package edu.whut.smilepicturebackend.aop;

import edu.whut.smilepicturebackend.annotation.AuthCheck;
import edu.whut.smilepicturebackend.exception.BusinessException;
import edu.whut.smilepicturebackend.exception.ErrorCode;
import edu.whut.smilepicturebackend.model.entity.User;
import edu.whut.smilepicturebackend.model.enums.UserRoleEnum;
import edu.whut.smilepicturebackend.service.UserService;
import lombok.RequiredArgsConstructor;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;

@Aspect
@Component
@RequiredArgsConstructor
public class AuthInterceptor {

    private final UserService userService;

    /**
     * 执行拦截
     *
     * @param joinPoint 切入点
     * @param authCheck 权限校验注解
     */
    @Around("@annotation(authCheck)")
    public Object doInterceptor(ProceedingJoinPoint joinPoint, AuthCheck authCheck) throws Throwable {
        String mustRole = authCheck.mustRole();
        RequestAttributes requestAttributes = RequestContextHolder.currentRequestAttributes();
        HttpServletRequest request = ((ServletRequestAttributes) requestAttributes).getRequest();
        // 获取当前登录用户
        User loginUser = userService.getLoginUser(request);
        UserRoleEnum mustRoleEnum = UserRoleEnum.getEnumByValue(mustRole);
        // 如果不需要权限，放行
        if (mustRoleEnum == null) {
            return joinPoint.proceed();
        }
        // 以下的代码：必须有权限，才会通过
        UserRoleEnum userRoleEnum = UserRoleEnum.getEnumByValue(loginUser.getUserRole());
        if (userRoleEnum == null) {
            throw new BusinessException(ErrorCode.NO_AUTH_ERROR);
        }
        // 要求必须有管理员权限，但用户没有管理员权限，拒绝
        if (UserRoleEnum.ADMIN.equals(mustRoleEnum) && !UserRoleEnum.ADMIN.equals(userRoleEnum)) {
            throw new BusinessException(ErrorCode.NO_AUTH_ERROR);
        }
        // 通过权限校验，放行
        return joinPoint.proceed();
    }
}
