/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dubbo.admin.authentication.impl;

import org.apache.dubbo.admin.annotation.Authority;
import org.apache.dubbo.admin.authentication.InterceptorAuthentication;
import org.apache.dubbo.admin.interceptor.AuthInterceptor;
import org.apache.dubbo.admin.utils.JwtTokenUtil;
import org.apache.dubbo.admin.utils.SpringBeanUtils;

import org.springframework.util.StringUtils;
import org.springframework.web.method.HandlerMethod;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

public class DefaultPreHandle implements InterceptorAuthentication {

    private JwtTokenUtil jwtTokenUtil = SpringBeanUtils.getBean(JwtTokenUtil.class);

    @Override
    public boolean authentication(HttpServletRequest request, HttpServletResponse response, Object handler) {
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        Method method = handlerMethod.getMethod();
        Authority authority = method.getDeclaredAnnotation(Authority.class);
        if (null == authority) {
            authority = method.getDeclaringClass().getDeclaredAnnotation(Authority.class);
        }

        String token = request.getHeader("Authorization");

        if (null != authority && authority.needLogin()) {
            //check if 'authorization' is empty to prevent NullPointException
            if (StringUtils.isEmpty(token)) {
                //While authentication is required and 'Authorization' string is missing in the request headers,
                //reject this request(http403).
                AuthInterceptor.authRejectedResponse(response);
                return false;
            }
            if (jwtTokenUtil.canTokenBeExpiration(token)) {
                return true;
            }
            //while user not found, or token timeout, reject this request(http401).
            AuthInterceptor.loginFailResponse(response);
            return false;
        } else {
            return true;
        }
    }
}