ews-fetch-calendar.py

#!/usr/bin/python

# This script was inspired by:
# http://blogs.msdn.com/b/exchangedev/archive/2009/02/05/quick-and-dirty-unix-shell-scripting-with-ews.aspx
# http://ewsmacwidget.codeplex.com/

import os
from lxml import etree
from datetime import datetime
from datetime import date
from datetime import timedelta
from pytz import timezone
import pytz
import httplib
import base64
import ConfigParser

# Read the config file
config = ConfigParser.RawConfigParser()
dir = os.path.realpath(__file__)[:-21]
config.read(dir + 'config.cfg')

# Exchange user and password
ewsHost = config.get('ews-orgmode', 'host')
ewsUrl = config.get('ews-orgmode', 'path')
ewsUser = config.get('ews-orgmode', 'username')
ewsPassword = config.get('ews-orgmode', 'password')
timezoneLocation = config.get('ews-orgmode', 'timezone')
daysHistory = config.getint('ews-orgmode', 'days_history')
daysFuture = config.getint('ews-orgmode', 'days_future')
maxEntries = config.getint('ews-orgmode', 'max_entries')

def parse_ews_date(dateStr):
  d = datetime.strptime(dateStr, "%Y-%m-%dT%H:%M:%SZ")
  exchangeTz = pytz.utc
  localTz = timezone(timezoneLocation)
  return exchangeTz.localize(d).astimezone(localTz);

def format_orgmode_date(dateObj):
  return dateObj.strftime("%Y-%m-%d %H:%M")

def format_orgmode_time(dateObj):
  return dateObj.strftime("%H:%M")

# Helper function to write an orgmode entry
def print_orgmode_entry(subject, start, end, location):
  startDate = parse_ews_date(start);
  endDate = parse_ews_date(end);
  # Check if the appointment starts and ends on the same day and use proper formatting
  dateStr = ""
  if startDate.date() == endDate.date():
    dateStr = "<" +  format_orgmode_date(startDate) + "-" + format_orgmode_time(endDate) + ">"
  else:
    dateStr = "<" +  format_orgmode_date(startDate) + ">--<" + format_orgmode_date(endDate) + ">"

  if subject is not None:
    if dateStr != "":
      print "* TODO " + dateStr + " " + subject.encode('ascii', 'ignore')
    else:
      print "* TODO " + subject.encode('ascii', 'ignore')

  if location is not None:
    print ":PROPERTIES:"
    print ":LOCATION: " + location.encode('utf-8')
    print ":END:"

  print ""

#Debug code
#print_orgmode_entry("subject", "2012-07-27T11:10:53Z", "2012-07-27T11:15:53Z", "location", "participants")
#exit(0)

# Build the soap request
# For CalendarItem documentation, http://msdn.microsoft.com/en-us/library/exchange/aa564765(v=exchg.140).aspx
start = date.today() - timedelta(days=daysHistory)
end = date.today() + timedelta(days=daysFuture)
request = """<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
               xmlns:xsd="http://www.w3.org/2001/XMLSchema"
               xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
               xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
  <soap:Body>
    <FindItem Traversal="Shallow" xmlns="http://schemas.microsoft.com/exchange/services/2006/messages">
      <ItemShape>
        <t:BaseShape>Default</t:BaseShape>
      </ItemShape>
      <CalendarView MaxEntriesReturned="{2}" StartDate="{0}T00:00:00-08:00" EndDate="{1}T00:00:00-08:00"/>
      <ParentFolderIds>
        <t:DistinguishedFolderId Id="calendar"/>
      </ParentFolderIds>
    </FindItem>
  </soap:Body>
</soap:Envelope>""".format(start, end, maxEntries)

# Build authentication string, remove newline for using it in a http header
auth = base64.encodestring("%s:%s" % (ewsUser, ewsPassword)).replace('\n', '')
conn = httplib.HTTPSConnection(ewsHost)
conn.request("POST", ewsUrl, body = request, headers = {
  "Host": ewsHost,
  "Content-Type": "text/xml; charset=UTF-8",
  "Content-Length": len(request),
  "Authorization" : "Basic %s" % auth
})

# Read the webservice response
resp = conn.getresponse()
data = resp.read()
conn.close()

# Debug code
# print data
# exit(0)

# Parse the result xml
root = etree.fromstring(data)

xpathStr = "/s:Envelope/s:Body/m:FindItemResponse/m:ResponseMessages/m:FindItemResponseMessage/m:RootFolder/t:Items/t:CalendarItem"
namespaces = {
    's': 'http://schemas.xmlsoap.org/soap/envelope/',
    't': 'http://schemas.microsoft.com/exchange/services/2006/types',
    'm': 'http://schemas.microsoft.com/exchange/services/2006/messages',
}

# Print calendar elements
elements = root.xpath(xpathStr, namespaces=namespaces)
for element in elements:
  subject= element.find('{http://schemas.microsoft.com/exchange/services/2006/types}Subject').text
  location= element.find('{http://schemas.microsoft.com/exchange/services/2006/types}Location').text
  start = element.find('{http://schemas.microsoft.com/exchange/services/2006/types}Start').text
  end = element.find('{http://schemas.microsoft.com/exchange/services/2006/types}End').text
  print_orgmode_entry(subject, start, end, location)