oracleCalSync.py

#!python

# This monstrosity was created to sync events from my Work calendar ical feed to a google calendar
#   Google Calendar already supports ical feeds you say?  Well... it would be nice if they 
#   updated them every once and awhile.

try:
    from xml.etree import ElementTree
except ImportError:
    from elementtree import ElementTree
import gdata.calendar.client
import gdata.calendar
import atom
import getopt
import sys
import string
import time
import re
import urllib2
from icalendar import Calendar, Event
import time
from datetime import date, datetime , timedelta


cal_client = gdata.calendar.client.CalendarClient(source='Google-Calendar_Python-2.0')
cal_client.ClientLogin("username", "password", cal_client.source) # Probably a bad idea

ical_feed = 'http://somefeed'
work_calendar = cal_client.GetCalendarEventFeedUri(calendar='somelonguniquestring@group.calendar.google.com',
                                                   visibility='private',
                                                   projection='full')

def DateRangeQuery(calendar_client, calendar, start_date, end_date):
    query = TryGoogleRequest(gdata.calendar.client.CalendarEventQuery)
    query.start_min = start_date
    query.start_max = end_date
    feed = TryGoogleRequest(calendar_client.GetCalendarEventFeed, q=query, uri=calendar)
    
    return feed

def InsertSingleWorkEvent( calendar_client, calendar, title, content, location, start_time, end_time ):
    event = gdata.calendar.data.CalendarEventEntry()
    event.title = atom.data.Title(text="%s" % title)
    if location is not None:
        event.where.append(gdata.calendar.data.CalendarWhere(value=location))
    if content is not None:
        event.content = atom.data.Content(text=content)

    start_time = start_time.strftime('%Y-%m-%dT%H:%M:%S.000Z')
    end_time = end_time.strftime('%Y-%m-%dT%H:%M:%S.000Z')
    event.when.append(gdata.calendar.data.When(start=start_time, end=end_time))
    
    TryGoogleRequest(calendar_client.InsertEvent, event, calendar)

def TryGoogleRequest( fun, *args, **kwargs ):
    ret = None
    tries = 0
    while tries < 10:
        if tries in [4, 8]:
            time.sleep(120) # Sometimes it seems to error out if you hit it too fast
        try:
            ret = fun(*args, **kwargs)
            break
        except gdata.client.RedirectError as e:
            tries += 1

    if tries is 10:
        raise Exception('Repeatedly failed contacting Google Calendar services')
    
    return ret

start_date = (date.today() - timedelta(days=7)).isoformat()
end_date = (date.today() + timedelta(days=30)).isoformat()

work_cal_feed = DateRangeQuery(cal_client, work_calendar , start_date, end_date)
ical = Calendar.from_string( urllib2.urlopen(ical_feed).read() )

# Remove old work events from the default calendar
print "Removing old events...\n"
for i, an_event in enumerate(work_cal_feed.entry):
    print 'Removing event: %s' % (an_event.title.text,)
    TryGoogleRequest( cal_client.Delete, an_event )

print "\nRe-Adding events from ical feed...\n"
for component in ical.walk('vevent'):
    title = component['summary']
    location = None
    descr = None
    start_date = None
    end_date = None
    print component['summary']
    try:
        location = u'{0}'.format(component['location'])
    except KeyError:
        location = None
    try:
        descr = u'{0}'.format(component['description'])
    except KeyError:
        descr = None
        
    try:
        start_date = datetime.strptime('{0}'.format(component['dtstart']), "%Y%m%dT%H%M%SZ")
    except ValueError:
        start_date = datetime.strptime('{0}'.format(component['dtstart']), "%Y%m%d")
    try:
        end_date = datetime.strptime('{0}'.format(component['dtend']), "%Y%m%dT%H%M%SZ")
    except ValueError:
        end_date = datetime.strptime('{0}'.format(component['dtend']), "%Y%m%d")

    InsertSingleWorkEvent( cal_client, work_calendar, title, descr, location, start_date, end_date )