from caldav import DAVClient, error
from icalendar import Calendar, Event
from datetime import datetime, timedelta
import pytz
import uuid
import sys

###############
### SETUP START
### rfc6638_users should be a list with three dicts containing credential details.
### if none is given, attempt to use three test users on tobixens private calendar
###
try:
    from tests.conf_private import rfc6638_users
except:
    rfc6638_users = None

## Some inital setup.  We'll need three caldav client objects, with
## corresponding principal objects and calendars.
class TestUser:
    def __init__(self, i):
        if rfc6638_users and len(rfc6638_users)>i-1:
            conndata = rfc6638_users[i-1].copy()
            if 'incompatibilities' in conndata:
                conndata.pop('incompatibilities')
            self.client = DAVClient(**conndata)
        else:
            self.client = DAVClient(username = "testuser%i" % i, password = "testpass%i" %i, url = "http://calendar.tobixen.no/caldav.php/")
        self.principal = self.client.principal()
        calendar_id = "schedulingtestcalendar%i" % i
        calendar_name = "calendar #%i for scheduling demo" % i
        self.cleanup(calendar_name)
        self.calendar = self.principal.make_calendar(name=calendar_name, cal_id=calendar_id)

    def cleanup(self, calendar_name):
        ## Cleanup from earlier runs
        try:
            self.calendar = self.principal.calendar(name=calendar_name)
            self.calendar.delete()
        except error.NotFoundError:
            pass

        ## Hmm ... perhaps we shouldn't delete inbox items
        #for inbox_item in self.principal.schedule_inbox().get_items():
            #inbox_item.delete()

organizer = TestUser(1)
attendee1 = TestUser(2)
attendee2 = TestUser(3)

### SETUP  END
###############

## Verify that the calendar server(s) supports scheduling
for test_user in organizer, attendee1, attendee2:
    if not test_user.client.check_scheduling_support():
        print("Server does not support RFC6638")
        sys.exit(1)

## We'll be using the icalendar library to set up a mock meeting,
## at some far point in the future.
caldata = Calendar()
caldata.add('prodid', '-//tobixen//python-icalendar//en_DK')
caldata.add('version', '2.0')

uid = uuid.uuid1()
event=Event()
event.add('dtstamp', datetime.now())
event.add('dtstart', datetime.now() + timedelta(days=4000))
event.add('dtend', datetime.now() + timedelta(days=4000, hours=1))
event.add('uid', uid)
event.add('summary', 'Some test event made to test scheduling in the caldav library')
caldata.add_component(event)

caldata2 = Calendar()
caldata2.add('prodid', '-//tobixen//python-icalendar//en_DK')
caldata2.add('version', '2.0')

uid = uuid.uuid1()
event=Event()
event.add('dtstamp', datetime.now())
event.add('dtstart', datetime.now() + timedelta(days=4000))
event.add('dtend', datetime.now() + timedelta(days=4000, hours=1))
event.add('uid', uid)
event.add('summary', 'Test event with participants but without invites')
caldata2.add_component(event)


## that event is without any attendee information.  If saved to the
## calendar, it will only be stored locally, no invitations sent.

## There are two ways to send calendar invites:

## * Add Attendee-lines and an Organizer-line to the event data, and
##   then use calendar.save_event(caldata) ... see RFC6638, appendix B.1
##   for an example.

## * Use convenience-method calendar.save_with_invites(caldata, attendees).
##   It will fetch organizer from the principal object.  Method should
##   accept different kind of attendees: strings, VCalAddress, (cn,
##   email)-tuple and principal object.

## Lets make a list of attendees
attendees = []

## The organizer will invite himself.  We'll pass a vCalAddress (from
## the icalendar library).
attendees.append(organizer.principal.get_vcal_address())

## Let's make it easy and add the other attendees by the Principal objects.
## note that we've used login credentials to get the principal
## objects below.  One would normally need to know the principal
## URLs to create principal objects of other users, or perhaps use
## the principal-collection-set prop to get a list.
attendees.append(attendee1.principal)
attendees.append(attendee2.principal)
    
## An attendee can also be added by email address
attendees.append('some-random-guy@example.com')

## Or by a (common_name, email) tuple
attendees.append(
    ('Some Other Random Guy', 'some-other-random-guy@example.com'))

print("Sending a calendar invite")
organizer.calendar.save_with_invites(caldata, attendees=attendees)

print("Storing another calendar event with the same participants, but without sending out emails")
organizer.calendar.save_with_invites(caldata2, attendees=attendees, schedule_agent='NONE')

## There are some attendee parameters that may be set (TODO: add
## example code), the convenience method above will use sensible
## defaults.

## The invite has now been shipped.  The attendees should now respond to it.

print("looking into the inbox of attendee1")
all_cnt = 0
invite_req_cnt = 0
for inbox_item in attendee1.principal.schedule_inbox().get_items():
    all_cnt += 1
    ## an inbox_item is an ordinary CalendarResourceObject/Event/Todo etc.
    ## is_invite_request will be implemented on the base class and will yield True
    ## for invite messages.
    print("Inbox item found for attendee1.  Here is the ical:")
    print(inbox_item.data)
    
    if inbox_item.is_invite_request():
        print("Inbox item is an invite request")
        invite_req_cnt += 1 ## TODO: assert(invite_req_cnt == 1) after loop
        
        ## Ref RFC6638, example B.3 ... to respond to an invite, it's
        ## needed to edit the ical data, find the correct
        ## "attendee"-field, change the attendee "partstat", put the
        ## ical object back to the server.  In addition one has to
        ## look out for race conflicts and retry the whole operation
        ## in case of race conflicts.  Editing ical data is a bit
        ## outside the scope of the CalDAV client library, but ... the
        ## library clearly needs convenience methods to deal with this.

        ## Invite objects will have methods accept_invite(),
        ## decline_invite(),
        ## tentatively_accept_invite().  .delete() is also an option
        ## (ref RFC6638, example B.2)
        inbox_item.accept_invite()
        inbox_item.delete()

## attendee2 has other long-term plans and can't join the event
for inbox_item in attendee2.principal.schedule_inbox().get_items():
    print("found an inbox item for attendee 2, here is the ical:")
    print(inbox_item.data)
    if inbox_item.is_invite_request():
        print("declining invite")
        inbox_item.decline_invite()
        inbox_item.delete()

## Oganizer will have an update on the participant status in the
## inbox (or perhaps two updates?)  If I've understood the standard
## correctly, testuser0 should not get an invite and should not have
## to respond to it, but just in case we'll accept it.  As far as I've
## understood, deleting the ical objects in the inbox should be
## harmless, it should still exist on the organizers calendar.
## (Example B.4 in RFC6638)
print("looking into organizers inbox")
for inbox_item in organizer.principal.schedule_inbox().get_items():
    print("Inbox item found, here is the ical:")
    print(inbox_item.data)
    if inbox_item.is_invite_request():
        print("It's an invite request, let's accept it")
        inbox_item.accept_invite()
    elif inbox_item.is_invite_reply():
        print("It's an invite reply, now that we've read it, we can delete it")
        inbox_item.delete()

## RFC6638/RFC5546 allows an organizer to check the freebusy status of
## multiple principals identified by email address.  It's covered in
## section 4.3.2. in RFC5546 and chapter 5 / example B.5 in RFC6638.
## Most of the logic is on the icalendar format (covered in RFC5546),
## and is a bit outside the scope of the caldav client library.
## However, I will probably make a convenience method for doing the
## query, and leaving the parsing of the returned icalendar data to
## the user of the library:
import pdb; pdb.set_trace()
some_data_returned = organizer.principal.freebusy_request(
    dtstart=datetime.now().astimezone(pytz.utc) + timedelta(days=399),
    dtend=datetime.now().astimezone(pytz.utc) + timedelta(days=399, hours=1),
    attendees=[attendee1.principal, attendee2.principal])

## Examples in RFC6638 goes on to describing how to accept and decline
## particular instances of a recurring events, and RFC5546 has a lot
## of extra information, like ways for a participant to signal back
## new suggestions for the meeting time, delegations, cancelling of
## events and whatnot.  It is possible to use the library for such
## things by saving appropriate icalendar data to the outbox and
## reading things from the inbox, but as for now there aren't any
## planned convenience methods for covering such things.