import os.path

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

############################################
## Параметры приложения

OLD_NUMBER_PREFIXES = ['+38071', '071']
NEW_NUMBER_PREFIXES = ['+7949']

# Функция для получения нового номера из основы старого
#
# Вернет номер в формате +7 949 123-45-67
def new_phone_number(base: str):
    num = '7949' + base

    return '+{} {} {}-{}-{}'.format(
        num[0],
        num[1:4],
        num[4:7],
        num[7:9],
        num[9:11]
    )

PHONE_TYPE = 'mobile'

###################################################
# Параметры Google API

CREDENTIALS_FILE = 'credentials.json'
TOKEN_FILE = 'token.json'
REDIRECT_PORT = 42047
SCOPES = ['https://www.googleapis.com/auth/contacts']

########

def main():
    creds = None

    if os.path.exists(TOKEN_FILE):
        creds = Credentials.from_authorized_user_file(TOKEN_FILE, SCOPES)

    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                CREDENTIALS_FILE, SCOPES)
            creds = flow.run_console()
            with open(TOKEN_FILE, 'w') as token:
                token.write(creds.to_json())

    try:
        service = build('people', 'v1', credentials=creds)
        print('Получаем список контактов...')
        results = service.people().connections().list(resourceName='people/me',
                                                      personFields='names,phoneNumbers').execute()
        connections = results.get('connections', [])

        print('Количество контактов: {}'.format(len(connections)))

        batch_request = {
            "contacts": {},
            "updateMask": "phoneNumbers"
        }

        for person in connections:
            phoneNumbers = person.get('phoneNumbers', [])

            has_old = False

            old_numbers = set()
            new_numbers = set()

            # Получаем номера нового и старого формата
            for phoneNumber in phoneNumbers:
                num = phoneNumber.get('canonicalForm')

                if not num:
                    continue

                base = get_number_without_prefix(num, OLD_NUMBER_PREFIXES)

                if (base):
                    has_old = True
                    old_numbers.add(base)

                base = get_number_without_prefix(num, NEW_NUMBER_PREFIXES)

                if (base):
                    new_numbers.add(base)

            # Если нет старого - пропускаем
            if not has_old:
                continue

            # Получаем старые номера, у которых нету парного нового
            numbers_not_updated = list(
                old_numbers.difference(new_numbers)
            )
        
            # Если нет старых номеров, которые нужно обновить - пропускаем
            if len(numbers_not_updated) == 0:
                continue

            # Получаем новые номера
            new_phone_numbers = [
                new_phone_number(x) for x in numbers_not_updated
            ]

            # batchUpdateContacts: https://developers.google.com/people/api/rest/v1/people/batchUpdateContacts
            # PhoneNumber: https://developers.google.com/people/api/rest/v1/people#phonenumber
            batch_request['contacts'][person['resourceName']] = {
                "phoneNumbers": [
                    *person['phoneNumbers'],
                    [
                        { 
                            "value": number, 
                            "type": PHONE_TYPE
                        } for number in new_phone_numbers
                    ]
            ],
            "etag": person['etag']
        }

        contacts_len = len(batch_request['contacts'])

        if (contacts_len > 0):
            print('Количество контактов для обновления: {}'.format(contacts_len))
            print('Обновляем контакты...')
            service.people().batchUpdateContacts(body = batch_request).execute()
            print('Обновление завершено!')
        else:
            print('Нечего обновлять!')
    except HttpError as err:
        print(err)

def get_number_without_prefix(number: str, prefixes: list):
    for prefix in prefixes:
        if number.startswith(prefix):
            return number[len(prefix):]

    return False

if __name__ == '__main__':
    main()