boards/utils.py

"""
This module contains helper functions and helper classes.
"""
import hashlib
import time

from django.utils import timezone
import boards

from neboard import settings
from boards.models import User
from boards.models.user import RANK_USER


KEY_CAPTCHA_FAILS = 'key_captcha_fails'
KEY_CAPTCHA_DELAY_TIME = 'key_captcha_delay_time'
KEY_CAPTCHA_LAST_ACTIVITY = 'key_captcha_last_activity'


def need_include_captcha(request):
    """
    Check if request is made by a user.
    It contains rules which check for bots.
    """

    if not settings.ENABLE_CAPTCHA:
        return False

    enable_captcha = False

    #newcomer
    if KEY_CAPTCHA_LAST_ACTIVITY not in request.session:
        return settings.ENABLE_CAPTCHA

    last_activity = request.session[KEY_CAPTCHA_LAST_ACTIVITY]
    current_delay = int(time.time()) - last_activity

    delay_time = (request.session[KEY_CAPTCHA_DELAY_TIME]
                  if KEY_CAPTCHA_DELAY_TIME in request.session
                  else settings.CAPTCHA_DEFAULT_SAFE_TIME)

    if current_delay < delay_time:
        enable_captcha = True

    print 'ENABLING' + str(enable_captcha)

    return enable_captcha


def update_captcha_access(request, passed):
    """
    Update captcha fields.
    It will reduce delay time if user passed captcha verification and
    it will increase it otherwise.
    """
    session = request.session

    delay_time = (request.session[KEY_CAPTCHA_DELAY_TIME]
                  if KEY_CAPTCHA_DELAY_TIME in request.session
                  else settings.CAPTCHA_DEFAULT_SAFE_TIME)

    print "DELAY TIME = " + str(delay_time)

    if passed:
        delay_time -= 2 if delay_time >= 7 else 5
    else:
        delay_time += 10

    session[KEY_CAPTCHA_LAST_ACTIVITY] = int(time.time())
    session[KEY_CAPTCHA_DELAY_TIME] = delay_time


def get_client_ip(request):
    x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
    if x_forwarded_for:
        ip = x_forwarded_for.split(',')[-1].strip()
    else:
        ip = request.META.get('REMOTE_ADDR')
    return ip


def datetime_to_epoch(datetime):
    return int(time.mktime(timezone.localtime(
        datetime,timezone.get_current_timezone()).timetuple())
               * 1000000 + datetime.microsecond)


def get_user(request):
    """
    Get current user from the session. If the user does not exist, create
    a new one.
    """

    session = request.session
    if not 'user_id' in session:
        request.session.save()

        md5 = hashlib.md5()
        md5.update(session.session_key)
        new_id = md5.hexdigest()

        while User.objects.filter(user_id=new_id).exists():
            md5.update(str(timezone.now()))
            new_id = md5.hexdigest()

        time_now = timezone.now()
        user = User.objects.create(user_id=new_id, rank=RANK_USER,
                                   registration_time=time_now)

        session['user_id'] = user.id
    else:
        user = User.objects.select_related('fav_tags').get(
            id=session['user_id'])

    return user


def get_theme(request, user=None):
    """
    Get user's CSS theme
    """

    if not user:
        user = get_user(request)
    theme = user.get_setting('theme')
    if not theme:
        theme = boards.settings.DEFAULT_THEME

    return theme