refactor: allow multiple payment requests through customer portal

erpnext/accounts/doctype/payment_request/payment_request.py

@@ -1,7 +1,7 @@
 import json
 
 import frappe
-from frappe import _
+from frappe import _, qb
 from frappe.model.document import Document
 from frappe.query_builder.functions import Sum
 from frappe.utils import flt, nowdate
@@ -563,11 +563,24 @@ def make_payment_request(**args):
 	# fetches existing payment request `grand_total` amount
 	existing_payment_request_amount = get_existing_payment_request_amount(ref_doc.doctype, ref_doc.name)
 
-	if existing_payment_request_amount:
+	def validate_and_calculate_grand_total(grand_total, existing_payment_request_amount):
 		grand_total -= existing_payment_request_amount
-
 		if not grand_total:
 			frappe.throw(_("Payment Request is already created"))
+		return grand_total
+
+	if existing_payment_request_amount:
+		if args.order_type == "Shopping Cart":
+			# If Payment Request is in an advanced stage, then create for remaining amount.
+			if get_existing_payment_request_amount(
+				ref_doc.doctype, ref_doc.name, ["Initiated", "Partially Paid", "Payment Ordered", "Paid"]
+			):
+				grand_total = validate_and_calculate_grand_total(grand_total, existing_payment_request_amount)
+			else:
+				# If PR's are processed, cancel all of them.
+				cancel_old_payment_requests(ref_doc.doctype, ref_doc.name)
+		else:
+			grand_total = validate_and_calculate_grand_total(grand_total, existing_payment_request_amount)
 
 	if draft_payment_request:
 		frappe.db.set_value(
@@ -683,21 +696,65 @@ def get_amount(ref_doc, payment_account=None):
 		frappe.throw(_("Payment Entry is already created"))
 
 
-def get_existing_payment_request_amount(ref_dt, ref_dn):
+def get_irequest_status(payment_requests: None | list = None) -> list:
+	IR = frappe.qb.DocType("Integration Request")
+	res = []
+	if payment_requests:
+		res = (
+			frappe.qb.from_(IR)
+			.select(IR.name)
+			.where(IR.reference_doctype.eq("Payment Request"))
+			.where(IR.reference_docname.isin(payment_requests))
+			.where(IR.status.isin(["Authorized", "Completed"]))
+			.run(as_dict=True)
+		)
+	return res
+
+
+def cancel_old_payment_requests(ref_dt, ref_dn):
+	PR = frappe.qb.DocType("Payment Request")
+
+	if res := (
+		frappe.qb.from_(PR)
+		.select(PR.name)
+		.where(PR.reference_doctype == ref_dt)
+		.where(PR.reference_name == ref_dn)
+		.where(PR.docstatus == 1)
+		.where(PR.status.isin(["Draft", "Requested"]))
+		.run(as_dict=True)
+	):
+		if get_irequest_status([x.name for x in res]):
+			frappe.throw(_("Another Payment Request is already processed"))
+		else:
+			for x in res:
+				doc = frappe.get_doc("Payment Request", x.name)
+				doc.flags.ignore_permissions = True
+				doc.cancel()
+
+				if ireqs := get_irequests_of_payment_request(doc.name):
+					for ireq in ireqs:
+						frappe.db.set_value("Integration Request", ireq.name, "status", "Cancelled")
+
+
+def get_existing_payment_request_amount(ref_dt, ref_dn, statuses: list | None = None) -> list:
 	"""
 	Return the total amount of Payment Requests against a reference document.
 	"""
 	PR = frappe.qb.DocType("Payment Request")
 
-	response = (
+	query = (
 		frappe.qb.from_(PR)
 		.select(Sum(PR.grand_total))
 		.where(PR.reference_doctype == ref_dt)
 		.where(PR.reference_name == ref_dn)
 		.where(PR.docstatus == 1)
-		.run()
 	)
 
+	if statuses:
+		query = query.where(PR.status.isin(statuses))
+
+	response = query.run()
+
 	return response[0][0] if response[0] else 0
 
 
@@ -915,3 +972,17 @@ def get_open_payment_requests_query(doctype, txt, searchfield, start, page_len,
 		)
 		for pr in open_payment_requests
 	]
+
+
+def get_irequests_of_payment_request(doc: str | None = None) -> list:
+	res = []
+	if doc:
+		res = frappe.db.get_all(
+			"Integration Request",
+			{
+				"reference_doctype": "Payment Request",
+				"reference_docname": doc,
+				"status": "Queued",
+			},
+		)
+	return res