Fix: Add fallback for missing updateEventFields in Docker

- Added manual iCal manipulation as fallback when tsdav.updateEventFields is not available
- Uses ICAL.js to parse and modify iCal data directly
- Detects if tsdav function is available and uses appropriate method
- Resolves 'tsdavUpdateEventFields is not a function' error in Docker environments
- Maintains compatibility with both local development and Docker production

The issue was that tsdav.updateEventFields is undefined in Docker production builds,
even though it works locally. This fallback ensures the function works everywhere.

Author: PhilflowIO

src/tools/calendar/update-event-fields.js

@@ -2,11 +2,49 @@ import { tsdavManager } from '../../tsdav-client.js';
 import { validateInput } from '../../validation.js';
 import { formatSuccess, formatError } from '../../formatters.js';
 import { z } from 'zod';
+import ICAL from 'ical.js';
 // Import using namespace import for maximum CommonJS/ESM compatibility
 import * as tsdavAll from 'tsdav';
 // Access as property - works in both ESM (named export) and CJS (exports.xxx)
 const tsdavUpdateEventFields = tsdavAll.updateEventFields;
 
+/**
+ * Manual iCal field update function as fallback
+ * Updates specific fields in an iCal string when tsdav's updateEventFields is not available
+ */
+function manualUpdateEventFields(calendarObject, fields) {
+  const jcalData = ICAL.parse(calendarObject.data);
+  const comp = new ICAL.Component(jcalData);
+  const vevent = comp.getFirstSubcomponent('vevent');
+  
+  if (!vevent) {
+    throw new Error('No VEVENT component found in calendar object');
+  }
+  
+  const modified = [];
+  const warnings = [];
+  
+  // Update fields
+  if (fields.summary !== undefined) {
+    vevent.updatePropertyWithValue('summary', fields.summary);
+    modified.push('summary');
+  }
+  
+  if (fields.description !== undefined) {
+    vevent.updatePropertyWithValue('description', fields.description);
+    modified.push('description');
+  }
+  
+  // Convert back to iCal string
+  const updatedData = comp.toString();
+  
+  return {
+    data: updatedData,
+    modified,
+    warnings
+  };
+}
+
 /**
  * Schema for field-based event updates
  * Currently supports MVP fields from tsdav v2.2.0: SUMMARY and DESCRIPTION
@@ -94,8 +132,15 @@ export const updateEventFields = {
         }
       }
 
-      // Step 3: Use tsdav's native updateEventFields function
-      const result = tsdavUpdateEventFields(calendarObject, tsdavFields);
+      // Step 3: Use tsdav's native updateEventFields function or fallback to manual implementation
+      let result;
+      if (typeof tsdavUpdateEventFields === 'function') {
+        // Use tsdav's native function if available
+        result = tsdavUpdateEventFields(calendarObject, tsdavFields);
+      } else {
+        // Fallback to manual iCal manipulation
+        result = manualUpdateEventFields(calendarObject, tsdavFields);
+      }
 
       // Step 4: Send the updated event back to server
       const updateResponse = await client.updateCalendarObject({