Deduce ignored sale quantity from credit limit

Closes #12226

modules/sale_credit_limit/CHANGELOG

@@ -1,3 +1,4 @@
+* Deduce ignored sale quantity from credit limit
 
 Version 6.8.0 - 2023-05-01
 --------------------------

modules/sale_credit_limit/__init__.py

@@ -10,4 +10,5 @@ def register():
     Pool.register(
         party.Party,
         sale.Sale,
+        sale.Line,
         module='sale_credit_limit', type_='model')

modules/sale_credit_limit/party.py

@@ -31,8 +31,8 @@ class Party(metaclass=PoolMeta):
         for sale in sales:
             amount = 0
             for line in sale.lines:
-                quantity = line.quantity
-                if (line.type != 'line') or (quantity <= 0):
+                quantity = line.credit_limit_quantity
+                if quantity is None:
                     continue
                 for invoice_line in line.invoice_lines:
                     if invoice_line.type != 'line':

modules/sale_credit_limit/sale.py

@@ -1,7 +1,7 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
 from trytond.model import ModelView, Workflow
-from trytond.pool import PoolMeta
+from trytond.pool import Pool, PoolMeta
 
 
 class Sale(metaclass=PoolMeta):
@@ -25,3 +25,25 @@ class Sale(metaclass=PoolMeta):
                 party.check_credit_limit(
                     sale.credit_limit_amount, origin=str(sale))
         super(Sale, cls).confirm(sales)
+
+
+class Line(metaclass=PoolMeta):
+    __name__ = 'sale.line'
+
+    @property
+    def credit_limit_quantity(self):
+        pool = Pool()
+        UoM = pool.get('product.uom')
+        if (self.type != 'line') or (self.quantity <= 0):
+            return None
+        quantity = self.quantity
+        if self.sale.invoice_method == 'shipment':
+            for move in self.moves_ignored:
+                quantity -= UoM.compute_qty(
+                    move.uom, move.quantity, self.unit, round=False)
+        for invoice_line in self.invoice_lines:
+            if invoice_line.invoice in self.sale.invoices_ignored:
+                quantity -= UoM.compute_qty(
+                    invoice_line.unit, invoice_line.quantity, self.unit,
+                    round=False)
+        return quantity