Implement arithmetic formulas for cost value components

src/ifcopenshell-python/ifcopenshell/api/cost/add_cost_item_value.py

@@ -1,16 +0,0 @@
-import ifcopenshell.api
-
-
-class Usecase:
-    def __init__(self, file, **settings):
-        self.file = file
-        self.settings = {"cost_item": None, "ifc_class": "IfcQuantityCount"}
-        for key, value in settings.items():
-            self.settings[key] = value
-
-    def execute(self):
-        value = self.file.create_entity("IfcCostValue")
-        values = list(self.settings["cost_item"].CostValues or [])
-        values.append(value)
-        self.settings["cost_item"].CostValues = values
-        return value

src/ifcopenshell-python/ifcopenshell/api/cost/add_cost_value.py

@@ -0,0 +1,18 @@
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"parent": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        value = self.file.create_entity("IfcCostValue")
+        if self.settings["parent"].is_a("IfcCostItem"):
+            values = list(self.settings["parent"].CostValues or [])
+            values.append(value)
+            self.settings["parent"].CostValues = values
+        elif self.settings["parent"].is_a("IfcCostValue"):
+            values = list(self.settings["parent"].Components or [])
+            values.append(value)
+            self.settings["parent"].Components = values
+        return value

src/ifcopenshell-python/ifcopenshell/api/cost/data.py

@@ -87,12 +87,31 @@ class Data:
         value_data["Components"] = [c.id() for c in value_data["Components"] or []]
         value_data["AppliedValue"] = cls.calculate_applied_value(cost_item, cost_value)
         cls.cost_values[cost_value.id()] = value_data
+        for component in cost_value.Components or []:
+            cls.load_cost_item_value(cost_item, component)
 
     @classmethod
     def calculate_applied_value(cls, cost_item, cost_value, category_filter=None):
-        result = 0
         if cost_value.ArithmeticOperator and cost_value.Components:
-            pass  # TODO
+            component_values = []
+            for component in cost_value.Components:
+                component_values.append(cls.calculate_applied_value(cost_item, component, category_filter))
+            if cost_value.ArithmeticOperator == "ADD":
+                return sum(component_values)
+            result = component_values.pop(0)
+            if cost_value.ArithmeticOperator == "DIVIDE":
+                for value in component_values:
+                    try:
+                        result /= value
+                    except ZeroDivisionError:
+                        pass
+            elif cost_value.ArithmeticOperator == "MULTIPLY":
+                for value in component_values:
+                    result *= value
+            elif cost_value.ArithmeticOperator == "SUBTRACT":
+                for value in component_values:
+                    result -= value
+            return result
         if cost_value.Category is None:
             return cls.get_primitive_applied_value(cost_value.AppliedValue)
         elif cost_value.Category == "*":
@@ -105,7 +124,7 @@ class Data:
                 return cls.sum_child_cost_items(cost_item, category_filter=cost_value.Category)
             else:
                 return cls.get_primitive_applied_value(cost_value.AppliedValue)
-        return result
+        return 0
 
     @classmethod
     def sum_child_cost_items(cls, cost_item, category_filter=None):