arms

#!/usr/bin/env python2

import sys, json, time, datetime, re, argparse, os.path, pickle
from netrc import netrc
from urllib2 import Request, urlopen
from base64 import encodestring

class DayAction(argparse.Action):
  def __call__(self, parser, namespace, values, option_string=None):
    today = datetime.date.today()
    if values == 'today':
      values = today
    elif values == 'tomorrow':
      values = (today + datetime.timedelta(days=1)).strftime('%Y-%m-%d')
    elif re.match('^[\+\-]\d+$', values or ''):
      values = (today + datetime.timedelta(days=int(values))).strftime('%Y-%m-%d')
    setattr(namespace, self.dest, values)

parser = argparse.ArgumentParser(description="""Fetch ARBS calendar using ARMS.
    Authentication information can be stored in your .netrc under arms.staffanenberg.com""")
parser.add_argument('-u', '--user',     help='ARMS username')
parser.add_argument('-p', '--password', help='ARMS password')
parser.add_argument('--past',           help='Include the past',
    action='store_true', default=False)
parser.add_argument('-f', '--force',    help='Force a cache refresh',
    action='store_true', default=False)
parser.add_argument('--format',         help='Specify the output format passed to format()',
    default="{0}-{1}\t{2} ({3})")
parser.add_argument('--separator',      help='Specify the separator beneath the day name',
    default="="*80)
parser.add_argument('--date_format',    help='Specify the date format for strftotime().',
    default="%a %d %B")
parser.add_argument('day',              help="""Specific day to display, either as
    YYYY-MM-DD, "today", "tomorrow", +offset, -offset""",
    action=DayAction, nargs='?')

toTime = lambda timestamp: time.strftime('%H:%M', time.localtime(int(timestamp)))
arms_url = 'http://arms.staffanenberg.com/api/v1/arbs/%s'
args = parser.parse_args()
cache_file = '/tmp/arms/arms_%s' % args.day
cache_time = 60 * 60

def main():
  if args.force or not cacheIsValid(cache_file):
    cache_dir = os.path.dirname(cache_file)
    data = fetchFreshData()
    if not os.path.isdir(cache_dir):
      os.makedirs(cache_dir)
    pickle.dump(data, open(cache_file, 'w'))
  else:
    data = pickle.load(open(cache_file, 'r'))

  if isinstance(data, IOError):
    print data
    sys.exit(1)

  if args.day == None:
    if not args.past:
      today = datetime.date.today().strftime("%Y-%m-%d")
      data = dict((key, value) for key, value in data.iteritems() if key >= today)
    for day in sorted(data, reverse=True):
      date_string = datetime.datetime.strptime(day, "%Y-%m-%d").strftime(args.date_format)
      print date_string + '\n' + args.separator
      outputLessons(data[day])
      print
  elif len(data) > 0:
    outputLessons(data)
  else:
    print "Nothing today"

def cacheIsValid(cache):
  if not os.path.exists(cache): return False
  return (os.path.getmtime(cache) + cache_time) > time.time()

def fetchFreshData():
  if args.user == None:
    rc = netrc()
    (args.user, args.host, args.password) = (netrc()).authenticators('arms.staffanenberg.com')

  url = arms_url % (args.day if args.day else "")
  data = getJson(url, args.user, args.password)
  return data

def getJson(url, username, password):
  req = Request(url)
  auth = 'Basic %s' % encodestring('%s:%s' % (username, password))[:-1]
  req.add_header('Authorization', auth);
  try:
    handle = urlopen(req)
    return json.loads(handle.read())
  except IOError, e:
    return e

def outputLessons(day):
  for timestamp in sorted(day.items()):
    for entry in timestamp[1]:
      print args.format.format(
        toTime(entry["start"]),
        toTime(entry["end"]),
        entry["summary"].encode('utf8'),
        entry["location"].encode('utf8'))

if __name__ == "__main__":
  main()