/*
 * 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.jclouds.openstack.keystone.v1_1.functions;

import jakarta.inject.Inject;
import jakarta.inject.Singleton;

import org.jclouds.location.Provider;
import org.jclouds.openstack.keystone.v1_1.domain.Endpoint;

import com.google.common.net.InternetDomainName;

@Singleton
public class RegionFirstPartOfDNSNameOrProvider implements EndpointToRegion {
   private final String provider;

   @Inject
   RegionFirstPartOfDNSNameOrProvider(@Provider String provider) {
      this.provider = provider;
   }

   @Override
   public String apply(Endpoint input) {
      if (input.getRegion() != null)
         return input.getRegion();
      String host = input.getPublicURL().getHost();
      if (InternetDomainName.isValid(host)) {
         InternetDomainName domain = InternetDomainName.from(host);
         return domain.parts().get(0);
      }
      return provider;
   }
}
