUtils;
import org.redisson.api.RAtomicLong;
import org.redisson.api.RQueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Component;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;

@Component
public class ApplyTaskCacheService implements CacheConstants {

    private static final Logger log = LoggerFactory.getLogger(ApplyTaskCacheService.class);

    @Autowired
    private RedisClient redisClient;

    @Autowired
    private ApplyTaskService applyTaskService;

    @Autowired
    private ExamSiteService examSiteService;

    @Autowired
    private TimePeriodService timePeriodService;

    @Autowired
    private StudentService studentService;

    @Autowired
    private StudentApplyService studentApplyService;

    @Autowired
    private ConcurrentService concurrentService;

    /**
     * 获取当前启用的预约任务缓存
     */
    public CurrentApplyTaskVO currentApplyTask(Long orgId) {
        String cacheKey = String.format(CACHE_CURRENT_APPLY_TASK, orgId);
        CurrentApplyTaskVO value = redisClient.get(cacheKey, CurrentApplyTaskVO.class);
        if (value != null) {
            return value;
        }

        value = applyTaskService.currentApplyTask(orgId);
        if (value == null) {
            return null;
        }

        redisClient.set(cacheKey, value, CACHE_TIME_OUT_10, TimeUnit.MINUTES);
        log.info("SET cacheKey:{} curApplyTaskId:{}", cacheKey, value.getTaskId());

        return value;
    }

    /**
     * 清除当前启用的预约任务缓存
     */
    public void clearCurrentApplyTaskCache(Long orgId) {
        String cacheKey = String.format(CACHE_CURRENT_APPLY_TASK, orgId);
        redisClient.delete(cacheKey);
        log.warn("DELETE cacheKey:{}", cacheKey);
    }

    /**
     * 获取某考生的“允许预约时段次数”缓存
     */
    public int getStudentApplyNumber(Long studentId) {
        String cacheKey = String.format(CACHE_STUDENT_APPLY_NUMBER, studentId);
        Integer value = redisClient.get(cacheKey, Integer.class);
        if (value != null) {
            return value;
        }

        value = studentService.findStudentApplyNumberById(studentId);
        redisClient.set(cacheKey, value, CACHE_TIME_OUT_10, TimeUnit.MINUTES);
        log.info("SET cacheKey:{} value:{}", cacheKey, value);

        return value;
    }

    /**
     * 清除某考生的“允许预约时段次数”缓存
     */
    public void clearStudentApplyNumberCache(Long studentId) {
        String cacheKey = String.format(CACHE_STUDENT_APPLY_NUMBER, studentId);
        redisClient.delete(cacheKey);
        log.warn("DELETE cacheKey:{}", cacheKey);
    }

    /**
     * 获取某考点某时段的“剩余可约数量”缓存
     */
    public int getApplyAvailableCount(Long examSiteId, Long timePeriodId) {
        String cacheKey = String.format(CACHE_APPLY_AVAILABLE_COUNT, examSiteId, timePeriodId);
        RAtomicLong atomic = redisClient.getRedissonClient().getAtomicLong(cacheKey);
        return (int) atomic.get();
    }

    /**
     * 累加 某考点某时段的“剩余可约数量”缓存
     */
    public void increaseApplyAvailableCount(Long examSiteId, Long timePeriodId) {
        String cacheKey = String.format(CACHE_APPLY_AVAILABLE_COUNT, examSiteId, timePeriodId);
        RAtomicLong atomic = redisClient.getRedissonClient().getAtomicLong(cacheKey);
        long value = atomic.incrementAndGet();
        log.warn("累加成功，最新考点剩余可约数量:{} cacheKey:{}", value, cacheKey);
    }

    /**
     * 累减 某考点某时段的“剩余可约数量”缓存
     */
    public boolean decreaseApplyAvailableCount(Long examSiteId, Long timePeriodId) {
        String cacheKey = String.format(CACHE_APPLY_AVAILABLE_COUNT, examSiteId, timePeriodId);

        StringBuilder luaScript = new StringBuilder();
        luaScript.append("local key = KEYS[1];");
        luaScript.append("if (redis.call('exists', key) == 1) then");
        luaScript.append("   local stock = tonumber(redis.call('get', key));");
        luaScript.append("   local amount = tonumber(ARGV[1]);");
        luaScript.append("   if (stock >= amount) then");
        luaScript.append("      return redis.call('decrby', key, amount);");
        luaScript.append("   end;");
        luaScript.append("   return -1;");
        luaScript.append("end;");
        luaScript.append("return -2;");
        List<String> keys = Collections.singletonList(cacheKey);
        Object[] args = new Object[]{1};

        // 执行Lua脚本，传入键列表和参数列表
        DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>(luaScript.toString(), Long.class);
        Long result = redisClient.getRedisTemplate().execute(redisScript, keys, args);
        Objects.requireNonNull(result, "缓存操作异常，返回结果为空！");

        if (-2 == result) {
            log.warn("扣减失败，考点剩余可约数量缓存不存在！cacheKey:{}", cacheKey);
            return false;
        } else if (-1 == result) {
            log.warn("扣减失败，考点剩余可约数量为0不足！cacheKey:{}", cacheKey);
            return false;
        }
        log.info("扣减成功，最新考点剩余可约数量:{} cacheKey:{}", result, cacheKey);
        return true;
    }

    /**
     * 刷新 某考点某时段的“剩余可约数量”缓存
     */
    public void refreshApplyAvailableCountCache(Long examSiteId, int oldCapacity, int newCapacity) {
        String lockKey = String.format(CacheConstants.LOCK_EXAM_SITE_CAPACITY, examSiteId);
        Lock lock = concurrentService.getLock(lockKey);

        try {
            if (!lock.tryLock()) {
                throw new RuntimeException("获取锁失败，不允许同时操作！" + lockKey);
            }

            // 获取所有时段ID集合
            List<TimePeriodEntity> timePeriods = timePeriodService.list(new LambdaQueryWrapper<TimePeriodEntity>().select(TimePeriodEntity::getId));
            if (CollectionUtils.isEmpty(timePeriods)) {
                return;
            }

            // 新、旧考点容量差额
            int diffCapacity = newCapacity - oldCapacity;
            for (TimePeriodEntity timePeriod : timePeriods) {
                String cacheKey = String.format(CACHE_APPLY_AVAILABLE_COUNT, examSiteId, timePeriod.getId());
                if (redisClient.exist(cacheKey)) {
                    if (diffCapacity == 0) {
                        // 考点总容量未变化，不用更新缓存
                        continue;
                    }

                    // 总容量变化时，则更新考点剩余可约数量缓存
                    RAtomicLong atomic = redisClient.getRedissonClient().getAtomicLong(cacheKey);
                    long availableCount = Math.max(atomic.get() + diffCapacity, 0);
                    atomic.set(availableCount);
                    log.warn("SET cacheKey:{} value:{}", cacheKey, availableCount);
                } else {
                    // 初始考点剩余可约数量缓存
                    RAtomicLong atomic = redisClient.getRedissonClient().getAtomicLong(cacheKey);
                    atomic.set(newCapacity);
                    log.info("SET cacheKey:{} value:{}", cacheKey, newCapacity);
                }
            }
        } finally {
            try {
                lock.unlock();
            } catch (Exception e) {
                log.warn("解锁失败！lockKey:{} err:{}", lockKey, e.getMessage());
            }
        }
    }

    /**
     * 初始或重置计算 所有考点所有时段的“剩余可约数量”缓存
     */
    public void initApplyAvailableCountCacheForAllExamSites(boolean skipExisted) {
        // 获取所有考点和考点总容量集合
        List<ExamSiteCapacityInfo> examSites = examSiteService.findAllExamSiteCapacityList();
        if (CollectionUtils.isEmpty(examSites)) {
            return;
        }

        // 获取所有时段ID集合
        List<TimePeriodEntity> timePeriods = timePeriodService.list(new LambdaQueryWrapper<TimePeriodEntity>().select(TimePeriodEntity::getId));
        if (CollectionUtils.isEmpty(timePeriods)) {
            return;
        }

        for (ExamSiteCapacityInfo examSite : examSites) {
            String lockKey = String.format(CacheConstants.LOCK_EXAM_SITE_CAPACITY, examSite.getExamSiteId());
            Lock lock = concurrentService.getLock(lockKey);

            try {
                if (!lock.tryLock()) {
                    log.warn("获取锁失败，不允许同时操作！{}", lockKey);
                    return;
                }

                for (TimePeriodEntity timePeriod : timePeriods) {
                    String cacheKey = String.format(CACHE_APPLY_AVAILABLE_COUNT, examSite.getExamSiteId(), timePeriod.getId());
                    if (redisClient.exist(cacheKey) && skipExisted) {
                        // 跳过存在的缓存
                        continue;
                    }

                    // 获取某考点某时段的“已预约数量”（仅查数据库会有误差，需等预约队列中全部完成数据库持久化后再执行！）
                    int finishCount = studentApplyService.countApplyFinishForExamSiteAndTimePeriod(examSite.getExamSiteId(), timePeriod.getId());
                    // 剩余可约数量
                    int availableCount = Math.max(examSite.getCapacity() - finishCount, 0);
                    RAtomicLong atomic = redisClient.getRedissonClient().getAtomicLong(cacheKey);
                    atomic.set(availableCount);
                    log.warn("SET cacheKey:{} value:{}", cacheKey, availableCount);
                }
            } finally {
                try {
                    lock.unlock();
                } catch (Exception e) {
                    log.warn("解锁失败！lockKey:{} err:{}", lockKey, e.getMessage());
                }
            }
        }
    }

    /**
     * 获取某考生的 已完成预约次数缓存（查数据库）
     */
    public int getStudentApplyFinishCountFromDB(Long studentId) {
        LambdaQueryWrapper<StudentApplyEntity> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(StudentApplyEntity::getStudentId, studentId);
        wrapper.eq(StudentApplyEntity::getCancel, Boolean.FALSE);
        return studentApplyService.count(wrapper);
    }

    /**
     * 获取某考生的 已完成预约次数缓存
     */
    public int getStudentApplyFinishCount(Long studentId) {
        Map<String, ApplyRecordCacheBean> maps = this.getStudentApplyRecords(studentId);
        int studentApplyFinishCount = 0;
        for (ApplyRecordCacheBean bean : maps.values()) {
            if (!bean.getCancel()) {
                studentApplyFinishCount++;
            }
        }
        return studentApplyFinishCount;
    }

    /**
     * 获取某考生的 所有的“预约记录”缓存
     */
    public Map<String, ApplyRecordCacheBean> getStudentApplyRecords(Long studentId) {
        String cacheKey = String.format(CACHE_STUDENT_APPLY_RECORD, studentId);
        if (!redisClient.exist(cacheKey)) {
            Map<String, ApplyRecordCacheBean> maps = this.getStudentApplyRecordsFromDB(studentId);
            if (MapUtils.isEmpty(maps)) {
                return new HashMap<>();
            }

            for (ApplyRecordCacheBean bean : maps.values()) {
                this.saveStudentApplyRecord(bean);
            }

            redisClient.expire(cacheKey, CACHE_TIME_OUT_30, TimeUnit.DAYS);
            return maps;
        }

        return redisClient.getEntriesForHash(cacheKey, ApplyRecordCacheBean.class);
    }

    /**
     * 获取某考生的 所有的“预约记录”（查数据库）
     */
    public Map<String, ApplyRecordCacheBean> getStudentApplyRecordsFromDB(Long studentId) {
        LambdaQueryWrapper<StudentApplyEntity> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(StudentApplyEntity::getStudentId, studentId);
        List<StudentApplyEntity> list = studentApplyService.list(wrapper);

        if (CollectionUtils.isEmpty(list)) {
            return new HashMap<>();
        }

        Map<String, ApplyRecordCacheBean> maps = new HashMap<>();
        for (StudentApplyEntity entity : list) {
            ApplyRecordCacheBean bean = new ApplyRecordCacheBean();
            bean.setStudentId(entity.getStudentId());
            bean.setExamSiteId(entity.getExamSiteId());
            bean.setTimePeriodId(entity.getTimePeriodId());
            bean.setCancel(entity.getCancel());
            bean.setOperateId(entity.getOperateId());
            bean.setOperateTime(entity.getUpdateTime());

            String hashKey = String.format("%s_%s", entity.getExamSiteId(), entity.getTimePeriodId());
            maps.put(hashKey, bean);
        }

        return maps;
    }

    /**
     * 获取某考生的 某考点某时段的“预约记录”缓存
     */
    public ApplyRecordCacheBean getStudentApplyRecord(Long studentId, Long examSiteId, Long timePeriodId) {
        String cacheKey = String.format(CACHE_STUDENT_APPLY_RECORD, studentId);
        String hashKey = String.format("%s_%s", examSiteId, timePeriodId);
        ApplyRecordCacheBean cacheBean = redisClient.getForHash(cacheKey, hashKey, ApplyRecordCacheBean.class);
        if (cacheBean != null) {
            return cacheBean;
        }

        // 缓存不存在时，从数据库再查一次
        StudentApplyEntity entity = this.getStudentApplyRecordFormDB(studentId, examSiteId, timePeriodId);
        if (entity != null) {
            cacheBean = new ApplyRecordCacheBean();
            cacheBean.setStudentId(entity.getStudentId());
            cacheBean.setExamSiteId(entity.getExamSiteId());
            cacheBean.setTimePeriodId(entity.getTimePeriodId());
            cacheBean.setCancel(entity.getCancel());
            cacheBean.setOperateId(entity.getOperateId());
            cacheBean.setOperateTime(entity.getUpdateTime());
            return cacheBean;
        }

        return null;
    }

    /**
     * 获取某考生的 某考点某时段的“预约记录”（查数据库）
     */
    public StudentApplyEntity getStudentApplyRecordFormDB(Long studentId, Long examSiteId, Long timePeriodId) {
        LambdaQueryWrapper<StudentApplyEntity> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(StudentApplyEntity::getExamSiteId, examSiteId);
        wrapper.eq(StudentApplyEntity::getTimePeriodId, timePeriodId);
        wrapper.eq(StudentApplyEntity::getStudentId, studentId);
        return studentApplyService.getOne(wrapper);
    }

    /**
     * 保存某考生的 某考点某时段的“预约记录”缓存
     */
    public void saveStudentApplyRecord(ApplyRecordCacheBean value) {
        String cacheKey = String.format(CACHE_STUDENT_APPLY_RECORD, value.getStudentId());
        String hashKey = String.format("%s_%s", value.getExamSiteId(), value.getTimePeriodId());
        redisClient.setForHash(cacheKey, hashKey, value);
        log.info("SET cacheKey:{} hashKey:{} cancel:{}", cacheKey, hashKey, value.getCancel());
    }

    /**
     * 推送至考生预约记录队列
     */
    public void pushStudentApplyRecordQueue(ApplyRecordCacheBean value) {
        if (value == null) {
            return;
        }

        RQueue<ApplyRecordCacheBean> queue = redisClient.getRedissonClient()
                .getQueue(QUEUE_STUDENT_APPLY_RECORD);

        boolean success = queue.offer(value);
        log.info("{}_{}_{}_{} offerQueue:{}", value.getStudentId(), value.getExamSiteId(),
                value.getTimePeriodId(), value.getCancel(), success);
        if (!success) {
            throw new RuntimeException("推送至考生预约记录队列失败");
        }
    }

}