/*
    * 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.hadoop.hbase.security.token;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.security.token.Token;
  import org.apache.hadoop.security.token.TokenIdentifier;
  import org.apache.hadoop.security.token.TokenSelector;
  
  import java.util.Collection;
  
  @InterfaceAudience.Private
  public class AuthenticationTokenSelector
      implements TokenSelector<AuthenticationTokenIdentifier> {
    private static final Log LOG = LogFactory.getLog(AuthenticationTokenSelector.class);
  
    public AuthenticationTokenSelector() {
    }
  
    @Override
    public Token<AuthenticationTokenIdentifier> selectToken(Text serviceName,
        Collection<Token<? extends TokenIdentifier>> tokens) {
      if (serviceName != null) {
        for (Token ident : tokens) {
          if (serviceName.equals(ident.getService()) &&
              AuthenticationTokenIdentifier.AUTH_TOKEN_TYPE.equals(ident.getKind())) {
            if (LOG.isDebugEnabled()) {
              LOG.debug("Returning token "+ident);
            }
            return (Token<AuthenticationTokenIdentifier>)ident;
          }
        }
      }
      LOG.debug("No matching token found");
      return null;
    }
  }