Add email preference links to email footers

Summary: Ref T1217, Add link to email preferences to email template

Test Plan: Add comment to object like Maniphest task, check that email has a footer with a link to email preferences.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T1217

Differential Revision: https://secure.phabricator.com/D10883

src/applications/config/option/PhabricatorMetaMTAConfigOptions.php

@@ -98,6 +98,12 @@ from replying. However, it may also cause deliverability issues -- notably, you
 currently can not send this header via Amazon SES, and enabling this option with
 SES will prevent delivery of any affected mail.
 EODOC
+));
+
+    $email_preferences_description = $this->deformat(pht(<<<EODOC
+You can disable the email preference link in emails if users prefer smaller
+emails.
+EODOC
 ));
 
     $re_prefix_description = $this->deformat(pht(<<<EODOC
@@ -257,6 +263,14 @@ EODOC
           ))
         ->setSummary(pht('Show "To:" and "Cc:" footer hints in email.'))
         ->setDescription($recipient_hints_description),
+      $this->newOption('metamta.email-preferences', 'bool', true)
+        ->setBoolOptions(
+          array(
+            pht('Show Email Preferences Link'),
+            pht('No Email Preferences Link'),
+          ))
+        ->setSummary(pht('Show email preferences link in email.'))
+        ->setDescription($email_preferences_description),
       $this->newOption('metamta.precedence-bulk', 'bool', false)
         ->setBoolOptions(
           array(

src/applications/metamta/view/PhabricatorMetaMTAMailBody.php

@@ -179,6 +179,23 @@ final class PhabricatorMetaMTAMailBody {
     return $this;
   }
 
+  /**
+   * Add a section with a link to email preferences.
+   *
+   * @return this
+   * @task compose
+   */
+  public function addEmailPreferenceSection() {
+    if (!PhabricatorEnv::getEnvConfig('metamta.email-preferences')) {
+      return $this;
+    }
+
+    $href = PhabricatorEnv::getProductionURI(
+      '/settings/panel/emailpreferences/');
+    $this->addLinkSection(pht('EMAIL PREFERENCES'), $href);
+
+    return $this;
+  }
 
   /**
    * Add an attachment.

src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php

@@ -1899,6 +1899,8 @@ abstract class PhabricatorApplicationTransactionEditor
       $body->addReplySection($reply_section);
     }
 
+    $body->addEmailPreferenceSection();
+
     $template
       ->setFrom($this->getActingAsPHID())
       ->setSubjectPrefix($this->getMailSubjectPrefix())
@@ -2013,7 +2015,6 @@ abstract class PhabricatorApplicationTransactionEditor
     throw new Exception('Capability not supported.');
   }
 
-
   /**
    * @task mail
    */