import cn.hutool.core.util.ArrayUtil;
import com.alibaba.fastjson.JSON;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.List;

/**
 *
 * 可以添加下列特性：
 *
 * 1. mdc
 * 2. 入参
 * 3. 出参
 * 4. 统一异常处理
 *
 * 暂时先处理 1/2
 * @author binbin.hou
 * @since 1.0.0
 */
@Aspect
@Component
@EnableAspectJAutoProxy
public class PegasusServerInterceptor {

    /**
     * 日志实例
     * @since 1.0.0
     */
    private static final Logger LOG = LoggerFactory.getLogger(PegasusServerInterceptor.class);

    /**
     * 拦截 services 下所有的 public方法
     */
    @Pointcut("execution(public * com.xxx.pegasus.server.services..*(..))")
    public void pointCut() {
        //
    }

    /**
     * 拦截处理
     *
     * @param point point 信息
     * @return result
     * @throws Throwable if any
     */
    @Around("pointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        //1. 设置 MDC
        LogUtil.putMdcIfAbsent();
        try {
            // 获取当前拦截的方法签名
            String signatureShortStr = point.getSignature().toShortString();
            //2. 打印入参信息
            Object[] args = point.getArgs();
            List filterArgs = getFilterArgs(args);
            LOG.info("服务 {}, 入参: {}", signatureShortStr, JSON.toJSON(filterArgs));

            //1.1 参数校验
            Object firstParam = filterArgs.get(0);
            if(firstParam != null) {
                ValidateUtils.validate(firstParam);

                //1.2 签名校验
                BaseRpcRequest baseRpcRequest = (BaseRpcRequest) firstParam;
                // 签名校验
                Md5SignCheckUtils.checkSign(baseRpcRequest.getTraceId(), baseRpcRequest.getSign());
            }

            Object result = point.proceed();
            LOG.info("服务 {}, 出参: {}", signatureShortStr, JSON.toJSON(result));
            return result;
        } finally {
            LogUtil.removeMdc();
        }
    }

    /**
     * 避免 http 复杂参数异常
     * @param args 参数
     * @return 结果
     */
    private List getFilterArgs(Object[] args) {
        List list = new ArrayList<>();
        if(ArrayUtil.isEmpty(args)) {
            return list;
        }

        for(Object o : args) {
            if(o instanceof HttpServletRequest) {
                continue;
            }

            if(o instanceof HttpServletResponse) {
                continue;
            }

            if(o instanceof MultipartFile) {
                continue;
            }

            list.add(o);
        }

        return list;
    }

}

public class MyDubboFilter implements Filter {
    public Result invoke(Invoker invoker, Invocation invocation) throws RpcException {
        // before filter ...
        Result result = invoker.invoke(invocation);
        // after filter ...
        return result;
    }
}