Add the ability to dump the history of a single resource

This would have saved me 2+ hours yesterday of mucking around
in datastore and manually copying out the xml bytes so that
I could base64decode them.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=139472542

java/google/registry/tools/CommandUtilities.java

@@ -16,10 +16,39 @@ package google.registry.tools;
 
 import com.google.common.base.Ascii;
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableMap;
+import com.googlecode.objectify.Key;
+import google.registry.model.EppResource;
+import google.registry.model.contact.ContactResource;
+import google.registry.model.domain.DomainApplication;
+import google.registry.model.domain.DomainResource;
+import google.registry.model.host.HostResource;
+import google.registry.model.index.ForeignKeyIndex;
+import org.joda.time.DateTime;
 
 /** Container class for static utility methods. */
 class CommandUtilities {
 
+  /** A useful parameter enum for commands that operate on {@link EppResource} objects. */
+  public enum ResourceType {
+    CONTACT,
+    HOST,
+    DOMAIN,
+    APPLICATION;
+
+    public Key<? extends EppResource> getKey(String uniqueId, DateTime now) {
+      return this == APPLICATION
+          ? Key.create(DomainApplication.class, uniqueId)
+          : ForeignKeyIndex.loadAndGetKey(
+              ImmutableMap.of(
+                  CONTACT, ContactResource.class,
+                  HOST, HostResource.class,
+                  DOMAIN, DomainResource.class).get(this),
+              uniqueId,
+              now);
+    }
+  }
+
   static String addHeader(String header, String body) {
     return String.format("%s:\n%s\n%s", header, Strings.repeat("-", header.length() + 1), body);
   }

java/google/registry/tools/GetHistoryEntriesCommand.java

@@ -14,14 +14,19 @@
 
 package google.registry.tools;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.util.DateTimeUtils.END_OF_TIME;
 import static google.registry.util.DateTimeUtils.START_OF_TIME;
+import static org.joda.time.DateTimeZone.UTC;
 
 import com.beust.jcommander.Parameter;
 import com.beust.jcommander.Parameters;
+import com.googlecode.objectify.Key;
+import google.registry.model.EppResource;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.tools.Command.RemoteApiCommand;
+import google.registry.tools.CommandUtilities.ResourceType;
 import google.registry.xml.XmlTransformer;
 import org.joda.time.DateTime;
 
@@ -40,9 +45,29 @@ final class GetHistoryEntriesCommand implements RemoteApiCommand {
       description = "Only show history entries that occurred at or before this time")
   private DateTime before = END_OF_TIME;
 
+  @Parameter(
+    names = "--type",
+    description = "Resource type.")
+  private ResourceType type;
+
+  @Parameter(
+    names = "--id",
+    description = "Foreign key of the resource, or application ID of the domain application.")
+  private String uniqueId;
+
   @Override
   public void run() {
-    for (HistoryEntry entry : ofy().load().type(HistoryEntry.class)
+    Key<? extends EppResource> parentKey = null;
+    if (type != null || uniqueId != null) {
+      checkArgument(
+          type != null && uniqueId != null,
+          "If either of 'type' or 'id' are set then both must be");
+      parentKey = type.getKey(uniqueId, DateTime.now(UTC));
+    }
+    for (HistoryEntry entry :
+            (parentKey == null
+                ? ofy().load().type(HistoryEntry.class)
+                : ofy().load().type(HistoryEntry.class).ancestor(parentKey))
         .order("modificationTime")
         .filter("modificationTime >=", after)
         .filter("modificationTime <=", before)) {

java/google/registry/tools/ResaveEppResourceCommand.java

@@ -14,7 +14,6 @@
 
 package google.registry.tools;
 
-import static google.registry.model.index.ForeignKeyIndex.loadAndGetKey;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.util.PreconditionsUtils.checkArgumentNotNull;
 import static org.joda.time.DateTimeZone.UTC;
@@ -23,10 +22,7 @@ import com.beust.jcommander.Parameter;
 import com.beust.jcommander.Parameters;
 import com.googlecode.objectify.Key;
 import google.registry.model.EppResource;
-import google.registry.model.contact.ContactResource;
-import google.registry.model.domain.DomainApplication;
-import google.registry.model.domain.DomainResource;
-import google.registry.model.host.HostResource;
+import google.registry.tools.CommandUtilities.ResourceType;
 import org.joda.time.DateTime;
 
 /**
@@ -40,8 +36,6 @@ import org.joda.time.DateTime;
     commandDescription = "Load and resave EPP resources by foreign key")
 public final class ResaveEppResourceCommand extends MutatingCommand {
 
-  private enum ResourceType { CONTACT, HOST, DOMAIN, APPLICATION }
-
   @Parameter(
     names = "--type",
     description = "Resource type.")
@@ -55,27 +49,11 @@ public final class ResaveEppResourceCommand extends MutatingCommand {
   @Override
   protected void init() throws Exception {
     Key<? extends EppResource> resourceKey = checkArgumentNotNull(
-        getResourceKey(type, uniqueId, DateTime.now(UTC)),
+        type.getKey(uniqueId, DateTime.now(UTC)),
         "Could not find active resource of type %s: %s", type, uniqueId);
     // Load the resource directly to bypass running cloneProjectedAtTime() automatically, which can
     // cause stageEntityChange() to fail due to implicit projection changes.
     EppResource resource = ofy().load().key(resourceKey).now();
     stageEntityChange(resource, resource);
   }
-
-  private Key<? extends EppResource> getResourceKey(
-      ResourceType type, String uniqueId, DateTime now) {
-    switch (type) {
-      case CONTACT:
-        return loadAndGetKey(ContactResource.class, uniqueId, now);
-      case HOST:
-        return loadAndGetKey(HostResource.class, uniqueId, now);
-      case DOMAIN:
-        return loadAndGetKey(DomainResource.class, uniqueId, now);
-      case APPLICATION:
-        return Key.create(DomainApplication.class, uniqueId);
-      default:
-        throw new IllegalStateException("Unknown type: " + type);
-    }
-  }
 }