from pyparsing import Optional, oneOf, Dict, Literal, Word, printables, Group, OneOrMore, ZeroOrMore

"""
A simple parser for calendar (*.ics) files,
as exported by the Mozilla calendar.

Any suggestions and comments welcome.

Version:   0.1
Copyright: Petri Savolainen <firstname.lastname@iki.fi>
License:   Free for any use
"""


# TERMINALS

BEGIN      =   Literal("BEGIN:").suppress()
END        =   Literal("END:").suppress()
str        =   printables + "\xe4\xf6\xe5\xd6\xc4\xc5"
valstr     =   str + " "

EQ         =   Literal("=").suppress()
SEMI       =   Literal(";").suppress()
COLON      =   Literal(":").suppress()

EVENT      =   Literal("VEVENT").suppress()
CALENDAR   =   Literal("VCALENDAR").suppress()
ALARM      =   Literal("VALARM").suppress()

# TOKENS

CALPROP   =   oneOf("VERSION PRODID METHOD")
ALMPROP   =   oneOf("TRIGGER")
EVTPROP   =   oneOf("X-MOZILLA-RECUR-DEFAULT-INTERVAL \
                     X-MOZILLA-RECUR-DEFAULT-UNITS \
                     UID DTSTAMP LAST-MODIFIED X RRULE EXDATE")

propval   =   Word(valstr)
typeval   =   Word(valstr)
typename  =   oneOf("VALUE MEMBER FREQ UNTIL INTERVAL")

proptype = Group(SEMI + typename + EQ + typeval).suppress()

calprop = Group(CALPROP + ZeroOrMore(proptype) + COLON + propval)
almprop = Group(ALMPROP + ZeroOrMore(proptype) + COLON + propval)
evtprop = Group(EVTPROP + ZeroOrMore(proptype) + COLON + propval).suppress() \
   | "CATEGORIES" + COLON + propval.setResultsName("categories") \
   | "CLASS" + COLON + propval.setResultsName("class") \
   | "DESCRIPTION" + COLON + propval.setResultsName("description") \
   | "DTSTART" + proptype + COLON + propval.setResultsName("begin") \
   | "DTEND" + proptype + COLON + propval.setResultsName("end") \
   | "LOCATION" + COLON + propval.setResultsName("location") \
   | "PRIORITY" + COLON + propval.setResultsName("priority") \
   | "STATUS" + COLON + propval.setResultsName("status") \
   | "SUMMARY" + COLON + propval.setResultsName("summary") \
   | "URL" + COLON + propval.setResultsName("url") \

calprops = Group(OneOrMore(calprop)).suppress()
evtprops = Group(OneOrMore(evtprop))
almprops = Group(OneOrMore(almprop)).suppress()

alarm      = BEGIN + ALARM + almprops + END + ALARM
event      = BEGIN + EVENT + evtprops + Optional(alarm) + END + EVENT
events     = Group(OneOrMore(event))
calendar   = BEGIN + CALENDAR + calprops + ZeroOrMore(event) + END + CALENDAR
calendars  =   OneOrMore(calendar)


# PARSE ACTIONS

def gotEvent(s,loc,toks):
   for event in toks:
      print (event['summary'], "from", event["begin"], "to", event["end"])

event.setParseAction(gotEvent)


# MAIN PROGRAM

if __name__=="__main__":

   calendars.parseFile("mozilla.ics")
