content: /*
   *  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.causeway.viewer.restfulobjects.client.auth.basic;
  
  import org.apache.causeway.viewer.restfulobjects.client.AuthenticationMode;
  import org.apache.causeway.viewer.restfulobjects.client.RestfulClientConfig;
  import org.apache.causeway.viewer.restfulobjects.client.auth.AuthorizationHeaderFactory;
  
  public class AuthorizationHeaderFactoryBasic implements AuthorizationHeaderFactory {
  
      private final BasicCreds creds;
  
      public AuthorizationHeaderFactoryBasic(final RestfulClientConfig restfulClientConfig) {
          if (restfulClientConfig.getAuthenticationMode() != AuthenticationMode.BASIC) {
              throw new IllegalArgumentException(String.format("config.authenticationMode must be '%s'", AuthenticationMode.BASIC));
          }
          this.creds = basicCredsFrom(restfulClientConfig);
      }
  
      static BasicCreds basicCredsFrom(final RestfulClientConfig restfulClientConfig) {
          if (restfulClientConfig.getBasicAuthUser() == null) {
              throw new IllegalArgumentException("config.basicAuthUser must be set");
          }
          if (restfulClientConfig.getBasicAuthPassword() == null) {
              throw new IllegalArgumentException("config.basicAuthPassword must be set");
          }
          return BasicCreds.builder()
                  .username(restfulClientConfig.getBasicAuthUser())
                  .password(restfulClientConfig.getBasicAuthPassword())
                  .build();
      }
  
      @Override
      public String create() {
          return "Basic " + encode(creds.username(), creds.password());
      }
  
      static String encode(final String username, final String password) {
          return java.util.Base64.getEncoder().encodeToString(asBytes(username, password));
      }
  
      static byte[] asBytes(final String username, final String password) {
          return String.format("%s:%s", username, password).getBytes();
      }
  
  }
  