feat: add validation for inter company transactions

erpnext/accounts/doctype/accounts_settings/accounts_settings.json

@@ -38,6 +38,11 @@
   "show_taxes_as_table_in_print",
   "column_break_12",
   "show_payment_schedule_in_print",
+  "item_price_settings_section",
+  "maintain_same_internal_transaction_rate",
+  "column_break_feyo",
+  "maintain_same_rate_action",
+  "role_to_override_stop_action",
   "currency_exchange_section",
   "allow_stale",
   "column_break_yuug",
@@ -556,6 +561,37 @@
    "fieldname": "legacy_section",
    "fieldtype": "Section Break",
    "label": "Legacy Fields"
+  },
+  {
+   "default": "0",
+   "fieldname": "maintain_same_internal_transaction_rate",
+   "fieldtype": "Check",
+   "label": "Maintain Same Rate Throughout Internal Transaction"
+  },
+  {
+   "default": "Stop",
+   "depends_on": "maintain_same_internal_transaction_rate",
+   "fieldname": "maintain_same_rate_action",
+   "fieldtype": "Select",
+   "label": "Action if Same Rate is Not Maintained Throughout  Internal Transaction",
+   "mandatory_depends_on": "maintain_same_internal_transaction_rate",
+   "options": "Stop\nWarn"
+  },
+  {
+   "depends_on": "eval: doc.maintain_same_internal_transaction_rate && doc.maintain_same_rate_action == 'Stop'",
+   "fieldname": "role_to_override_stop_action",
+   "fieldtype": "Link",
+   "label": "Role Allowed to Override Stop Action",
+   "options": "Role"
+  },
+  {
+   "fieldname": "item_price_settings_section",
+   "fieldtype": "Section Break",
+   "label": "Item Price Settings"
+  },
+  {
+   "fieldname": "column_break_feyo",
+   "fieldtype": "Column Break"
   }
  ],
  "icon": "icon-cog",

erpnext/accounts/doctype/accounts_settings/accounts_settings.py

@@ -50,6 +50,8 @@ class AccountsSettings(Document):
 		general_ledger_remarks_length: DF.Int
 		ignore_account_closing_balance: DF.Check
 		ignore_is_opening_check_for_reporting: DF.Check
+		maintain_same_internal_transaction_rate: DF.Check
+		maintain_same_rate_action: DF.Literal["Stop", "Warn"]
 		make_payment_via_journal_entry: DF.Check
 		merge_similar_account_heads: DF.Check
 		over_billing_allowance: DF.Currency
@@ -58,6 +60,7 @@ class AccountsSettings(Document):
 		receivable_payable_remarks_length: DF.Int
 		reconciliation_queue_size: DF.Int
 		role_allowed_to_over_bill: DF.Link | None
+		role_to_override_stop_action: DF.Link | None
 		round_row_wise_tax: DF.Check
 		show_balance_in_coa: DF.Check
 		show_inclusive_tax_in_print: DF.Check

erpnext/controllers/accounts_controller.py

@@ -230,6 +230,8 @@ class AccountsController(TransactionBase):
 		self.validate_party_accounts()
 
 		self.validate_inter_company_reference()
+		# validate inter  company transaction rate
+		self.validate_internal_transaction()
 
 		self.disable_pricing_rule_on_internal_transfer()
 		self.disable_tax_included_prices_for_internal_transfer()
@@ -740,6 +742,91 @@ class AccountsController(TransactionBase):
 					msg = f"At Row {row.idx}: The field {bold(label)} is mandatory for internal transfer"
 					frappe.throw(_(msg), title=_("Internal Transfer Reference Missing"))
 
+	def validate_internal_transaction(self):
+		if not cint(
+			frappe.db.get_single_value("Accounts Settings", "maintain_same_internal_transaction_rate")
+		):
+			return
+
+		doctypes_list = ["Sales Order", "Sales Invoice", "Purchase Order", "Purchase Invoice"]
+
+		if self.doctype in doctypes_list and (
+			self.get("is_internal_customer") or self.get("is_internal_supplier")
+		):
+			self.validate_internal_transaction_based_on_voucher_type()
+
+	def validate_internal_transaction_based_on_voucher_type(self):
+		order = ["Sales Order", "Purchase Order"]
+		invoice = ["Sales Invoice", "Purchase Invoice"]
+
+		if self.doctype in order and self.get("inter_company_order_reference"):
+			# Fetch the linked order
+			linked_doctype = "Sales Order" if self.doctype == "Purchase Order" else "Purchase Order"
+			self.validate_line_items(
+				linked_doctype,
+				"sales_order" if linked_doctype == "Sales Order" else "purchase_order",
+				"sales_order_item" if linked_doctype == "Sales Order" else "purchase_order_item",
+			)
+		elif self.doctype in invoice and self.get("inter_company_invoice_reference"):
+			# Fetch the linked invoice
+			linked_doctype = "Sales Invoice" if self.doctype == "Purchase Invoice" else "Purchase Invoice"
+			self.validate_line_items(
+				linked_doctype,
+				"sales_invoice" if linked_doctype == "Sales Invoice" else "purchase_invoice",
+				"sales_invoice_item" if linked_doctype == "Sales Invoice" else "purchase_invoice_item",
+			)
+
+	def validate_line_items(self, ref_dt, ref_dn_field, ref_link_field):
+		action, role_allowed_to_override = frappe.get_cached_value(
+			"Accounts Settings", "None", ["maintain_same_rate_action", "role_to_override_stop_action"]
+		)
+
+		reference_names = [d.get(ref_link_field) for d in self.get("items") if d.get(ref_link_field)]
+		reference_details = self.get_reference_details(reference_names, ref_dt + " Item")
+
+		stop_actions = []
+
+		for d in self.get("items"):
+			if d.get(ref_link_field):
+				ref_rate = reference_details.get(d.get(ref_link_field))
+				if ref_rate is not None and abs(flt(d.rate - ref_rate, d.precision("rate"))) >= 0.01:
+					if action == "Stop":
+						user_roles = [
+							r["role"]
+							for r in frappe.get_all(
+								"Has Role", filters={"parent": frappe.session.user}, fields=["role"]
+							)
+						]
+						if role_allowed_to_override not in user_roles:
+							stop_actions.append(
+								_("Row #{0}: Rate must be same as {1}: {2} ({3} / {4})").format(
+									d.idx,
+									ref_dt,
+									self.inter_company_invoice_reference
+									if d.parenttype in ("Sales Invoice", "Purchase Invoice")
+									else d.get(ref_dn_field),
+									d.rate,
+									ref_rate,
+								)
+							)
+					else:
+						frappe.msgprint(
+							_("Row #{0}: Rate must be same as {1}: {2} ({3} / {4})").format(
+								d.idx,
+								ref_dt,
+								self.inter_company_invoice_reference
+								if d.parenttype in ("Sales Invoice", "Purchase Invoice")
+								else d.get(ref_dn_field),
+								d.rate,
+								ref_rate,
+							),
+							title=_("Warning"),
+							indicator="orange",
+						)
+
+		if stop_actions:
+			frappe.throw(stop_actions, as_list=True)
+
 	def disable_pricing_rule_on_internal_transfer(self):
 		if not self.get("ignore_pricing_rule") and self.is_internal_transfer():
 			self.ignore_pricing_rule = 1