brotherton-erpnext/erpnext/patches/v14_0/single_to_multi_dunning.py

import frappe

from erpnext.accounts.general_ledger import make_reverse_gl_entries


def execute():
	frappe.reload_doc("accounts", "doctype", "overdue_payment")
	frappe.reload_doc("accounts", "doctype", "dunning")

	all_dunnings = frappe.get_all("Dunning", filters={"docstatus": ("!=", 2)}, pluck="name")
	for dunning_name in all_dunnings:
		dunning = frappe.get_doc("Dunning", dunning_name)
		if not dunning.sales_invoice:
			# nothing we can do
			continue

		if dunning.overdue_payments:
			# something's already here, doesn't need patching
			continue

		payment_schedules = frappe.get_all(
			"Payment Schedule",
			filters={"parent": dunning.sales_invoice},
			fields=[
				"parent as sales_invoice",
				"name as payment_schedule",
				"payment_term",
				"due_date",
				"invoice_portion",
				"payment_amount",
				# at the time of creating this dunning, the full amount was outstanding
				"payment_amount as outstanding",
				"'0' as paid_amount",
				"discounted_amount",
			],
		)

		dunning.extend("overdue_payments", payment_schedules)
		dunning.validate()

		dunning.flags.ignore_validate_update_after_submit = True
		dunning.save()

		if dunning.status != "Resolved":
			# With the new logic, dunning amount gets recorded as additional income
			# at time of payment. We don't want to record the dunning amount twice,
			# so we reverse previous GL Entries that recorded the dunning amount at
			# time of submission of the Dunning.
			make_reverse_gl_entries(voucher_type="Dunning", voucher_no=dunning.name)