get_mails.py

from __future__ import print_function

import csv
import os.path
import pickle
import re
from collections import namedtuple
from datetime import datetime, timedelta
from typing import List

from google.auth.transport.requests import Request
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build
from configuration import configuration

# If modifying these scopes, delete the file token.pickle.
from kaggle import api

SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']

rate_csv_columns = ['message_id', 'date', 'rate']
RateRow = namedtuple('RateRow', rate_csv_columns)
rate_file = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'dataset', configuration.rateFile)


def load_rates():
    rates = {}
    try:
        with open(rate_file, 'r+') as chf_rate_file:
            rates_dict = csv.DictReader(chf_rate_file)
            for rate_row in rates_dict:
                rate = RateRow(**rate_row)
                rates[rate.message_id] = rate
    except FileNotFoundError:
        with open(rate_file, 'w+') as chf_rate_file:
            writer = csv.DictWriter(chf_rate_file, rate_csv_columns)
            writer.writeheader()
        return load_rates()
    return rates


def update_rates(to_append: List[RateRow]):
    with open(rate_file, 'a+') as chf_rate_file:
        writer = csv.DictWriter(chf_rate_file, rate_csv_columns)
        dict_row = [row._asdict() for row in to_append]
        writer.writerows(dict_row)


def main():
    """Shows basic usage of the Gmail API.
    Lists the user's Gmail labels.
    """
    service = build('gmail', 'v1', credentials=get_credentials())

    # Call the Gmail API
    results = service.users().messages().list(q=configuration.query, userId=configuration.userId).execute()
    rates = load_rates()
    messages = results.get('messages')
    to_request = [message_res for message_res in messages if message_res['id'] not in rates]
    print('I will request for', len(to_request), 'messages')
    to_append: List[RateRow] = []
    one_delta = timedelta(days=1)
    for msg_resource in to_request:
        message = service.users().messages().get(userId='me', id=msg_resource['id'], format='minimal').execute()
        searchObj = re.search('1 CHF = ([0-9.]+) EUR', message['snippet'])
        if searchObj.group():
            rate_date = datetime.fromtimestamp(float(int(message['internalDate']) / 1000)).date()
            row = RateRow(message_id=msg_resource['id'], date=rate_date, rate=searchObj.group(1))
            to_append.append(row)
            if rate_date.weekday() == 4:
                for weekend in [rate_date + one_delta, rate_date + (one_delta * 2)]:
                    row_dict = row._asdict()
                    row_dict['date'] = weekend
                    to_append.append(RateRow(**row_dict))
    if len(to_append) == 0:
        exit(0)
    update_rates(to_append)

    api.dataset_create_version(folder=os.path.dirname(rate_file),
                               version_notes='Script ran on {}'.format(datetime.now().strftime('%Y-%m-%d')))


def get_credentials():
    creds = None
    # The file token.pickle stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    if os.path.exists('token.pickle'):
        with open('token.pickle', 'rb') as token:
            creds = pickle.load(token)
    # If there are no (valid) credentials available, let the user log in.
    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.json', SCOPES)
            creds = flow.run_local_server()
        # Save the credentials for the next run
        with open('token.pickle', 'wb') as token:
            pickle.dump(creds, token)
    return creds


if __name__ == '__main__':
    main()