Implemented ChangeRequest.

gcloud-java-dns/src/main/java/com/google/gcloud/dns/ChangeRequest.java

@@ -0,0 +1,340 @@
+/*
+ * Copyright 2016 Google Inc. 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 com.google.gcloud.dns;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.Lists;
+
+import org.joda.time.DateTime;
+import org.joda.time.format.ISODateTimeFormat;
+
+import java.io.Serializable;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * A class representing a change. A change is an atomic update to a collection of {@link DnsRecord}s
+ * within a {@code ManagedZone}.
+ *
+ * @see <a href="https://cloud.google.com/dns/api/v1/changes">Google Cloud DNS documentation</a>
+ */
+public class ChangeRequest implements Serializable {
+
+  private static final long serialVersionUID = 201601251649L;
+  private final List<DnsRecord> additions;
+  private final List<DnsRecord> deletions;
+  private final String id;
+  private final Long startTimeMillis;
+  private final Status status;
+
+  /**
+   * This enumerates the possible states of a {@code ChangeRequest}.
+   *
+   * @see <a href="https://cloud.google.com/dns/api/v1/changes#resource">Google Cloud DNS
+   * documentation</a>
+   */
+  public enum Status {
+    PENDING("pending"),
+    DONE("done");
+
+    private final String status;
+
+    Status(String status) {
+      this.status = status;
+    }
+
+    static Status translate(String status) {
+      if ("pending".equals(status)) {
+        return PENDING;
+      } else if ("done".equals(status)) {
+        return DONE;
+      } else {
+        throw new IllegalArgumentException("Such a status is unknown.");
+      }
+    }
+  }
+
+  /**
+   * A builder for {@code ChangeRequest}s.
+   */
+  public static class Builder {
+
+    private List<DnsRecord> additions = new LinkedList<>();
+    private List<DnsRecord> deletions = new LinkedList<>();
+    private String id;
+    private Long startTimeMillis;
+    private Status status;
+
+    private Builder(ChangeRequest cr) {
+      this.additions = Lists.newLinkedList(cr.additions());
+      this.deletions = Lists.newLinkedList(cr.deletions());
+      this.id = cr.id();
+      this.startTimeMillis = cr.startTimeMillis();
+      this.status = cr.status();
+    }
+
+    private Builder() {
+    }
+
+    /**
+     * Sets a collection of {@link DnsRecord}s which are to be added to the zone upon executing this
+     * {@code ChangeRequest}.
+     */
+    public Builder additions(List<DnsRecord> additions) {
+      this.additions = Lists.newLinkedList(checkNotNull(additions));
+      return this;
+    }
+
+    /**
+     * Adds a {@link DnsRecord} which to be <strong>added</strong> to the zone upon executing this
+     * {@code ChangeRequest}.
+     */
+    public Builder add(DnsRecord record) {
+      this.additions.add(checkNotNull(record));
+      return this;
+    }
+
+    /**
+     * Adds a {@link DnsRecord} which to be <strong>deleted</strong> to the zone upon executing this
+     * {@code ChangeRequest}.
+     */
+    public Builder delete(DnsRecord record) {
+      this.deletions.add(checkNotNull(record));
+      return this;
+    }
+
+    /**
+     * Clears the collection of {@link DnsRecord}s which are to be added to the zone upon executing
+     * this {@code ChangeRequest}.
+     */
+    public Builder clearAdditions() {
+      this.additions.clear();
+      return this;
+    }
+
+    /**
+     * Clears the collection of {@link DnsRecord}s which are to be deleted from the zone upon
+     * executing this {@code ChangeRequest}.
+     */
+    public Builder clearDeletions() {
+      this.deletions.clear();
+      return this;
+    }
+
+    /**
+     * Removes a single {@link DnsRecord} from the collection of of records to be
+     * <strong>added</strong> to the zone upon executing this {@code ChangeRequest}.
+     */
+    public Builder removeAddition(DnsRecord record) {
+      this.additions.remove(record);
+      return this;
+    }
+
+    /**
+     * Removes a single {@link DnsRecord} from the collection of of records to be
+     * <strong>deleted</strong> from the zone upon executing this {@code ChangeRequest}.
+     */
+    public Builder removeDeletion(DnsRecord record) {
+      this.deletions.remove(record);
+      return this;
+    }
+
+    /**
+     * Sets a collection of {@link DnsRecord}s which are to be deleted from the zone upon executing
+     * this {@code ChangeRequest}.
+     */
+    public Builder deletions(List<DnsRecord> deletions) {
+      this.deletions = Lists.newLinkedList(checkNotNull(deletions));
+      return this;
+    }
+
+    /**
+     * Associates a server-assigned id to this {@code ChangeRequest}.
+     */
+    Builder id(String id) {
+      this.id = checkNotNull(id);
+      return this;
+    }
+
+    /**
+     * Sets the time when this {@code ChangeRequest} was started by a server.
+     */
+    Builder startTimeMillis(long startTimeMillis) {
+      this.startTimeMillis = startTimeMillis;
+      return this;
+    }
+
+    /**
+     * Sets the current status of this {@code ChangeRequest}.
+     */
+    Builder status(Status status) {
+      this.status = checkNotNull(status);
+      return this;
+    }
+
+    /**
+     * Creates a {@code ChangeRequest} instance populated by the values associated with this
+     * builder.
+     */
+    public ChangeRequest build() {
+      return new ChangeRequest(this);
+    }
+  }
+
+  private ChangeRequest(Builder builder) {
+    this.additions = builder.additions;
+    this.deletions = builder.deletions;
+    this.id = builder.id;
+    this.startTimeMillis = builder.startTimeMillis;
+    this.status = builder.status;
+  }
+
+  /**
+   * Returns an empty builder for the {@code ChangeRequest} class.
+   */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  /**
+   * Creates a builder populated with values of this {@code ChangeRequest}.
+   */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  /**
+   * Returns the list of {@link DnsRecord}s to be added to the zone upon executing this {@code
+   * ChangeRequest}.
+   */
+  public List<DnsRecord> additions() {
+    return additions;
+  }
+
+  /**
+   * Returns the list of {@link DnsRecord}s to be deleted from the zone upon executing this {@code
+   * ChangeRequest}.
+   */
+  public List<DnsRecord> deletions() {
+    return deletions;
+  }
+
+  /**
+   * Returns the id assigned to this {@code ChangeRequest} by the server.
+   */
+  public String id() {
+    return id;
+  }
+
+  /**
+   * Returns the time when this {@code ChangeRequest} was started by the server.
+   */
+  public Long startTimeMillis() {
+    return startTimeMillis;
+  }
+
+  /**
+   * Returns the status of this {@code ChangeRequest}.
+   */
+  public Status status() {
+    return status;
+  }
+
+  com.google.api.services.dns.model.Change toPb() {
+    com.google.api.services.dns.model.Change pb =
+        new com.google.api.services.dns.model.Change();
+    // set id
+    if (id() != null) {
+      pb.setId(id());
+    }
+    // set timestamp
+    if (startTimeMillis() != null) {
+      pb.setStartTime(ISODateTimeFormat.dateTime().withZoneUTC().print(startTimeMillis()));
+    }
+    // set status
+    if (status() != null) {
+      pb.setStatus(status().status);
+    }
+    // set a list of additions
+    if (additions() != null) {
+      LinkedList<com.google.api.services.dns.model.ResourceRecordSet> additionsPb =
+          new LinkedList<>();
+      for (DnsRecord addition : additions()) {
+        additionsPb.add(addition.toPb());
+      }
+      pb.setAdditions(additionsPb);
+    }
+    // set a list of deletions
+    if (deletions() != null) {
+      LinkedList<com.google.api.services.dns.model.ResourceRecordSet> deletionsPb =
+          new LinkedList<>();
+      for (DnsRecord deletion : deletions()) {
+        deletionsPb.add(deletion.toPb());
+      }
+      pb.setDeletions(deletionsPb);
+    }
+    return pb;
+  }
+
+  static ChangeRequest fromPb(com.google.api.services.dns.model.Change pb) {
+    Builder b = builder();
+    if (pb.getId() != null) {
+      b.id(pb.getId());
+    }
+    if (pb.getStartTime() != null) {
+      b.startTimeMillis(DateTime.parse(pb.getStartTime()).getMillis());
+    }
+    if (pb.getStatus() != null) {
+      b.status(ChangeRequest.Status.translate(pb.getStatus()));
+    }
+    if (pb.getDeletions() != null) {
+      for (com.google.api.services.dns.model.ResourceRecordSet deletion : pb.getDeletions()) {
+        b.delete(DnsRecord.fromPb(deletion));
+      }
+    }
+    if (pb.getAdditions() != null) {
+      for (com.google.api.services.dns.model.ResourceRecordSet addition : pb.getAdditions()) {
+        b.add(DnsRecord.fromPb(addition));
+      }
+    }
+    return b.build();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return (o instanceof ChangeRequest) && this.toPb().equals(((ChangeRequest) o).toPb());
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(additions, deletions, id, startTimeMillis, status);
+  }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+        .add("additions", additions)
+        .add("deletions", deletions)
+        .add("id", id)
+        .add("startTimeMillis", startTimeMillis)
+        .add("status", status)
+        .toString();
+  }
+}