fix: incorrect TCS amount while customer has advance payment (#35397)

* fix: incorrect TCS amount while customer has advance payment

* test: only unallocated advance should for threshold breach validation

erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py

@@ -3,8 +3,10 @@
 
 
 import frappe
-from frappe import _
+from frappe import _, qb
 from frappe.model.document import Document
+from frappe.query_builder import Criterion
+from frappe.query_builder.functions import Abs, Sum
 from frappe.utils import cint, getdate
 
 
@@ -346,26 +348,33 @@ def get_invoice_vouchers(parties, tax_details, company, party_type="Supplier"):
 def get_advance_vouchers(
 	parties, company=None, from_date=None, to_date=None, party_type="Supplier"
 ):
-	# for advance vouchers, debit and credit is reversed
-	dr_or_cr = "debit" if party_type == "Supplier" else "credit"
+	"""
+	Use Payment Ledger to fetch unallocated Advance Payments
+	"""
 
-	filters = {
-		dr_or_cr: [">", 0],
-		"is_opening": "No",
-		"is_cancelled": 0,
-		"party_type": party_type,
-		"party": ["in", parties],
-	}
+	ple = qb.DocType("Payment Ledger Entry")
 
-	if party_type == "Customer":
-		filters.update({"against_voucher": ["is", "not set"]})
+	conditions = []
+
+	conditions.append(ple.amount.lt(0))
+	conditions.append(ple.delinked == 0)
+	conditions.append(ple.party_type == party_type)
+	conditions.append(ple.party.isin(parties))
+	conditions.append(ple.voucher_no == ple.against_voucher_no)
 
 	if company:
-		filters["company"] = company
-	if from_date and to_date:
-		filters["posting_date"] = ["between", (from_date, to_date)]
+		conditions.append(ple.company == company)
 
-	return frappe.get_all("GL Entry", filters=filters, distinct=1, pluck="voucher_no") or [""]
+	if from_date and to_date:
+		conditions.append(ple.posting_date[from_date:to_date])
+
+	advances = (
+		qb.from_(ple).select(ple.voucher_no).distinct().where(Criterion.all(conditions)).run(as_list=1)
+	)
+	if advances:
+		advances = [x[0] for x in advances]
+
+	return advances
 
 
 def get_taxes_deducted_on_advances_allocated(inv, tax_details):
@@ -499,6 +508,7 @@ def get_tds_amount(ldc, parties, inv, tax_details, tax_deducted, vouchers):
 
 def get_tcs_amount(parties, inv, tax_details, vouchers, adv_vouchers):
 	tcs_amount = 0
+	ple = qb.DocType("Payment Ledger Entry")
 
 	# sum of debit entries made from sales invoices
 	invoiced_amt = (
@@ -516,18 +526,20 @@ def get_tcs_amount(parties, inv, tax_details, vouchers, adv_vouchers):
 	)
 
 	# sum of credit entries made from PE / JV with unset 'against voucher'
+
+	conditions = []
+	conditions.append(ple.amount.lt(0))
+	conditions.append(ple.delinked == 0)
+	conditions.append(ple.party.isin(parties))
+	conditions.append(ple.voucher_no == ple.against_voucher_no)
+	conditions.append(ple.company == inv.company)
+
+	advances = (
+		qb.from_(ple).select(Abs(Sum(ple.amount))).where(Criterion.all(conditions)).run(as_list=1)
+	)
+
 	advance_amt = (
-		frappe.db.get_value(
-			"GL Entry",
-			{
-				"is_cancelled": 0,
-				"party": ["in", parties],
-				"company": inv.company,
-				"voucher_no": ["in", adv_vouchers],
-			},
-			"sum(credit)",
-		)
-		or 0.0
+		qb.from_(ple).select(Abs(Sum(ple.amount))).where(Criterion.all(conditions)).run()[0][0] or 0.0
 	)
 
 	# sum of credit entries made from sales invoice

erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py

@@ -152,6 +152,60 @@ class TestTaxWithholdingCategory(unittest.TestCase):
 		for d in reversed(invoices):
 			d.cancel()
 
+	def test_tcs_on_unallocated_advance_payments(self):
+		frappe.db.set_value(
+			"Customer", "Test TCS Customer", "tax_withholding_category", "Cumulative Threshold TCS"
+		)
+
+		vouchers = []
+
+		# create advance payment
+		pe = create_payment_entry(
+			payment_type="Receive", party_type="Customer", party="Test TCS Customer", paid_amount=20000
+		)
+		pe.paid_from = "Debtors - _TC"
+		pe.paid_to = "Cash - _TC"
+		pe.submit()
+		vouchers.append(pe)
+
+		# create invoice
+		si1 = create_sales_invoice(customer="Test TCS Customer", rate=5000)
+		si1.submit()
+		vouchers.append(si1)
+
+		# reconcile
+		pr = frappe.get_doc("Payment Reconciliation")
+		pr.company = "_Test Company"
+		pr.party_type = "Customer"
+		pr.party = "Test TCS Customer"
+		pr.receivable_payable_account = "Debtors - _TC"
+		pr.get_unreconciled_entries()
+		invoices = [x.as_dict() for x in pr.get("invoices")]
+		payments = [x.as_dict() for x in pr.get("payments")]
+		pr.allocate_entries(frappe._dict({"invoices": invoices, "payments": payments}))
+		pr.reconcile()
+
+		# make another invoice
+		# sum of unallocated amount from payment entry and this sales invoice will breach cumulative threashold
+		# TDS should be calculated
+		si2 = create_sales_invoice(customer="Test TCS Customer", rate=15000)
+		si2.submit()
+		vouchers.append(si2)
+
+		si3 = create_sales_invoice(customer="Test TCS Customer", rate=10000)
+		si3.submit()
+		vouchers.append(si3)
+
+		# assert tax collection on total invoice amount created until now
+		tcs_charged = sum([d.base_tax_amount for d in si2.taxes if d.account_head == "TCS - _TC"])
+		tcs_charged += sum([d.base_tax_amount for d in si3.taxes if d.account_head == "TCS - _TC"])
+		self.assertEqual(tcs_charged, 1500)
+
+		# cancel invoice and payments to avoid clashing
+		for d in reversed(vouchers):
+			d.reload()
+			d.cancel()
+
 	def test_tds_calculation_on_net_total(self):
 		frappe.db.set_value(
 			"Supplier", "Test TDS Supplier4", "tax_withholding_category", "Cumulative Threshold TDS"