#!/usr/bin/env python
from icalendar import Calendar, Event, UTC
from datetime import datetime, timedelta
import sys, os
 
skipdays = []
adddays = []
# Read a file in this format:
# Project name
# Total # days to count
# Start date
# Skipped days, one per line
baseproject = os.path.basename(os.path.splitext(sys.argv[1])[0])
 
f = open(sys.argv[1], 'rb')
state = 1
for line in f:
    line = line.rstrip()
    if len(line) == 0 or line[0] == '#':
        continue
    if state == 1:
        project = line
    if state == 2:
        count = int(line)
    if state == 3:
        startday = datetime.strptime(line, "%Y/%m/%d")
    if state == 4:
        if line[0] == '+':
            adddays.append(datetime.strptime(line[1:], "%Y/%m/%d"))
        else:
            skipdays.append(datetime.strptime(line, "%Y/%m/%d"))
        # About to increment the state otherwise
        continue
    state += 1
 
f.close()
 
days = {}
days[0] = startday + timedelta(-1)
 
cal = Calendar()
cal.add('prodid', "-//Tildee's project day counter//rumsey.org//")
cal.add('version', "2.0")
 
for i in range(1, count + 1):
    day = days[i - 1]
    day = day + timedelta(1)
    while (day in skipdays) or ((day.weekday() == 5 or day.weekday() == 6) and not (day in adddays)):
        day = day + timedelta(1)
    days[i] = day
    event = Event()
    event.add('summary', '%s, Day %d' % (project, i))
    event.add('dtstart', day)
    event.add('dtend', day)
    event.add('dtstamp', day)
    event['uid']="D%d/%d%d%d@rumsey.org" % (i, day.year, day.month, day.day)
    event.add('priority', 5)
    cal.add_component(event)
 
    print "Day " + str(i) + ": " + str(day)
 
output = '/tmp/%s.ics' % (baseproject)
f = open(output, 'wb')
f.write(cal.as_string())
f.close()