Files
edx-platform/openedx/features/discounts/utils.py
2021-03-19 22:42:14 +05:00

230 lines
8.4 KiB
Python

"""
Utility functions for working with discounts and discounted pricing.
"""
from datetime import datetime
import pytz
from django.utils.translation import get_language
from django.utils.translation import ugettext as _
from edx_django_utils.cache import RequestCache
from web_fragments.fragment import Fragment
from common.djangoapps.course_modes.models import format_course_price, get_course_prices
from common.djangoapps.util.date_utils import strftime_localized_html
from lms.djangoapps.experiments.models import ExperimentData
from lms.djangoapps.courseware.utils import verified_upgrade_deadline_link
from openedx.core.djangoapps.content.course_overviews.models import CourseOverview
from openedx.core.djangolib.markup import HTML, Text
from openedx.features.discounts.applicability import (
REV1008_EXPERIMENT_ID,
can_receive_discount,
discount_percentage,
get_discount_expiration_date
)
def offer_banner_wrapper(user, block, view, frag, context): # pylint: disable=W0613
"""
A wrapper that prepends the First Purchase Discount banner if
the user hasn't upgraded yet.
"""
if block.category != 'vertical':
return frag
offer_banner_fragment = get_first_purchase_offer_banner_fragment_from_key(
user, block.course_id
)
if not offer_banner_fragment:
return frag
# Course content must be escaped to render correctly due to the way the
# way the XBlock rendering works. Transforming the safe markup to unicode
# escapes correctly.
offer_banner_fragment.content = str(offer_banner_fragment.content)
offer_banner_fragment.add_content(frag.content)
offer_banner_fragment.add_fragment_resources(frag)
return offer_banner_fragment
def _get_discount_prices(user, course, assume_discount=False):
"""
Return a tuple of (original, discounted, percentage)
If assume_discount is True, we do not check if a discount applies and just go ahead with discount math anyway.
Each returned price is a string with appropriate currency formatting added already.
discounted and percentage will be returned as None if no discount is applicable.
"""
base_price = get_course_prices(course, verified_only=True)[0]
can_discount = assume_discount or can_receive_discount(user, course)
if can_discount:
percentage = discount_percentage(course)
discounted_price = base_price * ((100.0 - percentage) / 100)
if discounted_price: # leave 0 prices alone, as format_course_price below will adjust to 'Free'
if discounted_price == int(discounted_price):
discounted_price = f'{discounted_price:0.0f}'
else:
discounted_price = f'{discounted_price:0.2f}'
return format_course_price(base_price), format_course_price(discounted_price), percentage
else:
return format_course_price(base_price), None, None
def generate_offer_data(user, course):
"""
Create a dictionary of information about the current discount offer.
Used by serializers to pass onto frontends and by the LMS locally to generate HTML for template rendering.
Returns a dictionary of data, or None if no offer is applicable.
"""
if not user or not course or user.is_anonymous:
return None
ExperimentData.objects.get_or_create(
user=user, experiment_id=REV1008_EXPERIMENT_ID, key=str(course),
defaults={
'value': datetime.now(tz=pytz.UTC).strftime('%Y-%m-%d %H:%M:%S%z'),
},
)
expiration_date = get_discount_expiration_date(user, course)
if not expiration_date:
return None
if not can_receive_discount(user, course, discount_expiration_date=expiration_date):
return None
original, discounted, percentage = _get_discount_prices(user, course, assume_discount=True)
return {
'code': 'BIENVENIDOAEDX' if get_language() == 'es-419' else 'EDXWELCOME',
'expiration_date': expiration_date,
'original_price': original,
'discounted_price': discounted,
'percentage': percentage,
'upgrade_url': verified_upgrade_deadline_link(user, course=course),
}
def _format_discounted_price(original_price, discount_price):
"""Helper method that returns HTML containing a strikeout price with discount."""
# Separate out this string because it has a lot of syntax but no actual information for
# translators to translate
formatted_discount_price = HTML(
'{s_dp}{discount_price}{e_p} {s_st}{s_op}{original_price}{e_p}{e_st}'
).format(
original_price=original_price,
discount_price=discount_price,
s_op=HTML("<span class='price original'>"),
s_dp=HTML("<span class='price discount'>"),
s_st=HTML("<del aria-hidden='true'>"),
e_p=HTML('</span>'),
e_st=HTML('</del>'),
)
return (
HTML(_(
'{s_sr}Original price: {s_op}{original_price}{e_p}, discount price: {e_sr}{formatted_discount_price}'
)).format(
original_price=original_price,
formatted_discount_price=formatted_discount_price,
s_sr=HTML("<span class='sr-only'>"),
s_op=HTML("<span class='price original'>"),
e_p=HTML('</span>'),
e_sr=HTML('</span>'),
)
)
def format_strikeout_price(user, course):
"""
Return a formatted price, including a struck-out original price if a discount applies, and also
whether a discount was applied, as the tuple (formatted_price, has_discount).
"""
original_price, discounted_price, _ = _get_discount_prices(user, course)
if discounted_price is None:
return HTML("<span class='price'>{}</span>").format(original_price), False
else:
return _format_discounted_price(original_price, discounted_price), True
def generate_offer_html(user, course):
"""
Create the actual HTML object with the offer text in it.
Returns a openedx.core.djangolib.markup.HTML object, or None if the user
should not be shown an offer message.
"""
data = generate_offer_data(user, course)
if not data:
return None
# Translator: xgettext:no-python-format
offer_message = _('{banner_open} Upgrade by {discount_expiration_date} and save {percentage}% '
'[{strikeout_price}]{span_close}{br}Use code {b_open}{code}{b_close} at checkout! '
'{a_open}Upgrade Now{a_close}{div_close}')
message_html = HTML(offer_message).format(
a_open=HTML('<a id="welcome" href="{upgrade_link}">').format(upgrade_link=data['upgrade_url']),
a_close=HTML('</a>'),
b_open=HTML('<b>'),
code=Text(data['code']),
b_close=HTML('</b>'),
br=HTML('<br>'),
banner_open=HTML(
'<div class="first-purchase-offer-banner" role="note">'
'<span class="first-purchase-offer-banner-bold"><b>'
),
discount_expiration_date=strftime_localized_html(data['expiration_date'], 'SHORT_DATE'),
percentage=data['percentage'],
span_close=HTML('</b></span>'),
div_close=HTML('</div>'),
strikeout_price=_format_discounted_price(data['original_price'], data['discounted_price']),
)
return message_html
def get_first_purchase_offer_banner_fragment(user, course):
"""
Return an HTML Fragment with First Purcahse Discount message,
which has the discount_expiration_date, price,
discount percentage and a link to upgrade.
"""
offer_html = generate_offer_html(user, course)
if offer_html is None:
return None
return Fragment(offer_html)
def get_first_purchase_offer_banner_fragment_from_key(user, course_key):
"""
Like `get_first_purchase_offer_banner_fragment`, but using a CourseKey
instead of a CourseOverview and using request-level caching.
Either returns WebFragment to inject XBlock content into, or None if we
shouldn't show a first purchase offer message for this user.
"""
request_cache = RequestCache('get_first_purchase_offer_banner_fragment_from_key')
cache_key = f'html:{user.id},{course_key}'
cache_response = request_cache.get_cached_response(cache_key)
if cache_response.is_found:
cached_html = cache_response.value
if cached_html is None:
return None
return Fragment(cached_html)
course = CourseOverview.get_from_id(course_key)
offer_html = generate_offer_html(user, course)
request_cache.set(cache_key, offer_html)
return Fragment(offer_html)