package com.example.demo.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

@Service
public class LikeService {
    private final RedisTemplate<String, Object> redisTemplate;

    @Autowired
    public LikeService(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    public void like(String targetId, String userId) {
        // 使用集合记录点赞用户，防止重复点赞
        redisTemplate.opsForSet().add(targetId + ":likes", userId);
        // 点赞数自增，使用字符串存储点赞数，方便后续展示
        redisTemplate.opsForValue().increment(targetId + ":likeCount", 1);
    }
    public void unlike(String targetId, String userId) {
        redisTemplate.opsForSet().remove(targetId + ":likes", userId);
        redisTemplate.opsForValue().decrement(targetId + ":likeCount", 1);
    }
    public boolean hasLiked(String targetId, String userId) {
        return redisTemplate.opsForSet().isMember(targetId + ":likes", userId);
    }
    public long getLikeCount(String targetId) {
        Long count = (Long) redisTemplate.opsForValue().get(targetId + ":likeCount");
        return count == null? 0 : count;
    }



}