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.common.acl;
  
  import java.util.Objects;
  
  /**
   * Represents a filter which matches access control entries.
   */
  public class AccessControlEntryFilter {
      private final AccessControlEntryData data;
  
      /**
       * Matches any access control entry.
       */
      public static final AccessControlEntryFilter ANY =
          new AccessControlEntryFilter(null, null, AclOperation.ANY, AclPermissionType.ANY);
  
      /**
       * Create an instance of an access control entry filter with the provided parameters.
       *
       * @param principal the principal or null
       * @param host the host or null
       * @param operation non-null operation
       * @param permissionType non-null permission type
       */
      public AccessControlEntryFilter(String principal, String host, AclOperation operation, AclPermissionType permissionType) {
          Objects.requireNonNull(operation);
          Objects.requireNonNull(permissionType);
          this.data = new AccessControlEntryData(principal, host, operation, permissionType);
      }
  
      /**
       * This is a non-public constructor used in AccessControlEntry#toFilter
       *
       * @param data     The access control data.
       */
      AccessControlEntryFilter(AccessControlEntryData data) {
          this.data = data;
      }
  
      /**
       * Return the principal or null.
       */
      public String principal() {
          return data.principal();
      }
  
      /**
       * Return the host or null. The value `*` means any host.
       */
      public String host() {
          return data.host();
      }
  
      /**
       * Return the AclOperation.
       */
      public AclOperation operation() {
          return data.operation();
      }
  
      /**
       * Return the AclPermissionType.
       */
      public AclPermissionType permissionType() {
          return data.permissionType();
      }
  
      @Override
      public String toString() {
          return data.toString();
      }
  
      /**
       * Return true if there are any UNKNOWN components.
       */
      public boolean isUnknown() {
          return data.isUnknown();
      }
  
      /**
       * Returns true if this filter matches the given AccessControlEntry.
       */
      public boolean matches(AccessControlEntry other) {
          if ((principal() != null) && (!principal().equals(other.principal())))
              return false;
          if ((host() != null) && (!host().equals(other.host())))
              return false;
          if ((operation() != AclOperation.ANY) && (!operation().equals(other.operation())))
              return false;
          return (permissionType() == AclPermissionType.ANY) || (permissionType().equals(other.permissionType()));
      }
  
      /**
       * Returns true if this filter could only match one ACE -- in other words, if
       * there are no ANY or UNKNOWN fields.
       */
      public boolean matchesAtMostOne() {
          return findIndefiniteField() == null;
      }
  
      /**
       * Returns a string describing an ANY or UNKNOWN field, or null if there is
       * no such field.
       */
      public String findIndefiniteField() {
          return data.findIndefiniteField();
      }
  
      @Override
      public boolean equals(Object o) {
          if (!(o instanceof AccessControlEntryFilter))
              return false;
          AccessControlEntryFilter other = (AccessControlEntryFilter) o;
          return data.equals(other.data);
      }
  
      @Override
      public int hashCode() {
          return data.hashCode();
      }
  }
  