from bs4 import BeautifulSoup
from django.utils import timezone
from edt.models import Group, Room, Course

import datetime
import requests


class Week:
    def __init__(self, number, start):
        self.number = number
        self.start = timezone.make_aware(datetime.datetime.strptime(start, "%d/%m/%Y"))

    def get_day(self, id):
        return self.start + datetime.timedelta(id)

def add_time(date, time):
    delta = datetime.timedelta(hours=time.hour, minutes=time.minute)
    return date + delta

def delete_courses_in_week(year, week):
    start = timezone.make_aware(datetime.datetime.strptime("{0}-W{1:02d}-1".format(year, week), "%Y-W%W-%w"))
    end = start + datetime.timedelta(weeks=1)

    Course.objects.filter(begin__gte=start, begin__lt=end).delete()

def get_from_db_or_create(cls, name, timetable=None):
    obj = cls.objects.all().filter(name=name)
    if timetable is not None:
        obj = obj.filter(timetable=timetable)

    obj = obj.first()
    if obj is None:
        obj = cls(name=name)
        obj.timetable = timetable
        obj.save()

    return obj

def get_events(soup, weeks, week, timetable):
    for event in soup.find_all("event"):
        title = None
        type_ = None
        groups = None
        rooms = None

        if weeks[event.rawweeks.text].number != week:
            continue

        if event.resources.module is not None:
            title = event.resources.module.text

        if event.category is not None and title is not None:
            type_ = event.category.text

        if event.resources.group is not None and type_ is not None:
            groups = [get_from_db_or_create(Group, item.text, timetable) for item in event.resources.group.find_all("item")]

        if event.resources.room is not None and groups is not None:
            rooms = [get_from_db_or_create(Room, item.text) for item in event.resources.room.find_all("item")]

            date = weeks[event.rawweeks.text].get_day(int(event.day.text))
            begin = add_time(date, datetime.datetime.strptime(event.starttime.text, "%H:%M"))
            end = add_time(date, datetime.datetime.strptime(event.endtime.text, "%H:%M"))

            yield title, type_, groups, rooms, begin, end

def get_weeks(soup):
    weeks = {}
    for span in soup.find_all("span"):
        weeks[span.alleventweeks.text] = Week(int(span.title.text), span["date"])

    return weeks

def get_xml(url):
    r = requests.get(url)
    r.encoding = "utf8"

    soup = BeautifulSoup(r.text, "html.parser")
    return soup