RevisionApi: Add method to list votes per revision

The current API allows to get votes either:

- By revision, but only the votes from a specific reviewer

- By change, but only all votes on the current patch set

Add a method that allows to get all the votes for a specific revision.

The result is returned as a multimap of the label name to a list
of approval infos for that label. The approval infos contain the Id,
name, username and email fields.

Change-Id: I35cde09b3ee059e8b03aff1c4ee2747944c3d37c

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/revision/RevisionIT.java

@@ -35,6 +35,7 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterators;
+import com.google.common.collect.ListMultimap;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.RestResponse;
@@ -1332,6 +1333,47 @@ public class RevisionIT extends AbstractDaemonTest {
         .containsExactlyElementsIn(ImmutableSet.of(admin.getId(), user.getId()));
   }
 
+  @Test
+  public void listVotesByRevision() throws Exception {
+    // Create patch set 1 and vote on it
+    String changeId = createChange().getChangeId();
+    ListMultimap<String, ApprovalInfo> votes = gApi.changes().id(changeId).current().votes();
+    assertThat(votes).isEmpty();
+    recommend(changeId);
+    votes = gApi.changes().id(changeId).current().votes();
+    assertThat(votes.keySet()).containsExactly("Code-Review");
+    List<ApprovalInfo> approvals = votes.get("Code-Review");
+    assertThat(approvals).hasSize(1);
+    ApprovalInfo approval = approvals.get(0);
+    assertThat(approval._accountId).isEqualTo(admin.id.get());
+    assertThat(approval.email).isEqualTo(admin.email);
+    assertThat(approval.username).isEqualTo(admin.username);
+
+    // Also vote on it with another user
+    setApiUser(user);
+    gApi.changes().id(changeId).current().review(ReviewInput.dislike());
+
+    // Patch set 1 has 2 votes on Code-Review
+    setApiUser(admin);
+    votes = gApi.changes().id(changeId).current().votes();
+    assertThat(votes.keySet()).containsExactly("Code-Review");
+    approvals = votes.get("Code-Review");
+    assertThat(approvals).hasSize(2);
+    assertThat(approvals.stream().map(a -> a._accountId))
+        .containsExactlyElementsIn(ImmutableList.of(admin.id.get(), user.id.get()));
+
+    // Create a new patch set which does not have any votes
+    amendChange(changeId);
+    votes = gApi.changes().id(changeId).current().votes();
+    assertThat(votes).isEmpty();
+
+    // Votes are still returned for ps 1
+    votes = gApi.changes().id(changeId).revision(1).votes();
+    assertThat(votes.keySet()).containsExactly("Code-Review");
+    approvals = votes.get("Code-Review");
+    assertThat(approvals).hasSize(2);
+  }
+
   private static void assertCherryPickResult(
       ChangeInfo changeInfo, CherryPickInput input, String srcChangeId) throws Exception {
     assertThat(changeInfo.changeId).isEqualTo(srcChangeId);

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/RevisionApi.java

@@ -14,8 +14,10 @@
 
 package com.google.gerrit.extensions.api.changes;
 
+import com.google.common.collect.ListMultimap;
 import com.google.gerrit.extensions.client.SubmitType;
 import com.google.gerrit.extensions.common.ActionInfo;
+import com.google.gerrit.extensions.common.ApprovalInfo;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.common.CommitInfo;
 import com.google.gerrit.extensions.common.EditInfo;
@@ -129,6 +131,9 @@ public interface RevisionApi {
 
   RelatedChangesInfo related() throws RestApiException;
 
+  /** Returns votes on the revision. */
+  ListMultimap<String, ApprovalInfo> votes() throws RestApiException;
+
   abstract class MergeListRequest {
     private boolean addLinks;
     private int uninterestingParent = 1;
@@ -361,6 +366,11 @@ public interface RevisionApi {
       throw new NotImplementedException();
     }
 
+    @Override
+    public ListMultimap<String, ApprovalInfo> votes() throws RestApiException {
+      throw new NotImplementedException();
+    }
+
     @Override
     public void description(String description) throws RestApiException {
       throw new NotImplementedException();

gerrit-server/src/main/java/com/google/gerrit/server/api/changes/RevisionApiImpl.java

@@ -18,6 +18,8 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.gerrit.server.api.ApiUtil.asRestApiException;
 
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ListMultimap;
+import com.google.common.collect.MultimapBuilder.ListMultimapBuilder;
 import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.Changes;
 import com.google.gerrit.extensions.api.changes.CherryPickInput;
@@ -35,6 +37,7 @@ import com.google.gerrit.extensions.api.changes.RobotCommentApi;
 import com.google.gerrit.extensions.api.changes.SubmitInput;
 import com.google.gerrit.extensions.client.SubmitType;
 import com.google.gerrit.extensions.common.ActionInfo;
+import com.google.gerrit.extensions.common.ApprovalInfo;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.common.CommitInfo;
 import com.google.gerrit.extensions.common.EditInfo;
@@ -46,7 +49,13 @@ import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.IdString;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.reviewdb.client.PatchSetApproval;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.ApprovalsUtil;
+import com.google.gerrit.server.account.AccountDirectory.FillOptions;
+import com.google.gerrit.server.account.AccountLoader;
 import com.google.gerrit.server.change.ApplyFix;
+import com.google.gerrit.server.change.ChangeJson;
 import com.google.gerrit.server.change.CherryPick;
 import com.google.gerrit.server.change.Comments;
 import com.google.gerrit.server.change.CreateDraftComment;
@@ -79,6 +88,7 @@ import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -128,6 +138,9 @@ class RevisionApiImpl implements RevisionApi {
   private final GetRelated getRelated;
   private final PutDescription putDescription;
   private final GetDescription getDescription;
+  private final ApprovalsUtil approvalsUtil;
+  private final Provider<ReviewDb> db;
+  private final AccountLoader.Factory accountLoaderFactory;
 
   @Inject
   RevisionApiImpl(
@@ -168,6 +181,9 @@ class RevisionApiImpl implements RevisionApi {
       GetRelated getRelated,
       PutDescription putDescription,
       GetDescription getDescription,
+      ApprovalsUtil approvalsUtil,
+      Provider<ReviewDb> db,
+      AccountLoader.Factory accountLoaderFactory,
       @Assisted RevisionResource r) {
     this.repoManager = repoManager;
     this.changes = changes;
@@ -206,6 +222,9 @@ class RevisionApiImpl implements RevisionApi {
     this.getRelated = getRelated;
     this.putDescription = putDescription;
     this.getDescription = getDescription;
+    this.approvalsUtil = approvalsUtil;
+    this.db = db;
+    this.accountLoaderFactory = accountLoaderFactory;
     this.revision = r;
   }
 
@@ -577,6 +596,42 @@ class RevisionApiImpl implements RevisionApi {
     }
   }
 
+  @Override
+  public ListMultimap<String, ApprovalInfo> votes() throws RestApiException {
+    ListMultimap<String, ApprovalInfo> result =
+        ListMultimapBuilder.treeKeys().arrayListValues().build();
+    try {
+      Iterable<PatchSetApproval> approvals =
+          approvalsUtil.byPatchSet(
+              db.get(),
+              revision.getNotes(),
+              revision.getChangeResource().getUser(),
+              revision.getPatchSet().getId(),
+              null,
+              null);
+      AccountLoader accountLoader =
+          accountLoaderFactory.create(
+              EnumSet.of(
+                  FillOptions.ID, FillOptions.NAME, FillOptions.EMAIL, FillOptions.USERNAME));
+      for (PatchSetApproval approval : approvals) {
+        String label = approval.getLabel();
+        ApprovalInfo info =
+            ChangeJson.getApprovalInfo(
+                approval.getAccountId(),
+                Integer.valueOf(approval.getValue()),
+                null,
+                approval.getTag(),
+                approval.getGranted());
+        accountLoader.put(info);
+        result.get(label).add(info);
+      }
+      accountLoader.fill();
+    } catch (Exception e) {
+      throw asRestApiException("Cannot get votes", e);
+    }
+    return result;
+  }
+
   @Override
   public void description(String description) throws RestApiException {
     PutDescription.Input in = new PutDescription.Input();