Rename "MetaMTA" mail attachments and add more mail message objects

Summary:
Depends on D19953. Ref T9141. We have a "MetaMTAAttachment" object, rename it to "MailAttachment".

Also add a "Header" object and an "EmailMessage" object. Currently, mail adapters have a large number of methods like `setSubject()`, `addTo()`, etc, that I would like to remove.

I'd like the API to be more like `sendMessage(PhabricatorMailExternalMessage $message)`. This is likely a significant simplification anyway, since the implementations of all these methods are just copy/pasted boilerplate anyway (lots of `$this->subject = $subject;`) and this will let Adapters support other message media (SMS, APNS, Whatsapp, etc.)

That's a larger change, but move toward a world where we can build a concrete `$message` object for "email" or "sms".

The `PhabricatorMailEmailMessage` object is just a dumb, flat object representation of the information an adapter needs to actually send mail. The existing `PhabricatorMetaMTAMail` is a much more complex object and has a lot of rich data (delivery status, related object PHIDs, etc) and is a storage object.

The new flow will be something like:

  - `PhabricatorMetaMTAMail` (possibly renamed) is the storage object for any outbound message on this channel. It tracks message content, acceptable delivery media (SMS vs email), delivery status, related objects, has a PHID, and has a daemon worker associated with delivering it.
  - It builds a `PhabricatorMailExternalMessage`, which is a simple, flat description of the message it wants to send. The subclass of this object depends on the message medium. For email, this will be an `EmailMessage`. This is just a "bag of strings" sort of object, with appropriate flattened values for the adapter to work with (e.g., Email has email addresses, SMS has phone numbers).
  - It passes the `ExternalMessage` (which is a `MailMessage` or `SMSMessage` or whatever) to the adapter.
  - The adapter reads the nice flat properties off it and turns them into an API request, SMTP call, etc.

This is sort of how things work today anyway. The major change is that I want to hand off a "bag of strings" object instead of calling `setX()`, `setY()`, `setZ()` with each individual value.

Test Plan: Grepped for `MetaMTAAttachment`. This doesn't change any behavior yet.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T9141

Differential Revision: https://secure.phabricator.com/D19954

src/__phutil_library_map__.php

@@ -3373,11 +3373,15 @@ phutil_register_library_map(array(
     'PhabricatorMacroTransactionQuery' => 'applications/macro/query/PhabricatorMacroTransactionQuery.php',
     'PhabricatorMacroTransactionType' => 'applications/macro/xaction/PhabricatorMacroTransactionType.php',
     'PhabricatorMacroViewController' => 'applications/macro/controller/PhabricatorMacroViewController.php',
+    'PhabricatorMailAttachment' => 'applications/metamta/message/PhabricatorMailAttachment.php',
     'PhabricatorMailConfigTestCase' => 'applications/metamta/storage/__tests__/PhabricatorMailConfigTestCase.php',
     'PhabricatorMailEmailHeraldField' => 'applications/metamta/herald/PhabricatorMailEmailHeraldField.php',
     'PhabricatorMailEmailHeraldFieldGroup' => 'applications/metamta/herald/PhabricatorMailEmailHeraldFieldGroup.php',
+    'PhabricatorMailEmailMessage' => 'applications/metamta/message/PhabricatorMailEmailMessage.php',
     'PhabricatorMailEmailSubjectHeraldField' => 'applications/metamta/herald/PhabricatorMailEmailSubjectHeraldField.php',
     'PhabricatorMailEngineExtension' => 'applications/metamta/engine/PhabricatorMailEngineExtension.php',
+    'PhabricatorMailExternalMessage' => 'applications/metamta/message/PhabricatorMailExternalMessage.php',
+    'PhabricatorMailHeader' => 'applications/metamta/message/PhabricatorMailHeader.php',
     'PhabricatorMailImplementationAdapter' => 'applications/metamta/adapter/PhabricatorMailImplementationAdapter.php',
     'PhabricatorMailImplementationAmazonSESAdapter' => 'applications/metamta/adapter/PhabricatorMailImplementationAmazonSESAdapter.php',
     'PhabricatorMailImplementationMailgunAdapter' => 'applications/metamta/adapter/PhabricatorMailImplementationMailgunAdapter.php',
@@ -3443,7 +3447,6 @@ phutil_register_library_map(array(
     'PhabricatorMetaMTAApplicationEmailQuery' => 'applications/metamta/query/PhabricatorMetaMTAApplicationEmailQuery.php',
     'PhabricatorMetaMTAApplicationEmailTransaction' => 'applications/metamta/storage/PhabricatorMetaMTAApplicationEmailTransaction.php',
     'PhabricatorMetaMTAApplicationEmailTransactionQuery' => 'applications/metamta/query/PhabricatorMetaMTAApplicationEmailTransactionQuery.php',
-    'PhabricatorMetaMTAAttachment' => 'applications/metamta/storage/PhabricatorMetaMTAAttachment.php',
     'PhabricatorMetaMTAConfigOptions' => 'applications/config/option/PhabricatorMetaMTAConfigOptions.php',
     'PhabricatorMetaMTAController' => 'applications/metamta/controller/PhabricatorMetaMTAController.php',
     'PhabricatorMetaMTADAO' => 'applications/metamta/storage/PhabricatorMetaMTADAO.php',
@@ -9182,11 +9185,15 @@ phutil_register_library_map(array(
     'PhabricatorMacroTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
     'PhabricatorMacroTransactionType' => 'PhabricatorModularTransactionType',
     'PhabricatorMacroViewController' => 'PhabricatorMacroController',
+    'PhabricatorMailAttachment' => 'Phobject',
     'PhabricatorMailConfigTestCase' => 'PhabricatorTestCase',
     'PhabricatorMailEmailHeraldField' => 'HeraldField',
     'PhabricatorMailEmailHeraldFieldGroup' => 'HeraldFieldGroup',
+    'PhabricatorMailEmailMessage' => 'PhabricatorMailExternalMessage',
     'PhabricatorMailEmailSubjectHeraldField' => 'PhabricatorMailEmailHeraldField',
     'PhabricatorMailEngineExtension' => 'Phobject',
+    'PhabricatorMailExternalMessage' => 'Phobject',
+    'PhabricatorMailHeader' => 'Phobject',
     'PhabricatorMailImplementationAdapter' => 'Phobject',
     'PhabricatorMailImplementationAmazonSESAdapter' => 'PhabricatorMailImplementationPHPMailerLiteAdapter',
     'PhabricatorMailImplementationMailgunAdapter' => 'PhabricatorMailImplementationAdapter',
@@ -9259,7 +9266,6 @@ phutil_register_library_map(array(
     'PhabricatorMetaMTAApplicationEmailQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorMetaMTAApplicationEmailTransaction' => 'PhabricatorApplicationTransaction',
     'PhabricatorMetaMTAApplicationEmailTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
-    'PhabricatorMetaMTAAttachment' => 'Phobject',
     'PhabricatorMetaMTAConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorMetaMTAController' => 'PhabricatorController',
     'PhabricatorMetaMTADAO' => 'PhabricatorLiskDAO',

src/applications/audit/editor/PhabricatorAuditEditor.php

@@ -611,7 +611,7 @@ final class PhabricatorAuditEditor
       $commit->getCommitIdentifier());
 
     $template->addAttachment(
-      new PhabricatorMetaMTAAttachment(
+      new PhabricatorMailAttachment(
         $raw_patch,
         $commit_name.'.patch',
         'text/x-patch; charset='.$encoding));

src/applications/calendar/editor/PhabricatorCalendarEventEditor.php

@@ -364,7 +364,7 @@ final class PhabricatorCalendarEventEditor
       ->setEvents(array($event))
       ->writeICSDocument();
 
-    $ics_attachment = new PhabricatorMetaMTAAttachment(
+    $ics_attachment = new PhabricatorMailAttachment(
       $ics_data,
       $event->getICSFilename(),
       'text/calendar');

src/applications/differential/editor/DifferentialTransactionEditor.php

@@ -715,7 +715,7 @@ final class DifferentialTransactionEditor
             $name = pht('D%s.%s.patch', $object->getID(), $diff->getID());
             $mime_type = 'text/x-patch; charset=utf-8';
             $body->addAttachment(
-              new PhabricatorMetaMTAAttachment($patch, $name, $mime_type));
+              new PhabricatorMailAttachment($patch, $name, $mime_type));
           }
         }
       }

src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php

@@ -193,7 +193,7 @@ final class PhabricatorMailManagementSendTestWorkflow
       $data = Filesystem::readFile($attachment);
       $name = basename($attachment);
       $mime = Filesystem::getMimeType($attachment);
-      $file = new PhabricatorMetaMTAAttachment($data, $name, $mime);
+      $file = new PhabricatorMailAttachment($data, $name, $mime);
       $mail->addAttachment($file);
     }
 

src/applications/metamta/message/PhabricatorMailAttachment.php

@@ -1,6 +1,6 @@
 <?php
 
-final class PhabricatorMetaMTAAttachment extends Phobject {
+final class PhabricatorMailAttachment extends Phobject {
 
   private $data;
   private $filename;

src/applications/metamta/message/PhabricatorMailEmailMessage.php

@@ -0,0 +1,103 @@
+<?php
+
+final class PhabricatorMailEmailMessage
+  extends PhabricatorMailExternalMessage {
+
+  const MESSAGETYPE = 'email';
+
+  private $fromAddress;
+  private $replyToAddress;
+  private $toAddresses = array();
+  private $ccAddresses = array();
+  private $headers = array();
+  private $attachments = array();
+  private $subject;
+  private $textBody;
+  private $htmlBody;
+
+  public function setFromAddress(PhutilEmailAddress $from_address) {
+    $this->fromAddress = $from_address;
+    return $this;
+  }
+
+  public function getFromAddress() {
+    return $this->fromAddress;
+  }
+
+  public function setReplyToAddress(PhutilEmailAddress $address) {
+    $this->replyToAddress = $address;
+    return $this;
+  }
+
+  public function getReplyToAddress() {
+    return $this->replyToAddress;
+  }
+
+  public function setToAddresses(array $addresses) {
+    assert_instances_of($addresses, 'PhutilEmailAddress');
+    $this->toAddresses = $addresses;
+    return $this;
+  }
+
+  public function getToAddresses() {
+    return $this->toAddresses;
+  }
+
+  public function setCCAddresses(array $addresses) {
+    assert_instances_of($addresses, 'PhutilEmailAddress');
+    $this->ccAddresses = $addresses;
+    return $this;
+  }
+
+  public function getCCAddresses() {
+    return $this->ccAddresses;
+  }
+
+  public function setHeaders(array $headers) {
+    assert_instances_of($headers, 'PhabricatorMailHeader');
+    $this->headers = $headers;
+    return $this;
+  }
+
+  public function getHeaders() {
+    return $this->headers;
+  }
+
+  public function setAttachments(array $attachments) {
+    assert_instances_of($attachments, 'PhabricatorMailAttachment');
+    $this->attachments = $attachments;
+    return $this;
+  }
+
+  public function getAttachments() {
+    return $this->attachments;
+  }
+
+  public function setSubject($subject) {
+    $this->subject = $subject;
+    return $this;
+  }
+
+  public function getSubject() {
+    return $this->subject;
+  }
+
+  public function setTextBody($text_body) {
+    $this->textBody = $text_body;
+    return $this;
+  }
+
+  public function getTextBody() {
+    return $this->textBody;
+  }
+
+  public function setHTMLBody($html_body) {
+    $this->htmlBody = $html_body;
+    return $this;
+  }
+
+  public function getHTMLBody() {
+    return $this->htmlBody;
+  }
+
+}

src/applications/metamta/message/PhabricatorMailExternalMessage.php

@@ -0,0 +1,10 @@
+<?php
+
+abstract class PhabricatorMailExternalMessage
+  extends Phobject {
+
+  final public function getMessageType() {
+    return $this->getPhobjectClassConstant('MESSAGETYPE');
+  }
+
+}

src/applications/metamta/message/PhabricatorMailHeader.php

@@ -0,0 +1,27 @@
+<?php
+
+final class PhabricatorMailHeader
+  extends Phobject {
+
+  private $name;
+  private $value;
+
+  public function setName($name) {
+    $this->name = $name;
+    return $this;
+  }
+
+  public function getName() {
+    return $this->name;
+  }
+
+  public function setValue($value) {
+    $this->value = $value;
+    return $this;
+  }
+
+  public function getValue() {
+    return $this->value;
+  }
+
+}

src/applications/metamta/storage/PhabricatorMetaMTAMail.php

@@ -191,7 +191,7 @@ final class PhabricatorMetaMTAMail
     return $this;
   }
 
-  public function addAttachment(PhabricatorMetaMTAAttachment $attachment) {
+  public function addAttachment(PhabricatorMailAttachment $attachment) {
     $this->parameters['attachments'][] = $attachment->toDictionary();
     return $this;
   }
@@ -201,7 +201,7 @@ final class PhabricatorMetaMTAMail
 
     $result = array();
     foreach ($dicts as $dict) {
-      $result[] = PhabricatorMetaMTAAttachment::newFromDictionary($dict);
+      $result[] = PhabricatorMailAttachment::newFromDictionary($dict);
     }
     return $result;
   }
@@ -236,7 +236,7 @@ final class PhabricatorMetaMTAMail
   }
 
   public function setAttachments(array $attachments) {
-    assert_instances_of($attachments, 'PhabricatorMetaMTAAttachment');
+    assert_instances_of($attachments, 'PhabricatorMailAttachment');
     $this->setParam('attachments', mpull($attachments, 'toDictionary'));
     return $this;
   }

src/applications/metamta/view/PhabricatorMetaMTAMailBody.php

@@ -155,11 +155,11 @@ final class PhabricatorMetaMTAMailBody extends Phobject {
   /**
    * Add an attachment.
    *
-   * @param PhabricatorMetaMTAAttachment Attachment.
+   * @param PhabricatorMailAttachment Attachment.
    * @return this
    * @task compose
    */
-  public function addAttachment(PhabricatorMetaMTAAttachment $attachment) {
+  public function addAttachment(PhabricatorMailAttachment $attachment) {
     $this->attachments[] = $attachment;
     return $this;
   }
@@ -187,7 +187,7 @@ final class PhabricatorMetaMTAMailBody extends Phobject {
   /**
    * Retrieve attachments.
    *
-   * @return list<PhabricatorMetaMTAAttachment> Attachments.
+   * @return list<PhabricatorMailAttachment> Attachments.
    * @task render
    */
   public function getAttachments() {