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.node;
  
  import org.apache.kafka.common.quota.ClientQuotaEntity;
  import org.apache.kafka.image.ClientQuotaImage;
  import org.apache.kafka.image.ClientQuotasImage;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import static org.apache.kafka.common.quota.ClientQuotaEntity.CLIENT_ID;
  import static org.apache.kafka.common.quota.ClientQuotaEntity.IP;
  import static org.apache.kafka.common.quota.ClientQuotaEntity.USER;
  
  
  public class ClientQuotasImageNode implements MetadataNode {
      /**
       * The name of this node.
       */
      public static final String NAME = "clientQuotas";
  
      /**
       * The topics image.
       */
      private final ClientQuotasImage image;
  
      public ClientQuotasImageNode(ClientQuotasImage image) {
          this.image = image;
      }
  
      @Override
      public Collection<String> childNames() {
          ArrayList<String> childNames = new ArrayList<>();
          for (ClientQuotaEntity entity : image.entities().keySet()) {
              childNames.add(clientQuotaEntityToString(entity));
          }
          return childNames;
      }
  
      static String clientQuotaEntityToString(ClientQuotaEntity entity) {
          if (entity.entries().isEmpty()) {
              throw new RuntimeException("Invalid empty entity");
          }
          String clientId = null;
          String ip = null;
          String user = null;
          for (Map.Entry<String, String> entry : entity.entries().entrySet()) {
              if (entry.getKey().equals(CLIENT_ID)) {
                  clientId = entry.getValue();
              } else if (entry.getKey().equals(IP)) {
                  ip = entry.getValue();
              } else if (entry.getKey().equals(USER)) {
                  user = entry.getValue();
              } else {
                  throw new RuntimeException("Invalid entity type " + entry.getKey());
              }
          }
          StringBuilder bld = new StringBuilder();
          String prefix = "";
          if (clientId != null) {
              bld.append(prefix).append("clientId(").append(escape(clientId)).append(")");
              prefix = "_";
          }
          if (ip != null) {
              bld.append(prefix).append("ip(").append(escape(ip)).append(")");
              prefix = "_";
          }
          if (user != null) {
              bld.append(prefix).append("user(").append(escape(user)).append(")");
              prefix = "_";
          }
          return bld.toString();
      }
  
      static String escape(String input) {
          return input.replace("\\", "\\\\").replace("(", "\\(").replace(")", "\\)");
      }
  
      @Override
      public MetadataNode child(String name) {
          ClientQuotaEntity entity = decodeEntity(name);
          if (entity == null) return null;
          ClientQuotaImage clientQuotaImage = image.entities().get(entity);
          if (clientQuotaImage == null) return null;
          return new ClientQuotaImageNode(clientQuotaImage);
      }
  
      static ClientQuotaEntity decodeEntity(String input) {
          Map<String, String> entries = new HashMap<>();
          String type = null;
          StringBuilder value = new StringBuilder();
          boolean escaping = false;
          int i = 0;
          while (true) {
              if (i >= input.length()) return null;
              if (type == null) {
                  if (input.substring(i).startsWith("clientId(")) {
                      type = CLIENT_ID;
                      i += "clientId(".length();
                  } else if (input.substring(i).startsWith("ip(")) {
                      type = IP;
                      i += "ip(".length();
                  } else if (input.substring(i).startsWith("user(")) {
                      type = USER;
                      i += "user(".length();
                  } else {
                      return null;
                  }
              } else {
                  char c = input.charAt(i++);
                  if (escaping) {
                      value.append(c);
                      escaping = false;
                  } else {
                      switch (c) {
                          case ')':
                              entries.put(type, value.toString());
                              type = null;
                              value = new StringBuilder();
                              break;
                          case '\\':
                              escaping = true;
                              break;
                          default:
                              value.append(c);
                              break;
                      }
                  }
                  if (type == null) {
                      if (i >= input.length()) {
                          return new ClientQuotaEntity(entries);
                      } else if (input.charAt(i++) != '_') {
                          return null;
                      }
                  }
              }
          }
      }
  }
  