Implement combine_itemz

usage_function/tests/test_utils.py

@@ -308,6 +308,13 @@ def test_combine_items(self) -> None:
         )
         self.assertEqual(expected, existing_item)
 
+
+class TestCombineItems(TestCase):
+    """Tests for the utils.usage.combine_itemz function."""
+
+    # todo: can we combine effective price?
+    # todo: warnable fields (ones we presume are the same but could not be).
+
     def test_combine_itemz_1(self) -> None:
         """Check that we sum the costs."""
         items_a = [
@@ -325,6 +332,22 @@ def test_combine_itemz_1(self) -> None:
                 total_cost=1,
                 subscription_id=UUID(int=0),
             ),
+            models.Usage(
+                id="someid",
+                date=date.today(),
+                amortised_cost=1,
+                total_cost=1,
+                subscription_id=UUID(int=0),
+                reservation_id="somereservation",
+            ),
+            models.Usage(
+                id="someid",
+                date=date.today(),
+                amortised_cost=1,
+                total_cost=1,
+                subscription_id=UUID(int=0),
+                reservation_id="somereservation",
+            ),
         ]
 
         actual = utils.usage.combine_itemz(items_a)
@@ -337,6 +360,14 @@ def test_combine_itemz_1(self) -> None:
                 total_cost=2,
                 subscription_id=UUID(int=0),
             ),
+            models.Usage(
+                id="someid",
+                date=date.today(),
+                amortised_cost=2,
+                total_cost=2,
+                subscription_id=UUID(int=0),
+                reservation_id="somereservation",
+            ),
         ]
         self.assertListEqual(expected, actual)
 

usage_function/utils/usage.py

@@ -1,5 +1,6 @@
 """Utils for collecting and sending Azure usage data."""
 
+import copy
 import logging
 from datetime import datetime, timedelta
 from functools import lru_cache
@@ -103,9 +104,39 @@ def combine_items(item_to_update: models.Usage, other_item: models.Usage) -> Non
     item_to_update.cost += other_item.cost
 
 
-def combine_itemz(a):
-    """Sample docstring."""
-    pass
+def combine_itemz(items: list[models.Usage]) -> list[models.Usage]:
+    """Combine usage items.
+
+    If two or more usage items share all the same values,
+    ignoring cost, total_cost, amortised_cost, and quantity,
+    combine them into one item.
+    """
+    combinable_fields = {
+        "cost",
+        "amortised_cost",
+        "total_cost",
+        "quantity",
+    }
+
+    ret_list = []
+    for item in items:
+        curr_item_fields_dict = item.model_dump(exclude=combinable_fields)
+
+        match_found = False
+        for idx, ret_item in enumerate(ret_list):
+            existing_fields_dict = ret_item.model_dump(exclude=combinable_fields)
+
+            if existing_fields_dict == curr_item_fields_dict:
+                # item can be combined.
+                match_found = True
+                break
+
+        if match_found:
+            combine_items(ret_list[idx], item)
+        else:
+            # insert item into ret_list
+            ret_list.append(copy.deepcopy(item))
+    return ret_list
 
 
 def retrieve_usage(