Allow attaching invoices to emails

src/pretix/base/models/orders.py

@@ -368,7 +368,7 @@ class Order(LoggedModel):
 
     def send_mail(self, subject: str, template: Union[str, LazyI18nString],
                   context: Dict[str, Any]=None, log_entry_type: str='pretix.event.order.email.sent',
-                  user: User=None, headers: dict=None, sender: str=None):
+                  user: User=None, headers: dict=None, sender: str=None, invoices: list=None):
         """
         Sends an email to the user that placed this order. Basically, this method does two things:
 
@@ -393,7 +393,8 @@ class Order(LoggedModel):
                 email_content = render_mail(template, context)[0]
                 mail(
                     recipient, subject, template, context,
-                    self.event, self.locale, self, headers, sender
+                    self.event, self.locale, self, headers, sender,
+                    invoices=invoices
                 )
         except SendMailException:
             raise
@@ -404,7 +405,8 @@ class Order(LoggedModel):
                 data={
                     'subject': subject,
                     'message': email_content,
-                    'recipient': recipient
+                    'recipient': recipient,
+                    'invoices': [i.pk for i in invoices] if invoices else []
                 }
             )
 

src/pretix/base/services/invoices.py

@@ -158,7 +158,7 @@ def build_cancellation(invoice: Invoice):
     return invoice
 
 
-def generate_cancellation(invoice: Invoice):
+def generate_cancellation(invoice: Invoice, trigger_pdf=True):
     cancellation = copy.copy(invoice)
     cancellation.pk = None
     cancellation.invoice_no = None
@@ -170,7 +170,8 @@ def generate_cancellation(invoice: Invoice):
     cancellation.save()
 
     cancellation = build_cancellation(cancellation)
-    invoice_pdf(cancellation.pk)
+    if trigger_pdf:
+        invoice_pdf(cancellation.pk)
     return cancellation
 
 
@@ -183,7 +184,7 @@ def regenerate_invoice(invoice: Invoice):
     return invoice
 
 
-def generate_invoice(order: Order):
+def generate_invoice(order: Order, trigger_pdf=True):
     locale = order.event.settings.get('invoice_language')
     if locale:
         if locale == '__user__':
@@ -197,10 +198,11 @@ def generate_invoice(order: Order):
         locale=locale
     )
     invoice = build_invoice(invoice)
-    invoice_pdf(invoice.pk)
+    if trigger_pdf:
+        invoice_pdf(invoice.pk)
 
     if order.status in (Order.STATUS_CANCELED, Order.STATUS_REFUNDED):
-        generate_cancellation(invoice)
+        generate_cancellation(invoice, trigger_pdf)
 
     return invoice
 

src/pretix/base/services/mail.py

@@ -4,6 +4,7 @@ from typing import Any, Dict, List, Union
 import bleach
 import cssutils
 import markdown
+from celery import chain
 from django.conf import settings
 from django.core.mail import EmailMultiAlternatives, get_connection
 from django.template.loader import get_template
@@ -12,7 +13,8 @@ from i18nfield.strings import LazyI18nString
 from inlinestyler.utils import inline_css
 
 from pretix.base.i18n import language
-from pretix.base.models import Event, InvoiceAddress, Order
+from pretix.base.models import Event, Invoice, InvoiceAddress, Order
+from pretix.base.services.invoices import invoice_pdf_task
 from pretix.celery_app import app
 from pretix.multidomain.urlreverse import build_absolute_uri
 
@@ -33,7 +35,7 @@ class SendMailException(Exception):
 
 def mail(email: str, subject: str, template: Union[str, LazyI18nString],
          context: Dict[str, Any]=None, event: Event=None, locale: str=None,
-         order: Order=None, headers: dict=None, sender: str=None):
+         order: Order=None, headers: dict=None, sender: str=None, invoices: list=None):
     """
     Sends out an email to a user. The mail will be sent synchronously or asynchronously depending on the installation.
 
@@ -61,6 +63,8 @@ def mail(email: str, subject: str, template: Union[str, LazyI18nString],
     :param sender: Set the sender email address. If not set and ``event`` is set, the event's default will be used,
         otherwise the system default.
 
+    :param invoices: A list of invoices to attach to this email.
+
     :raises MailOrderException: on obvious, immediate failures. Not raising an exception does not necessarily mean
         that the email has been sent, just that it has been queued by the email backend.
     """
@@ -137,15 +141,42 @@ def mail(email: str, subject: str, template: Union[str, LazyI18nString],
 
         tpl = get_template('pretixbase/email/plainwrapper.html')
         body_html = tpl.render(htmlctx)
-        return mail_send([email], subject, body_plain, body_html, sender, event.id if event else None, headers)
+
+        send_task = mail_send_task.si(
+            to=[email],
+            subject=subject,
+            body=body_plain,
+            html=body_html,
+            sender=sender,
+            event=event.id if event else None,
+            headers=headers,
+            invoices=[i.pk for i in invoices]
+        )
+
+        if invoices:
+            task_chain = [invoice_pdf_task.si(i.pk).on_error(send_task) for i in invoices if not i.file]
+        else:
+            task_chain = []
+
+        task_chain.append(send_task)
+        chain(*task_chain).apply_async()
 
 
 @app.task
-def mail_send_task(to: List[str], subject: str, body: str, html: str, sender: str,
-                   event: int=None, headers: dict=None, bcc: List[str]=None) -> bool:
+def mail_send_task(*args, to: List[str], subject: str, body: str, html: str, sender: str,
+                   event: int=None, headers: dict=None, bcc: List[str]=None, invoices: List[int]=None) -> bool:
     email = EmailMultiAlternatives(subject, body, sender, to=to, bcc=bcc, headers=headers)
     if html is not None:
         email.attach_alternative(inline_css(html), "text/html")
+    if invoices:
+        invoices = Invoice.objects.filter(pk__in=invoices)
+        for inv in invoices:
+            if inv.file:
+                email.attach(
+                    '{}.pdf'.format(inv.number),
+                    inv.file.file.read(),
+                    'application/pdf'
+                )
     if event:
         event = Event.objects.get(id=event)
         backend = event.get_mail_backend()

src/pretix/base/services/orders.py

@@ -127,9 +127,13 @@ def mark_order_paid(order: Order, provider: str=None, info: str=None, date: date
     }, user=user, api_token=api_token)
     order_paid.send(order.event, order=order)
 
+    invoice = None
     if order.event.settings.get('invoice_generate') in ('True', 'paid') and invoice_qualified(order):
         if not order.invoices.exists():
-            generate_invoice(order)
+            invoice = generate_invoice(
+                order,
+                trigger_pdf=not send_mail or not order.event.settings.invoice_email_attachment
+            )
 
     if send_mail:
         with language(order.locale):
@@ -155,7 +159,8 @@ def mark_order_paid(order: Order, provider: str=None, info: str=None, date: date
             try:
                 order.send_mail(
                     email_subject, email_template, email_context,
-                    'pretix.event.order.email.order_paid', user
+                    'pretix.event.order.email.order_paid', user,
+                    invoices=[invoice] if invoice and order.event.settings.invoice_email_attachment else []
                 )
             except SendMailException:
                 logger.exception('Order paid email could not be sent')
@@ -502,9 +507,11 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
         order = _create_order(event, email, positions, now_dt, pprov,
                               locale=locale, address=addr, meta_info=meta_info)
 
+    invoice = order.invoices.last()  # Might be generated by plugin already
     if event.settings.get('invoice_generate') == 'True' and invoice_qualified(order):
-        if not order.invoices.exists():
-            generate_invoice(order)
+        if not invoice:
+            invoice = generate_invoice(order, trigger_pdf=not event.settings.invoice_email_attachment)
+            # send_mail will trigger PDF generation later
 
     if order.total == Decimal('0.00'):
         email_template = event.settings.mail_text_order_free
@@ -536,7 +543,8 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
     try:
         order.send_mail(
             email_subject, email_template, email_context,
-            log_entry
+            log_entry,
+            invoices=[invoice] if invoice and event.settings.invoice_email_attachment else []
         )
     except SendMailException:
         logger.exception('Order received email could not be sent')

src/pretix/base/settings.py

@@ -129,6 +129,10 @@ DEFAULTS = {
         'default': '__user__',
         'type': str
     },
+    'invoice_email_attachment': {
+        'default': 'False',
+        'type': bool
+    },
     'show_items_outside_presale_period': {
         'default': 'True',
         'type': bool

src/pretix/control/forms/event.py

@@ -544,7 +544,16 @@ class InvoiceSettingsForm(SettingsForm):
             ('user', _('Automatically on user request')),
             ('True', _('Automatically for all created orders')),
             ('paid', _('Automatically on payment')),
-        )
+        ),
+        help_text=_("Invoices will never be automatically generated for free orders.")
+    )
+    invoice_email_attachment = forms.BooleanField(
+        label=_("Attach invoices to emails"),
+        help_text=_("If invocies are automatically generated for all orders, they will be attached to the order "
+                    "confirmation mail. If they are automatically generated on payment, they will be attached to the "
+                    "payment confirmation mail. If they are not automatically generated, they will not be attached "
+                    "to emails."),
+        required=False
     )
     invoice_renderer = forms.ChoiceField(
         label=_("Invoice style"),

src/pretix/control/templates/pretixcontrol/event/invoicing.html

@@ -11,6 +11,7 @@
             {% bootstrap_field form.invoice_address_required layout="control" %}
             {% bootstrap_field form.invoice_name_required layout="control" %}
             {% bootstrap_field form.invoice_generate layout="control" %}
+            {% bootstrap_field form.invoice_email_attachment layout="control" %}
             {% bootstrap_field form.invoice_address_vatid layout="control" %}
             {% bootstrap_field form.invoice_numbers_consecutive layout="control" %}
             {% bootstrap_field form.invoice_numbers_prefix layout="control" %}