fix: last purchase rate for purchase invoice (backport frappe#43448) (f…

…rappe#43452)

* fix: last purchase rate for purchase invoice

(cherry picked from commit fb9d106)

# Conflicts:
#	erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py

* chore: fix conflicts

---------

Co-authored-by: Rohit Waghchaure <rohitw1991@gmail.com>

erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py

@@ -2292,6 +2292,24 @@ def test_adjust_incoming_rate_from_pi_with_multi_currency(self):
 
 		frappe.db.set_single_value("Buying Settings", "maintain_same_rate", 1)
 
+	def test_last_purchase_rate(self):
+		item = create_item("_Test Item For Last Purchase Rate from PI", is_stock_item=1)
+		pi1 = make_purchase_invoice(item_code=item.item_code, qty=10, rate=100)
+		item.reload()
+		self.assertEqual(item.last_purchase_rate, 100)
+
+		pi2 = make_purchase_invoice(item_code=item.item_code, qty=10, rate=200)
+		item.reload()
+		self.assertEqual(item.last_purchase_rate, 200)
+
+		pi2.cancel()
+		item.reload()
+		self.assertEqual(item.last_purchase_rate, 100)
+
+		pi1.cancel()
+		item.reload()
+		self.assertEqual(item.last_purchase_rate, 0)
+
 
 def set_advance_flag(company, flag, default_account):
 	frappe.db.set_value(

erpnext/controllers/buying_controller.py

@@ -702,9 +702,11 @@ def on_cancel(self):
 		if self.get("is_return"):
 			return
 
-		if self.doctype in ["Purchase Order", "Purchase Receipt"] and not frappe.db.get_single_value(
-			"Buying Settings", "disable_last_purchase_rate"
-		):
+		if self.doctype in [
+			"Purchase Order",
+			"Purchase Receipt",
+			"Purchase Invoice",
+		] and not frappe.db.get_single_value("Buying Settings", "disable_last_purchase_rate"):
 			update_last_purchase_rate(self, is_submit=0)
 
 		if self.doctype in ["Purchase Receipt", "Purchase Invoice"]:

erpnext/public/js/controllers/transaction.js

@@ -1277,6 +1277,10 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 				.filter(Boolean).length > 0;
 		} else if (this.frm.doc?.items) {
 			let first_row = this.frm.doc.items[0];
+			if (!first_row) {
+				return false
+			};
+
 			let mapped_rows = mappped_fields.filter(d => first_row[d])
 
 			return mapped_rows?.length > 0;

erpnext/stock/doctype/item/item.py

@@ -22,6 +22,7 @@
 	strip_html,
 )
 from frappe.utils.html_utils import clean_html
+from pypika import Order
 
 import erpnext
 from erpnext.controllers.item_variant import (
@@ -1136,34 +1137,10 @@ def get_last_purchase_details(item_code, doc_name=None, conversion_rate=1.0):
 	"""returns last purchase details in stock uom"""
 	# get last purchase order item details
 
-	last_purchase_order = frappe.db.sql(
-		"""\
-		select po.name, po.transaction_date, po.conversion_rate,
-			po_item.conversion_factor, po_item.base_price_list_rate,
-			po_item.discount_percentage, po_item.base_rate, po_item.base_net_rate
-		from `tabPurchase Order` po, `tabPurchase Order Item` po_item
-		where po.docstatus = 1 and po_item.item_code = %s and po.name != %s and
-			po.name = po_item.parent
-		order by po.transaction_date desc, po.name desc
-		limit 1""",
-		(item_code, cstr(doc_name)),
-		as_dict=1,
-	)
+	last_purchase_order = get_purchase_voucher_details("Purchase Order", item_code, doc_name)
 
 	# get last purchase receipt item details
-	last_purchase_receipt = frappe.db.sql(
-		"""\
-		select pr.name, pr.posting_date, pr.posting_time, pr.conversion_rate,
-			pr_item.conversion_factor, pr_item.base_price_list_rate, pr_item.discount_percentage,
-			pr_item.base_rate, pr_item.base_net_rate
-		from `tabPurchase Receipt` pr, `tabPurchase Receipt Item` pr_item
-		where pr.docstatus = 1 and pr_item.item_code = %s and pr.name != %s and
-			pr.name = pr_item.parent
-		order by pr.posting_date desc, pr.posting_time desc, pr.name desc
-		limit 1""",
-		(item_code, cstr(doc_name)),
-		as_dict=1,
-	)
+	last_purchase_receipt = get_purchase_voucher_details("Purchase Receipt", item_code, doc_name)
 
 	purchase_order_date = getdate(
 		last_purchase_order and last_purchase_order[0].transaction_date or "1900-01-01"
@@ -1184,7 +1161,13 @@ def get_last_purchase_details(item_code, doc_name=None, conversion_rate=1.0):
 		purchase_date = purchase_receipt_date
 
 	else:
-		return frappe._dict()
+		last_purchase_invoice = get_purchase_voucher_details("Purchase Invoice", item_code, doc_name)
+
+		if last_purchase_invoice:
+			last_purchase = last_purchase_invoice[0]
+			purchase_date = getdate(last_purchase.posting_date)
+		else:
+			return frappe._dict()
 
 	conversion_factor = flt(last_purchase.conversion_factor)
 	out = frappe._dict(
@@ -1210,6 +1193,40 @@ def get_last_purchase_details(item_code, doc_name=None, conversion_rate=1.0):
 	return out
 
 
+def get_purchase_voucher_details(doctype, item_code, document_name):
+	parent_doc = frappe.qb.DocType(doctype)
+	child_doc = frappe.qb.DocType(doctype + " Item")
+
+	query = (
+		frappe.qb.from_(parent_doc)
+		.inner_join(child_doc)
+		.on(parent_doc.name == child_doc.parent)
+		.select(
+			parent_doc.name,
+			parent_doc.conversion_rate,
+			child_doc.conversion_factor,
+			child_doc.base_price_list_rate,
+			child_doc.discount_percentage,
+			child_doc.base_rate,
+			child_doc.base_net_rate,
+		)
+		.where(parent_doc.docstatus == 1)
+		.where(child_doc.item_code == item_code)
+		.where(parent_doc.name != document_name)
+	)
+
+	if doctype in ("Purchase Receipt", "Purchase Invoice"):
+		query = query.select(parent_doc.posting_date, parent_doc.posting_time)
+		query = query.orderby(
+			parent_doc.posting_date, parent_doc.posting_time, parent_doc.name, order=Order.desc
+		)
+	else:
+		query = query.select(parent_doc.transaction_date)
+		query = query.orderby(parent_doc.transaction_date, parent_doc.name, order=Order.desc)
+
+	return query.run(as_dict=1)
+
+
 def check_stock_uom_with_bin(item, stock_uom):
 	if stock_uom == frappe.db.get_value("Item", item, "stock_uom"):
 		return