consider unit basis for calculating resource costs #4122

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

@@ -106,14 +106,15 @@ class Usecase:
 
         total_cost = 0
         for resource in resources:
-            cost = ifcopenshell.util.resource.get_cost(resource)
+            cost, unit = ifcopenshell.util.resource.get_cost(resource)
-            quantity = ifcopenshell.util.resource.get_quantity(resource)
             if not cost:
                 cost = ifcopenshell.util.resource.get_parent_cost(resource) # Concept to standardise - Not defined in schema, but this makes manual scheduling of resources 10x faster and less duplicate data.
+            quantity = ifcopenshell.util.resource.get_quantity(resource)
             if not cost or not quantity:
                 continue
+            if unit and "day" in unit:
+                quantity = quantity / 8 # Assume 8 hour working day - TODO implement resource calendar
             total_cost += cost * quantity
-
         if total_cost:
             cost_value = ifcopenshell.api.run("cost.add_cost_value", self.file, parent=self.settings["cost_item"])
             cost_value.AppliedValue = self.file.createIfcMonetaryMeasure(total_cost)

src/ifcopenshell-python/ifcopenshell/util/resource.py

@@ -119,22 +119,25 @@ def get_nested_resources(resource):
 
 
 def get_cost(resource):
-    total = 0
+    costs = [
-    for cost_value in resource.BaseCosts or []:
+        ifcopenshell.util.cost.calculate_applied_value(resource, cost_value)
-        total += cost_value.AppliedValue.wrappedValue if cost_value.AppliedValue else 0
+        for cost_value in getattr(resource, "BaseCosts", [])
-    return total
+    ]
-
+    cost = costs[0] if costs else None
+    unit_basis = next(
+        (cost_value.UnitBasis for cost_value in getattr(resource, "BaseCosts", []) if cost_value.UnitBasis),
+        None
+    )
+    unit = unit_basis.UnitComponent.Name if unit_basis and unit_basis.UnitComponent.is_a("IfcConversionBasedUnit") else None
+    return cost, unit
 
 def get_quantity(resource):
     total = 0
     if resource.BaseQuantity:
         return resource.BaseQuantity[3]
     if resource.Usage and resource.Usage.ScheduleWork:
-        # For now we assume either hourly or daily depending on how duration is stored
         duration = ifcopenshell.util.date.ifc2datetime(resource.Usage.ScheduleWork)
-        if duration.days:
+        return duration.total_seconds() / 3600
-            return duration.days
-        return duration.seconds / 60 / 60
 
 def get_parent_cost(resource):
     if not resource.Nests: