from ics import Calendar, Event
from datetime import datetime, timedelta
import pytz

from models.schedule import Schedule
from models.user import User


timezone = pytz.timezone("Europe/Moscow") 
class ICS:
    def __init__(self, user: User, use_this_week: bool = False) -> None:
        self.userID: int = user.id
        schedule: Schedule = user.schedule()
        if not schedule: raise ValueError
        
        if not use_this_week:  # happens only on Sunday -> move to next week
            schedule.weekNumber += 1 
            self.start_week_date = timezone.localize(datetime.now()) + timedelta(days=7-schedule.weekDay) 
        
        else:  # on this week
            self.start_week_date = timezone.localize(datetime.now()) - timedelta(days=schedule.weekDay)
        
        self.calendar = Calendar()
        
        for target in range(5):
            schedule.weekDay = target
            event_date = self.start_week_date + timedelta(days=target)
            # print(f'\n\n--- {target} -> {event_date.strftime("%Y-%m-%d")} ---')
            
            for lesson in schedule.today():
                event = Event()
                
                event.name = f'{lesson.name}'
                event.description = f'{lesson.type} ({", ".join([_ for _ in lesson.info  if "ауд" in _])})'
                if ' ()' in event.description: event.description = event.description.replace(' ()', '')
                
                event.begin = event_date.replace(hour=lesson.start[0], minute=lesson.start[1], second=0, microsecond=0)
                event.duration = timedelta(hours=1, minutes=30)
                event.end =  event_date.replace(hour=lesson.end[0], minute=lesson.end[1], second=0, microsecond=0)
                
                self.calendar.events.add(event) 
                # print(event.name, '|', event.description, f'[{event.begin} - {event.end}]')
                
                # break
            # break

    def save(self) -> str:
        """returns path to file"""
        content = self.calendar.serialize()
        for line in self.calendar.serialize().split('\n'):
            if 'DTSTART' in line: 
                ts = line.split(':')[1]
                content = content.replace(f'DTSTART:{ts}', f'DTSTART:{ts}\nDTSTAMP:{ts}')
        
        path = f'./temp/{self.userID}.ics'
        with open(path, 'w', encoding='utf-8', newline='') as file: file.writelines(content)
        return path