/*
 *  Copyright (c) 2019-2020, 冷冷 (wangiegie@gmail.com).
 *  <p>
 *  Licensed under the GNU Lesser General Public License 3.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  <p>
 * https://www.gnu.org/licenses/lgpl.html
 *  <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 com.mzl.flower.config.security;

import cn.hutool.core.codec.Base64;
import cn.hutool.core.util.CharsetUtil;
import lombok.SneakyThrows;
import lombok.experimental.UtilityClass;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpHeaders;

import javax.servlet.http.HttpServletRequest;

/**
 * 认证授权相关工具类
 */
@Slf4j
@UtilityClass
public class AuthUtils {
    private final String BASIC_ = "Basic ";

    /**
     * 从header 请求中的clientId/clientsecect
     *
     * @param header header中的参数
     */
    @SneakyThrows
    public String[] extractAndDecodeHeader(String header) {

        byte[] base64Token = header.substring(6).getBytes("UTF-8");
        byte[] decoded;
        try {
            decoded = Base64.decode(base64Token);
        } catch (IllegalArgumentException e) {
            throw new RuntimeException(
                    "Failed to decode basic authentication token");
        }

        String token = new String(decoded, CharsetUtil.UTF_8);

        int delim = token.indexOf(":");

        if (delim == -1) {
            throw new RuntimeException("Invalid basic authentication token");
        }
        return new String[]{token.substring(0, delim), token.substring(delim + 1)};
    }

    /**
     * *从header 请求中的clientId/clientsecect
     *
     * @param request
     * @return
     */
    @SneakyThrows
    public String[] extractAndDecodeHeader(HttpServletRequest request) {
        String header = request.getHeader(HttpHeaders.AUTHORIZATION);

        if (header == null || !header.startsWith(BASIC_)) {
            throw new RuntimeException("请求头中client信息为空");
        }

        return extractAndDecodeHeader(header);
    }
}