v0.1.12

backend/tests/test_product_costing.py

@@ -0,0 +1,169 @@
+from app.services.product_costing_service import (
+    ProductCostAssumptions,
+    ProductCostInputItem,
+    calculate_product_cost_item,
+)
+
+
+def assumptions() -> ProductCostAssumptions:
+    return ProductCostAssumptions(
+        grading_per_kg=0.05,
+        cracking_per_kg=0.03,
+        process_costs={
+            "Bagging + Grading": 0.04,
+            "Standard Bagging": 0.02,
+            "PHF Horse Mixes": 0.01,
+            "Peckish": 0.08,
+            "Hay & Straw": 0.09,
+        },
+        client_margins={
+            "Specialty": {"distributor_margin": 0.2, "wholesale_margin": 0.1},
+            "Peckish": {"distributor_margin": 0.25, "wholesale_margin": 0.15},
+            "Hay & Straw": {"distributor_margin": 0.3, "wholesale_margin": 0.2},
+            "Straight Grain": {"distributor_margin": 0.1, "wholesale_margin": 0.08},
+            "PHF Horse Mixes": {"distributor_margin": 0.18, "wholesale_margin": 0.12},
+        },
+        bag_costs={
+            "20kg_bag": 0.6,
+            "bulka_bag": 22.0,
+            "own_bag_credit": 0.2,
+            "1_5kg_bagging": 0.35,
+            "peckish_bag": 0.4,
+        },
+        freight_costs={
+            "freight_per_pallet": 80.0,
+            "peckish_freight_per_pallet": 96.0,
+            "hay_straw_freight_per_pallet": 120.0,
+        },
+    )
+
+
+def item(**overrides) -> ProductCostInputItem:
+    values = {
+        "client_category": "Specialty",
+        "product_name": "Pigeon Mix 20kg",
+        "mix_product_name": "Pigeon Mix",
+        "unit_type": "Standard",
+        "own_bag": None,
+        "unit_kg": 20.0,
+        "items_per_pallet": 40,
+        "bagging_process": "Bagging + Grading",
+        "manual_distributor_margin": None,
+        "manual_wholesale_margin": None,
+    }
+    values.update(overrides)
+    return ProductCostInputItem(**values)
+
+
+def test_standard_product_uses_per_kg_components_unit_bag_freight_and_default_margins():
+    result = calculate_product_cost_item(item(), assumptions(), 0.5)
+
+    assert result.grading_cost_per_kg == 0.05
+    assert result.bagging_cost_per_kg == 0.04
+    assert result.bag_cost_per_unit == 0.6
+    assert result.freight_cost_per_unit == 2.0
+    assert result.finished_product_delivered_cost == 14.4
+    assert result.distributor_price == 18.0
+    assert result.wholesale_price == 16.0
+    assert result.warnings == []
+
+
+def test_bulka_uses_per_kg_delivered_formula_and_bulka_bag_and_freight_divided_by_unit_kg():
+    result = calculate_product_cost_item(item(unit_type="Bulka", unit_kg=1000, items_per_pallet=1), assumptions(), 0.5)
+
+    assert result.bag_cost_per_unit == 0.022
+    assert result.freight_cost_per_unit == 0.08
+    assert result.finished_product_delivered_cost == 0.692
+
+
+def test_per_unit_uses_per_kg_delivered_formula_but_standard_pallet_freight():
+    result = calculate_product_cost_item(item(unit_type="Per Unit", unit_kg=1, items_per_pallet=10), assumptions(), 0.5)
+
+    assert result.freight_cost_per_unit == 8.0
+    assert result.finished_product_delivered_cost == 8.59
+
+
+def test_peckish_uses_peckish_bag_freight_and_zero_grading():
+    result = calculate_product_cost_item(
+        item(client_category="Peckish", bagging_process="Peckish", items_per_pallet=24),
+        assumptions(),
+        0.5,
+    )
+
+    assert result.grading_cost_per_kg == 0
+    assert result.bagging_cost_per_kg == 0.08
+    assert result.bag_cost_per_unit == 0.4
+    assert result.freight_cost_per_unit == 4.0
+
+
+def test_hay_and_straw_uses_hay_freight_and_zero_grading():
+    result = calculate_product_cost_item(
+        item(client_category="Hay & Straw", bagging_process="Hay & Straw", items_per_pallet=30),
+        assumptions(),
+        0.5,
+    )
+
+    assert result.grading_cost_per_kg == 0
+    assert result.freight_cost_per_unit == 4.0
+
+
+def test_phf_horse_mixes_have_zero_grading():
+    result = calculate_product_cost_item(
+        item(client_category="PHF Horse Mixes", bagging_process="PHF Horse Mixes"),
+        assumptions(),
+        0.5,
+    )
+
+    assert result.grading_cost_per_kg == 0
+
+
+def test_own_bag_subtracts_credit_and_no_bag_sets_bag_cost_to_zero():
+    own_bag = calculate_product_cost_item(item(own_bag="Yes"), assumptions(), 0.5)
+    no_bag = calculate_product_cost_item(item(own_bag="No Bag"), assumptions(), 0.5)
+
+    assert own_bag.bag_cost_per_unit == 0.4
+    assert no_bag.bag_cost_per_unit == 0
+
+
+def test_one_point_five_kg_branch_multiplies_pack_formula_by_eight():
+    result = calculate_product_cost_item(item(unit_type="1.5 kg", unit_kg=1.5), assumptions(), 0.5)
+
+    assert result.bag_cost_per_unit == 0.35
+    assert result.finished_product_delivered_cost == 10.84
+
+
+def test_cracked_product_adds_cracking_cost_and_manual_margins_override_defaults():
+    result = calculate_product_cost_item(
+        item(product_name="Cracked Maize 20kg", manual_distributor_margin=0.1, manual_wholesale_margin=0.05),
+        assumptions(),
+        0.5,
+    )
+
+    assert result.cracking_cost_per_kg == 0.03
+    assert result.distributor_price == 16.6667
+    assert result.wholesale_price == 15.8
+
+
+def test_straight_grain_bulka_wholesale_rounds_up_to_two_decimals():
+    result = calculate_product_cost_item(
+        item(client_category="Straight Grain", unit_type="Bulka", unit_kg=1000, items_per_pallet=1),
+        assumptions(),
+        0.5,
+    )
+
+    assert result.wholesale_price == 0.76
+
+
+def test_missing_lookup_and_invalid_inputs_generate_warnings_without_prices():
+    result = calculate_product_cost_item(
+        item(unit_kg=None, items_per_pallet=0, manual_distributor_margin=1.2),
+        assumptions(),
+        None,
+    )
+
+    assert "Missing mix/product cost lookup" in result.warnings
+    assert "Missing unit kg" in result.warnings
+    assert "Missing pallet quantity" in result.warnings
+    assert "Invalid distributor margin" in result.warnings
+    assert result.finished_product_delivered_cost is None
+    assert result.distributor_price is None