From c1ffbc3f3a524156abe1e99ce05a2ca8f0d9cf46 Mon Sep 17 00:00:00 2001
From: luxick <git@luxick.de>
Date: Mon, 6 Apr 2026 08:49:14 +0200
Subject: [PATCH] Improve date handling for the calendar widget

---
 js/calendar-widget.js | 63 ++++++++++++++++++++++++++++---------------
 syntax/calendar.php   | 29 ++++++++++++++++++++
 2 files changed, 71 insertions(+), 21 deletions(-)

diff --git a/js/calendar-widget.js b/js/calendar-widget.js
index 9cdd159..ca1ca7f 100644
--- a/js/calendar-widget.js
+++ b/js/calendar-widget.js
@@ -51,19 +51,33 @@
 
   function getCalendarStateKey(calendar) {
     var baseNs = calendar.getAttribute('data-base-ns') || 'chronological';
-    return 'luxtools.calendar.month.' + baseNs;
+    return 'luxtools_calendar_month_' + baseNs.replace(/[^a-zA-Z0-9]/g, '_');
   }
 
   function shouldPersistCalendarMonth(calendar) {
     return (calendar.getAttribute('data-luxtools-size') || 'large') === 'small';
   }
 
+  function getCookieValue(name) {
+    var match = document.cookie.match('(^|;)\\s*' + name.replace(/[.*+?^${}()|[\]\\]/g, '\\$&') + '\\s*=\\s*([^;]+)');
+    return match ? decodeURIComponent(match[2]) : null;
+  }
+
+  function setCookie(name, value) {
+    var date = new Date();
+    date.setFullYear(date.getFullYear() + 1);
+    document.cookie = name + '=' + encodeURIComponent(value) + '; expires=' + date.toUTCString() + '; path=/; SameSite=Lax';
+  }
+
+  function deleteCookie(name) {
+    document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/; SameSite=Lax';
+  }
+
   function readSavedCalendarMonth(calendar) {
     if (!shouldPersistCalendarMonth(calendar)) return null;
-    if (!window.localStorage) return null;
 
     try {
-      var raw = window.localStorage.getItem(getCalendarStateKey(calendar));
+      var raw = getCookieValue(getCalendarStateKey(calendar));
       if (!raw) return null;
 
       var parsed = JSON.parse(raw);
@@ -79,31 +93,17 @@
 
   function saveCalendarMonth(calendar) {
     if (!shouldPersistCalendarMonth(calendar)) return;
-    if (!window.localStorage) return;
 
     var year = parseInt(calendar.getAttribute('data-current-year') || '', 10);
     var month = parseInt(calendar.getAttribute('data-current-month') || '', 10);
     if (!year || month < 1 || month > 12) return;
 
-    try {
-      window.localStorage.setItem(getCalendarStateKey(calendar), JSON.stringify({
-        year: year,
-        month: month
-      }));
-    } catch (e) {
-      // ignore storage failures
-    }
+    setCookie(getCalendarStateKey(calendar), JSON.stringify({ year: year, month: month }));
   }
 
   function clearSavedCalendarMonth(calendar) {
     if (!shouldPersistCalendarMonth(calendar)) return;
-    if (!window.localStorage) return;
-
-    try {
-      window.localStorage.removeItem(getCalendarStateKey(calendar));
-    } catch (e) {
-      // ignore storage failures
-    }
+    deleteCookie(getCalendarStateKey(calendar));
   }
 
   function fetchCalendarMonth(calendar, year, month) {
@@ -227,11 +227,22 @@
 
   function restoreCalendarMonth(calendar) {
     if (!shouldPersistCalendarMonth(calendar)) return;
-    var saved = readSavedCalendarMonth(calendar);
-    if (!saved) return;
 
     var year = parseInt(calendar.getAttribute('data-current-year') || '', 10);
     var month = parseInt(calendar.getAttribute('data-current-month') || '', 10);
+    if (!year || !month) return;
+
+    var saved = readSavedCalendarMonth(calendar);
+    if (!saved) {
+      var now = new Date();
+      var todayYear = now.getFullYear();
+      var todayMonth = now.getMonth() + 1;
+      if (year !== todayYear || month !== todayMonth) {
+        loadCalendarMonth(calendar, todayYear, todayMonth, false);
+      }
+      return;
+    }
+
     if (saved.year === year && saved.month === month) return;
 
     loadCalendarMonth(calendar, saved.year, saved.month, true);
@@ -258,7 +269,17 @@
     navigateCalendarMonth(calendar, direction, true);
   }
 
+  function updateClientDateCookie() {
+    var now = new Date();
+    setCookie('luxtools_client_month', JSON.stringify({
+      year: now.getFullYear(),
+      month: now.getMonth() + 1
+    }));
+  }
+
   function initCalendarWidgets() {
+    updateClientDateCookie();
+
     var calendars = document.querySelectorAll('div.luxtools-calendar[data-luxtools-calendar="1"]');
     for (var i = 0; i < calendars.length; i++) {
       syncCalendarToday(calendars[i]);
diff --git a/syntax/calendar.php b/syntax/calendar.php
index 5fac241..566a670 100644
--- a/syntax/calendar.php
+++ b/syntax/calendar.php
@@ -91,6 +91,16 @@ class syntax_plugin_luxtools_calendar extends SyntaxPlugin
         $size = ChronologicalCalendarWidget::normalizeSize((string)($data['size'] ?? 'large'));
         $showTimes = (bool)($data['show_times'] ?? true);
 
+        if ($size === 'small') {
+            $resolved = $this->resolveMonthFromCookie(
+                'luxtools_calendar_month_' . preg_replace('/[^a-zA-Z0-9]/', '_', $baseNs)
+            ) ?? $this->resolveMonthFromCookie('luxtools_client_month');
+            if ($resolved !== null) {
+                $year = $resolved['year'];
+                $month = $resolved['month'];
+            }
+        }
+
         $slots = CalendarSlot::loadEnabled($this);
         $widgetSlots = CalendarSlot::filterWidgetVisible($slots);
         $indicators = [];
@@ -122,6 +132,25 @@ class syntax_plugin_luxtools_calendar extends SyntaxPlugin
         return true;
     }
 
+    /**
+     * @param string $cookieName
+     * @return array{year:int,month:int}|null
+     */
+    protected function resolveMonthFromCookie(string $cookieName): ?array
+    {
+        $raw = $_COOKIE[$cookieName] ?? null;
+        if ($raw === null) return null;
+
+        $decoded = json_decode($raw, true);
+        if (!is_array($decoded)) return null;
+
+        $year = (int)($decoded['year'] ?? 0);
+        $month = (int)($decoded['month'] ?? 0);
+        if ($year < 1 || $month < 1 || $month > 12) return null;
+
+        return ['year' => $year, 'month' => $month];
+    }
+
     /**
      * @param string $flags
      * @return array<string,string>