icsjson.py

import os, sys
import datetime
from icalendar import Calendar
import json

def dateToJson(dateObj):
	if isinstance(dateObj.dt, datetime.date):
		# { "date": "2010-08-04" }
		dateStr = dateObj.dt.isoformat()
		return { 'date': dateStr } 
	else: # datetime
		# { "dateTime": "2010-08-04T02:44:20.063Z" }
		dateTimeStr = dateObj.dt.isoformat() # 2014-10-02T18:00:00+00:00
		return { 'dateTime': dateTimeStr }

def eventsToJson(eventList=None, indent=4):
	if eventList is None:
		eventList = list(self.cal.walk('vevent'))

	data = {}
	data['items'] = []
	for event in eventList:
		item = {}

		item['kind'] = 'calendar#event'
		item['etag'] = '\"0123456789012345\"'
		item['iCalUID'] = event['UID']
		item['id'] = "ics_{}_{}_{}".format(item['iCalUID'],
			event['DTSTART'].dt.isoformat(),
			event['DTEND'].dt.isoformat()
		)
		
		item['status'] = 'confirmed' # TODO: event['STATUS']
		item['htmlLink'] = ''
		item['created'] = event['CREATED'].dt.isoformat()
		item['updated'] = event['LAST-MODIFIED'].dt.isoformat()

		item['summary'] = event['SUMMARY']
		if event['LOCATION']:
			item['location'] = event['LOCATION']

		item['start'] = dateToJson(event['DTSTART'])
		item['end'] = dateToJson(event['DTEND'])
		
		# item['transparency'] = event['TRANSP'] # 'transparent'
		# item['recurringEventId'] = ''

		data['items'].append(item)

	return json.dumps(data, indent=indent)

def ensureDateTime(dt):
	if isinstance(dt, datetime.date):
		return datetime.datetime.combine(dt, datetime.time.min)
	else:
		return dt

def eventWithin(event, startTime, endTime):
	eventStart = ensureDateTime(event['DTSTART'].dt)
	eventEnd = ensureDateTime(event['DTEND'].dt)
	startTime = ensureDateTime(startTime)
	endTime = ensureDateTime(endTime)
	# If it starts before endTime and it ends after startTime
	return eventStart <= endTime and eventEnd >= startTime

class CalendarManager:
	def __init__(self, filename):
		self.filename = filename
		self.cal = None
	
	def read(self):
		with open(self.filename, "r") as f:
			text = f.read()
			self.cal = Calendar.from_ical(text)

	@property
	def events(self):
		return self.cal.walk('vevent')

	def query(self, startTime, endTime):
		for event in self.events:
			if eventWithin(event, startTime, endTime):
				print("within", event['DTSTART'].dt, event['DTEND'].dt)
				yield event
			else:
				print("out", event['DTSTART'].dt, event['DTEND'].dt)


	def toJson(self):
		return eventsToJson(self.events)


if __name__ == '__main__':
	manager = CalendarManager('basic.ics')
	manager.read()
	# for e in manager.cal.walk('vevent'):
	# 	print(e)
	# print(manager.toJson())

	startTime = datetime.datetime.strptime('2016-09-15', '%Y-%m-%d')
	endTime = datetime.datetime.strptime('2016-09-16', '%Y-%m-%d')
	eventList = manager.query(startTime, endTime)
	print(eventsToJson(eventList))