From fe443bf2e64f6ce21c08a7890f9e418548df4c22 Mon Sep 17 00:00:00 2001
From: Jamie McClymont <jamiemcclymont@catalyst.net.nz>
Date: Tue, 8 Jan 2019 13:05:34 +1300
Subject: [PATCH] Update instance range columns when a collection's timezone
 changes

TODO: Handle the case where it is updated through the web UI
---
 inc/auth-functions.php     |  3 +++
 inc/caldav-PROPPATCH.php   |  4 +++
 inc/instance_range.php     | 55 ++++++++++++++++++++++++++++++++++++++
 inc/ui/collection-edit.php | 14 ++++++++++
 4 files changed, 76 insertions(+)
 create mode 100644 inc/instance_range.php

diff --git a/inc/auth-functions.php b/inc/auth-functions.php
index 6ec757d3..e97743f6 100644
--- a/inc/auth-functions.php
+++ b/inc/auth-functions.php
@@ -231,6 +231,9 @@ function UpdateCollectionTimezones( $username, $new_timezone=null ) {
   if ( empty($new_timezone) ) return;
   $qry = new AwlQuery('UPDATE collection SET timezone=? WHERE dav_name LIKE ? AND is_calendar', '/'.$username.'/%', $new_timezone);
   $qry->Exec();
+
+  require_once("instance_range.php");
+  update_instance_ranges($dav_resource->dav_name());
 }
 
 /**
diff --git a/inc/caldav-PROPPATCH.php b/inc/caldav-PROPPATCH.php
index d4b94ff8..7bda9408 100644
--- a/inc/caldav-PROPPATCH.php
+++ b/inc/caldav-PROPPATCH.php
@@ -275,6 +275,8 @@ foreach( $setprops AS $k => $setting ) {
 
         $qry->QDo('UPDATE collection SET timezone = :tzid WHERE dav_name = :dav_name',
                                        array( ':tzid' => $tzid, ':dav_name' => $dav_resource->dav_name()) );
+        require_once("instance_range.php");
+        update_instance_ranges($dav_resource->dav_name());
       }
       else {
         add_failure('set', $tag, 'HTTP/1.1 409 Conflict', translate("calendar-timezone property is only valid for a calendar."));
@@ -389,6 +391,8 @@ foreach( $rmprops AS $k => $setting ) {
     case 'urn:ietf:params:xml:ns:caldav:calendar-timezone':
       if ( $dav_resource->IsCollection() && $dav_resource->IsCalendar() && ! $dav_resource->IsBinding() ) {
         $qry->QDo('UPDATE collection SET timezone = NULL WHERE dav_name = :dav_name', array( ':dav_name' => $dav_resource->dav_name()) );
+        require_once("instance_range.php");
+        update_instance_ranges($dav_resource->dav_name());
       }
       else {
         add_failure('rm', $tag, 'HTTP/1.1 403 Forbidden',
diff --git a/inc/instance_range.php b/inc/instance_range.php
new file mode 100644
index 00000000..c1cdee17
--- /dev/null
+++ b/inc/instance_range.php
@@ -0,0 +1,55 @@
+<?php
+
+require_once("RRule.php");
+require_once("vCalendar.php");
+
+function update_instance_ranges(string $collection_dav_name) {
+  // This can take a while, since vCalendar parsing is very slow, and we're
+  // going to parse every event in the collection!
+  //
+  // Since we might be doing this during a caldav request which we'd rather not
+  // have fail, we increase the execution time limit to prevent timeouts
+  set_time_limit(120);
+
+  $qry = new AwlQuery();
+
+  $in_transaction = ($qry->TransactionState() == 1);
+  if ( ! $in_transaction ) $qry->Begin();
+
+  $qry->QDo(
+    "SELECT d.dav_id, c.collection_id, d.caldav_data, c.timezone, i.first_instance_start, i.last_instance_end
+     FROM caldav_data d
+     INNER JOIN collection    c ON d.collection_id = c.collection_id
+     INNER JOIN calendar_item i ON d.collection_id = i.collection_id AND d.dav_id = i.dav_id
+     WHERE c.dav_name = :dav_name",
+    [":dav_name" => $collection_dav_name]
+  );
+
+  while( $row = $qry->Fetch() ) {
+    $range = getVCalendarRange(new vCalendar($row->caldav_data), $row->timezone);
+
+    $new_start = isset($range->from)  ? $range->from->UTC()  : null;
+    $new_end   = isset($range->until) ? $range->until->UTC() : null;
+
+    if ($new_start != $row->first_instance_start || $new_end != $row->last_instance_end) {
+      $inner_qry = new AwlQuery(
+        "UPDATE calendar_item
+        SET first_instance_start = :first_instance_start,
+            last_instance_end = :last_instance_end
+        WHERE collection_id = :collection_id AND dav_id = :dav_id",
+        [
+          ":dav_id"               => $row->dav_id,
+          ":collection_id"        => $row->collection_id,
+
+          ":first_instance_start" => $new_start,
+          ":last_instance_end"    => $new_end
+        ]
+      );
+      $inner_qry->Exec('UpdateInstanceRange',__LINE__,__FILE__);
+    }
+  }
+
+  if ( ! $in_transaction ) $qry->Commit();
+}
+
+?>
diff --git a/inc/ui/collection-edit.php b/inc/ui/collection-edit.php
index 8c1d8401..4fa778c9 100644
--- a/inc/ui/collection-edit.php
+++ b/inc/ui/collection-edit.php
@@ -91,7 +91,14 @@ if ( $can_write_collection && $editor->IsSubmit() ) {
   }
   else {
     $c->messages[] = i18n("Updating Collection.");
+
+    // We need to know whether to update_instance_ranges, which is an expensive
+    // operation we should only do if the collection timezone has been updated
+    $tzqry = new AwlQuery( "SELECT timezone FROM collection WHERE collection_id=:id", [ ":id" => $id ] );
+    $tzqry->Exec('collection-edit',__LINE__,__FILE__);
+    $old_tz = $tzqry->Fetch()->timezone;
   }
+
   if ( !$editor->Write() ) {
     $c->messages[] = i18n("Failed to write collection.");
     if ( $id > 0 ) $editor->GetRecord();
@@ -121,6 +128,13 @@ if ( $can_write_collection && $editor->IsSubmit() ) {
       $c->messages[] =  i18n('The file is not UTF-8 encoded, please check the error for more details.');
     }
   }
+
+  if ($editor->IsCreate() || $old_tz != $_POST['timezone']) {
+    dbg_error_log('collection-edit', 'Need to update instance ranges, this will take a while...');
+    require_once("instance_range.php");
+    update_instance_ranges($editor->Value('dav_name'));
+  }
+
   // Uncache anything to do with the collection
   $cache = getCacheInstance();
   $cache->delete( 'collection-'.$editor->Value('dav_name'), null );