Fire a specific event when a vote is deleted from a change

Currently, removing a vote causes a "comment added" event to be
fired.

Replace it with a specific event. The event contains the approvals
before and after the removal, the removed vote(s), and the message.

Note that while the current implementation of DeleteVote only allows
to delete a single vote, the event allows for multiple removed votes
in case this is implemented in DeleteVote in future.

Change-Id: I8d62dc61c13d231a47d109f544c472d974031f0c

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/events/VoteDeletedListener.java

@@ -0,0 +1,33 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// 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 com.google.gerrit.extensions.events;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+import com.google.gerrit.extensions.common.ApprovalInfo;
+
+import java.util.Map;
+
+/** Notified whenever a vote is removed from a change. */
+@ExtensionPoint
+public interface VoteDeletedListener {
+  interface Event extends RevisionEvent {
+    Map<String, ApprovalInfo> getOldApprovals();
+    Map<String, ApprovalInfo> getApprovals();
+    Map<String, ApprovalInfo> getRemoved();
+    String getMessage();
+  }
+
+  void onVoteDeleted(Event event);
+}

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteVote.java

@@ -36,7 +36,7 @@ import com.google.gerrit.server.ChangeMessagesUtil;
 import com.google.gerrit.server.ChangeUtil;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.PatchSetUtil;
-import com.google.gerrit.server.extensions.events.CommentAdded;
+import com.google.gerrit.server.extensions.events.VoteDeleted;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.BatchUpdate.ChangeContext;
 import com.google.gerrit.server.git.BatchUpdate.Context;
@@ -67,7 +67,7 @@ public class DeleteVote
   private final PatchSetUtil psUtil;
   private final ChangeMessagesUtil cmUtil;
   private final IdentifiedUser.GenericFactory userFactory;
-  private final CommentAdded commentAdded;
+  private final VoteDeleted voteDeleted;
   private final DeleteVoteSender.Factory deleteVoteSenderFactory;
 
   @Inject
@@ -77,7 +77,7 @@ public class DeleteVote
       PatchSetUtil psUtil,
       ChangeMessagesUtil cmUtil,
       IdentifiedUser.GenericFactory userFactory,
-      CommentAdded commentAdded,
+      VoteDeleted voteDeleted,
       DeleteVoteSender.Factory deleteVoteSenderFactory) {
     this.db = db;
     this.batchUpdateFactory = batchUpdateFactory;
@@ -85,7 +85,7 @@ public class DeleteVote
     this.psUtil = psUtil;
     this.cmUtil = cmUtil;
     this.userFactory = userFactory;
-    this.commentAdded = commentAdded;
+    this.voteDeleted = voteDeleted;
     this.deleteVoteSenderFactory = deleteVoteSenderFactory;
   }
 
@@ -215,10 +215,9 @@ public class DeleteVote
         }
       }
 
-      commentAdded.fire(change, ps, user.getAccount(),
+      voteDeleted.fire(change, ps,
-          changeMessage.getMessage(),
+          newApprovals, oldApprovals, input.notify, changeMessage.getMessage(),
-          newApprovals, oldApprovals,
+          user.getAccount(), ctx.getWhen());
-          ctx.getWhen());
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -50,6 +50,7 @@ import com.google.gerrit.extensions.events.ReviewerDeletedListener;
 import com.google.gerrit.extensions.events.RevisionCreatedListener;
 import com.google.gerrit.extensions.events.TopicEditedListener;
 import com.google.gerrit.extensions.events.UsageDataPublishedListener;
+import com.google.gerrit.extensions.events.VoteDeletedListener;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.registration.DynamicSet;
@@ -306,6 +307,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.setOf(binder(), ChangeRevertedListener.class);
     DynamicSet.setOf(binder(), ReviewerAddedListener.class);
     DynamicSet.setOf(binder(), ReviewerDeletedListener.class);
+    DynamicSet.setOf(binder(), VoteDeletedListener.class);
     DynamicSet.setOf(binder(), RevisionCreatedListener.class);
     DynamicSet.setOf(binder(), TopicEditedListener.class);
     DynamicSet.setOf(binder(), AgreementSignupListener.class);

gerrit-server/src/main/java/com/google/gerrit/server/extensions/events/VoteDeleted.java

@@ -0,0 +1,133 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// 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 com.google.gerrit.server.extensions.events;
+
+import com.google.common.collect.Maps;
+import com.google.gerrit.extensions.api.changes.NotifyHandling;
+import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.common.ApprovalInfo;
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.common.RevisionInfo;
+import com.google.gerrit.extensions.events.VoteDeletedListener;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.server.GpgException;
+import com.google.gerrit.server.patch.PatchListNotAvailableException;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.sql.Timestamp;
+import java.util.Map;
+
+public class VoteDeleted {
+  private static final Logger log =
+      LoggerFactory.getLogger(VoteDeleted.class);
+
+  private final DynamicSet<VoteDeletedListener> listeners;
+  private final EventUtil util;
+
+  @Inject
+  VoteDeleted(DynamicSet<VoteDeletedListener> listeners,
+      EventUtil util) {
+    this.listeners = listeners;
+    this.util = util;
+  }
+
+  public void fire(ChangeInfo change, RevisionInfo revision,
+      Map<String, ApprovalInfo> approvals,
+      Map<String, ApprovalInfo> oldApprovals,
+      NotifyHandling notify, String message,
+      AccountInfo remover, Timestamp when) {
+    if (!listeners.iterator().hasNext()) {
+      return;
+    }
+    Event event = new Event(
+        change, revision, approvals, oldApprovals, notify, message,
+        remover, when);
+    for (VoteDeletedListener l : listeners) {
+      try {
+        l.onVoteDeleted(event);
+      } catch (Exception e) {
+        log.warn("Error in event listener", e);
+      }
+    }
+  }
+
+  public void fire(Change change, PatchSet ps,
+      Map<String, Short> approvals,
+      Map<String, Short> oldApprovals,
+      NotifyHandling notify, String message,
+      Account remover, Timestamp when) {
+    if (!listeners.iterator().hasNext()) {
+      return;
+    }
+    try {
+      fire(util.changeInfo(change),
+          util.revisionInfo(change.getProject(), ps),
+          util.approvals(remover, approvals, when),
+          util.approvals(remover, oldApprovals, when),
+          notify, message,
+          util.accountInfo(remover), when);
+    } catch (PatchListNotAvailableException | GpgException | IOException
+        | OrmException e) {
+      log.error("Couldn't fire event", e);
+    }
+  }
+
+  private static class Event extends AbstractRevisionEvent
+      implements VoteDeletedListener.Event {
+
+    private final Map<String, ApprovalInfo> approvals;
+    private final Map<String, ApprovalInfo> oldApprovals;
+    private final String message;
+
+    Event(ChangeInfo change, RevisionInfo revision,
+        Map<String, ApprovalInfo> approvals,
+        Map<String, ApprovalInfo> oldApprovals,
+        NotifyHandling notify, String message,
+        AccountInfo remover, Timestamp when) {
+      super(change, revision, remover, when, notify);
+      this.approvals = approvals;
+      this.oldApprovals = oldApprovals;
+      this.message = message;
+    }
+
+    @Override
+    public Map<String, ApprovalInfo> getApprovals() {
+      return approvals;
+    }
+
+    @Override
+    public Map<String, ApprovalInfo> getOldApprovals() {
+      return oldApprovals;
+    }
+
+    @Override
+    public Map<String, ApprovalInfo> getRemoved() {
+      return Maps.difference(oldApprovals, approvals).entriesOnlyOnLeft();
+    }
+
+    @Override
+    public String getMessage() {
+      return message;
+    }
+  }
+}