Add MR to expand billing events into OneTimes

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=124837292

java/google/registry/env/common/backend/WEB-INF/web.xml

@@ -265,6 +265,12 @@
     <url-pattern>/_dr/task/dnsRefreshForHostRename</url-pattern>
   </servlet-mapping>
 
+  <!--  Mapreduce to expand recurring billing events into OneTimes. -->
+  <servlet-mapping>
+    <servlet-name>backend-servlet</servlet-name>
+    <url-pattern>/_dr/task/expandRecurringBillingEvents</url-pattern>
+  </servlet-mapping>
+
   <!-- Security config -->
   <security-constraint>
     <web-resource-collection>

java/google/registry/model/common/Cursor.java

@@ -20,8 +20,6 @@ import static google.registry.model.common.EntityGroupRoot.getCrossTldKey;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.util.DateTimeUtils.START_OF_TIME;
 
-import com.google.common.annotations.VisibleForTesting;
-
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Entity;
 import com.googlecode.objectify.annotation.Id;
@@ -69,7 +67,12 @@ public class Cursor extends ImmutableObject {
      */
     RDE_UPLOAD_SFTP(Registry.class),
 
-    /** Cursor for ensuring rolling transactional isolation of recurring billing expansion. */
+    /**
+     * Cursor for ensuring rolling transactional isolation of recurring billing expansion. The
+     * value of this cursor represents the exclusive upper bound on the range of billing times
+     * for which Recurring billing events have been expanded (i.e. the inclusive first billing time
+     * for the next expansion job).
+     */
     RECURRING_BILLING(EntityGroupRoot.class);
 
     /** See the definition of scope on {@link #getScopeClass}. */
@@ -120,16 +123,14 @@ public class Cursor extends ImmutableObject {
   }
 
   /** Creates a unique key for a given scope and cursor type. */
-  @VisibleForTesting
-  static Key<Cursor> createKey(CursorType cursorType, ImmutableObject scope) {
+  public static Key<Cursor> createKey(CursorType cursorType, ImmutableObject scope) {
     Key<? extends ImmutableObject> scopeKey = Key.create(scope);
     checkValidCursorTypeForScope(cursorType, scopeKey);
     return Key.create(getCrossTldKey(), Cursor.class, generateId(cursorType, scopeKey));
   }
 
   /** Creates a unique key for a given global cursor type. */
-  @VisibleForTesting
-  static Key<Cursor> createGlobalKey(CursorType cursorType) {
+  public static Key<Cursor> createGlobalKey(CursorType cursorType) {
     checkArgument(
         cursorType.getScopeClass().equals(EntityGroupRoot.class),
         "Cursor type is not a global cursor.");

java/google/registry/module/backend/BUILD

@@ -14,11 +14,11 @@ java_library(
         "//java/com/google/common/net",
         "//java/google/registry/backup",
         "//java/google/registry/bigquery",
+        "//java/google/registry/billing",
         "//java/google/registry/config",
         "//java/google/registry/cron",
         "//java/google/registry/dns",
         "//java/google/registry/dns/writer/api",
-        "//java/google/registry/dns/writer/dnsupdate",
         "//java/google/registry/export",
         "//java/google/registry/export/sheet",
         "//java/google/registry/flows",
@@ -35,6 +35,7 @@ java_library(
         "//java/google/registry/util",
         "//third_party/java/bouncycastle",
         "//third_party/java/dagger",
+        "//third_party/java/joda_time",
         "//third_party/java/jsr305_annotations",
         "//third_party/java/jsr330_inject",
         "//third_party/java/servlet/servlet_api",

java/google/registry/module/backend/BackendModule.java

@@ -15,14 +15,20 @@
 package google.registry.module.backend;
 
 import static google.registry.model.registry.Registries.assertTldExists;
+import static google.registry.request.RequestParameters.extractOptionalDatetimeParameter;
 import static google.registry.request.RequestParameters.extractRequiredParameter;
 
+import com.google.common.base.Optional;
+
 import dagger.Module;
 import dagger.Provides;
 
+import google.registry.billing.ExpandRecurringBillingEventsAction;
 import google.registry.request.Parameter;
 import google.registry.request.RequestParameters;
 
+import org.joda.time.DateTime;
+
 import javax.servlet.http.HttpServletRequest;
 
 /**
@@ -36,4 +42,11 @@ public class BackendModule {
   static String provideTld(HttpServletRequest req) {
     return assertTldExists(extractRequiredParameter(req, RequestParameters.PARAM_TLD));
   }
+
+  @Provides
+  @Parameter("cursorTime")
+  static Optional<DateTime> provideCursorTime(HttpServletRequest req) {
+    return extractOptionalDatetimeParameter(
+        req, ExpandRecurringBillingEventsAction.PARAM_CURSOR_TIME);
+  }
 }

java/google/registry/request/RequestParameters.java

@@ -160,6 +160,25 @@ public final class RequestParameters {
     }
   }
 
+  /**
+   * Returns first request parameter associated with {@code name} parsed as an
+   * <a href="https://goo.gl/pk5Q2k">ISO 8601</a> timestamp, e.g. {@code 1984-12-18TZ},
+   * {@code 2000-01-01T16:20:00Z}.
+   *
+   * @throws BadRequestException if request parameter is present but not a valid {@link DateTime}.
+   */
+  public static Optional<DateTime> extractOptionalDatetimeParameter(
+      HttpServletRequest req, String name) {
+    String stringParam = req.getParameter(name);
+    try {
+      return isNullOrEmpty(stringParam)
+          ? Optional.<DateTime>absent()
+          : Optional.of(DateTime.parse(stringParam));
+    } catch (IllegalArgumentException e) {
+      throw new BadRequestException("Bad ISO 8601 timestamp: " + name);
+    }
+  }
+
   /**
    * Returns first request parameter associated with {@code name} parsed as an optional
    * {@link InetAddress} (which might be IPv6).

javatests/google/registry/request/RequestParametersTest.java

@@ -17,6 +17,7 @@ package google.registry.request;
 import static com.google.common.truth.Truth.assertThat;
 import static google.registry.request.RequestParameters.extractBooleanParameter;
 import static google.registry.request.RequestParameters.extractEnumParameter;
+import static google.registry.request.RequestParameters.extractOptionalDatetimeParameter;
 import static google.registry.request.RequestParameters.extractOptionalParameter;
 import static google.registry.request.RequestParameters.extractRequiredDatetimeParameter;
 import static google.registry.request.RequestParameters.extractRequiredMaybeEmptyParameter;
@@ -184,6 +185,26 @@ public class RequestParametersTest {
     extractRequiredDatetimeParameter(req, "timeParam");
   }
 
+  @Test
+  public void testExtractOptionalDatetimeParameter_correctValue_works() throws Exception {
+    when(req.getParameter("timeParam")).thenReturn("2015-08-27T13:25:34.123Z");
+    assertThat(extractOptionalDatetimeParameter(req, "timeParam"))
+        .hasValue(DateTime.parse("2015-08-27T13:25:34.123Z"));
+  }
+
+  @Test
+  public void testExtractOptionalDatetimeParameter_badValue_throwsBadRequest() throws Exception {
+    when(req.getParameter("timeParam")).thenReturn("Tuesday at three o'clock");
+    thrown.expect(BadRequestException.class, "timeParam");
+    extractOptionalDatetimeParameter(req, "timeParam");
+  }
+
+  @Test
+  public void testExtractOptionalDatetimeParameter_empty_returnsAbsent() throws Exception {
+    when(req.getParameter("timeParam")).thenReturn("");
+    assertThat(extractOptionalDatetimeParameter(req, "timeParam")).isAbsent();
+  }
+
   @Test
   public void testExtractRequiredDatetimeParameter_noValue_throwsBadRequest() throws Exception {
     thrown.expect(BadRequestException.class, "timeParam");