Make Diffusion Herald emails thread with Audit emails

Summary:
  - Users may elect to receive an initial notification about a commit; allow it to be replied to in order to interact with the object.
  - Share thread headers between emails.
  - Add the "REPLY HANDLER ACTIONS" section to both emails.

Test Plan:
  - Used "reparse.php --herald" to trigger herald emails, verified reply-to and email body.
  - Made audit comments, verified body.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, epriestley

Maniphest Tasks: T904

Differential Revision: https://secure.phabricator.com/D1762

src/applications/audit/editor/comment/PhabricatorAuditCommentEditor.php

@@ -185,14 +185,20 @@ final class PhabricatorAuditCommentEditor {
     );
     $verb = idx($map, $comment->getAction(), 'Commented On');
 
+    $reply_handler = self::newReplyHandlerForCommit($commit);
+
     $prefix = PhabricatorEnv::getEnvConfig('metamta.diffusion.subject-prefix');
     $subject = "{$prefix} [{$verb}] {$name}: {$summary}";
-    $thread_id  = '<diffusion-audit-'.$commit->getPHID().'>';
+
+    $threading = self::getMailThreading($commit->getPHID());
+    list($thread_id, $thread_topic) = $threading;
+
     $is_new     = !count($other_comments);
     $body       = $this->renderMailBody(
       $comment,
       "{$name}: {$summary}",
-      $handle);
+      $handle,
+      $reply_handler);
 
     $email_to = array();
 
@@ -212,14 +218,12 @@ final class PhabricatorAuditCommentEditor {
     $template = id(new PhabricatorMetaMTAMail())
       ->setSubject($subject)
       ->setFrom($comment->getActorPHID())
-      ->addHeader('Thread-Topic', 'Diffusion Audit '.$commit->getPHID())
       ->setThreadID($thread_id, $is_new)
+      ->addHeader('Thread-Topic', $thread_topic)
       ->setRelatedPHID($commit->getPHID())
       ->setIsBulk(true)
       ->setBody($body);
 
-    $reply_handler = self::newReplyHandlerForCommit($commit);
-
     $mails = $reply_handler->multiplexMail(
       $template,
       array_select_keys($handles, $email_to),
@@ -230,6 +234,13 @@ final class PhabricatorAuditCommentEditor {
     }
   }
 
+  public static function getMailThreading($phid) {
+    return array(
+      '<diffusion-audit-'.$phid.'>',
+      'Diffusion Audit '.$phid,
+    );
+  }
+
   public static function newReplyHandlerForCommit($commit) {
     $handler_class = PhabricatorEnv::getEnvConfig(
       'metamta.diffusion.reply-handler');
@@ -241,7 +252,8 @@ final class PhabricatorAuditCommentEditor {
   private function renderMailBody(
     PhabricatorAuditComment $comment,
     $cname,
-    PhabricatorObjectHandle $handle) {
+    PhabricatorObjectHandle $handle,
+    PhabricatorMailReplyHandler $reply_handler) {
 
     $commit = $this->commit;
     $user = $this->user;
@@ -259,6 +271,11 @@ final class PhabricatorAuditCommentEditor {
 
     $body[] = "COMMIT\n  ".PhabricatorEnv::getProductionURI($handle->getURI());
 
+    $reply_instructions = $reply_handler->getReplyHandlerInstructions();
+    if ($reply_instructions) {
+      $body[] = "REPLY HANDLER ACTIONS\n  ".$reply_instructions;
+    }
+
     return implode("\n\n", $body)."\n";
   }
 

src/applications/repository/worker/herald/PhabricatorRepositoryCommitHeraldWorker.php

@@ -106,6 +106,18 @@ class PhabricatorRepositoryCommitHeraldWorker
     $why_uri = PhabricatorEnv::getProductionURI(
       '/herald/transcript/'.$xscript_id.'/');
 
+    $reply_handler = PhabricatorAuditCommentEditor::newReplyHandlerForCommit(
+      $commit);
+
+    $reply_instructions = $reply_handler->getReplyHandlerInstructions();
+    if ($reply_instructions) {
+      $reply_instructions =
+        "\n".
+        "REPLY HANDLER ACTIONS\n".
+        "  ".$reply_instructions."\n";
+    }
+
+
     $body = <<<EOBODY
 DESCRIPTION
 {$description}
@@ -118,7 +130,7 @@ DIFFERENTIAL REVISION
 
 AFFECTED FILES
   {$files}
-
+{$reply_instructions}
 MANAGE HERALD COMMIT RULES
   {$manage_uri}
 
@@ -129,19 +141,31 @@ EOBODY;
 
     $subject = "[Herald/Commit] {$commit_name} ({$who}){$name}";
 
-    $mailer = new PhabricatorMetaMTAMail();
-    $mailer->setRelatedPHID($commit->getPHID());
-    $mailer->addTos($email_phids);
-    $mailer->setSubject($subject);
-    $mailer->setBody($body);
-    $mailer->setIsBulk(true);
+    $threading = PhabricatorAuditCommentEditor::getMailThreading(
+      $commit->getPHID());
+    list($thread_id, $thread_topic) = $threading;
 
-    $mailer->addHeader('X-Herald-Rules', $xscript->getXHeraldRulesHeader());
+    $template = new PhabricatorMetaMTAMail();
+    $template->setRelatedPHID($commit->getPHID());
+    $template->setSubject($subject);
+    $template->setBody($body);
+    $template->setThreadID($thread_id, $is_new = true);
+    $template->addHeader('Thread-Topic', $thread_topic);
+    $template->setIsBulk(true);
+
+    $template->addHeader('X-Herald-Rules', $xscript->getXHeraldRulesHeader());
     if ($author_phid) {
-      $mailer->setFrom($author_phid);
+      $template->setFrom($author_phid);
     }
 
-    $mailer->saveAndSend();
+    $mails = $reply_handler->multiplexMail(
+      $template,
+      id(new PhabricatorObjectHandleData($email_phids))->loadHandles(),
+      array());
+
+    foreach ($mails as $mail) {
+      $mail->saveAndSend();
+    }
   }
 
   private function createAudits(

src/applications/repository/worker/herald/__init__.php

@@ -7,6 +7,7 @@
 
 
 phutil_require_module('phabricator', 'applications/audit/constants/status');
+phutil_require_module('phabricator', 'applications/audit/editor/comment');
 phutil_require_module('phabricator', 'applications/herald/adapter/commit');
 phutil_require_module('phabricator', 'applications/herald/config/contenttype');
 phutil_require_module('phabricator', 'applications/herald/engine/engine');