Add sales channels (#1103)

- [x] Data model
- [x] Enforce constraint
- [x] Filter order list
- [x] Set channel on created order
- [x] Products API
- [x] Order API
- [x] Tests
- [x] Filter reports
- [x] Resellers
- [ ] deploy plugins
  - [ ] posbackend
  - [ ] resellers
  - [ ] reports
- [x] Ticketlayouts
- [x] Support in pretixPOS

src/pretix/base/services/orders.py

@@ -498,7 +498,7 @@ def _get_fees(positions: List[CartPosition], payment_provider: BasePaymentProvid
 
 def _create_order(event: Event, email: str, positions: List[CartPosition], now_dt: datetime,
                   payment_provider: BasePaymentProvider, locale: str=None, address: InvoiceAddress=None,
-                  meta_info: dict=None):
+                  meta_info: dict=None, sales_channel: str='web'):
     fees, pf = _get_fees(positions, payment_provider, address, meta_info, event)
     total = sum([c.price for c in positions]) + sum([c.value for c in fees])
 
@@ -511,7 +511,8 @@ def _create_order(event: Event, email: str, positions: List[CartPosition], now_d
             locale=locale,
             total=total,
             meta_info=json.dumps(meta_info or {}),
-            require_approval=any(p.item.require_approval for p in positions)
+            require_approval=any(p.item.require_approval for p in positions),
+            sales_channel=sales_channel
         )
         order.set_expires(now_dt, event.subevents.filter(id__in=[p.subevent_id for p in positions]))
         order.save()
@@ -550,7 +551,7 @@ def _create_order(event: Event, email: str, positions: List[CartPosition], now_d
 
 
 def _perform_order(event: str, payment_provider: str, position_ids: List[str],
-                   email: str, locale: str, address: int, meta_info: dict=None):
+                   email: str, locale: str, address: int, meta_info: dict=None, sales_channel: str='web'):
 
     event = Event.objects.get(id=event)
     if payment_provider:
@@ -579,7 +580,7 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
             raise OrderError(error_messages['internal'])
         _check_positions(event, now_dt, positions, address=addr)
         order = _create_order(event, email, positions, now_dt, pprov,
-                              locale=locale, address=addr, meta_info=meta_info)
+                              locale=locale, address=addr, meta_info=meta_info, sales_channel=sales_channel)
 
     invoice = order.invoices.last()  # Might be generated by plugin already
     if event.settings.get('invoice_generate') == 'True' and invoice_qualified(order):
@@ -1318,11 +1319,13 @@ class OrderChangeManager:
 
 @app.task(base=ProfiledTask, bind=True, max_retries=5, default_retry_delay=1, throws=(OrderError,))
 def perform_order(self, event: str, payment_provider: str, positions: List[str],
-                  email: str=None, locale: str=None, address: int=None, meta_info: dict=None):
+                  email: str=None, locale: str=None, address: int=None, meta_info: dict=None,
+                  sales_channel: str='web'):
     with language(locale):
         try:
             try:
-                return _perform_order(event, payment_provider, positions, email, locale, address, meta_info)
+                return _perform_order(event, payment_provider, positions, email, locale, address, meta_info,
+                                      sales_channel)
             except LockTimeoutException:
                 self.retry()
         except (MaxRetriesExceededError, LockTimeoutException):