Completes DnsRpc interface by adding methods and doc.

Closes googleapis#594.

gcloud-java-dns/src/main/java/com/google/gcloud/spi/DnsRpc.java

@@ -16,6 +16,12 @@
 
 package com.google.gcloud.spi;
 
+import com.google.api.services.dns.model.Change;
+import com.google.api.services.dns.model.ManagedZone;
+import com.google.api.services.dns.model.Project;
+import com.google.api.services.dns.model.ResourceRecordSet;
+import com.google.gcloud.dns.DnsException;
+
 import java.util.Map;
 
 public interface DnsRpc {
@@ -52,5 +58,114 @@ Integer getInt(Map<Option, ?> options) {
     }
   }
 
-  //TODO(mderka) add supported operations. Created issue #594.
+  class Tuple<X, Y> {
+
+    private final X x;
+    private final Y y;
+
+    private Tuple(X x, Y y) {
+      this.x = x;
+      this.y = y;
+    }
+
+    public static <X, Y> Tuple<X, Y> of(X x, Y y) {
+      return new Tuple<>(x, y);
+    }
+
+    public X x() {
+      return x;
+    }
+
+    public Y y() {
+      return y;
+    }
+  }
+
+  /**
+   * Creates a new zone.
+   *
+   * @param zone a zone to be created
+   * @return Updated {@link ManagedZone} object
+   * @throws DnsException upon failure
+   */
+  ManagedZone create(ManagedZone zone) throws DnsException;
+
+  /**
+   * Retrieves and returns an existing zone.
+   *
+   * @param zoneName name of the zone to be returned
+   * @param options a map of options for the service call
+   * @return a zone or {@code null} if not found
+   * @throws DnsException upon failure
+   */
+  ManagedZone getZone(String zoneName, Map<Option, ?> options) throws DnsException;
+
+  /**
+   * Lists the zones that exist within the project.
+   *
+   * @param options a map of options for the service call
+   * @throws DnsException upon failure
+   */
+  Tuple<String, Iterable<ManagedZone>> listZones(Map<Option, ?> options) throws DnsException;
+
+  /**
+   * Deletes the zone identified by the name.
+   *
+   * @return {@code true} if the zone was deleted and {@code false} otherwise
+   * @throws DnsException upon failure
+   */
+  boolean deleteZone(String zoneName) throws DnsException;
+
+  /**
+   * Lists DNS records for a given zone.
+   *
+   * @param zoneName name of the zone to be listed
+   * @param options a map of options for the service call
+   * @throws DnsException upon failure or if zone not found
+   */
+  Tuple<String, Iterable<ResourceRecordSet>> listDnsRecords(String zoneName,
+      Map<Option, ?> options) throws DnsException;
+
+  /**
+   * Returns information about the current project.
+   * 
+   * @param options a map of options for the service call
+   * @return up-to-date project information
+   * @throws DnsException upon failure
+   */
+  Project getProject(Map<Option, ?> options) throws DnsException;
+
+  /**
+   * Applies change request to a zone. 
+   *
+   * @param zoneName the name of a zone to which the {@link Change} should be applied
+   * @param changeRequest change to be applied
+   * @param options a map of options for the service call
+   * @return updated change object with server-assigned ID
+   * @throws DnsException upon failure or if zone not found
+   */
+  Change applyChangeRequest(String zoneName, Change changeRequest, Map<Option, ?> options) 
+      throws DnsException;
+
+  /**
+   * Returns an existing change request.
+   *
+   * @param zoneName the name of a zone to which the {@link Change} was be applied
+   * @param changeRequestId the unique id assigned to the change by the server
+   * @param options a map of options for the service call
+   * @return up-to-date change object
+   * @throws DnsException upon failure or if zone not found
+   */
+  Change getChangeRequest(String zoneName, String changeRequestId, Map<Option, ?> options) 
+      throws DnsException;
+
+  /**
+   * List an existing change requests for a zone.
+   *
+   * @param zoneName the name of a zone to which the {@link Change}s were be applied
+   * @param options a map of options for the service call
+   * @throws DnsException upon failure or if zone not found
+   */
+  Tuple<String, Iterable<Change>> listChangeRequests(String zoneName, Map<Option, ?> options) 
+      throws DnsException;
 }