// Copyright 2016 The Domain Registry 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.model.dns;

/**
 * Transaction object for sending an atomic batch of updates for a single zone to the DNS server.
 *
 * <p>Here's an example of how you would publish updates for a domain and host:
 * <pre>
 * &#064;Inject Provider&lt;DnsWriter&gt; dnsWriter;
 * try (DnsWriter writer = dnsWriter.get()) {
 *   writer.publishDomain(domainName);
 *   writer.publishHost(hostName);
 * }
 * </pre>
 */
public interface DnsWriter extends AutoCloseable {

  /**
   * Loads {@code domainName} from datastore and publishes its NS/DS records to the DNS server.
   * Replaces existing records for the exact name supplied with an NS record for each name server
   * and a DS record for each delegation signer stored in the registry for the supplied domain name.
   * If the domain is deleted or is in a "non-publish" state then any existing records are deleted.
   *
   * @param domainName the fully qualified domain name, with no trailing dot
   */
  void publishDomain(String domainName);

  /**
   * Loads {@code hostName} from datastore and publishes its A/AAAA glue records to the DNS server,
   * if it is used as an in-bailiwick nameserver. Orphaned glue records are prohibited. Replaces
   * existing records for the exact name supplied, with an A or AAAA record (as appropriate) for
   * each address stored in the registry, for the supplied host name. If the host is deleted then
   * the existing records are deleted. Assumes that this method will only be called for in-bailiwick
   * hosts. The registry does not have addresses for other hosts.
   *
   * @param hostName the fully qualified host name, with no trailing dot
   */
  void publishHost(String hostName);

  /** Commits the updates to the DNS server atomically. */
  @Override
  void close();
}