Hook Ponder to Subscriptions

Summary: Adding email aggro email aggro

Test Plan: Added some content; annoyed some coworkers.

Reviewers: epriestley, nh, vrana

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1808

Differential Revision: https://secure.phabricator.com/D3643

src/__phutil_library_map__.php

@@ -1200,15 +1200,19 @@ phutil_register_library_map(array(
     'PonderAnswerQuery' => 'applications/ponder/query/PonderAnswerQuery.php',
     'PonderAnswerSaveController' => 'applications/ponder/controller/PonderAnswerSaveController.php',
     'PonderAnswerViewController' => 'applications/ponder/controller/PonderAnswerViewController.php',
+    'PonderAnsweredMail' => 'applications/ponder/mail/PonderAnsweredMail.php',
     'PonderComment' => 'applications/ponder/storage/PonderComment.php',
     'PonderCommentEditor' => 'applications/ponder/editor/PonderCommentEditor.php',
     'PonderCommentListView' => 'applications/ponder/view/PonderCommentListView.php',
+    'PonderCommentMail' => 'applications/ponder/mail/PonderCommentMail.php',
     'PonderCommentQuery' => 'applications/ponder/query/PonderCommentQuery.php',
     'PonderCommentSaveController' => 'applications/ponder/controller/PonderCommentSaveController.php',
     'PonderConstants' => 'applications/ponder/PonderConstants.php',
     'PonderController' => 'applications/ponder/controller/PonderController.php',
     'PonderDAO' => 'applications/ponder/storage/PonderDAO.php',
     'PonderFeedController' => 'applications/ponder/controller/PonderFeedController.php',
+    'PonderMail' => 'applications/ponder/mail/PonderMail.php',
+    'PonderMentionMail' => 'applications/ponder/mail/PonderMentionMail.php',
     'PonderPostBodyView' => 'applications/ponder/view/PonderPostBodyView.php',
     'PonderQuestion' => 'applications/ponder/storage/PonderQuestion.php',
     'PonderQuestionAskController' => 'applications/ponder/controller/PonderQuestionAskController.php',
@@ -1218,6 +1222,7 @@ phutil_register_library_map(array(
     'PonderQuestionQuery' => 'applications/ponder/query/PonderQuestionQuery.php',
     'PonderQuestionSummaryView' => 'applications/ponder/view/PonderQuestionSummaryView.php',
     'PonderQuestionViewController' => 'applications/ponder/controller/PonderQuestionViewController.php',
+    'PonderReplyHandler' => 'applications/ponder/PonderReplyHandler.php',
     'PonderRuleQuestion' => 'infrastructure/markup/rule/PonderRuleQuestion.php',
     'PonderUserProfileView' => 'applications/ponder/view/PonderUserProfileView.php',
     'PonderVotableInterface' => 'applications/ponder/storage/PonderVotableInterface.php',
@@ -2318,23 +2323,27 @@ phutil_register_library_map(array(
     'PonderAnswerQuery' => 'PhabricatorOffsetPagedQuery',
     'PonderAnswerSaveController' => 'PonderController',
     'PonderAnswerViewController' => 'PonderController',
+    'PonderAnsweredMail' => 'PonderMail',
     'PonderComment' =>
     array(
       0 => 'PonderDAO',
       1 => 'PhabricatorMarkupInterface',
     ),
     'PonderCommentListView' => 'AphrontView',
+    'PonderCommentMail' => 'PonderMail',
     'PonderCommentQuery' => 'PhabricatorQuery',
     'PonderCommentSaveController' => 'PonderController',
     'PonderController' => 'PhabricatorController',
     'PonderDAO' => 'PhabricatorLiskDAO',
     'PonderFeedController' => 'PonderController',
+    'PonderMentionMail' => 'PonderMail',
     'PonderPostBodyView' => 'AphrontView',
     'PonderQuestion' =>
     array(
       0 => 'PonderDAO',
       1 => 'PhabricatorMarkupInterface',
       2 => 'PonderVotableInterface',
+      3 => 'PhabricatorSubscribableInterface',
     ),
     'PonderQuestionAskController' => 'PonderController',
     'PonderQuestionDetailView' => 'AphrontView',
@@ -2342,6 +2351,7 @@ phutil_register_library_map(array(
     'PonderQuestionQuery' => 'PhabricatorOffsetPagedQuery',
     'PonderQuestionSummaryView' => 'AphrontView',
     'PonderQuestionViewController' => 'PonderController',
+    'PonderReplyHandler' => 'PhabricatorMailReplyHandler',
     'PonderRuleQuestion' => 'PhabricatorRemarkupRuleObjectName',
     'PonderUserProfileView' => 'AphrontView',
     'PonderVotableView' => 'AphrontView',

src/applications/ponder/PonderReplyHandler.php

@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+final class PonderReplyHandler extends PhabricatorMailReplyHandler {
+
+  public function validateMailReceiver($mail_receiver) {
+    if (!($mail_receiver instanceof PonderQuestion)) {
+      throw new Exception("Mail receiver is not a PonderQuestion!");
+    }
+  }
+
+  public function getPrivateReplyHandlerEmailAddress(
+    PhabricatorObjectHandle $handle) {
+    return $this->getDefaultPrivateReplyHandlerEmailAddress($handle, 'Q');
+  }
+
+  public function getPublicReplyHandlerEmailAddress() {
+    return $this->getDefaultPublicReplyHandlerEmailAddress('Q');
+  }
+
+  public function getReplyHandlerDomain() {
+    return PhabricatorEnv::getEnvConfig(
+      'metamta.maniphest.reply-handler-domain');
+  }
+
+  public function getReplyHandlerInstructions() {
+    return null;
+  }
+
+  protected function receiveEmail(PhabricatorMetaMTAReceivedMail $mail) {
+    // ignore this entirely for now
+  }
+}

src/applications/ponder/controller/PonderAnswerSaveController.php

@@ -60,6 +60,7 @@ final class PonderAnswerSaveController extends PonderController {
       ->setContentSource($content_source);
 
     id(new PonderAnswerEditor())
+      ->setUser($user)
       ->setQuestion($question)
       ->setAnswer($res)
       ->saveAnswer();

src/applications/ponder/controller/PonderCommentSaveController.php

@@ -38,6 +38,7 @@ final class PonderCommentSaveController extends PonderController {
     if (!$objects) {
       return new Aphront404Response();
     }
+
     $content = $request->getStr('content');
 
     if (!strlen(trim($content))) {
@@ -59,6 +60,8 @@ final class PonderCommentSaveController extends PonderController {
     id(new PonderCommentEditor())
       ->setQuestion($question)
       ->setComment($res)
+      ->setTargetPHID($target)
+      ->setUser($user)
       ->save();
 
     return id(new AphrontRedirectResponse())

src/applications/ponder/controller/PonderQuestionAskController.php

@@ -53,6 +53,7 @@ final class PonderQuestionAskController extends PonderController {
 
         id(new PonderQuestionEditor())
           ->setQuestion($question)
+          ->setUser($user)
           ->save();
 
         return id(new AphrontRedirectResponse())

src/applications/ponder/controller/PonderQuestionViewController.php

@@ -52,6 +52,11 @@ final class PonderQuestionViewController extends PonderController {
       }
     }
 
+    $subscribers = PhabricatorSubscribersQuery::loadSubscribersForPHID(
+      $question->getPHID());
+
+    $object_phids = array_merge($object_phids, $subscribers);
+
     $handles = $this->loadViewerHandles($object_phids);
     $this->loadHandles($object_phids);
 
@@ -79,7 +84,7 @@ final class PonderQuestionViewController extends PonderController {
       ->setHeader($question->getTitle());
 
     $actions = $this->buildActionListView($question);
-    $properties = $this->buildPropertyListView($question);
+    $properties = $this->buildPropertyListView($question, $subscribers);
 
     $nav = $this->buildSideNavView($question);
     $nav->appendChild(
@@ -112,7 +117,10 @@ final class PonderQuestionViewController extends PonderController {
     return $view;
   }
 
-  private function buildPropertyListView(PonderQuestion $question) {
+  private function buildPropertyListView(
+    PonderQuestion $question,
+    array $subscribers) {
+
     $viewer = $this->getRequest()->getUser();
     $view = new PhabricatorPropertyListView();
 
@@ -124,6 +132,17 @@ final class PonderQuestionViewController extends PonderController {
       pht('Created'),
       phabricator_datetime($question->getDateCreated(), $viewer));
 
+    if ($subscribers) {
+      foreach ($subscribers as $key => $subscriber) {
+        $subscribers[$key] = $this->getHandle($subscriber)->renderLink();
+      }
+      $subscribers = implode(', ', $subscribers);
+    }
+
+    $view->addProperty(
+      pht('Subscribers'),
+      nonempty($subscribers, '<em>'.pht('None').'</em>'));
+
     return $view;
   }
 }

src/applications/ponder/editor/PonderAnswerEditor.php

@@ -16,11 +16,11 @@
  * limitations under the License.
  */
 
-
 final class PonderAnswerEditor {
-
   private $question;
   private $answer;
+  private $viewer;
+  private $shouldEmail = true;
 
   public function setQuestion($question) {
     $this->question = $question;
@@ -32,7 +32,15 @@ final class PonderAnswerEditor {
     return $this;
   }
 
+  public function setUser(PhabricatorUser $user) {
+    $this->viewer = $user;
+    return $this;
+  }
+
   public function saveAnswer() {
+    if (!$this->viewer) {
+      throw new Exception("Must set user before saving question");
+    }
     if (!$this->question) {
       throw new Exception("Must set question before saving answer");
     }
@@ -42,6 +50,7 @@ final class PonderAnswerEditor {
 
     $question = $this->question;
     $answer = $this->answer;
+    $viewer = $this->viewer;
     $conn = $answer->establishConnection('w');
     $trans = $conn->openTransaction();
     $trans->beginReadLocking();
@@ -63,5 +72,53 @@ final class PonderAnswerEditor {
 
     $question->attachRelated();
     PhabricatorSearchPonderIndexer::indexQuestion($question);
+
+    // subscribe author and @mentions
+    $subeditor = id(new PhabricatorSubscriptionsEditor())
+      ->setObject($question)
+      ->setUser($viewer);
+
+    $subeditor->subscribeExplicit(array($answer->getAuthorPHID()));
+
+    $content = $answer->getContent();
+    $at_mention_phids = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      array($content)
+    );
+    $subeditor->subscribeImplicit($at_mention_phids);
+    $subeditor->save();
+
+    if ($this->shouldEmail) {
+      // now load subscribers, including implicitly-added @mention victims
+      $subscribers = PhabricatorSubscribersQuery
+        ::loadSubscribersForPHID($question->getPHID());
+
+
+      // @mention emails (but not for anyone who has explicitly unsubscribed)
+      if (array_intersect($at_mention_phids, $subscribers)) {
+        id(new PonderMentionMail(
+          $question,
+          $answer,
+          $viewer))
+          ->setToPHIDs($at_mention_phids)
+          ->send();
+      }
+
+      $other_subs =
+        array_diff(
+          $subscribers,
+          $at_mention_phids
+        );
+
+      // 'Answered' emails for subscribers who are not @mentiond (and excluding
+      // author depending on their MetaMTA settings).
+      if ($other_subs) {
+        id(new PonderAnsweredMail(
+          $question,
+          $answer,
+          $viewer))
+          ->setToPHIDs($other_subs)
+          ->send();
+      }
+    }
   }
 }

src/applications/ponder/editor/PonderCommentEditor.php

@@ -21,6 +21,9 @@ final class PonderCommentEditor {
 
   private $question;
   private $comment;
+  private $targetPHID;
+  private $viewer;
+  private $shouldEmail = true;
 
   public function setComment(PonderComment $comment) {
     $this->comment = $comment;
@@ -32,6 +35,16 @@ final class PonderCommentEditor {
     return $this;
   }
 
+  public function setTargetPHID($target) {
+    $this->targetPHID = $target;
+    return $this;
+  }
+
+  public function setUser(PhabricatorUser $user) {
+    $this->viewer = $user;
+    return $this;
+  }
+
   public function save() {
     if (!$this->comment) {
       throw new Exception("Must set comment before saving it");
@@ -39,13 +52,82 @@ final class PonderCommentEditor {
     if (!$this->question) {
       throw new Exception("Must set question before saving comment");
     }
+    if (!$this->targetPHID) {
+      throw new Exception("Must set target before saving comment");
+    }
+    if (!$this->viewer) {
+      throw new Exception("Must set viewer before saving comment");
+    }
 
     $comment  = $this->comment;
     $question = $this->question;
-
+    $target   = $this->targetPHID;
+    $viewer   = $this->viewer;
     $comment->save();
 
     $question->attachRelated();
     PhabricatorSearchPonderIndexer::indexQuestion($question);
+
+    // subscribe author and @mentions
+    $subeditor = id(new PhabricatorSubscriptionsEditor())
+      ->setObject($question)
+      ->setUser($viewer);
+
+    $subeditor->subscribeExplicit(array($comment->getAuthorPHID()));
+
+    $content = $comment->getContent();
+    $at_mention_phids = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      array($content)
+    );
+    $subeditor->subscribeImplicit($at_mention_phids);
+    $subeditor->save();
+
+    if ($this->shouldEmail) {
+      // now load subscribers, including implicitly-added @mention victims
+      $subscribers = PhabricatorSubscribersQuery
+        ::loadSubscribersForPHID($question->getPHID());
+
+      // @mention emails (but not for anyone who has explicitly unsubscribed)
+      if (array_intersect($at_mention_phids, $subscribers)) {
+        id(new PonderMentionMail(
+          $question,
+          $comment,
+          $viewer))
+          ->setToPHIDs($at_mention_phids)
+          ->send();
+      }
+
+      if ($target === $question->getPHID()) {
+        $target = $question;
+      }
+      else {
+        $answers_by_phid = mgroup($question->getAnswers(), 'getPHID');
+        $target = head($answers_by_phid[$target]);
+      }
+
+      // only send emails to others in the same thread
+      $thread = mpull($target->getComments(), 'getAuthorPHID');
+      $thread[] = $target->getAuthorPHID();
+      $thread[] = $question->getAuthorPHID();
+
+      $other_subs =
+        array_diff(
+          array_intersect($thread, $subscribers),
+          $at_mention_phids
+        );
+
+      // 'Comment' emails for subscribers who are in the same comment thread,
+      // including the author of the parent question and/or answer, excluding
+      // @mentions (and excluding the author, depending on their MetaMTA
+      // settings).
+      if ($other_subs) {
+        id(new PonderCommentMail(
+          $question,
+          $comment,
+          $viewer))
+          ->setToPHIDs($other_subs)
+          ->send();
+      }
+    }
   }
 }

src/applications/ponder/editor/PonderQuestionEditor.php

@@ -21,21 +21,60 @@ final class PonderQuestionEditor {
 
   private $question;
   private $viewer;
+  private $shouldEmail = true;
 
   public function setQuestion(PonderQuestion $question) {
     $this->question = $question;
     return $this;
   }
 
+  public function setUser(PhabricatorUser $user) {
+    $this->viewer = $user;
+    return $this;
+  }
+
+  public function setShouldEmail($se) {
+    $this->shouldEmail = $se;
+    return $this;
+  }
+
   public function save() {
+    if (!$this->viewer) {
+      throw new Exception("Must set user before saving question");
+    }
     if (!$this->question) {
       throw new Exception("Must set question before saving it");
     }
 
+    $viewer = $this->viewer;
     $question = $this->question;
     $question->save();
 
+    // search index
     $question->attachRelated();
     PhabricatorSearchPonderIndexer::indexQuestion($question);
+
+    // subscribe author and @mentions
+    $subeditor = id(new PhabricatorSubscriptionsEditor())
+      ->setObject($question)
+      ->setUser($viewer);
+
+    $subeditor->subscribeExplicit(array($question->getAuthorPHID()));
+
+    $content = $question->getContent();
+    $at_mention_phids = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      array($content)
+    );
+    $subeditor->subscribeImplicit($at_mention_phids);
+    $subeditor->save();
+
+    if ($this->shouldEmail && $at_mention_phids) {
+      id(new PonderMentionMail(
+         $question,
+         $question,
+         $viewer))
+        ->setToPHIDs($at_mention_phids)
+        ->send();
+    }
   }
 }

src/applications/ponder/mail/PonderAnsweredMail.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+final class PonderAnsweredMail extends PonderMail {
+
+  public function __construct(
+    PonderQuestion $question,
+    PonderAnswer $target,
+    PhabricatorUser $actor) {
+
+    $this->setQuestion($question);
+    $this->setTarget($target);
+    $this->setActorHandle($actor);
+  }
+
+  protected function renderVaryPrefix() {
+    return "[Answered]";
+  }
+
+  protected function renderBody() {
+    $question = $this->getQuestion();
+    $target = $this->getTarget();
+    $actor = $this->getActorName();
+    $name  = $question->getTitle();
+
+    $body = array();
+    $body[] = "{$actor} answered a question that you are subscribed to.";
+    $body[] = null;
+
+    $content = $target->getContent();
+    if (strlen($content)) {
+      $body[] = $this->formatText($content);
+      $body[] = null;
+    }
+
+    return implode("\n", $body);
+  }
+}

src/applications/ponder/mail/PonderCommentMail.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+final class PonderCommentMail extends PonderMail {
+
+  public function __construct(
+    PonderQuestion $question,
+    PonderComment $target,
+    PhabricatorUser $actor) {
+
+    $this->setQuestion($question);
+    $this->setTarget($target);
+    $this->setActorHandle($actor);
+  }
+
+  protected function renderVaryPrefix() {
+    return "[Commented]";
+  }
+
+  protected function renderBody() {
+    $question = $this->getQuestion();
+    $target = $this->getTarget();
+    $actor = $this->getActorName();
+    $name  = $question->getTitle();
+
+    $body = array();
+    $body[] = "{$actor} commented on a question that you are subscribed to.";
+    $body[] = null;
+
+    $content = $target->getContent();
+    if (strlen($content)) {
+      $body[] = $this->formatText($content);
+      $body[] = null;
+    }
+
+    return implode("\n", $body);
+  }
+}

src/applications/ponder/mail/PonderMail.php

@@ -0,0 +1,144 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+abstract class PonderMail {
+
+  protected $to = array();
+  protected $actorHandle;
+  protected $question;
+  protected $target;
+
+  protected $isFirstMailAboutQuestion;
+
+  // protected $replyHandler;
+
+  protected $parentMessageID;
+
+  protected function renderSubject() {
+    $question = $this->getQuestion();
+    $title = $question->getTitle();
+    $id = $question->getID();
+    return "Q{$id}: {$title}";
+  }
+
+  abstract protected function renderVaryPrefix();
+  abstract protected function renderBody();
+
+  public function setActorHandle($actor_handle) {
+    $this->actorHandle = $actor_handle;
+    return $this;
+  }
+
+  public function getActorHandle() {
+    return $this->actorHandle;
+  }
+
+  protected function getActorName() {
+    return $this->actorHandle->getRealName();
+  }
+
+  protected function getSubjectPrefix() {
+    return "[Ponder]";
+  }
+
+  public function setToPHIDs(array $to) {
+    $this->to = $to;
+    return $this;
+  }
+
+  protected function getToPHIDs() {
+    return $this->to;
+  }
+
+  public function setQuestion($question) {
+    $this->question = $question;
+    return $this;
+  }
+
+  public function getQuestion() {
+    return $this->question;
+  }
+
+  public function setTarget($target) {
+    $this->target = $target;
+    return $this;
+  }
+
+  public function getTarget() {
+    return $this->target;
+  }
+
+  protected function getThreadID() {
+    $phid = $this->getQuestion()->getPHID();
+    return "ponder-ques-{$phid}";
+  }
+
+  protected function getThreadTopic() {
+    $id = $this->getQuestion()->getID();
+    $title = $this->getQuestion()->getTitle();
+    return "Q{$id}: {$title}";
+  }
+
+  public function send() {
+    $email_to = array_filter(array_unique($this->to));
+    $question = $this->getQuestion();
+    $target = $this->getTarget();
+
+    $uri = PhabricatorEnv::getURI('/Q'. $question->getID());
+    $thread_id = $this->getThreadID();
+
+    $handles = id(new PhabricatorObjectHandleData($email_to))
+      ->loadHandles();
+
+    $reply_handler = new PonderReplyHandler();
+
+    $body = new PhabricatorMetaMTAMailBody();
+    $body->addRawSection($this->renderBody());
+    $body->addTextSection(pht('QUESTION DETAIL'), $uri);
+
+    $template = id(new PhabricatorMetaMTAMail())
+      ->setSubject($this->getThreadTopic())
+      ->setSubjectPrefix($this->getSubjectPrefix())
+      ->setVarySubjectPrefix($this->renderVaryPrefix())
+      ->setFrom($target->getAuthorPHID())
+      ->setParentMessageID($this->parentMessageID)
+      ->addHeader('Thread-Topic', $this->getThreadTopic())
+      ->setThreadID($this->getThreadID(), false)
+      ->setRelatedPHID($question->getPHID())
+      ->setIsBulk(true)
+      ->setBody($body->render());
+
+    $mails = $reply_handler->multiplexMail(
+      $template,
+      array_select_keys($handles, $email_to),
+      array());
+
+    foreach ($mails as $mail) {
+      $mail->saveAndSend();
+    }
+  }
+
+  protected function formatText($text) {
+    $text = explode("\n", rtrim($text));
+    foreach ($text as &$line) {
+      $line = rtrim('  '.$line);
+    }
+    unset($line);
+    return implode("\n", $text);
+  }
+}

src/applications/ponder/mail/PonderMentionMail.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+final class PonderMentionMail extends PonderMail {
+
+  public function __construct(
+    PonderQuestion $question,
+    $target,
+    PhabricatorUser $actor) {
+
+    $this->setQuestion($question);
+    $this->setTarget($target);
+    $this->setActorHandle($actor);
+  }
+
+  protected function renderVaryPrefix() {
+    return "[Mentioned]";
+  }
+
+  protected function renderBody() {
+    $question = $this->getQuestion();
+    $target = $this->getTarget();
+    $actor = $this->getActorName();
+    $name  = $question->getTitle();
+
+    $targetkind = "somewhere";
+    if ($target instanceof PonderQuestion) {
+      $targetkind = "in a question";
+    }
+    else if ($target instanceof PonderAnswer) {
+      $targetkind = "in an answer";
+    }
+    else if ($target instanceof PonderComment) {
+      $targetkind = "in a comment";
+    }
+
+    $body = array();
+    $body[] = "{$actor} mentioned you {$targetkind}.";
+    $body[] = null;
+
+    $content = $target->getContent();
+    if (strlen($content)) {
+      $body[] = $this->formatText($content);
+      $body[] = null;
+    }
+
+    return implode("\n", $body);
+  }
+}

src/applications/ponder/storage/PonderQuestion.php

@@ -17,7 +17,10 @@
  */
 
 final class PonderQuestion extends PonderDAO
-  implements PhabricatorMarkupInterface, PonderVotableInterface {
+  implements
+    PhabricatorMarkupInterface,
+    PonderVotableInterface,
+    PhabricatorSubscribableInterface {
 
   const MARKUP_FIELD_CONTENT = 'markup:content';
 
@@ -168,4 +171,8 @@ final class PonderQuestion extends PonderDAO
   public function getVotablePHID() {
     return $this->getPHID();
   }
+
+  public function isAutomaticallySubscribed($phid) {
+    return false;
+  }
 }