/*
    * 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.shardingsphere.authority.rule;
  
  import lombok.Getter;
  import org.apache.shardingsphere.authority.config.AuthorityRuleConfiguration;
  import org.apache.shardingsphere.authority.model.ShardingSpherePrivileges;
  import org.apache.shardingsphere.authority.spi.PrivilegeProvider;
  import org.apache.shardingsphere.infra.annotation.HighFrequencyInvocation;
  import org.apache.shardingsphere.infra.metadata.user.Grantee;
  import org.apache.shardingsphere.infra.metadata.user.ShardingSphereUser;
  import org.apache.shardingsphere.infra.rule.scope.GlobalRule;
  import org.apache.shardingsphere.infra.rule.attribute.RuleAttributes;
  import org.apache.shardingsphere.infra.spi.type.typed.TypedSPILoader;
  
  import java.util.Map;
  import java.util.Optional;
  
  /**
   * Authority rule.
   */
  public final class AuthorityRule implements GlobalRule {
      
      @Getter
      private final AuthorityRuleConfiguration configuration;
      
      private final Map<Grantee, ShardingSpherePrivileges> privileges;
      
      public AuthorityRule(final AuthorityRuleConfiguration ruleConfig) {
          configuration = ruleConfig;
          privileges = TypedSPILoader.getService(PrivilegeProvider.class, ruleConfig.getPrivilegeProvider().getType(), ruleConfig.getPrivilegeProvider().getProps()).build(ruleConfig);
      }
      
      /**
       * Get authenticator type.
       *
       * @param user user
       * @return authenticator type
       */
      public String getAuthenticatorType(final ShardingSphereUser user) {
          if (configuration.getAuthenticators().containsKey(user.getAuthenticationMethodName())) {
              return configuration.getAuthenticators().get(user.getAuthenticationMethodName()).getType();
          }
          if (configuration.getAuthenticators().containsKey(configuration.getDefaultAuthenticator())) {
              return configuration.getAuthenticators().get(configuration.getDefaultAuthenticator()).getType();
          }
          return "";
      }
      
      /**
       * Find user.
       *
       * @param grantee grantee user
       * @return found user
       */
      @HighFrequencyInvocation
      public Optional<ShardingSphereUser> findUser(final Grantee grantee) {
          return configuration.getUsers().stream().filter(each -> each.getGrantee().accept(grantee)).findFirst();
      }
      
      /**
       * Find privileges.
       *
       * @param grantee grantee
       * @return found privileges
       */
      @HighFrequencyInvocation
      public Optional<ShardingSpherePrivileges> findPrivileges(final Grantee grantee) {
          return privileges.keySet().stream().filter(each -> each.accept(grantee)).findFirst().map(privileges::get);
      }
      
      @Override
      public RuleAttributes getAttributes() {
          return new RuleAttributes();
      }
  }