fix: incorrect cost center in the purchase invoice (#37591)

diff --git a/erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py b/erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py
index e365d60..13593bc 100644
--- a/erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py
+++ b/erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py
@@ -1949,6 +1949,30 @@
 		self.assertEqual(po.docstatus, 1)
 		self.assertEqual(pi.docstatus, 1)
 
+	def test_default_cost_center_for_purchase(self):
+		from erpnext.accounts.doctype.cost_center.test_cost_center import create_cost_center
+
+		for c_center in ["_Test Cost Center Selling", "_Test Cost Center Buying"]:
+			create_cost_center(cost_center_name=c_center)
+
+		item = create_item(
+			"_Test Cost Center Item For Purchase",
+			is_stock_item=1,
+			buying_cost_center="_Test Cost Center Buying - _TC",
+			selling_cost_center="_Test Cost Center Selling - _TC",
+		)
+
+		pi = make_purchase_invoice(
+			item=item.name, qty=1, rate=1000, update_stock=True, do_not_submit=True, cost_center=""
+		)
+
+		pi.items[0].cost_center = ""
+		pi.set_missing_values()
+		pi.calculate_taxes_and_totals()
+		pi.save()
+
+		self.assertEqual(pi.items[0].cost_center, "_Test Cost Center Buying - _TC")
+
 
 def set_advance_flag(company, flag, default_account):
 	frappe.db.set_value(
diff --git a/erpnext/stock/doctype/item/test_item.py b/erpnext/stock/doctype/item/test_item.py
index 0c6dc77..a942f58 100644
--- a/erpnext/stock/doctype/item/test_item.py
+++ b/erpnext/stock/doctype/item/test_item.py
@@ -907,6 +907,8 @@
 	opening_stock=0,
 	is_fixed_asset=0,
 	asset_category=None,
+	buying_cost_center=None,
+	selling_cost_center=None,
 	company="_Test Company",
 ):
 	if not frappe.db.exists("Item", item_code):
@@ -924,7 +926,15 @@
 		item.is_purchase_item = is_purchase_item
 		item.is_customer_provided_item = is_customer_provided_item
 		item.customer = customer or ""
-		item.append("item_defaults", {"default_warehouse": warehouse, "company": company})
+		item.append(
+			"item_defaults",
+			{
+				"default_warehouse": warehouse,
+				"company": company,
+				"selling_cost_center": selling_cost_center,
+				"buying_cost_center": buying_cost_center,
+			},
+		)
 		item.save()
 	else:
 		item = frappe.get_doc("Item", item_code)
diff --git a/erpnext/stock/get_item_details.py b/erpnext/stock/get_item_details.py
index a6ab63b..5954462 100644
--- a/erpnext/stock/get_item_details.py
+++ b/erpnext/stock/get_item_details.py
@@ -737,6 +737,12 @@
 			data = frappe.get_attr(path)(args.get("item_code"), company)
 
 			if data and (data.selling_cost_center or data.buying_cost_center):
+				if args.get("customer") and data.selling_cost_center:
+					return data.selling_cost_center
+
+				elif args.get("supplier") and data.buying_cost_center:
+					return data.buying_cost_center
+
 				return data.selling_cost_center or data.buying_cost_center
 
 	if not cost_center and args.get("cost_center"):