import com.alibaba.fastjson.JSON;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.concurrent.TimeUnit;

/**
 * Redis工具类
 */
@Service
public class RedisUtils {
    @Resource(name = "redisTemplate")
    private RedisTemplate<String, String> redisTemplate;
    /**  默认过期时长，单位：秒 */
    public final static long DEFAULT_EXPIRE = 60 * 60 * 24L;
    /**  不设置过期时长 */
    public final static long NOT_EXPIRE = -1L;

    public void set(String key, Object value, long expire){
        redisTemplate.opsForValue().set(key, toJson(value));
        if(expire != NOT_EXPIRE){
            redisTemplate.expire(key, expire, TimeUnit.SECONDS);
        }
    }

    public void set(String key, Object value){
        set(key, value, DEFAULT_EXPIRE);
    }

    public <T> T get(String key, Class<T> clazz, long expire) {
        String value = redisTemplate.opsForValue().get(key);
        if(expire != NOT_EXPIRE){
            redisTemplate.expire(key, expire, TimeUnit.SECONDS);
        }
        return value == null ? null : fromJson(value, clazz);
    }

    public <T> T get(String key, Class<T> clazz) {
        return get(key, clazz, NOT_EXPIRE);
    }

    public String get(String key, long expire) {
        String value = redisTemplate.opsForValue().get(key);
        if(expire != NOT_EXPIRE){
            redisTemplate.expire(key, expire, TimeUnit.SECONDS);
        }
        return value;
    }

    public String get(String key) {
        return get(key, NOT_EXPIRE);
    }

    public void delete(String key) {
        redisTemplate.delete(key);
    }

    /**
     * Object转成JSON数据
     */
    private String toJson(Object object){
        if(object instanceof Integer || object instanceof Long || object instanceof Float ||
                object instanceof Double || object instanceof Boolean || object instanceof String){
            return String.valueOf(object);
        }
        return JSON.toJSONString(object);
    }

    /**
     * JSON数据，转成Object
     */
    private <T> T fromJson(String json, Class<T> clazz){
        return JSON.parseObject(json, clazz);
    }
}