import google.oauth2.credentials

from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError

from datetime import datetime
from dateutil.relativedelta import relativedelta

import os


class GoogleCalendar:
    def __init__(self):
        self.creds = None
        self.service = None
        self.SCOPES = ['https://www.googleapis.com/auth/calendar.readonly']
        self.authfile = os.path.join(os.path.dirname(__file__), '../googleoauth.json')
        self.grantfile = os.path.join(os.path.dirname(__file__), '../googleoauth_grant.json')

        if os.path.exists(self.authfile):
            try:
                self.creds = Credentials.from_authorized_user_file(self.authfile, self.SCOPES)
            except ValueError as error:
                print(error)

        self.checkAuth()
        self.buildService()

    def serverAuth(self):
        flow = InstalledAppFlow.from_client_secrets_file(self.grantfile, self.SCOPES)
        self.creds = flow.run_local_server(port=0)

    def saveAuth(self):
        with open(self.authfile, 'w') as token:
            token.write(self.creds.to_json())

    def refreshAuth(self):
        self.creds.refresh(Request())

    def checkAuth(self):
        if not self.creds or not self.creds.valid:
            if self.creds and self.creds.expired and self.creds.refresh_token:
                try:
                    self.refreshAuth()
                except google.oauth2.credentials.exceptions.RefreshError as rerror:
                    self.serverAuth()
            else:
                self.serverAuth()

            self.saveAuth()

    def buildService(self):
        self.service = build('calendar', 'v3', credentials=self.creds)

    def getNow(self):
        return datetime.utcnow().strftime('%Y-%m-%dT00:00:00Z')

    def getNowAfterOneDay(self):
        return (datetime.utcnow() + relativedelta(days=1)).strftime('%Y-%m-%dT00:00:00Z')

    def getEvent(self):
        try:
            now = self.getNow()
            now_after_one_day = self.getNowAfterOneDay()

            events_result_autoficher = self.service.events().list(
                calendarId='e51d3bfb6b352c48afb8bd7a5d494599cc3eaa686800a856796306f50c6d72fd@group.calendar.google.com',
                timeMin=now,
                timeMax=now_after_one_day, maxResults=10, singleEvents=True,
                orderBy='startTime').execute()
            events_result_holiday = self.service.events().list(
                calendarId='es.spain#holiday@group.v.calendar.google.com',
                timeMin=now,
                timeMax=now_after_one_day,
                maxResults=10, singleEvents=True,
                orderBy='startTime').execute()

            events = events_result_autoficher.get('items', []) + events_result_holiday.get('items', [])

            if not events:
                return False

            # Prints the start and name of the next 10 events
            for event in events:
                start = event['start'].get('dateTime', event['start'].get('date'))
                end = event['end'].get('dateTime', event['end'].get('date'))

                if datetime.fromisoformat(start).timestamp() <= datetime.now().timestamp() <= datetime.fromisoformat(
                        end).timestamp():
                    if event['organizer']['displayName'] == 'autoficher':
                        return 'Forzado desde autoficher - ' + event.get("summary", "Sin Título")

                    if 'description' in event and ("Cataluña" in event['description'] or 'Día festivo' in event[
                        'description'] or 'Celebración\n' in event['description']) and not 'Cambio de horario' in event[
                        'summary']:
                        return event['summary']
        except HttpError as error:
            print(f'An error occurred: {error}')
            return 'Error de llama a Google Calendar'

        return False