src/paypal/rest.py

   1 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 from datetime import date, datetime, timedelta
   5 from decimal import Decimal
   6 import paypalrestsdk
   7 import pytz
   8 from django.contrib.sites.models import Site
   9 from django.urls import reverse
  10 from django.utils import timezone
  11 from django.conf import settings
  12 from .models import BillingPlan, BillingAgreement
  13
  14 paypalrestsdk.configure(settings.PAYPAL_CONFIG)
  15
  16
  17 class PaypalError(Exception):
  18     pass
  19
  20
  21 def absolute_url(url_name, kwargs=None):
  22     return "http://%s%s" % (Site.objects.get_current().domain, reverse(url_name, kwargs=kwargs))
  23
  24
  25 def create_plan(amount):
  26     billing_plan = paypalrestsdk.BillingPlan({
  27         "name": "Cykliczna darowizna na Wolne Lektury: %s zł" % amount,
  28         "description": "Cykliczna darowizna na wsparcie Wolnych Lektur",
  29         "merchant_preferences": {
  30             "auto_bill_amount": "yes",
  31             "return_url": absolute_url('paypal_return', {'key': '-'}),
  32             "cancel_url": absolute_url('paypal_cancel'),
  33             # "initial_fail_amount_action": "continue",
  34             "max_fail_attempts": "3",
  35         },
  36         "payment_definitions": [
  37             {
  38                 "amount": {
  39                     "currency": "PLN",
  40                     "value": str(amount),
  41                 },
  42                 "cycles": "0",
  43                 "frequency": "MONTH",
  44                 "frequency_interval": "1",
  45                 "name": "Cykliczna darowizna",
  46                 "type": "REGULAR",
  47             }
  48         ],
  49         "type": "INFINITE",
  50     })
  51
  52     if not billing_plan.create():
  53         raise PaypalError(billing_plan.error)
  54     if not billing_plan.activate():
  55         raise PaypalError(billing_plan.error)
  56     plan, created = BillingPlan.objects.get_or_create(amount=amount, defaults={'plan_id': billing_plan.id})
  57     return plan.plan_id
  58
  59
  60 def get_link(links, rel):
  61     for link in links:
  62         if link.rel == rel:
  63             return link.href
  64
  65
  66 def create_agreement(amount, key, app=False):
  67     try:
  68         plan = BillingPlan.objects.get(amount=amount)
  69     except BillingPlan.DoesNotExist:
  70         plan_id = create_plan(amount)
  71     else:
  72         plan_id = plan.plan_id
  73     start = (timezone.now() + timedelta(0, 3600*24)).astimezone(pytz.utc).strftime('%Y-%m-%dT%H:%M:%SZ')
  74     billing_agreement = paypalrestsdk.BillingAgreement({
  75         "name": "Subskrypcja klubu WL",
  76         "description": "Stałe wsparcie Wolnych Lektur kwotą %s złotych" % amount,
  77         "start_date": start,
  78         "plan": {
  79             "id": plan_id,
  80         },
  81         "payer": {
  82             "payment_method": "paypal"
  83         },
  84     })
  85     if app:
  86         billing_agreement['override_merchant_preferences'] = {
  87             'return_url': absolute_url('paypal_app_return', {'key': key}),
  88         }
  89     else:
  90         billing_agreement['override_merchant_preferences'] = {
  91             'return_url': absolute_url('paypal_return', {'key': key}),
  92         }
  93
  94
  95     response = billing_agreement.create()
  96     if response:
  97         return billing_agreement
  98     else:
  99         raise PaypalError(billing_agreement.error)
 100
 101
 102 def agreement_approval_url(amount, key, app=False):
 103     agreement = create_agreement(amount, key, app=app)
 104     return get_link(agreement.links, 'approval_url')
 105
 106
 107 def get_agreement(agreement_id):
 108     try:
 109         return paypalrestsdk.BillingAgreement.find(agreement_id)
 110     except paypalrestsdk.ResourceNotFound:
 111         return None
 112
 113
 114 def check_agreement(agreement_id):
 115     a = get_agreement(agreement_id)
 116     if a:
 117         return a.state == 'Active'
 118
 119
 120 def user_is_subscribed(user):
 121     agreements = BillingAgreement.objects.filter(user=user)
 122     return any(agreement.check_agreement() for agreement in agreements)
 123
 124
 125 def execute_agreement(token):
 126     return paypalrestsdk.BillingAgreement.execute(token)
 127
 128
 129 def get_donations(agreement_id, year):
 130     a = get_agreement(agreement_id)
 131     transactions = []
 132     for transaction in a.search_transactions(
 133             date(year - 1, 12, 31),
 134             date(year + 1, 1, 1))['agreement_transaction_list']:
 135         if transaction['status'] != 'Completed':
 136             continue
 137         dt = datetime.strptime(
 138             transaction['time_stamp'],
 139             '%Y-%m-%dT%H:%M:%S%z'
 140         ).astimezone()
 141         if dt.year != year:
 142             continue
 143         assert transaction['amount']['currency'] == 'PLN'
 144         transactions.append({
 145             'timestamp': dt,
 146             'amount': Decimal(transaction['amount']['value'])
 147         })
 148     return transactions