From b084efb36290cb19d37e6db2145fd4edf30cd46c Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Mon, 31 Oct 2016 13:47:45 -0700
Subject: [PATCH] Record a "series parent PHID" on Calendar events that retains
 relationships after forks

Summary:
When you edit "X and all future events", X becomes the new parent of an event series.

Currently, it loses its relationship to its original parent. Instead, retain that relationship -- it's separate from the normal "parent", but we can use it to make the UI more clear or tweak behaviors later.

This mostly just keeps us from losing/destroying data that we might need/want later.

Test Plan:
  - Ran migrations.
  - Cancelled "X and all future events", saw sensible-appearing beahvior in the database for "seriesParentPHID".

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D16780
---
 .../autopatches/20161031.calendar.01.seriesparent.sql |  5 +++++
 .../PhabricatorCalendarEventCancelController.php      |  7 +++++++
 .../calendar/storage/PhabricatorCalendarEvent.php     | 11 +++++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 resources/sql/autopatches/20161031.calendar.01.seriesparent.sql

diff --git a/resources/sql/autopatches/20161031.calendar.01.seriesparent.sql b/resources/sql/autopatches/20161031.calendar.01.seriesparent.sql
new file mode 100644
index 0000000000..7589a161bc
--- /dev/null
+++ b/resources/sql/autopatches/20161031.calendar.01.seriesparent.sql
@@ -0,0 +1,5 @@
+ALTER TABLE {$NAMESPACE}_calendar.calendar_event
+  ADD seriesParentPHID VARBINARY(64);
+
+UPDATE {$NAMESPACE}_calendar.calendar_event
+  SET seriesParentPHID = instanceOfEventPHID;
diff --git a/src/applications/calendar/controller/PhabricatorCalendarEventCancelController.php b/src/applications/calendar/controller/PhabricatorCalendarEventCancelController.php
index 9f4e0e508e..447e3a3c74 100644
--- a/src/applications/calendar/controller/PhabricatorCalendarEventCancelController.php
+++ b/src/applications/calendar/controller/PhabricatorCalendarEventCancelController.php
@@ -84,6 +84,13 @@ final class PhabricatorCalendarEventCancelController
           // NOTE: If you can't edit some of the future events, we just
           // don't try to update them. This seems like it's probably what
           // users are likely to expect.
+
+          // NOTE: This only affects events that are currently in the same
+          // series, not all events that were ever in the original series.
+          // We could use series PHIDs instead of parent PHIDs to affect more
+          // events if this turns out to be counterintuitive. Other
+          // applications differ in their behavior.
+
           $future = id(new PhabricatorCalendarEventQuery())
             ->setViewer($viewer)
             ->withParentEventPHIDs(array($event->getPHID()))
diff --git a/src/applications/calendar/storage/PhabricatorCalendarEvent.php b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
index 7ebcbced72..1a629e07cb 100644
--- a/src/applications/calendar/storage/PhabricatorCalendarEvent.php
+++ b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
@@ -27,6 +27,7 @@ final class PhabricatorCalendarEvent extends PhabricatorCalendarDAO
 
   protected $isRecurring = 0;
 
+  protected $seriesParentPHID;
   protected $instanceOfEventPHID;
   protected $sequenceIndex;
 
@@ -140,10 +141,16 @@ final class PhabricatorCalendarEvent extends PhabricatorCalendarDAO
           'a recurring parent event!'));
     }
 
+    $series_phid = $this->getSeriesParentPHID();
+    if (!$series_phid) {
+      $series_phid = $this->getPHID();
+    }
+
     $child = id(new self())
       ->setIsCancelled(0)
       ->setIsStub(0)
       ->setInstanceOfEventPHID($this->getPHID())
+      ->setSeriesParentPHID($series_phid)
       ->setSequenceIndex($sequence)
       ->setIsRecurring(true)
       ->attachParentEvent($this)
@@ -401,6 +408,7 @@ final class PhabricatorCalendarEvent extends PhabricatorCalendarDAO
         'icon' => 'text32',
         'mailKey' => 'bytes20',
         'isRecurring' => 'bool',
+        'seriesParentPHID' => 'phid?',
         'instanceOfEventPHID' => 'phid?',
         'sequenceIndex' => 'uint32?',
         'isStub' => 'bool',
@@ -435,6 +443,9 @@ final class PhabricatorCalendarEvent extends PhabricatorCalendarDAO
           'columns' => array('instanceOfEventPHID', 'utcInstanceEpoch'),
           'unique' => true,
         ),
+        'key_series' => array(
+          'columns' => array('seriesParentPHID', 'utcInitialEpoch'),
+        ),
       ),
       self::CONFIG_SERIALIZATION => array(
         'recurrenceFrequency' => self::SERIALIZATION_JSON,