uvaclient.py

import requests
from bs4 import BeautifulSoup
import getpass
from uvasettings import uvasettings
import uvaapi as api
import udebug
import utils
import constants

settings = uvasettings()

'''

Main level of abstraction for interfacing with UVa.

'''

BASE_URL   = "https://uva.onlinejudge.org/"
LOGIN_URL  = BASE_URL + "index.php?option=com_comprofiler&task=login"
SUBMIT_URL = BASE_URL + "index.php?option=com_onlinejudge&Itemid=25&page=save_submission"

class uvaclient:
    def __init__(self):
        # Create a session for making requests
        # Nessesary to persist login information
        self.session = requests.Session()
        self.username = settings['username']
        self.uid = api.get_uid(self.username)

    def prompt_password(self):
        return getpass.getpass("Password: ")

    # Helpers for making post requests through our session with
    # an option for adding custom headers or overwriting defaults
    def _post(self, url, data, custom_headers=None, redirects=True):
        custom_headers = custom_headers or {}
        headers = utils.merge_dicts(constants.uva_headers, custom_headers)

        return self.session.post(url, data=data, headers=headers,
                allow_redirects=redirects)

    def _get(self, url, custom_headers=None, redirects=True):
        custom_headers = custom_headers or {}
        headers = utils.merge_dicts(constants.uva_headers, custom_headers)

        return self.session.get(url, headers=headers, allow_redirects=redirects)

    # Query the homepage for login tokens and fill in username and password
    # UVa generates some random token for security so we need to load the page
    # and grab it before making our login request
    def _login_data(self):
        soup = BeautifulSoup(self._get(BASE_URL).text, "html.parser")
        login_form = soup.find_all("form")[0]

        d = {e['name']: e.get('value', '') for e in login_form.find_all("input", {'name': True})}
        d['username'] = self.username
        d['passwd'] = self.prompt_password()
        return d

    # Grab nesseary security info and then authenticate
    def login(self):
        data = self._login_data()
        self._post(LOGIN_URL, data, {'Referer': BASE_URL}, False)
        if len(self.session.cookies) == 1:
            print "Authentication failed"
            self.login()

    def get_baseurl(self):
            return BASE_URL

    def get_problem_name(self, problem_num):
        return api.get_problem_name(problem_num)

    # Submits a problem with the given parameters
    # Must be logged in for this to work
    def submit(self, problemid, f, language = settings['language']):
        data = {
            "localid":   problemid,
            "code":      open(f, "r").read(),
            "language":  language,
            "codeupl":   "",
            "problemid": "",
            "category":  ""
        }
        self._post(SUBMIT_URL, data, {"Referer": SUBMIT_URL})

    # Proxy calls to the API
    def submissions(self, n = 3):
        return api.submissions(self.uid, n)

    def leaderboard(self, problem_number, n = 10):
        return api.leaderboard(problem_number, n)

    def user_submissions(self, user, n = 10):
        return api.user_submissions(user, n)

    def user_submissions_problem(self, user, problem_number):
        return api.user_submissions_problem(user, problem_number)

    def testcases(self, problem_num):
        return udebug.testcases(problem_num)

    # Calls to utils
    def change_username(self, username):
        settings["username"] = username

    def change_language(self, language):
        settings["language"] = language

    def get_username(self):
        return settings['username']

    def get_language(self):
        return constants.language[int(settings['language'])]