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.kafka.image;
  
  import org.apache.kafka.clients.admin.ScramMechanism;
  import org.apache.kafka.common.message.DescribeUserScramCredentialsRequestData;
  import org.apache.kafka.common.message.DescribeUserScramCredentialsRequestData.UserName;
  import org.apache.kafka.common.message.DescribeUserScramCredentialsResponseData;
  import org.apache.kafka.common.message.DescribeUserScramCredentialsResponseData.CredentialInfo;
  import org.apache.kafka.common.message.DescribeUserScramCredentialsResponseData.DescribeUserScramCredentialsResult;
  import org.apache.kafka.common.protocol.Errors;
  import org.apache.kafka.image.node.ScramImageNode;
  import org.apache.kafka.image.writer.ImageWriter;
  import org.apache.kafka.image.writer.ImageWriterOptions;
  import org.apache.kafka.metadata.ScramCredentialData;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  
  /**
   * Represents the SCRAM credentials in the metadata image.
   *
   * This class is thread-safe.
   */
  public final class ScramImage {
      public static final ScramImage EMPTY = new ScramImage(Map.of());
  
      private final Map<ScramMechanism, Map<String, ScramCredentialData>> mechanisms;
  
      public ScramImage(Map<ScramMechanism, Map<String, ScramCredentialData>> mechanisms) {
          this.mechanisms = Collections.unmodifiableMap(mechanisms);
      }
  
      public void write(ImageWriter writer, ImageWriterOptions options) {
          if (options.metadataVersion().isScramSupported()) {
              for (Entry<ScramMechanism, Map<String, ScramCredentialData>> mechanismEntry : mechanisms.entrySet()) {
                  for (Entry<String, ScramCredentialData> userEntry : mechanismEntry.getValue().entrySet()) {
                      writer.write(0, userEntry.getValue().toRecord(userEntry.getKey(), mechanismEntry.getKey()));
                  }
              }
          } else {
              boolean isEmpty = true;
              StringBuilder scramImageString = new StringBuilder("ScramImage({");
              for (Entry<ScramMechanism, Map<String, ScramCredentialData>> mechanismEntry : mechanisms.entrySet()) {
                  if (!mechanismEntry.getValue().isEmpty()) {
                      scramImageString.append(mechanismEntry.getKey()).append(":");
                      List<String> users = new ArrayList<>(mechanismEntry.getValue().keySet());
                      scramImageString.append(String.join(", ", users));
                      scramImageString.append("},{");
                      isEmpty = false;
                  }
              }
  
              if (!isEmpty) {
                  scramImageString.append("})");
                  options.handleLoss(scramImageString.toString());
              }
          }
      }
  
      private static final String DESCRIBE_DUPLICATE_USER = "Cannot describe SCRAM credentials for the same user twice in a single request: ";
      private static final String DESCRIBE_USER_THAT_DOES_NOT_EXIST = "Attempt to describe a user credential that does not exist: ";
  
      public DescribeUserScramCredentialsResponseData describe(DescribeUserScramCredentialsRequestData request) {
          List<UserName> users = request.users();
          Map<String, Boolean> uniqueUsers = new HashMap<>();
  
          if ((users == null) || (users.isEmpty())) {
              // If there are no users listed then get all the users
              for (Map<String, ScramCredentialData> scramCredentialDataSet : mechanisms.values()) {
                  for (String user : scramCredentialDataSet.keySet()) {
                      uniqueUsers.put(user, false);
                  }
              }
          } else {
              // Filter out duplicates
              for (UserName user : users) {
                  if (uniqueUsers.containsKey(user.name())) {
                      uniqueUsers.put(user.name(), true);
                  } else {
                      uniqueUsers.put(user.name(), false);
                  }
              }
          }
  
          DescribeUserScramCredentialsResponseData retval = new DescribeUserScramCredentialsResponseData();
  
          for (Map.Entry<String, Boolean> user : uniqueUsers.entrySet()) {
              DescribeUserScramCredentialsResult result = new DescribeUserScramCredentialsResult().setUser(user.getKey());
  
              if (!user.getValue()) {
                  boolean datafound = false;
                  List<CredentialInfo> credentialInfos = new ArrayList<>();
                  for (Map.Entry<ScramMechanism, Map<String, ScramCredentialData>> mechanismsEntry : mechanisms.entrySet()) {
                      Map<String, ScramCredentialData> credentialDataSet = mechanismsEntry.getValue();
                      if (credentialDataSet.containsKey(user.getKey())) {
                          credentialInfos.add(new CredentialInfo().setMechanism(mechanismsEntry.getKey().type())
                                                                  .setIterations(credentialDataSet.get(user.getKey()).iterations()));
                          datafound = true;
                      }
                  }
                  if (datafound) {
                      result.setCredentialInfos(credentialInfos);
                  } else {
                      result.setErrorCode(Errors.RESOURCE_NOT_FOUND.code())
                            .setErrorMessage(DESCRIBE_USER_THAT_DOES_NOT_EXIST + user.getKey());
                  }
              } else {
                  result.setErrorCode(Errors.DUPLICATE_RESOURCE.code())
                        .setErrorMessage(DESCRIBE_DUPLICATE_USER + user.getKey());
              }
              retval.results().add(result);
          }
          return retval;
      }
  
      public Map<ScramMechanism, Map<String, ScramCredentialData>> mechanisms() {
          return mechanisms;
      }
  
      public boolean isEmpty() {
          return mechanisms.isEmpty();
      }
  
      @Override
      public int hashCode() {
          return mechanisms.hashCode();
      }
  
      @Override
      public boolean equals(Object o) {
          if (o == null) return false;
          if (!o.getClass().equals(ScramImage.class)) return false;
          ScramImage other = (ScramImage) o;
          return mechanisms.equals(other.mechanisms);
      }
  
      @Override
      public String toString() {
          return new ScramImageNode(this).stringify();
      }
  }
  