amount_generator: make GeneratedAmountList really reusable

product/ERP5/GeneratedAmountList.py

@@ -27,6 +27,7 @@
 #
 ##############################################################################
 
+from collections import defaultdict
 import zope.interface
 from AccessControl import allow_class
 from Products.ERP5Type import interfaces
@@ -35,6 +36,13 @@ class GeneratedAmountList(list):
   """
     Temporary object needed to aggregate Amount value
     And to calculate some report or total value
+
+    For example, delivery.getGeneratedAmountList() returns an object of this
+    type, with amounts for each movement and/or for the delivery. This result
+    can be used to get:
+    1. totals for the delivery, by first using aggregate()
+    2. detailed information on each movement with split(), which would be
+       equivalent to call getGeneratedAmountList() on each movement
   """
   zope.interface.implements(interfaces.IAmountList)
 
@@ -61,6 +69,12 @@ class GeneratedAmountList(list):
     return result
 
   def aggregate(self):
+    """Return a list of aggregated amounts
+
+    Groups amounts with same price, efficiency, reference and categories, merge
+    them by summing their quantities, and return the new amounts in a new list.
+    """
+    from Products.ERP5Type.Document import newTempAmount
     # XXX: Do we handle rounding correctly ?
     #      What to do if only total price is rounded ??
     aggregate_dict = {}
@@ -71,14 +85,33 @@ class GeneratedAmountList(list):
       aggregate = aggregate_dict.get(key)
       if aggregate is None:
         aggregate_dict[key] = [amount, amount.getQuantity()]
-        result_list.append(amount)
       else:
         aggregate[1] += amount.getQuantity()
     for amount, quantity in aggregate_dict.itervalues():
       # Before we ignore 'quantity==0' amount here for better performance,
       # but it is not a good idea, especially when the first expand causes
       # non-zero quantity and then quantity becomes zero.
-      amount._setQuantity(quantity)
+      aggregate = newTempAmount(amount.aq_parent, '', notify_workflow=False)
+      result_list.append(aggregate)
+      aggregate.__dict__.update(amount.__dict__)
+      aggregate._setQuantity(quantity)
+      del aggregate._base
     return result_list
 
+  def split(self):
+    """Return a dictionary with all amounts grouped by base amount
+
+    Return {amount: amount_list} where
+      - amount is the Amount instance (e.g. movement, delivery)
+        that generated amounts
+      - amount_list is an instance of this class
+
+    This is the opposite of aggregate(), which merges amounts that only differ
+    by their base amounts.
+    """
+    result = defaultdict(self.__class__)
+    for amount in self:
+      result[amount._base].append(amount)
+    return result
+
 allow_class(GeneratedAmountList)

product/ERP5/mixin/amount_generator.py

@@ -474,6 +474,7 @@ class AmountGeneratorMixin:
           property_dict['causality_value_list'][-1]
             .getRelativeUrl().replace('/', '_'),
           notify_workflow=False)
+        amount._base = delivery_amount
         amount._setCategoryList(property_dict.pop('category_list', ()))
         if amount.getQuantityUnit():
           del property_dict['quantity_unit']