#!/usr/bin/env python
#-*- encoding: utf-8

import sys
import requests
from html.parser import HTMLParser
from datetime import datetime as dt, time
import caldav
from icalendar import Calendar, Event
import pytz


# Constants definition
URL = "https://docs.google.com/spreadsheets/u/0/d/e/2PACX-1vQ9yzFLr5mXbIZVK3ucdUZuScAbLoCyPqzHr-5V0aYeCFEz7LuidPdk_EnkkJT-zjemzQQHaKvpeXW2/pubhtml/sheet?headers=false&gid=1619638924"
TIMETABLE = [
    ('08:00','08:00'),
    ('09:00','09:00'),
    ('10:00','10:15'),
    ('11:15','11:15'),
    ('12:15','12:15'),
    ('13:00','13:00'),
    ('13:30','13:30'),
    ('14:30','14:30'),
    ('15:30','15:45'),
    ('16:45','16:45'),
    ('17:45','17:45'),
]
DAVURL = "https://cal.edgarpierre.fr"
CALURL = "https://cal.edgarpierre.fr/edpibu/817427eb-be7c-4540-872a-dfb723a205a6/"


class GoogleSheetsCalParser(HTMLParser):
    """
        Definition of a Google Sheets parser providing a table with each cell
        and its position and size
    """
    def __init__(self):
        self.inTable = False
        self.inCell = False
        self.inDate = False
        self.inEvent = False
        self.row = -1
        self.column = -1
        self.nextCol = -1
        self.rowspan = 0
        self.multirows = {}
        self.date = {}
        self.event = Event()
        self.event['uid'] = 0
        self.uids = []

        import priv

        client = caldav.DAVClient(url=DAVURL, username=priv.USERNAME,
                password=priv.PASSWORD)
        self.calendar = caldav.Calendar(client=client, url=CALURL)

        #print(self.calendar.event_by_uid('42x26').data)

        HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        dAttrs = dict(attrs)

        if self.inTable:
            if tag == 'tr':
                self.row += 1
                self.nextCol = -1
            elif tag == 'td':
                while self.nextCol in self.multirows.keys() and self.multirows[self.nextCol][1] > 0:
                    self.nextCol += self.multirows[self.nextCol][0]

                self.column = self.nextCol
                if 'colspan' in dAttrs.keys():
                    self.nextCol += int(dAttrs['colspan'])
                else: self.nextCol += 1

                if not (self.row < 3 or (self.row - 2) % 12 < 2):
                    self.inCell = True
                    if 'rowspan' in dAttrs.keys():
                        self.rowspan = int(dAttrs['rowspan'])
                        self.multirows[self.column] = [self.nextCol - self.column, self.rowspan]
                    else: self.rowspan = 1
                elif (self.row - 2) % 12 == 1:
                    self.inDate = True
        elif tag == 'tbody':
            self.inTable = True

    def handle_endtag(self, tag):
        if tag == 'td':
            self.inCell = False
            self.inDate = False
            if self.inEvent:
                self.inEvent = False
                cal = Calendar()
                cal.add('prodid', '-//edpibu//edt-parser//FR')
                cal.add('version', '2.0')
                cal.add_component(self.event)

                self.uids.append(self.event['uid'])
                try:
                    ev = self.calendar.event_by_uid(self.event['uid'])
                except caldav.lib.error.NotFoundError:
                    ev = None
                if ev:
                    icev = Calendar.from_ical(ev.data).subcomponents[1]
                    ex = True
                    if icev['summary'] != self.event['summary']:
                        ex = False
                    else:
                        for key in ['dtstart', 'dtend']:
                            if icev[key].to_ical() != self.event[key].to_ical():
                                ex = False
                    if ex: return
                    print(f'Change on {self.event.decoded("dtstart").isoformat()}')
                    ev.data = cal.to_ical().decode('utf-8')
                    ev.save()
                    return

                print(f'New event on {self.event.decoded("dtstart").isoformat()}')
                self.calendar.save_event(cal.to_ical().decode('utf-8'))
        elif tag == 'tr':
            for mr in self.multirows.values():
                mr[1] -= 1
        elif tag == 'tbody':
            self.inTable = False
            for ev in self.calendar.events():
                icev = Calendar.from_ical(ev.data).subcomponents[1]

                if icev['uid'] not in self.uids:
                    ev.delete()
                    print(f'Deleted event on {icev.decoded("dtstart").isoformat()}')

    def handle_data(self, data):
        if self.inDate:
            self.date[self.column] = dt.strptime(data, '%d-%b-%y').date()
        elif self.inCell and data not in ['', '-']:
            self.inEvent = True
            times = [time.fromisoformat(TIMETABLE[(self.row - 2) % 12 - 2][1]),
                time.fromisoformat(TIMETABLE[(self.row - 2) % 12 - 2 + self.rowspan][0])]

            if self.event['uid'] == f'{self.row}x{self.column}':
                self.event['summary'] = f'{self.event["summary"]} {data}'
            else:
                self.event = Event()
                self.event.add('uid', f'{self.row}x{self.column}')
                self.event.add('summary', data)
                self.event.add('dtstamp', dt.now())
                self.event.add('dtstart', dt.combine(self.date[self.column], times[0],
                    pytz.timezone('Europe/Paris')))
                self.event.add('dtend', dt.combine(self.date[self.column], times[1],
                    pytz.timezone('Europe/Paris')))


# Getting the Google Sheet
try:
    r = requests.get(URL)
except ConnectionError as e:
    print(e)
    sys.exit(1)

if r.status_code != 200:
    print(f'Status Code {r.status_code}; could not continue.')
    sys.exit(1)

# Parsing the Sheet
calParser = GoogleSheetsCalParser()
calParser.feed(r.text)