From cd6878f8cf048756e847a46dc2ff020633d633a0 Mon Sep 17 00:00:00 2001
From: Ace <saadnaseer63@yahoo.de>
Date: Sat, 14 Dec 2019 17:24:05 +0100
Subject: [PATCH] Added support for recurring events

This is a more thorough approach on fetching and parsing recurring events. It has been tested on Google and Yahoo iCalendar, so it might not work on others. As further testing and feedpack is required to test it's reliability, the parsing of reucrring events is switched off by default. Setting 'use_recurring_events' to 'True' activates parsing of recurring events.
---
 modules/inkycal_icalendar.py | 41 +++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/modules/inkycal_icalendar.py b/modules/inkycal_icalendar.py
index a7bff5b..f056fb3 100644
--- a/modules/inkycal_icalendar.py
+++ b/modules/inkycal_icalendar.py
@@ -10,13 +10,19 @@ from settings import ical_urls
 import arrow
 from ics import Calendar
 
+use_recurring_events = False ## Attention: experimental feature!
 print_events = False
 style = 'DD MMM YY HH:mm'
 
 
+if use_recurring_events == True:
+  from dateutil.rrule import rrulestr, rruleset
+  import re
+
 def fetch_events():
   """Set timelines for filtering upcoming events"""
-  now = arrow.now(tz=get_tz())
+  timezone = get_tz()
+  now = arrow.now(tz=timezone)
   beginning_of_month = now.replace(days= - now.day +1)
   near_future = now.replace(days= 30)
   further_future = now.replace(days=40)
@@ -29,6 +35,32 @@ def fetch_events():
     if beginning_of_month  <= events.end <= further_future or
     beginning_of_month <= events.begin <= near_future]
 
+  """Try to parse recurring events. This is clearly experimental! """
+  if use_recurring_events == True:
+    for ical in calendars:
+      for events in ical.events:
+        event_str = str(events)
+        if re.search('RRULE:(.+?)\n', event_str):
+          if events.all_day and events.duration.days > 1:
+            events.end = events.end.replace(days=-2)
+          else:
+            events.begin = events.begin.to(timezone)
+            events.end = events.end.to(timezone)
+          rule = re.search('RRULE:(.+?)\n', event_str).group(0)[:-2]
+          if re.search('UNTIL=(.+?);', rule) and not re.search('UNTIL=(.+?)Z;', rule):
+            rule = re.sub('UNTIL=(.+?);', 'UNTIL='+re.search('UNTIL=(.+?);', rule).group(0)[6:-1]+'T000000Z;', rule)
+          dates = rrulestr(rule, dtstart= events.begin.datetime).between(after= now.datetime, before = further_future.datetime)
+
+          if dates:
+            duration = events.duration
+            for date in dates:
+              cc = events.clone()
+              cc.end = arrow.get(date+duration)
+              cc.begin = arrow.get(date)
+              upcoming_events.append(cc)
+              #print("Added '{}' with new start at {}".format(cc.name, cc.begin.format('DD MMM YY')))
+
+
   """Sort events according to their beginning date"""
   def sort_dates(event):
     return event.begin
@@ -38,11 +70,10 @@ def fetch_events():
   for events in upcoming_events:
     if events.all_day and events.duration.days > 1:
       events.end = events.end.replace(days=-2)
-      
+
     if not events.all_day:
-      events.begin = events.begin.to(get_tz())
-      events.end = events.end.to(get_tz())
-    
+      events.begin = events.begin.to(timezone)
+      events.end = events.end.to(timezone)
 
   """ The list upcoming_events should not be modified. If you need the data from
   this one, copy the list or the contents to another one."""