Add extensible custom logic to the domain delete flow

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140534389

java/google/registry/flows/custom/CustomLogicFactory.java

@@ -55,4 +55,9 @@ public class CustomLogicFactory {
       EppInput eppInput, SessionMetadata sessionMetadata) {
     return new DomainRenewFlowCustomLogic(eppInput, sessionMetadata);
   }
+
+  public DomainDeleteFlowCustomLogic forDomainDeleteFlow(
+      EppInput eppInput, SessionMetadata sessionMetadata) {
+    return new DomainDeleteFlowCustomLogic(eppInput, sessionMetadata);
+  }
 }

java/google/registry/flows/custom/CustomLogicModule.java

@@ -52,4 +52,10 @@ public class CustomLogicModule {
       CustomLogicFactory factory, EppInput eppInput, SessionMetadata sessionMetadata) {
     return factory.forDomainRenewFlow(eppInput, sessionMetadata);
   }
+
+  @Provides
+  static DomainDeleteFlowCustomLogic provideDomainDeleteFlowCustomLogic(
+      CustomLogicFactory factory, EppInput eppInput, SessionMetadata sessionMetadata) {
+    return factory.forDomainDeleteFlow(eppInput, sessionMetadata);
+  }
 }

java/google/registry/flows/custom/DomainDeleteFlowCustomLogic.java

@@ -0,0 +1,190 @@
+// Copyright 2016 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.flows.custom;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
+import google.registry.flows.EppException;
+import google.registry.flows.SessionMetadata;
+import google.registry.flows.domain.DomainDeleteFlow;
+import google.registry.model.ImmutableObject;
+import google.registry.model.domain.DomainResource;
+import google.registry.model.eppinput.EppInput;
+import google.registry.model.eppoutput.EppResponse.ResponseExtension;
+import google.registry.model.eppoutput.Result;
+import google.registry.model.reporting.HistoryEntry;
+
+/**
+ * A no-op base class for {@link DomainDeleteFlow} custom logic.
+ *
+ * <p>Extend this class and override the hook(s) to perform custom logic.
+ */
+public class DomainDeleteFlowCustomLogic extends BaseFlowCustomLogic {
+
+  protected DomainDeleteFlowCustomLogic(EppInput eppInput, SessionMetadata sessionMetadata) {
+    super(eppInput, sessionMetadata);
+  }
+
+  /** A hook that runs before any validation. This is useful to e.g. add allowable extensions. */
+  @SuppressWarnings("unused")
+  public void beforeValidation() throws EppException {
+    // Do nothing.
+  }
+
+  /** A hook that runs at the end of the validation step to perform additional validation. */
+  @SuppressWarnings("unused")
+  public void afterValidation(AfterValidationParameters parameters) throws EppException {
+    // Do nothing.
+  }
+
+  /**
+   * A hook that runs before new entities are persisted, allowing them to be changed.
+   *
+   * <p>It returns the actual entity changes that should be persisted to Datastore. It is important
+   * to be careful when changing the flow behavior for existing entities, because the core logic
+   * across many different flows expects the existence of these entities and many of the fields on
+   * them.
+   */
+  @SuppressWarnings("unused")
+  public EntityChanges beforeSave(BeforeSaveParameters parameters) throws EppException {
+    return parameters.entityChanges();
+  }
+
+  /**
+   * A hook that runs before the response is returned.
+   *
+   * <p>This takes the {@link Result.Code} and {@link ResponseExtension}s as input and returns
+   * them, potentially with modifications.
+   */
+
+  @SuppressWarnings("unused")
+  public BeforeResponseReturnData beforeResponse(BeforeResponseParameters parameters)
+      throws EppException {
+    return BeforeResponseReturnData.newBuilder()
+        .setResultCode(parameters.resultCode())
+        .setResponseExtensions(parameters.responseExtensions())
+        .build();
+  }
+
+  /** A class to encapsulate parameters for a call to {@link #afterValidation}. */
+  @AutoValue
+  public abstract static class AfterValidationParameters extends ImmutableObject {
+
+    public abstract DomainResource existingDomain();
+
+    public static Builder newBuilder() {
+      return new AutoValue_DomainDeleteFlowCustomLogic_AfterValidationParameters.Builder();
+    }
+
+    /** Builder for {@link AfterValidationParameters}. */
+    @AutoValue.Builder
+    public abstract static class Builder {
+
+      public abstract Builder setExistingDomain(DomainResource existingDomain);
+
+      public abstract AfterValidationParameters build();
+    }
+  }
+
+  /**
+   * A class to encapsulate parameters for a call to {@link #beforeSave}.
+   *
+   * <p>Note that both newDomain and historyEntry are included in entityChanges. They are also
+   * passed separately for convenience, but they are the same instance, and changes to them will
+   * also affect what is persisted from entityChanges.
+   */
+  @AutoValue
+  public abstract static class BeforeSaveParameters extends ImmutableObject {
+
+    public abstract DomainResource existingDomain();
+
+    public abstract DomainResource newDomain();
+
+    public abstract HistoryEntry historyEntry();
+
+
+    public abstract EntityChanges entityChanges();
+
+    public static Builder newBuilder() {
+      return new AutoValue_DomainDeleteFlowCustomLogic_BeforeSaveParameters.Builder();
+    }
+
+    /** Builder for {@link BeforeSaveParameters}. */
+    @AutoValue.Builder
+    public abstract static class Builder {
+
+      public abstract Builder setExistingDomain(DomainResource existingDomain);
+
+      public abstract Builder setNewDomain(DomainResource newDomain);
+
+      public abstract Builder setHistoryEntry(HistoryEntry historyEntry);
+
+      public abstract Builder setEntityChanges(EntityChanges entityChanges);
+
+      public abstract BeforeSaveParameters build();
+    }
+  }
+    /** A class to encapsulate parameters for a call to {@link #beforeResponse}. */
+  @AutoValue
+  public abstract static class BeforeResponseParameters extends ImmutableObject {
+
+    public abstract Result.Code resultCode();
+
+    public abstract ImmutableList<? extends ResponseExtension> responseExtensions();
+
+    public static Builder newBuilder() {
+      return new AutoValue_DomainDeleteFlowCustomLogic_BeforeResponseParameters.Builder();
+    }
+
+    /** Builder for {@link BeforeResponseParameters}. */
+    @AutoValue.Builder
+    public abstract static class Builder {
+
+      public abstract Builder setResultCode(Result.Code resultCode);
+
+      public abstract Builder setResponseExtensions(
+          ImmutableList<? extends ResponseExtension> responseExtensions);
+
+      public abstract BeforeResponseParameters build();
+    }
+  }
+
+  /**
+   * A class to encapsulate parameters for the return values from a call to {@link #beforeResponse}.
+   */
+  @AutoValue
+  public abstract static class BeforeResponseReturnData extends ImmutableObject {
+
+    public abstract Result.Code resultCode();
+
+    public abstract ImmutableList<? extends ResponseExtension> responseExtensions();
+
+    public static Builder newBuilder() {
+      return new AutoValue_DomainDeleteFlowCustomLogic_BeforeResponseReturnData.Builder();
+    }
+
+    /** Builder for {@link BeforeResponseReturnData}. */
+    @AutoValue.Builder
+    public abstract static class Builder {
+
+      public abstract Builder setResultCode(Result.Code resultCode);
+
+      public abstract Builder setResponseExtensions(
+          ImmutableList<? extends ResponseExtension> responseExtensions);
+
+      public abstract BeforeResponseReturnData build();
+    }
+  }
+}

java/google/registry/flows/domain/DomainDeleteFlow.java

@@ -15,6 +15,7 @@
 package google.registry.flows.domain;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static google.registry.flows.FlowUtils.persistEntityChanges;
 import static google.registry.flows.FlowUtils.validateClientIsLoggedIn;
 import static google.registry.flows.ResourceFlowUtils.handlePendingTransferOnDelete;
 import static google.registry.flows.ResourceFlowUtils.loadAndVerifyExistence;
@@ -45,6 +46,12 @@ import google.registry.flows.FlowModule.TargetId;
 import google.registry.flows.ResourceFlowUtils;
 import google.registry.flows.SessionMetadata;
 import google.registry.flows.TransactionalFlow;
+import google.registry.flows.custom.DomainDeleteFlowCustomLogic;
+import google.registry.flows.custom.DomainDeleteFlowCustomLogic.AfterValidationParameters;
+import google.registry.flows.custom.DomainDeleteFlowCustomLogic.BeforeResponseParameters;
+import google.registry.flows.custom.DomainDeleteFlowCustomLogic.BeforeResponseReturnData;
+import google.registry.flows.custom.DomainDeleteFlowCustomLogic.BeforeSaveParameters;
+import google.registry.flows.custom.EntityChanges;
 import google.registry.model.ImmutableObject;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.domain.DomainResource;
@@ -106,11 +113,13 @@ public final class DomainDeleteFlow implements TransactionalFlow {
   @Inject DnsQueue dnsQueue;
   @Inject Trid trid;
   @Inject EppResponse.Builder responseBuilder;
+  @Inject DomainDeleteFlowCustomLogic customLogic;
   @Inject DomainDeleteFlow() {}
 
   @Override
   public final EppResponse run() throws EppException {
     extensionManager.register(MetadataExtension.class, SecDnsCreateExtension.class);
+    customLogic.beforeValidation();
     extensionManager.validate();
     validateClientIsLoggedIn(clientId);
     DateTime now = ofy().getTransactionTime();
@@ -118,6 +127,9 @@ public final class DomainDeleteFlow implements TransactionalFlow {
     DomainResource existingDomain = loadAndVerifyExistence(DomainResource.class, targetId, now);
     Registry registry = Registry.get(existingDomain.getTld());
     verifyDeleteAllowed(existingDomain, registry, now);
+    customLogic.afterValidation(
+        AfterValidationParameters.newBuilder().setExistingDomain(existingDomain).build());
+    ImmutableSet.Builder<ImmutableObject> entitiesToSave = new ImmutableSet.Builder<>();
     HistoryEntry historyEntry = buildHistoryEntry(existingDomain, now);
     Builder builder =
         ResourceFlowUtils.<DomainResource, DomainResource.Builder>resolvePendingTransfer(
@@ -132,7 +144,7 @@ public final class DomainDeleteFlow implements TransactionalFlow {
           .plus(registry.getPendingDeleteLength());
       PollMessage.OneTime deletePollMessage =
           createDeletePollMessage(existingDomain, historyEntry, deletionTime);
-      ofy().save().entity(deletePollMessage);
+      entitiesToSave.add(deletePollMessage);
       builder.setStatusValues(ImmutableSet.of(StatusValue.PENDING_DELETE))
           .setDeletionTime(deletionTime)
           // Clear out all old grace periods and add REDEMPTION, which does not include a key to a
@@ -157,15 +169,31 @@ public final class DomainDeleteFlow implements TransactionalFlow {
     for (GracePeriod gracePeriod : existingDomain.getGracePeriods()) {
       // No cancellation is written if the grace period was not for a billable event.
       if (gracePeriod.hasBillingEvent()) {
-        ofy().save().entity(
+        entitiesToSave.add(
             BillingEvent.Cancellation.forGracePeriod(gracePeriod, historyEntry, targetId));
       }
     }
-    ofy().save().<ImmutableObject>entities(newDomain, historyEntry);
+    entitiesToSave.add(newDomain, historyEntry);
+    EntityChanges entityChanges = customLogic.beforeSave(
+        BeforeSaveParameters.newBuilder()
+            .setExistingDomain(existingDomain)
+            .setNewDomain(newDomain)
+            .setHistoryEntry(historyEntry)
+            .setEntityChanges(EntityChanges.newBuilder().setSaves(entitiesToSave.build()).build())
+            .build());
+    persistEntityChanges(entityChanges);
+    BeforeResponseReturnData responseData =
+        customLogic.beforeResponse(
+            BeforeResponseParameters.newBuilder()
+                .setResultCode(
+                    newDomain.getDeletionTime().isAfter(now)
+                        ? SUCCESS_WITH_ACTION_PENDING
+                        : SUCCESS)
+                .setResponseExtensions(getResponseExtensions(existingDomain, now))
+                .build());
     return responseBuilder
-        .setResultFromCode(
-            newDomain.getDeletionTime().isAfter(now) ? SUCCESS_WITH_ACTION_PENDING : SUCCESS)
-        .setExtensions(getResponseExtensions(existingDomain, now))
+        .setResultFromCode(responseData.resultCode())
+        .setExtensions(responseData.responseExtensions())
         .build();
   }