Update New Features

calendar_service.py

@@ -0,0 +1,127 @@
+"""
+Calendar Service for generating iCalendar (.ics) data
+Implements RFC 5545 iCalendar format for universal calendar compatibility
+"""
+
+from icalendar import Calendar, Event as iCalEvent, Alarm
+from datetime import datetime, timedelta
+from zoneinfo import ZoneInfo
+import uuid
+import os
+
+
+class CalendarService:
+    """Service for generating iCalendar (.ics) data compatible with all calendar apps"""
+
+    def __init__(self):
+        self.domain = os.getenv('CALENDAR_DOMAIN', 'loaf.community')
+        self.timezone = ZoneInfo(os.getenv('CALENDAR_TIMEZONE', 'America/New_York'))
+
+    def generate_event_uid(self) -> str:
+        """
+        Generate unique event identifier (UUID4 hex-encoded per RFC 7986)
+
+        Returns:
+            str: Unique identifier in format {uuid}@{domain}
+        """
+        return f"{uuid.uuid4().hex}@{self.domain}"
+
+    def event_to_ical_event(self, event, include_reminder: bool = True):
+        """
+        Convert database Event model to iCalendar Event component
+
+        Args:
+            event: Event model instance from database
+            include_reminder: Whether to add 1-hour reminder alarm
+
+        Returns:
+            icalendar.Event: iCalendar event component
+        """
+        ical_event = iCalEvent()
+
+        # Required properties
+        ical_event.add('uid', event.calendar_uid or self.generate_event_uid())
+        ical_event.add('dtstamp', datetime.now(self.timezone))
+        ical_event.add('dtstart', event.start_at)
+        ical_event.add('dtend', event.end_at)
+        ical_event.add('summary', event.title)
+
+        # Optional properties
+        if event.description:
+            ical_event.add('description', event.description)
+        if event.location:
+            ical_event.add('location', event.location)
+
+        # Metadata
+        ical_event.add('url', f"https://{self.domain}/events/{event.id}")
+        ical_event.add('status', 'CONFIRMED')
+        ical_event.add('sequence', 0)
+
+        # Add 1-hour reminder (VALARM component)
+        if include_reminder:
+            alarm = Alarm()
+            alarm.add('action', 'DISPLAY')
+            alarm.add('description', f"Reminder: {event.title}")
+            alarm.add('trigger', timedelta(hours=-1))
+            ical_event.add_component(alarm)
+
+        return ical_event
+
+    def create_calendar(self, name: str, description: str = None):
+        """
+        Create base calendar with metadata
+
+        Args:
+            name: Calendar name (X-WR-CALNAME)
+            description: Optional calendar description
+
+        Returns:
+            icalendar.Calendar: Base calendar object
+        """
+        cal = Calendar()
+        cal.add('prodid', '-//LOAF Membership Platform//EN')
+        cal.add('version', '2.0')
+        cal.add('x-wr-calname', name)
+        cal.add('x-wr-timezone', str(self.timezone))
+        if description:
+            cal.add('x-wr-caldesc', description)
+        cal.add('method', 'PUBLISH')
+        cal.add('calscale', 'GREGORIAN')
+        return cal
+
+    def create_single_event_calendar(self, event) -> bytes:
+        """
+        Create calendar with single event for download
+
+        Args:
+            event: Event model instance
+
+        Returns:
+            bytes: iCalendar data as bytes
+        """
+        cal = self.create_calendar(event.title)
+        ical_event = self.event_to_ical_event(event)
+        cal.add_component(ical_event)
+        return cal.to_ics()
+
+    def create_subscription_feed(self, events: list, feed_name: str) -> bytes:
+        """
+        Create calendar subscription feed with multiple events
+
+        Args:
+            events: List of Event model instances
+            feed_name: Name for the calendar feed
+
+        Returns:
+            bytes: iCalendar data as bytes
+        """
+        cal = self.create_calendar(
+            feed_name,
+            description="LOAF Community Events - Auto-syncing calendar feed"
+        )
+
+        for event in events:
+            ical_event = self.event_to_ical_event(event)
+            cal.add_component(ical_event)
+
+        return cal.to_ics()