from datetime import date, time, datetime, timedelta
from pytz import timezone
from uuid import uuid4

from icalendar import Calendar, Event, vCalAddress, vText

from colloscope.models import *

LOCAL_TZ = "Europe/Paris"


def to_calendar(etudiant, periode):
    cal = Calendar()

    cal.add("prodid", "-//Colloscope//colles.mp2i-vms.fr//")
    cal.add("version", "2.0")
    cal.add(
        """
            BEGIN:VTIMEZONE
            TZID:Europe/Paris
            X-LIC-LOCATION:Europe/Paris
            BEGIN:DAYLIGHT
            TZOFFSETFROM:+0100
            TZOFFSETTO:+0200
            TZNAME:CEST
            DTSTART:19700329T020000
            RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
            END:DAYLIGHT
            BEGIN:STANDARD
            TZOFFSETFROM:+0200
            TZOFFSETTO:+0100
            TZNAME:CET
            DTSTART:19701025T030000
            RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
            END:STANDARD
            END:VTIMEZONE
            """
    )

    rotations = Rotation.objects \
            .filter(groupes__membres=etudiant) \
            .select_related("creneau__periode__classe__lycee") \
            .select_related("creneau__matiere") \
            .select_related("creneau__colleur") \

    for rotation in rotations:
        event = Event()

        summary = f"Colle {rotation.creneau.matiere} ({rotation.creneau.colleur})"
        event.add("summary", summary)
        
        start = rotation.datetime()
        fin = start + rotation.creneau.duree

        event.add("dtstart", start, parameters={"tzid": LOCAL_TZ})
        event.add("dtend", fin, parameters={"tzid": LOCAL_TZ})
        event.add("dtstamp", datetime.now())
        event.add("uid", str(uuid4()))
        

        event.add("location", f"{rotation.creneau.salle} ({rotation.creneau.periode.classe.lycee})")
        event.add("categories", "COLLE-" + str(rotation.creneau.matiere))

        description = "Groupes: {','.join(str(groupe) for groupe in rotation.groupes.all())}"
        event.add(description)
        
        organizer = vCalAddress("mailto:unknown@mp2i-vms.fr")
        organizer.params["cn"] = vText(str(rotation.creneau.colleur))
        organizer.params["role"] = vText("Colleur")
        event.add("organizer", organizer)

        for e in rotation.groupe_effectif():
            attendee = vCalAddress("mailto:unknown@mp2i-vms.fr")
            attendee.params["role"] = vText("Etudiant")
            attendee.params["cn"] = vText(str(e))

            event.add("attendee", attendee, encode=0)

        cal.add_component(event)

    return cal