"""
Shows basic usage of the Google Calendar API. Creates a Google Calendar API
service object and outputs a list of the next 10 events on the user's calendar.
"""
from __future__ import print_function
from googleapiclient.discovery import build
from httplib2 import Http
from oauth2client import file, client, tools
import datetime
import time

def arrayEqual(arr1, arr2):
    if len(arr1) != len(arr2):
        return False
    for i in range(len(arr1)):
        if arr1[i] != arr2[i]:
            return False
    return True

# Setup the Calendar API
SCOPES = 'https://www.googleapis.com/auth/calendar.readonly'
store = file.Storage('credentials.json')
creds = store.get()
events = []
while True:
    if not creds or creds.invalid:
        flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
        creds = tools.run_flow(flow, store)
    service = build('calendar', 'v3', http=creds.authorize(Http()))

    # Call the Calendar API
    now = datetime.datetime.utcnow().isoformat() + 'Z' # 'Z' indicates UTC time
    #print('Getting the upcoming 10 events')
    events_result = service.events().list(calendarId='primary', timeMin=now,
                                          maxResults=10, singleEvents=True,
                                          orderBy='startTime').execute()
    newEvents = events_result.get('items', [])
    if not arrayEqual(events, newEvents):
        events = newEvents
        print("Update")
        f = open("Calendar.txt", "w+")
        if not events:
            #print('No upcoming events found.')
            f.write("No events")
        for event in events:
            start = event['start'].get('dateTime', event['start'].get('date'))
            #print(start, event['summary'])
            print(event['start'].get('date'))
            f.write(start+" "+event['summary']+"\n")
        f.close()
    time.sleep(10)