package com.ruoyi.framework.aspectj;

import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Component;
import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.common.utils.ServletUtils;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.common.utils.ip.IpUtils;
import com.ruoyi.framework.aspectj.lang.annotation.RateLimiter;
import com.ruoyi.framework.aspectj.lang.enums.LimitType;

/**
 * 限流处理
 *
 * @author ruoyi
 */
@Aspect
@Component
public class RateLimiterAspect
{
    private static final Logger log = LoggerFactory.getLogger(RateLimiterAspect.class);

    private RedisTemplate<Object, Object> redisTemplate;

    private RedisScript<Long> limitScript;

    @Autowired
    public void setRedisTemplate1(RedisTemplate<Object, Object> redisTemplate)
    {
        this.redisTemplate = redisTemplate;
    }

    @Autowired
    public void setLimitScript(RedisScript<Long> limitScript)
    {
        this.limitScript = limitScript;
    }

    // 配置织入点
    @Pointcut("@annotation(com.ruoyi.framework.aspectj.lang.annotation.RateLimiter)")
    public void rateLimiterPointCut()
    {
    }

    @Before("rateLimiterPointCut()")
    public void doBefore(JoinPoint point) throws Throwable
    {
        RateLimiter rateLimiter = getAnnotationRateLimiter(point);
        String key = rateLimiter.key();
        int time = rateLimiter.time();
        int count = rateLimiter.count();

        String combineKey = getCombineKey(rateLimiter, point);
        List<Object> keys = Collections.singletonList(combineKey);
        try
        {
            Long number = redisTemplate.execute(limitScript, keys, count, time);
            if (StringUtils.isNull(number) || number.intValue() > count)
            {
                throw new ServiceException("访问过于频繁，请稍后再试");
            }
            log.info("限制请求'{}',当前请求'{}',缓存key'{}'", count, number.intValue(), key);
        }
        catch (ServiceException e)
        {
            throw e;
        }
        catch (Exception e)
        {
            throw new RuntimeException("服务器限流异常，请稍后再试");
        }
    }

    /**
     * 是否存在注解，如果存在就获取
     */
    private RateLimiter getAnnotationRateLimiter(JoinPoint joinPoint)
    {
        Signature signature = joinPoint.getSignature();
        MethodSignature methodSignature = (MethodSignature) signature;
        Method method = methodSignature.getMethod();

        if (method != null)
        {
            return method.getAnnotation(RateLimiter.class);
        }
        return null;
    }

    public String getCombineKey(RateLimiter rateLimiter, JoinPoint point)
    {
        StringBuffer stringBuffer = new StringBuffer(rateLimiter.key());
        if (rateLimiter.limitType() == LimitType.IP)
        {
            stringBuffer.append(IpUtils.getIpAddr(ServletUtils.getRequest()));
        }
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();
        Class<?> targetClass = method.getDeclaringClass();
        stringBuffer.append("-").append(targetClass.getName()).append("- ").append(method.getName());
        return stringBuffer.toString();
    }
}