import hashlib
import json
import logging
import urllib.parse
from collections import OrderedDict

import stripe
from django import forms
from django.conf import settings
from django.contrib import messages
from django.core import signing
from django.http import HttpRequest
from django.template.loader import get_template
from django.urls import reverse
from django.utils.crypto import get_random_string
from django.utils.http import urlquote
from django.utils.timezone import now
from django.utils.translation import pgettext, ugettext, ugettext_lazy as _
from django_countries import countries

from pretix import __version__
from pretix.base.decimal import round_decimal
from pretix.base.models import Event, OrderPayment, OrderRefund, Quota
from pretix.base.payment import BasePaymentProvider, PaymentException
from pretix.base.services.mail import SendMailException
from pretix.base.settings import SettingsSandbox
from pretix.helpers.urls import build_absolute_uri as build_global_uri
from pretix.multidomain.urlreverse import build_absolute_uri
from pretix.plugins.stripe.forms import StripeKeyValidator
from pretix.plugins.stripe.models import (
    ReferencedStripeObject, RegisteredApplePayDomain,
)
from pretix.plugins.stripe.tasks import (
    get_stripe_account_key, stripe_verify_domain,
)

logger = logging.getLogger('pretix.plugins.stripe')


class StripeSettingsHolder(BasePaymentProvider):
    identifier = 'stripe_settings'
    verbose_name = _('Stripe')
    is_enabled = False
    is_meta = True

    def __init__(self, event: Event):
        super().__init__(event)
        self.settings = SettingsSandbox('payment', 'stripe', event)

    def get_connect_url(self, request):
        request.session['payment_stripe_oauth_event'] = request.event.pk
        if 'payment_stripe_oauth_token' not in request.session:
            request.session['payment_stripe_oauth_token'] = get_random_string(32)
        return (
            "https://connect.stripe.com/oauth/authorize?response_type=code&client_id={}&state={}"
            "&scope=read_write&redirect_uri={}"
        ).format(
            self.settings.connect_client_id,
            request.session['payment_stripe_oauth_token'],
            urlquote(build_global_uri('plugins:stripe:oauth.return')),
        )

    def settings_content_render(self, request):
        if self.settings.connect_client_id and not self.settings.secret_key:
            # Use Stripe connect
            if not self.settings.connect_user_id:
                return (
                    "<p>{}</p>"
                    "<a href='{}' class='btn btn-primary btn-lg'>{}</a>"
                ).format(
                    _('To accept payments via Stripe, you will need an account at Stripe. By clicking on the '
                      'following button, you can either create a new Stripe account connect pretix to an existing '
                      'one.'),
                    self.get_connect_url(request),
                    _('Connect with Stripe')
                )
            else:
                return (
                    "<button formaction='{}' class='btn btn-danger'>{}</button>"
                ).format(
                    reverse('plugins:stripe:oauth.disconnect', kwargs={
                        'organizer': self.event.organizer.slug,
                        'event': self.event.slug,
                    }),
                    _('Disconnect from Stripe')
                )
        else:
            return "<div class='alert alert-info'>%s<br /><code>%s</code></div>" % (
                _('Please configure a <a href="https://dashboard.stripe.com/account/webhooks">Stripe Webhook</a> to '
                  'the following endpoint in order to automatically cancel orders when charges are refunded externally '
                  'and to process asynchronous payment methods like SOFORT.'),
                build_global_uri('plugins:stripe:webhook')
            )

    @property
    def settings_form_fields(self):
        if self.settings.connect_client_id and not self.settings.secret_key:
            # Stripe connect
            if self.settings.connect_user_id:
                fields = [
                    ('connect_user_name',
                     forms.CharField(
                         label=_('Stripe account'),
                         disabled=True
                     )),
                    ('endpoint',
                     forms.ChoiceField(
                         label=_('Endpoint'),
                         initial='live',
                         choices=(
                             ('live', pgettext('stripe', 'Live')),
                             ('test', pgettext('stripe', 'Testing')),
                         ),
                     )),
                ]
            else:
                return {}
        else:
            allcountries = list(countries)
            allcountries.insert(0, ('', _('Select country')))

            fields = [
                ('publishable_key',
                 forms.CharField(
                     label=_('Publishable key'),
                     help_text=_('<a target="_blank" rel="noopener" href="{docs_url}">{text}</a>').format(
                         text=_('Click here for a tutorial on how to obtain the required keys'),
                         docs_url='https://docs.pretix.eu/en/latest/user/payments/stripe.html'
                     ),
                     validators=(
                         StripeKeyValidator('pk_'),
                     ),
                 )),
                ('secret_key',
                 forms.CharField(
                     label=_('Secret key'),
                     validators=(
                         StripeKeyValidator(['sk_', 'rk_']),
                     ),
                 )),
                ('merchant_country',
                 forms.ChoiceField(
                     choices=allcountries,
                     label=_('Merchant country'),
                     help_text=_('The country in which your Stripe-account is registred in. Usually, this is your '
                                 'country of residence.'),
                 )),
            ]
        d = OrderedDict(
            fields + [
                ('ui',
                 forms.ChoiceField(
                     label=_('User interface'),
                     choices=(
                         ('pretix', _('Simple (pretix design)')),
                         ('checkout', _('Stripe Checkout')),
                     ),
                     help_text=_('Only relevant for credit card payments.')
                 )),
                ('method_cc',
                 forms.BooleanField(
                     label=_('Credit card payments'),
                     required=False,
                 )),
                ('method_giropay',
                 forms.BooleanField(
                     label=_('giropay'),
                     disabled=self.event.currency != 'EUR',
                     help_text=_('Needs to be enabled in your Stripe account first.'),
                     required=False,
                 )),
                ('method_ideal',
                 forms.BooleanField(
                     label=_('iDEAL'),
                     disabled=self.event.currency != 'EUR',
                     help_text=_('Needs to be enabled in your Stripe account first.'),
                     required=False,
                 )),
                ('method_alipay',
                 forms.BooleanField(
                     label=_('Alipay'),
                     disabled=self.event.currency not in ('EUR', 'AUD', 'CAD', 'GBP', 'HKD', 'JPY', 'NZD', 'SGD', 'USD'),
                     help_text=_('Needs to be enabled in your Stripe account first.'),
                     required=False,
                 )),
                ('method_bancontact',
                 forms.BooleanField(
                     label=_('Bancontact'),
                     disabled=self.event.currency != 'EUR',
                     help_text=_('Needs to be enabled in your Stripe account first.'),
                     required=False,
                 )),
                ('method_sofort',
                 forms.BooleanField(
                     label=_('SOFORT'),
                     disabled=self.event.currency != 'EUR',
                     help_text=(
                         _('Needs to be enabled in your Stripe account first.') +
                         '<div class="alert alert-warning">%s</div>' % _(
                             'Despite the name, Sofort payments via Stripe are <strong>not</strong> processed '
                             'instantly but might take up to <strong>14 days</strong> to be confirmed in some cases. '
                             'Please only activate this payment method if your payment term allows for this lag.'
                         )
                     ),
                     required=False,
                 )),
                ('cc_3ds_mode',
                 forms.ChoiceField(
                     label=_('3D Secure mode'),
                     help_text=_('This determines when we will use the 3D Secure methods for credit card payments. '
                                 'Using 3D Secure (also known as Verified by VISA or MasterCard SecureCode) reduces '
                                 'the risk of fraud but makes the payment process a bit longer.'),
                     choices=(
                         ('required', pgettext('stripe 3dsecure', 'Only when required by the card')),
                         ('recommended', pgettext('stripe 3dsecure', 'Always when recommended by Stripe')),
                         ('optional', pgettext('stripe 3dsecure', 'Always when supported by the card')),
                     ),
                 )),
            ] + list(super().settings_form_fields.items())
        )
        d.move_to_end('_enabled', last=False)
        return d


class StripeMethod(BasePaymentProvider):
    identifier = ''
    method = ''

    def __init__(self, event: Event):
        super().__init__(event)
        self.settings = SettingsSandbox('payment', 'stripe', event)

    @property
    def settings_form_fields(self):
        return {}

    @property
    def is_enabled(self) -> bool:
        return self.settings.get('_enabled', as_type=bool) and self.settings.get('method_{}'.format(self.method),
                                                                                 as_type=bool)

    def payment_refund_supported(self, payment: OrderPayment) -> bool:
        return True

    def payment_partial_refund_supported(self, payment: OrderPayment) -> bool:
        return True

    def payment_prepare(self, request, payment):
        return self.checkout_prepare(request, None)

    def _amount_to_decimal(self, cents):
        places = settings.CURRENCY_PLACES.get(self.event.currency, 2)
        return round_decimal(float(cents) / (10 ** places), self.event.currency)

    def _decimal_to_int(self, amount):
        places = settings.CURRENCY_PLACES.get(self.event.currency, 2)
        return int(amount * 10 ** places)

    def _get_amount(self, payment):
        return self._decimal_to_int(payment.amount)

    @property
    def api_kwargs(self):
        if self.settings.connect_client_id and self.settings.connect_user_id:
            if self.settings.get('endpoint', 'live') == 'live':
                kwargs = {
                    'api_key': self.settings.connect_secret_key,
                    'stripe_account': self.settings.connect_user_id
                }
            else:
                kwargs = {
                    'api_key': self.settings.connect_test_secret_key,
                    'stripe_account': self.settings.connect_user_id
                }
        else:
            kwargs = {
                'api_key': self.settings.secret_key,
            }
        return kwargs

    def _init_api(self):
        stripe.api_version = '2018-02-28'
        stripe.set_app_info("pretix", version=__version__, url="https://pretix.eu")

    def checkout_confirm_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_confirm.html')
        ctx = {'request': request, 'event': self.event, 'settings': self.settings, 'provider': self}
        return template.render(ctx)

    def payment_can_retry(self, payment):
        return self._is_still_available(order=payment.order)

    def _charge_source(self, request, source, payment):
        try:
            params = {}
            if not source.startswith('src_'):
                params['statement_descriptor'] = ugettext('{event}-{code}').format(
                    event=self.event.slug.upper(),
                    code=payment.order.code
                )[:22]
            params.update(self.api_kwargs)
            charge = stripe.Charge.create(
                amount=self._get_amount(payment),
                currency=self.event.currency.lower(),
                source=source,
                metadata={
                    'order': str(payment.order.id),
                    'event': self.event.id,
                    'code': payment.order.code
                },
                # TODO: Is this sufficient?
                idempotency_key=str(self.event.id) + payment.order.code + source,
                **params
            )
        except stripe.error.CardError as e:
            if e.json_body:
                err = e.json_body['error']
                logger.exception('Stripe error: %s' % str(err))
            else:
                err = {'message': str(e)}
                logger.exception('Stripe error: %s' % str(e))
            logger.info('Stripe card error: %s' % str(err))
            payment.info_data = {
                'error': True,
                'message': err['message'],
            }
            payment.state = OrderPayment.PAYMENT_STATE_FAILED
            payment.save()
            payment.order.log_action('pretix.event.order.payment.failed', {
                'local_id': payment.local_id,
                'provider': payment.provider,
                'message': err['message']
            })
            raise PaymentException(_('Stripe reported an error with your card: %s') % err['message'])

        except stripe.error.StripeError as e:
            if e.json_body:
                err = e.json_body['error']
                logger.exception('Stripe error: %s' % str(err))
            else:
                err = {'message': str(e)}
                logger.exception('Stripe error: %s' % str(e))
            payment.info_data = {
                'error': True,
                'message': err['message'],
            }
            payment.state = OrderPayment.PAYMENT_STATE_FAILED
            payment.save()
            payment.order.log_action('pretix.event.order.payment.failed', {
                'local_id': payment.local_id,
                'provider': payment.provider,
                'message': err['message']
            })
            raise PaymentException(_('We had trouble communicating with Stripe. Please try again and get in touch '
                                     'with us if this problem persists.'))
        else:
            ReferencedStripeObject.objects.get_or_create(
                reference=charge.id,
                defaults={'order': payment.order, 'payment': payment}
            )
            if charge.status == 'succeeded' and charge.paid:
                try:
                    payment.info = str(charge)
                    payment.confirm()
                except Quota.QuotaExceededException as e:
                    raise PaymentException(str(e))

                except SendMailException:
                    raise PaymentException(_('There was an error sending the confirmation mail.'))
            elif charge.status == 'pending':
                if request:
                    messages.warning(request, _('Your payment is pending completion. We will inform you as soon as the '
                                                'payment completed.'))
                payment.info = str(charge)
                payment.state = OrderPayment.PAYMENT_STATE_PENDING
                payment.save()
                return
            else:
                logger.info('Charge failed: %s' % str(charge))
                payment.info = str(charge)
                payment.state = OrderPayment.PAYMENT_STATE_FAILED
                payment.save()
                payment.order.log_action('pretix.event.order.payment.failed', {
                    'local_id': payment.local_id,
                    'provider': payment.provider,
                    'info': str(charge)
                })
                raise PaymentException(_('Stripe reported an error: %s') % charge.failure_message)

    def payment_pending_render(self, request, payment) -> str:
        if payment.info:
            payment_info = json.loads(payment.info)
        else:
            payment_info = None
        template = get_template('pretixplugins/stripe/pending.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
            'provider': self,
            'order': payment.order,
            'payment': payment,
            'payment_info': payment_info,
        }
        return template.render(ctx)

    def payment_control_render(self, request, payment) -> str:
        if payment.info:
            payment_info = json.loads(payment.info)
            if 'amount' in payment_info:
                payment_info['amount'] /= 10 ** settings.CURRENCY_PLACES.get(self.event.currency, 2)
        else:
            payment_info = None
        template = get_template('pretixplugins/stripe/control.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
            'payment_info': payment_info,
            'payment': payment,
            'method': self.method,
            'provider': self,
        }
        return template.render(ctx)

    def execute_refund(self, refund: OrderRefund):
        self._init_api()

        payment_info = refund.payment.info_data

        if not payment_info:
            raise PaymentException(_('No payment information found.'))

        try:
            ch = stripe.Charge.retrieve(payment_info['id'], **self.api_kwargs)
            r = ch.refunds.create(
                amount=self._get_amount(refund),
            )
            ch.refresh()
        except (stripe.error.InvalidRequestError, stripe.error.AuthenticationError, stripe.error.APIConnectionError) \
                as e:
            if e.json_body:
                err = e.json_body['error']
                logger.exception('Stripe error: %s' % str(err))
            else:
                err = {'message': str(e)}
                logger.exception('Stripe error: %s' % str(e))
            raise PaymentException(_('We had trouble communicating with Stripe. Please try again and contact '
                                     'support if the problem persists.'))
        except stripe.error.StripeError as err:
            logger.error('Stripe error: %s' % str(err))
            raise PaymentException(_('Stripe returned an error'))
        else:
            refund.info = str(r)
            if r.status in ('succeeded', 'pending'):
                refund.done()
            elif r.status in ('failed', 'canceled'):
                refund.state = OrderRefund.REFUND_STATE_FAILED
                refund.execution_date = now()
                refund.save()

    def execute_payment(self, request: HttpRequest, payment: OrderPayment):
        self._init_api()
        try:
            source = self._create_source(request, payment)
        except stripe.error.StripeError as e:
            if e.json_body:
                err = e.json_body['error']
                logger.exception('Stripe error: %s' % str(err))
            else:
                err = {'message': str(e)}
                logger.exception('Stripe error: %s' % str(e))
            payment.info_data = {
                'error': True,
                'message': err['message'],
            }
            payment.state = OrderPayment.PAYMENT_STATE_FAILED
            payment.save()
            payment.order.log_action('pretix.event.order.payment.failed', {
                'local_id': payment.local_id,
                'provider': payment.provider,
                'message': err['message']
            })
            raise PaymentException(_('We had trouble communicating with Stripe. Please try again and get in touch '
                                     'with us if this problem persists.'))

        ReferencedStripeObject.objects.get_or_create(
            reference=source.id,
            defaults={'order': payment.order, 'payment': payment}
        )
        payment.info = str(source)
        payment.state = OrderPayment.PAYMENT_STATE_PENDING
        payment.save()
        request.session['payment_stripe_order_secret'] = payment.order.secret
        return self.redirect(request, source.redirect.url)

    def redirect(self, request, url):
        if request.session.get('iframe_session', False):
            signer = signing.Signer(salt='safe-redirect')
            return (
                build_absolute_uri(request.event, 'plugins:stripe:redirect') + '?url=' +
                urllib.parse.quote(signer.sign(url))
            )
        else:
            return str(url)

    def shred_payment_info(self, obj: OrderPayment):
        if not obj.info:
            return
        d = json.loads(obj.info)
        new = {}
        if 'source' in d:
            new['source'] = {
                'id': d['source'].get('id'),
                'type': d['source'].get('type'),
                'brand': d['source'].get('brand'),
                'last4': d['source'].get('last4'),
                'bank_name': d['source'].get('bank_name'),
                'bank': d['source'].get('bank'),
                'bic': d['source'].get('bic'),
                'card': {
                    'brand': d['source'].get('card', {}).get('brand'),
                    'country': d['source'].get('card', {}).get('cuntry'),
                    'last4': d['source'].get('card', {}).get('last4'),
                }
            }
        if 'amount' in d:
            new['amount'] = d['amount']
        if 'currency' in d:
            new['currency'] = d['currency']
        if 'status' in d:
            new['status'] = d['status']
        if 'id' in d:
            new['id'] = d['id']

        new['_shredded'] = True
        obj.info = json.dumps(new)
        obj.save(update_fields=['info'])

        for le in obj.order.all_logentries().filter(
                action_type="pretix.plugins.stripe.event"
        ).exclude(data="", shredded=True):
            d = le.parsed_data
            if 'data' in d:
                for k, v in list(d['data']['object'].items()):
                    if v not in ('reason', 'status', 'failure_message', 'object', 'id'):
                        d['data']['object'][k] = '█'
                le.data = json.dumps(d)
                le.shredded = True
                le.save(update_fields=['data', 'shredded'])


class StripeCC(StripeMethod):
    identifier = 'stripe'
    verbose_name = _('Credit card via Stripe')
    public_name = _('Credit card')
    method = 'cc'

    def payment_form_render(self, request, total) -> str:
        account = get_stripe_account_key(self)
        if not RegisteredApplePayDomain.objects.filter(account=account, domain=request.host).exists():
            stripe_verify_domain.apply_async(args=(self.event.pk, request.host))

        ui = self.settings.get('ui', default='pretix')
        if ui == 'checkout':
            template = get_template('pretixplugins/stripe/checkout_payment_form_stripe_checkout.html')
        else:
            template = get_template('pretixplugins/stripe/checkout_payment_form.html')
        ctx = {
            'request': request,
            'event': self.event,
            'total': self._decimal_to_int(total),
            'settings': self.settings,
        }
        return template.render(ctx)

    def payment_is_valid_session(self, request):
        return request.session.get('payment_stripe_token', '') != ''

    def checkout_prepare(self, request, cart):
        token = request.POST.get('stripe_token', '')
        request.session['payment_stripe_token'] = token
        request.session['payment_stripe_brand'] = request.POST.get('stripe_card_brand', '')
        request.session['payment_stripe_last4'] = request.POST.get('stripe_card_last4', '')
        if token == '':
            messages.error(request, _('You may need to enable JavaScript for Stripe payments.'))
            return False
        return True

    def _use_3ds(self, card):
        if self.settings.cc_3ds_mode == 'recommended':
            return card.three_d_secure in ('required', 'recommended')
        elif self.settings.cc_3ds_mode == 'optional':
            return card.three_d_secure in ('required', 'recommended', 'optional')
        else:
            return card.three_d_secure == 'required'

    def execute_payment(self, request: HttpRequest, payment: OrderPayment):
        self._init_api()

        if request.session['payment_stripe_token'].startswith('src_'):
            try:
                src = stripe.Source.retrieve(request.session['payment_stripe_token'], **self.api_kwargs)
                if src.type == 'card' and src.card and self._use_3ds(src.card):
                    request.session['payment_stripe_order_secret'] = payment.order.secret
                    source = stripe.Source.create(
                        type='three_d_secure',
                        amount=self._get_amount(payment),
                        currency=self.event.currency.lower(),
                        three_d_secure={
                            'card': src.id
                        },
                        statement_descriptor=ugettext('{event}-{code}').format(
                            event=self.event.slug.upper(),
                            code=payment.order.code
                        )[:22],
                        metadata={
                            'order': str(payment.order.id),
                            'event': self.event.id,
                            'code': payment.order.code
                        },
                        redirect={
                            'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                                'order': payment.order.code,
                                'payment': payment.pk,
                                'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                            })
                        },
                        **self.api_kwargs
                    )
                    ReferencedStripeObject.objects.get_or_create(
                        reference=source.id,
                        defaults={'order': payment.order, 'payment': payment}
                    )
                    if source.status == "pending":
                        payment.info = str(source)
                        payment.state = OrderPayment.PAYMENT_STATE_PENDING
                        payment.save()
                        return self.redirect(request, source.redirect.url)
            except stripe.error.StripeError as e:
                if e.json_body:
                    err = e.json_body['error']
                    logger.exception('Stripe error: %s' % str(err))
                else:
                    err = {'message': str(e)}
                    logger.exception('Stripe error: %s' % str(e))
                payment.info_data = {
                    'error': True,
                    'message': err['message'],
                }
                payment.state = OrderPayment.PAYMENT_STATE_FAILED
                payment.save()
                payment.order.log_action('pretix.event.order.payment.failed', {
                    'local_id': payment.local_id,
                    'provider': payment.provider,
                    'message': err['message']
                })
                raise PaymentException(_('We had trouble communicating with Stripe. Please try again and get in touch '
                                         'with us if this problem persists.'))

        try:
            self._charge_source(request, request.session['payment_stripe_token'], payment)
        finally:
            del request.session['payment_stripe_token']


class StripeGiropay(StripeMethod):
    identifier = 'stripe_giropay'
    verbose_name = _('giropay via Stripe')
    public_name = _('giropay')
    method = 'giropay'

    def payment_form_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_form_giropay.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
            'form': self.payment_form(request)
        }
        return template.render(ctx)

    @property
    def payment_form_fields(self):
        return OrderedDict([
            ('account', forms.CharField(label=_('Account holder'))),
        ])

    def _create_source(self, request, payment):
        try:
            source = stripe.Source.create(
                type='giropay',
                amount=self._get_amount(payment),
                currency=self.event.currency.lower(),
                metadata={
                    'order': str(payment.order.id),
                    'event': self.event.id,
                    'code': payment.order.code
                },
                owner={
                    'name': request.session.get('payment_stripe_giropay_account') or ugettext('unknown name')
                },
                giropay={
                    'statement_descriptor': ugettext('{event}-{code}').format(
                        event=self.event.slug.upper(),
                        code=payment.order.code
                    )[:35]
                },
                redirect={
                    'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                        'order': payment.order.code,
                        'payment': payment.pk,
                        'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                    })
                },
                **self.api_kwargs
            )
            return source
        finally:
            if 'payment_stripe_giropay_account' in request.session:
                del request.session['payment_stripe_giropay_account']

    def payment_is_valid_session(self, request):
        return (
            request.session.get('payment_stripe_giropay_account', '') != ''
        )

    def checkout_prepare(self, request, cart):
        form = self.payment_form(request)
        if form.is_valid():
            request.session['payment_stripe_giropay_account'] = form.cleaned_data['account']
            return True
        return False


class StripeIdeal(StripeMethod):
    identifier = 'stripe_ideal'
    verbose_name = _('iDEAL via Stripe')
    public_name = _('iDEAL')
    method = 'ideal'

    def payment_form_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_form_simple.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
        }
        return template.render(ctx)

    def _create_source(self, request, payment):
        source = stripe.Source.create(
            type='ideal',
            amount=self._get_amount(payment),
            currency=self.event.currency.lower(),
            metadata={
                'order': str(payment.order.id),
                'event': self.event.id,
                'code': payment.order.code
            },
            ideal={
                'statement_descriptor': ugettext('{event}-{code}').format(
                    event=self.event.slug.upper(),
                    code=payment.order.code
                )[:22]
            },
            redirect={
                'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                    'order': payment.order.code,
                    'payment': payment.pk,
                    'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                })
            },
            **self.api_kwargs
        )
        return source

    def payment_is_valid_session(self, request):
        return True

    def checkout_prepare(self, request, cart):
        return True


class StripeAlipay(StripeMethod):
    identifier = 'stripe_alipay'
    verbose_name = _('Alipay via Stripe')
    public_name = _('Alipay')
    method = 'alipay'

    def payment_form_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_form_simple.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
        }
        return template.render(ctx)

    def _create_source(self, request, payment):
        source = stripe.Source.create(
            type='alipay',
            amount=self._get_amount(payment),
            currency=self.event.currency.lower(),
            metadata={
                'order': str(payment.order.id),
                'event': self.event.id,
                'code': payment.order.code
            },
            redirect={
                'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                    'order': payment.order.code,
                    'payment': payment.pk,
                    'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                })
            },
            **self.api_kwargs
        )
        return source

    def payment_is_valid_session(self, request):
        return True

    def checkout_prepare(self, request, cart):
        return True


class StripeBancontact(StripeMethod):
    identifier = 'stripe_bancontact'
    verbose_name = _('Bancontact via Stripe')
    public_name = _('Bancontact')
    method = 'bancontact'

    def payment_form_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_form_bancontact.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
            'form': self.payment_form(request)
        }
        return template.render(ctx)

    @property
    def payment_form_fields(self):
        return OrderedDict([
            ('account', forms.CharField(label=_('Account holder'), min_length=3)),
        ])

    def _create_source(self, request, payment):
        try:
            source = stripe.Source.create(
                type='bancontact',
                amount=self._get_amount(payment),
                currency=self.event.currency.lower(),
                metadata={
                    'order': str(payment.order.id),
                    'event': self.event.id,
                    'code': payment.order.code
                },
                owner={
                    'name': request.session.get('payment_stripe_bancontact_account') or ugettext('unknown name')
                },
                bancontact={
                    'statement_descriptor': ugettext('{event}-{code}').format(
                        event=self.event.slug.upper(),
                        code=payment.order.code
                    )[:35]
                },
                redirect={
                    'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                        'order': payment.order.code,
                        'payment': payment.pk,
                        'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                    })
                },
                **self.api_kwargs
            )
            return source
        finally:
            if 'payment_stripe_bancontact_account' in request.session:
                del request.session['payment_stripe_bancontact_account']

    def payment_is_valid_session(self, request):
        return (
            request.session.get('payment_stripe_bancontact_account', '') != ''
        )

    def checkout_prepare(self, request, cart):
        form = self.payment_form(request)
        if form.is_valid():
            request.session['payment_stripe_bancontact_account'] = form.cleaned_data['account']
            return True
        return False


class StripeSofort(StripeMethod):
    identifier = 'stripe_sofort'
    verbose_name = _('SOFORT via Stripe')
    public_name = _('SOFORT')
    method = 'sofort'

    def payment_form_render(self, request) -> str:
        template = get_template('pretixplugins/stripe/checkout_payment_form_sofort.html')
        ctx = {
            'request': request,
            'event': self.event,
            'settings': self.settings,
            'form': self.payment_form(request)
        }
        return template.render(ctx)

    @property
    def payment_form_fields(self):
        return OrderedDict([
            ('bank_country', forms.ChoiceField(label=_('Country of your bank'), choices=(
                ('de', _('Germany')),
                ('at', _('Austria')),
                ('be', _('Belgium')),
                ('nl', _('Netherlands')),
                ('es', _('Spain'))
            ))),
        ])

    def _create_source(self, request, payment):
        source = stripe.Source.create(
            type='sofort',
            amount=self._get_amount(payment),
            currency=self.event.currency.lower(),
            metadata={
                'order': str(payment.order.id),
                'event': self.event.id,
                'code': payment.order.code
            },
            sofort={
                'country': request.session.get('payment_stripe_sofort_bank_country'),
                'statement_descriptor': ugettext('{event}-{code}').format(
                    event=self.event.slug.upper(),
                    code=payment.order.code
                )[:35]
            },
            redirect={
                'return_url': build_absolute_uri(self.event, 'plugins:stripe:return', kwargs={
                    'order': payment.order.code,
                    'payment': payment.pk,
                    'hash': hashlib.sha1(payment.order.secret.lower().encode()).hexdigest(),
                })
            },
            **self.api_kwargs
        )
        return source

    def payment_is_valid_session(self, request):
        return (
            request.session.get('payment_stripe_sofort_bank_country', '') != ''
        )

    def checkout_prepare(self, request, cart):
        form = self.payment_form(request)
        if form.is_valid():
            request.session['payment_stripe_sofort_bank_country'] = form.cleaned_data['bank_country']
            return True
        return False

    def payment_can_retry(self, payment):
        return payment.state != OrderPayment.PAYMENT_STATE_PENDING and self._is_still_available(order=payment.order)