// Copyright 2017 The Nomulus Authors. All Rights Reserved.
//
// Licensed 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 google.registry.whois;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static google.registry.model.EppResourceUtils.queryNotDeleted;
import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Streams;
import com.google.common.net.InternetDomainName;
import google.registry.model.host.HostResource;
import google.registry.model.registry.Registries;
import java.net.InetAddress;
import org.joda.time.DateTime;

/**
 * Represents a WHOIS lookup for a nameserver based on its IP.
 *
 * <p>Both IPv4 and IPv6 addresses are supported. Unlike other WHOIS commands, this is an eventually
 * consistent query.
 *
 * <p><b>Note:</b> There may be multiple nameservers with the same IP.
 */
final class NameserverLookupByIpCommand implements WhoisCommand {

  @VisibleForTesting
  final InetAddress ipAddress;

  NameserverLookupByIpCommand(InetAddress ipAddress) {
    this.ipAddress = checkNotNull(ipAddress, "ipAddress");
  }

  @Override
  public WhoisResponse executeQuery(DateTime now) throws WhoisException {
    ImmutableList<HostResource> hosts =
        Streams.stream(queryNotDeleted(HostResource.class, now, "inetAddresses", ipAddress))
            .filter(
                host ->
                    Registries.findTldForName(
                            InternetDomainName.from(host.getFullyQualifiedHostName()))
                        .isPresent())
            .collect(toImmutableList());
    if (hosts.isEmpty()) {
      throw new WhoisException(now, SC_NOT_FOUND, "No nameservers found.");
    }
    return new NameserverWhoisResponse(hosts, now);
  }
}