vilniustransport.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

R"""vilniustransport.lt public transport subscription card status viewer

Script depends on "requests" and "beautifulsoup4" Python packages, use:

    $ pip install requests beautifulsoup4

to install them

HTTP request sequence 

[1] Obtain the login form with a new CSRF token
    Script automatically detects which form fields need to be populated

GET https://mano.vilniustransport.lt/login

<form id="loginFormCheck" action="/login_check" method="post">
<input name="_csrf_token" value="{CSRF_TOKEN}">
<input name="_username">
<input name="_password">
<input name="_submit" value="Prisijungti">
<input name="_remember_me" value="on">
</form>

[2] Authenticate by POSTing the form with provided credentials

POST https://mano.vilniustransport.lt/login_check

curl 'https://mano.vilniustransport.lt/login_check' \
-F '_csrf_token={CSRF_TOKEN}' \
-F '_username={USERNAME}' \
-F '_password={PASSWORD}' \
-F '_submit=Prisijungti' \
-F '_remember_me=on'

[3] After POSTing the form and following a redirect you get your card id
    numbers along with their names and codes (the ones below the barcode)

GET https://mano.vilniustransport.lt/ (follow redirect)

<select id="card_number" name="card[number]">
<option value="000001">Some card 1111111111</option>
<option value="000002">Another card 2222222222</option>
  This should match the code below barcode ^^^
...
</select>

[4] Make a POST request for each card id to retrieve its subscription status

POST 'https://mano.vilniustransport.lt/card-status'

curl 'https://mano.vilniustransport.lt/card-status' \
-b 'PHPSESSID={SESSION_ID}' \
-b 'REMEMBERME={TOKEN}%3D' \
-F 'card[number]={CARD_ID}'

[5] Make a GET request to logout to cleanup session

GET 'https://mano.vilniustransport.lt/logout'

"""

import os
from getpass import getpass

import requests

from bs4 import BeautifulSoup


BASE_URL = 'https://mano.vilniustransport.lt'
LOGIN_URI = '/login'
LOGIN_FORM_ID = 'loginFormCheck'
CARD_DROPDOWN_ID = 'card_number'
CARD_STATUS_URI = '/card-status'
LOGOUT_URI = '/logout'


def get_login_form(url, form_id, session=None):
    session = session if session else requests.Session()
    response = session.get(url)
    html = BeautifulSoup(response.content, 'html.parser')
    form = html.find(id=form_id)
    form_attrs = form.attrs
    form_action = form_attrs['action']
    form_method = form_attrs.get('method', 'post')
    # Collect form input field attributes
    fields = [field.attrs for field in form.find_all('input')]
    form_data = {}
    # Populate dictionary with form name:value pairs
    for field in fields:
        name = field.get('name')
        if name:
            form_data[name] = field.get('value')
    return {
        'action': form_action,
        'method': form_method,
        'data': form_data
    }


def fill_out_login_form(form_data):
    for field_name in form_data:
        if not form_data[field_name]:
            prompt = 'Enter %r: ' % field_name
            # don't echo typed chars if field_name has key or pass in it
            if 'key' in field_name or 'pass' in field_name:
                form_data[field_name] = getpass(prompt)
            else:
                form_data[field_name] = input(prompt)
    return form_data


def get_cards(url, form_data, dropdown_id=CARD_DROPDOWN_ID, session=None):
    session = session if session else requests.Session()
    response = session.post(url, data=form_data)
    html = BeautifulSoup(response.content, 'html.parser')
    # Get the <select> element
    card_dropdown = html.find('select', id=dropdown_id)
    cards = {}
    # Find all children <option> elements and extract their values
    for option in card_dropdown.find_all('option'):
        card_id = option.attrs['value']
        card_name = option.get_text()
        cards[card_id] = card_name
    return cards


def get_card_subscription_status(card_id, url, session=None):
    session = session if session else requests.Session()
    data = {'card[number]': card_id}
    response = session.post(url, data=data)
    html = BeautifulSoup(response.content, 'html.parser')
    output = []
    for card_row in html.find_all(class_='card-row'):
        line = ' '.join(card_row.stripped_strings)
        output.append(line)
    return os.linesep.join(output)


def logout(url, session=None):
    session = session if session else requests.Session()
    session.get(url)


def main():
    session = requests.Session()
    form = get_login_form(BASE_URL + LOGIN_URI, LOGIN_FORM_ID, session)
    fill_out_login_form(form['data'])
    print()
    # only POST methods are allowed
    if form['method'].lower() == 'post':
        action = form['action']
        data = form['data']
        cards = get_cards(BASE_URL + action, data, session=session)
        for card_id, card_name in cards.items():
            print(card_name)
            print('=' * 32)
            card_status = get_card_subscription_status(
                card_id, BASE_URL + CARD_STATUS_URI, session=session)
            print(card_status)
            print()
    else:
        raise NotImplementedError('Only POST method is supported')
    # logging out deletes your session
    logout(BASE_URL + LOGOUT_URI, session=session)


if __name__ == '__main__':
    main()