From a5295c5dd76f3cd9e2bf43463a8f90be9e645b80 Mon Sep 17 00:00:00 2001
From: mARTin <mail@martin-bierschenk.de>
Date: Mon, 23 Mar 2026 00:47:52 +0100
Subject: [PATCH] fix: retry Outlook API calls on 429 throttling with backoff

Respects Retry-After header when available, otherwise uses
exponential backoff (2s, 4s, 6s) for up to 3 attempts.

v1.57.11

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 package.json                |  2 +-
 src/lib/outlook-calendar.ts | 36 ++++++++++++++++++++++++------------
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/package.json b/package.json
index b2910d7..0f1615b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.57.10",
+  "version": "1.57.11",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {
diff --git a/src/lib/outlook-calendar.ts b/src/lib/outlook-calendar.ts
index 9a51b0e..e04dea0 100644
--- a/src/lib/outlook-calendar.ts
+++ b/src/lib/outlook-calendar.ts
@@ -152,20 +152,32 @@ export const getUpcomingEvents = async (
         '$top': '50'
     });
 
-    const response = await fetch(
-        `${GRAPH_ENDPOINT}/me/calendars/${encodeURIComponent(calendarId)}/calendarView?${params.toString()}`,
-        {
-            headers: {
-                'Authorization': `Bearer ${accessToken}`,
-                'Prefer': 'outlook.timezone="UTC"'
+    let response: Response | null = null;
+    for (let attempt = 0; attempt < 3; attempt++) {
+        response = await fetch(
+            `${GRAPH_ENDPOINT}/me/calendars/${encodeURIComponent(calendarId)}/calendarView?${params.toString()}`,
+            {
+                headers: {
+                    'Authorization': `Bearer ${accessToken}`,
+                    'Prefer': 'outlook.timezone="UTC"'
+                }
             }
-        }
-    );
+        );
 
-    if (!response.ok) {
-        const errorText = await response.text();
-        console.error(`[OUTLOOK] Failed to fetch events for calendar ${calendarId}:`, response.status, response.statusText, errorText);
-        throw new Error(`Failed to fetch events: ${response.status} ${response.statusText}`);
+        if (response.status === 429) {
+            const retryAfter = parseInt(response.headers.get('Retry-After') || '', 10);
+            const delay = (retryAfter > 0 ? retryAfter : (attempt + 1) * 2) * 1000;
+            console.warn(`[OUTLOOK] 429 throttled for calendar ${calendarId}, retrying in ${delay}ms (attempt ${attempt + 1}/3)`);
+            await new Promise(r => setTimeout(r, delay));
+            continue;
+        }
+        break;
+    }
+
+    if (!response!.ok) {
+        const errorText = await response!.text();
+        console.error(`[OUTLOOK] Failed to fetch events for calendar ${calendarId}:`, response!.status, response!.statusText, errorText);
+        throw new Error(`Failed to fetch events: ${response!.status} ${response!.statusText}`);
     }
 
     const data = await response.json();