Add ticket renderer RPC API (Z#23165429) (#4525)

---------

Co-authored-by: Mira Weller <weller@rami.io>

src/pretix/plugins/ticketoutputpdf/tasks.py

@@ -19,18 +19,26 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+import json
 import logging
+from io import BytesIO
 
 from django.core.files.base import ContentFile
+from django.db.models import Prefetch, prefetch_related_objects
+from pypdf import PdfWriter
 
 from pretix.base.models import (
-    CachedFile, Event, OrderPosition, cachedfile_name,
+    CachedFile, Checkin, Event, EventMetaValue, ItemMetaValue,
+    ItemVariationMetaValue, OrderPosition, SalesChannel, SubEventMetaValue,
+    cachedfile_name,
 )
 from pretix.base.services.orders import OrderError
 from pretix.base.services.tasks import EventTask
 from pretix.celery_app import app
 
+from ...base.i18n import language
 from ...base.services.export import ExportError
+from .models import TicketLayout
 from .ticketoutput import PdfTicketOutput
 
 logger = logging.getLogger(__name__)
@@ -46,3 +54,93 @@ def tickets_create_pdf(event: Event, fileid: int, position: int, channel) -> int
     file.file.save(cachedfile_name(file, file.filename), ContentFile(data))
     file.save()
     return file.pk
+
+
+@app.task(base=EventTask, throws=(OrderError, ExportError,))
+def bulk_render(event: Event, fileid: int, parts: list) -> int:
+    file = CachedFile.objects.get(id=fileid)
+
+    channels = SalesChannel.objects.in_bulk([p["override_channel"] for p in parts if p.get("override_channel")])
+    layouts = TicketLayout.objects.in_bulk([p["override_layout"] for p in parts if p.get("override_layout")])
+
+    positions = OrderPosition.objects.all()
+    prefetch_related_objects([event.organizer], 'meta_properties')
+    prefetch_related_objects(
+        [event],
+        Prefetch('meta_values', queryset=EventMetaValue.objects.select_related('property'),
+                 to_attr='meta_values_cached'),
+        'questions',
+        'item_meta_properties',
+    )
+    positions = positions.prefetch_related(
+        Prefetch('checkins', queryset=Checkin.objects.select_related("device")),
+        Prefetch('item', queryset=event.items.prefetch_related(
+            Prefetch('meta_values', ItemMetaValue.objects.select_related('property'),
+                     to_attr='meta_values_cached')
+        )),
+        'variation',
+        'answers', 'answers__options', 'answers__question',
+        'item__category',
+        'addon_to__answers', 'addon_to__answers__options', 'addon_to__answers__question',
+        Prefetch('addons', positions.select_related('item', 'variation')),
+        Prefetch('subevent', queryset=event.subevents.prefetch_related(
+            Prefetch('meta_values', to_attr='meta_values_cached',
+                     queryset=SubEventMetaValue.objects.select_related('property'))
+        )),
+        'linked_media',
+        Prefetch('order', event.orders.select_related('invoice_address').prefetch_related(
+            Prefetch(
+                'positions',
+                positions.prefetch_related(
+                    Prefetch('checkins', queryset=Checkin.objects.select_related('device')),
+                    Prefetch('item', queryset=event.items.prefetch_related(
+                        Prefetch('meta_values', ItemMetaValue.objects.select_related('property'),
+                                 to_attr='meta_values_cached')
+                    )),
+                    Prefetch('variation', queryset=event.items.prefetch_related(
+                        Prefetch('meta_values', ItemVariationMetaValue.objects.select_related('property'),
+                                 to_attr='meta_values_cached')
+                    )),
+                    'answers', 'answers__options', 'answers__question',
+                    'item__category',
+                    Prefetch('subevent', queryset=event.subevents.prefetch_related(
+                        Prefetch('meta_values', to_attr='meta_values_cached',
+                                 queryset=SubEventMetaValue.objects.select_related('property'))
+                    )),
+                    Prefetch('addons', positions.select_related('item', 'variation', 'seat'))
+                ).select_related('addon_to', 'seat', 'addon_to__seat')
+            )
+        ))
+    ).select_related(
+        'addon_to', 'seat', 'addon_to__seat'
+    )
+    positions = positions.in_bulk([p["orderposition"] for p in parts])
+
+    merger = PdfWriter()
+    for part in parts:
+        p = positions[part["orderposition"]]
+        p.order.event = event  # performance optimization
+        with (language(p.order.locale)):
+            kwargs = {}
+            if part.get("override_channel"):
+                kwargs["override_channel"] = channels[part["override_channel"]].identifier
+            if part.get("override_layout"):
+                l = layouts[part["override_layout"]]
+                kwargs["override_layout"] = json.loads(l.layout)
+                kwargs["override_background"] = l.background
+            prov = PdfTicketOutput(
+                event,
+                **kwargs,
+            )
+            filename, ctype, data = prov.generate(p)
+            merger.append(ContentFile(data))
+
+    outbuffer = BytesIO()
+    merger.write(outbuffer)
+    merger.close()
+    outbuffer.seek(0)
+
+    file.type = "application/pdf"
+    file.file.save(cachedfile_name(file, file.filename), ContentFile(outbuffer.getvalue()))
+    file.save()
+    return file.pk