import datetime

from yaml import load, FullLoader
from icalendar.parser import Contentlines, Contentline
from dateutil.rrule import rrule, FREQNAMES
import caldav


class Task:
    def __init__(self, reference_date, name, data):
        self.ref_date = reference_date
        self.name = name
        data['start']['freq'] = FREQNAMES.index(data['start']['freq'])
        self.date_begin = rrule(count=1, dtstart=reference_date, **data['start'])[0]
        self.date_end = self.date_begin + datetime.timedelta(microseconds=-1, **data['duration'])

        self.title = data['title']
        self.body = data['body']
        self.priority = data['priority']

    def to_ical(self):
        current_dtstamp = datetime.datetime.now().strftime('%Y%m%dT%H%M%SZ')
        uid = f"CaldavRecurringTask-{self.name}-{self.date_end.strftime('%Y%m%d')}"
        c = Contentlines([
            Contentline('BEGIN:VCALENDAR'),
            Contentline('VERSION:2.0'),
            Contentline('PRODID:-//DorfsvaldNet//CaldavRecuringTaskClient//FR'),
            Contentline('BEGIN:VTODO'),
            Contentline(f'DTSTAMP:{current_dtstamp}'),
            Contentline(f'UID:{uid}'),
            Contentline(f'CREATED:{current_dtstamp}'),
            Contentline(f'LAST-MODIFIED:{current_dtstamp}'),
            Contentline(f'SEQUENCE:{"4"}'),
            Contentline(f'DESCRIPTION:{self.body}'),
            Contentline(f'SUMMARY:{self.title}'),
            Contentline(f'PRIORITY:{self.priority}'),
            Contentline(f'DUE;VALUE=DATE:{self.date_end.strftime("%Y%m%d")}'),
            Contentline(f'DTSTART;VALUE=DATE:{self.date_begin.strftime("%Y%m%d")}'),
            Contentline('PERCENT-COMPLETE:0'),
            Contentline('STATUS:NEEDS-ACTION'),
            Contentline('END:VTODO'),
            Contentline('END:VCALENDAR')
        ])

        return c.to_ical()


class Client:
    def __init__(self, url, username, password, calendar_name):
        self.client = caldav.DAVClient(url, username=username, password=password)
        self.principal = self.client.principal()
        self.calendar = None
        for c in self.principal.calendars():
            if c.name == calendar_name:
                self.calendar = c
                break

        if self.calendar is None:
            raise LookupError('No calendar named "{}" found'.format(calendar_name))

    def add_event(self, new_task):
        self.calendar.add_event(new_task.to_ical())


if __name__ == "__main__":
    with open('./configuration.yml', 'r') as configuration_file:
        conf = load(configuration_file.read(), Loader=FullLoader)

    ref_date = datetime.date.today() + datetime.timedelta(days=2)
    with open('tasks.yml', 'r') as content_file:
        tasks_conf = load(content_file.read(), Loader=FullLoader)

    task_list = []
    for task_name, task_data in tasks_conf.items():
        t = Task(ref_date, task_name, task_data)
        if t.date_begin.date() == ref_date:
            task_list.append(t)

    if task_list:
        server = conf['dav_server']
        client = Client(server['url'], server['user'], server['pass'], server['calendar'])
        for task in task_list:
            client.add_event(task)

    print('process finished: {} tasks created'.format(len(task_list)))