From 5d852997c69a0b9278817d6aaa08ce73bff54ad8 Mon Sep 17 00:00:00 2001
From: campbell-m <87438215+campbell-m@users.noreply.github.com>
Date: Wed, 8 Nov 2023 18:15:15 +0000
Subject: [PATCH] Add the ability to override ICU values for week numbering -
 useful when the ICU library can't be updated.

---
 web/language.inc           | 29 ++++++++++++++++++++++++++++-
 web/lib/MRBS/DateTime.php  | 31 +++++++++++++++++++++++++++----
 web/systemdefaults.inc.php | 20 ++++++++++++++++++++
 3 files changed, 75 insertions(+), 5 deletions(-)

diff --git a/web/language.inc b/web/language.inc
index f1be869861..e14ac4ab59 100644
--- a/web/language.inc
+++ b/web/language.inc
@@ -786,6 +786,13 @@ function get_loc_field_name(string $table, string $name) : string
 
 function datetime_format(array $format, int $timestamp=null, string $locale=null) : string
 {
+  global $icu_override, $timezone;
+
+  if (!isset($timestamp))
+  {
+    $timestamp = time();
+  }
+
   if (!isset($locale))
   {
     $locale = get_mrbs_locale();
@@ -809,7 +816,27 @@ function datetime_format(array $format, int $timestamp=null, string $locale=null
     null, null, $pattern
   );
 
-  return $formatter->format($timestamp ?? time());
+  // If we're overriding the ICU value(s) then use those, provided that we're able to make use
+  // of them with the IntlCalendar and (standard, not emulated - hence the check for the loaded
+  // extension, rather than whether the class exists, which it always will) IntlDateFormatter classes.
+  if (isset($icu_override[$locale]) && extension_loaded('intl') && class_exists('IntlCalendar'))
+  {
+    $cal = \IntlCalendar::createInstance($timezone, $locale);
+    {
+      if (isset($icu_override[$locale]['first_day_of_week']))
+      {
+        $cal->setFirstDayOfWeek($icu_override[$locale]['first_day_of_week']);
+      }
+      if (isset($icu_override[$locale]['minimal_days_in_first_week']))
+      {
+        $cal->setMinimalDaysInFirstWeek($icu_override[$locale]['minimal_days_in_first_week']);
+      }
+    }
+    $cal->setTime($timestamp * 1000);
+    return $formatter->format($cal);
+  }
+
+  return $formatter->format($timestamp);
 }
 
 
diff --git a/web/lib/MRBS/DateTime.php b/web/lib/MRBS/DateTime.php
index 4f6b3f9783..7c869a4e31 100644
--- a/web/lib/MRBS/DateTime.php
+++ b/web/lib/MRBS/DateTime.php
@@ -42,6 +42,8 @@ public static function createFromFormat($format, $datetime, ?\DateTimeZone $time
   // the method assumes that the week starts on a Monday.
   public static function firstDayOfWeek(?string $timezone = null, ?string $locale = null) : int
   {
+    global $icu_override;
+
     $default = 1; // Monday
 
     if (!class_exists('\\IntlCalendar'))
@@ -56,11 +58,32 @@ public static function firstDayOfWeek(?string $timezone = null, ?string $locale
       return $default;
     }
 
-    $first_day = $calendar->getFirstDayOfWeek();
-    if ($first_day === false)
+    // If we're overriding the ICU library then use that value
+    if (isset($icu_override[$locale]['first_day_of_week']))
     {
-      trigger_error($calendar->getErrorMessage(), E_USER_WARNING);
-      return $default;
+      $first_day =  $icu_override[$locale]['first_day_of_week'];
+      // Check that it's a valid day
+      if (!in_array($first_day, array(
+          IntlCalendar::DOW_SUNDAY,
+          IntlCalendar::DOW_MONDAY,
+          IntlCalendar::DOW_TUESDAY,
+          IntlCalendar::DOW_WEDNESDAY,
+          IntlCalendar::DOW_THURSDAY,
+          IntlCalendar::DOW_FRIDAY,
+          IntlCalendar::DOW_SATURDAY
+        )))
+      {
+        throw new Exception('$icu_override[' . $locale . "]['first_day_of_week'] must be in the range [1..7]");
+      }
+    }
+    // Otherwise just get the standard value from ICU
+    else
+    {
+      $first_day = $calendar->getFirstDayOfWeek();
+      if ($first_day === false) {
+        trigger_error($calendar->getErrorMessage(), E_USER_WARNING);
+        return $default;
+      }
     }
 
     return $first_day - 1;  // IntlCalendar::DOW_SUNDAY = 1, so we need to subtract 1
diff --git a/web/systemdefaults.inc.php b/web/systemdefaults.inc.php
index 70c8561134..dbb37504f6 100644
--- a/web/systemdefaults.inc.php
+++ b/web/systemdefaults.inc.php
@@ -726,6 +726,26 @@
 );
 
 
+/***************
+ * ICU overrides
+ * *************/
+
+// Sometimes we may want to override the standard ICU library settings,
+// for example if the ICU library on the server is out of date and can't
+// be updated.  This can be done by setting:
+//
+// $icu_override[<locale>]['first_day_of_week'] and/or
+// $icu_override[<locale>]['minimal_days_in_first_week']
+//
+// where <locale> is a valid locale in BCP 47 format and both settings take
+// integer values in the range 1..7 (IntlCalendar days start with Sunday = 1).
+
+// For example:
+//
+// $icu_override['en-AU']['first_day_of_week'] = 2; // Monday
+// $icu_override['en-AU']['minimal_days_in_first_week'] = 1;
+
+
 /************************
  * Miscellaneous settings
  ************************/