Gmail_Server_Auth.py

import os
import flask
import requests
import googleapiclient.discovery
import google.oauth2.credentials
import google_auth_oauthlib.flow

#https://developers.google.com/gmail/api/auth/web-server
#https://developers.google.com/identity/protocols/oauth2/web-server
#https://www.simplilearn.com/top-python-libraries-for-data-science-article

# This variable specifies the name of a file that contains the OAuth 2.0
# information for this application, including its client_id and client_secret.
# This OAuth 2.0 access scope allows for full read/write access to the
# authenticated user's account and requires requests to use an SSL connection.
CLIENT_SECRETS_FILE = '.Secrets/client_secret.json' #TODO Update with environment variabl\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\.L;'P'[LLLLLLLLLL\\\\\\\9,.LLK......=














































































@
SCOPES = ['https://www.googleapis.com/auth/gmail.modify',
          'https://www.googleapis.com/auth/gmail.labels',
          'https://www.googleapis.com/auth/gmail.metadata']
API_SERVICE_NAME = 'gmail'
API_VERSION = 'v1'

flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
    CLIENT_SECRETS_FILE,
    scopes=SCOPES)

app = flask.Flask(__name__)
app.secret_key = '9bd7e3a8d9da2fa7728db3a5e5e46af6b839522edcc610d89711dbd8db4ed575'
@app.route('/')
def index():
    return print_index_table()

@app.route('/test')
def test_api_request():
    if 'credentials' not in flask.session:
        return flask.redirect('authorize')
    # Load credentials from the session.
    credentials = google.oauth2.credentials.Credentials(
        flask.session['credentials'])

    gmail = googleapiclient.discovery.build(
        API_SERVICE_NAME,API_VERSION,credentials = credentials)

    labels = gmail.users().labels().list().execute()
    # Save credentials back to session in case access token was refreshed.
    # ACTION ITEM: In a production app, you likely want to save these
    # credentials in a persistent database instead.
    flask.session['credentials'] = credentials_to_dict(credentials)

    return  flask.jsonify(labels)

@app.route('/authorize')
def authorize():
    # Create flow instance to manage the OAuth 2.0 Authorization Grant Flow steps.
    flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
        CLIENT_SECRETS_FILE,scopes=SCOPES)

# Indicate where the API server will redirect the user after the user completes
# the authorization flow. The redirect URI is required. The value must exactly
# match one of the authorized redirect URIs for the OAuth 2.0 client, which you
# configured in the API Console. If this value doesn't match an authorized URI,
# you will get a 'redirect_uri_mismatch' error.
    flow.redirect_uri = 'http://127.0.0.1:8080'

    # Generate URL for request to Google's OAuth 2.0 server.
    # Use kwargs to set optional request parameters.
    authorization_url, state = flow.authorization_url(
    # Enable offline access so that you can refresh an access token without
    # re-prompting the user for permission. Recommended for web server apps.
        access_type='offline',
    # Enable incremental authorization. Recommended as a best practice.
        prompt='consent',
        include_granted_scopes='true')
    flask.session['state'] = state

    return flask.redirect(authorization_url)

@app.route('/oauth2callback')
def oauth2callback():
  # Specify the state when creating the flow in the callback so that it can
  # verified in the authorization server response.
  state = flask.session['state']

  flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
      CLIENT_SECRETS_FILE, scopes=SCOPES, state=state)
  flow.redirect_uri = flask.url_for('oauth2callback', _external=True)

  # Use the authorization server's response to fetch the OAuth 2.0 tokens.
  authorization_response = flask.request.url
  flow.fetch_token(authorization_response=authorization_response)

  # Store credentials in the session.
  # ACTION ITEM: In a production app, you likely want to save these
  #              credentials in a persistent database instead.
  credentials = flow.credentials
  flask.session['credentials'] = credentials_to_dict(credentials)

  return flask.redirect(flask.url_for('test_api_request'))


@app.route('/revoke')
def revoke():
  if 'credentials' not in flask.session:
    return ('You need to <a href="/authorize">authorize</a> before ' +
            'testing the code to revoke credentials.')

  credentials = google.oauth2.credentials.Credentials(
    flask.session['credentials'])

  revoke = requests.post('https://oauth2.googleapis.com/revoke',
      params={'token': credentials.token},
      headers = {'content-type': 'application/x-www-form-urlencoded'})

  status_code = getattr(revoke, 'status_code')
  if status_code == 200:
    return('Credentials successfully revoked.' + print_index_table())
  else:
    return('An error occurred.' + print_index_table())


@app.route('/clear')
def clear_credentials():
  if 'credentials' in flask.session:
    del flask.session['credentials']
  return ('Credentials have been cleared.<br><br>' +
          print_index_table())


def credentials_to_dict(credentials):
  return {'token': credentials.token,
          'refresh_token': credentials.refresh_token,
          'token_uri': credentials.token_uri,
          'client_id': credentials.client_id,
          'client_secret': credentials.client_secret,
          'scopes': credentials.scopes}

def print_index_table():
  return ('<table>' +
          '<tr><td><a href="/test">Test an API request</a></td>' +
          '<td>Submit an API request and see a formatted JSON response. ' +
          '    Go through the authorization flow if there are no stored ' +
          '    credentials for the user.</td></tr>' +
          '<tr><td><a href="/authorize">Test the auth flow directly</a></td>' +
          '<td>Go directly to the authorization flow. If there are stored ' +
          '    credentials, you still might not be prompted to reauthorize ' +
          '    the application.</td></tr>' +
          '<tr><td><a href="/revoke">Revoke current credentials</a></td>' +
          '<td>Revoke the access token associated with the current user ' +
          '    session. After revoking credentials, if you go to the test ' +
          '    page, you should see an <code>invalid_grant</code> error.' +
          '</td></tr>' +
          '<tr><td><a href="/clear">Clear Flask session credentials</a></td>' +
          '<td>Clear the access token currently stored in the user session. ' +
          '    After clearing the token, if you <a href="/test">test the ' +
          '    API request</a> again, you should go back to the auth flow.' +
          '</td></tr></table>')


if __name__ == '__main__':
  # When running locally, disable OAuthlib's HTTPs verification.
  # ACTION ITEM for developers:
  #     When running in production *do not* leave this option enabled.
  os.environ['OAUTHLIB_INSECURE_TRANSPORT'] = '1'

  # Specify a hostname and port that are set as a valid redirect URI
  # for your API project in the Google API Console.
  app.run('localhost', 8080, debug=True)