/**
 * Copyright 2018-2020 stylefeng & fengshuonan (https://gitee.com/stylefeng)
 * <p>
 * Licensed 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 cn.stylefeng.guns.api.core.aop;

import cn.stylefeng.guns.api.core.constant.JwtConstants;
import cn.stylefeng.guns.api.core.exception.RestExceptionEnum;
import cn.stylefeng.guns.api.core.util.JwtTokenUtil;
import cn.stylefeng.roses.core.reqres.response.ErrorResponseData;
import cn.stylefeng.roses.core.util.RenderUtil;
import io.jsonwebtoken.JwtException;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


/**
 * Rest Api接口鉴权
 *
 * @author stylefeng
 * @Date 2018/7/20 23:11
 */
public class RestApiInteceptor extends HandlerInterceptorAdapter {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        if (handler instanceof org.springframework.web.servlet.resource.ResourceHttpRequestHandler) {
            return true;
        }
        return check(request, response);
    }

    private boolean check(HttpServletRequest request, HttpServletResponse response) {
        if (request.getServletPath().equals(JwtConstants.AUTH_PATH)) {
            return true;
        }
        final String requestHeader = request.getHeader(JwtConstants.AUTH_HEADER);
        String authToken;
        if (requestHeader != null && requestHeader.startsWith("Bearer ")) {
            authToken = requestHeader.substring(7);

            //验证token是否过期,包含了验证jwt是否正确
            try {
                boolean flag = JwtTokenUtil.isTokenExpired(authToken);
                if (flag) {
                    RenderUtil.renderJson(response, new ErrorResponseData(
                            RestExceptionEnum.TOKEN_EXPIRED.getCode(), RestExceptionEnum.TOKEN_EXPIRED.getMessage()));
                    return false;
                }
            } catch (JwtException e) {

                //有异常就是token解析失败
                RenderUtil.renderJson(response, new ErrorResponseData(
                        RestExceptionEnum.TOKEN_ERROR.getCode(), RestExceptionEnum.TOKEN_ERROR.getMessage()));
                return false;
            }
        } else {

            //header没有带Bearer字段
            RenderUtil.renderJson(response, new ErrorResponseData(
                    RestExceptionEnum.TOKEN_ERROR.getCode(), RestExceptionEnum.TOKEN_ERROR.getMessage()));
            return false;
        }
        return true;
    }

}
