fix: ineligible ITC due to Pos value in GSTR3b (#2197)

* fix: itc calculated for pos rule

* fix: changes as per review

* fix: make separate function for pos rule

* fix: changes as per review

* fix: None error handling

* fix: changes as per review

* fix: remove unrequired condition for ineligible transactions

---------

Co-authored-by: ljain112 <[email protected]>

india_compliance/gst_india/doctype/gstr_3b_report/gstr_3b_report.py

@@ -123,7 +123,13 @@ def get_itc_reversal_entries(self):
     def update_itc_reversal_from_purchase_invoice(self):
         ineligible_credit = IneligibleITC(
             self.company, self.gst_details.get("gstin"), self.month_no, self.year
-        ).get_for_purchase_invoice(group_by="ineligibility_reason")
+        ).get_ineligible_itc_us_17_5_for_purchase(group_by="ineligibility_reason")
+
+        ineligible_credit_due_to_pos = IneligibleITC(
+            self.company, self.gst_details.get("gstin"), self.month_no, self.year
+        ).get_ineligible_itc_due_to_pos_for_purchase(group_by="ineligibility_reason")
+
+        ineligible_credit.extend(ineligible_credit_due_to_pos)
 
         return self.process_ineligible_credit(ineligible_credit)
 

india_compliance/gst_india/report/gstr_3b_details/gstr_3b_details.py

@@ -270,7 +270,7 @@ def get_itc_from_journal_entry(self):
     def get_ineligible_itc_from_purchase(self):
         ineligible_itc = IneligibleITC(
             self.company, self.company_gstin, self.filters.month, self.filters.year
-        ).get_for_purchase_invoice()
+        ).get_ineligible_itc_us_17_5_for_purchase()
 
         return self.process_ineligible_itc(ineligible_itc)
 
@@ -286,10 +286,6 @@ def process_ineligible_itc(self, ineligible_itc):
             return []
 
         for row in ineligible_itc.copy():
-            if row.itc_classification == "ITC restricted due to PoS rules":
-                ineligible_itc.remove(row)
-                continue
-
             for key in ["iamt", "camt", "samt", "csamt"]:
                 row[key] = row[key] * -1
 
@@ -429,11 +425,15 @@ def __init__(self, company, gstin, month, year) -> None:
         self.year = year
         self.gst_accounts = get_escaped_gst_accounts(company, "Input")
 
-    def get_for_purchase_invoice(self, group_by="name"):
+    def get_ineligible_itc_us_17_5_for_purchase(self, group_by="name"):
+        """
+        - Ineligible As Per Section 17(5)
+        - ITC restricted due to ineligible items in purchase invoice
+        """
         ineligible_transactions = self.get_vouchers_with_gst_expense("Purchase Invoice")
 
         if not ineligible_transactions:
-            return
+            return []
 
         pi = frappe.qb.DocType("Purchase Invoice")
 
@@ -446,9 +446,10 @@ def get_for_purchase_invoice(self, group_by="name"):
                 pi.name.as_("voucher_no"),
                 pi.ineligibility_reason.as_("itc_classification"),
             )
-            .where(IfNull(pi.ineligibility_reason, "") != "")
+            .where(
+                IfNull(pi.ineligibility_reason, "") == "Ineligible As Per Section 17(5)"
+            )
             .where(pi.name.isin(ineligible_transactions))
-            .where(pi.company_gstin != IfNull(pi.supplier_gstin, ""))
             .groupby(pi[group_by])
             .run(as_dict=1)
         )
@@ -465,15 +466,71 @@ def get_for_purchase_invoice(self, group_by="name"):
                 Sum(pi.itc_state_tax).as_("samt"),
                 Sum(pi.itc_cess_amount).as_("csamt"),
             )
-            .where(IfNull(pi.ineligibility_reason, "") != "")
+            .where(
+                IfNull(pi.ineligibility_reason, "") == "Ineligible As Per Section 17(5)"
+            )
             .where(pi.name.isin(ineligible_transactions))
-            .where(pi.company_gstin != IfNull(pi.supplier_gstin, ""))
             .groupby(pi[group_by])
             .run(as_dict=1)
         )
 
         return self.get_ineligible_credit(credit_availed, credit_available, group_by)
 
+    def get_ineligible_itc_due_to_pos_for_purchase(self, group_by="name"):
+        """
+        - ITC restricted due to PoS rules
+        """
+        ineligible_transactions = self.get_vouchers_with_gst_expense("Purchase Invoice")
+
+        if not ineligible_transactions:
+            return []
+
+        pi = frappe.qb.DocType("Purchase Invoice")
+        taxes = frappe.qb.DocType("Purchase Taxes and Charges")
+
+        # utility function
+        def get_tax_case_statement(account, alias):
+            return Sum(
+                Case()
+                .when(
+                    taxes.account_head.isin(account),
+                    taxes.base_tax_amount_after_discount_amount,
+                )
+                .else_(0)
+            ).as_(alias)
+
+        # Credit availed is not required as it will be always 0 for pos
+
+        ineligible_credit = (
+            frappe.qb.from_(pi)
+            .inner_join(taxes)
+            .on(pi.name == taxes.parent)
+            .select(
+                pi.name.as_("voucher_no"),
+                pi.posting_date,
+                pi.ineligibility_reason.as_("itc_classification"),
+                get_tax_case_statement([self.gst_accounts.igst_account], "iamt"),
+                get_tax_case_statement([self.gst_accounts.cgst_account], "camt"),
+                get_tax_case_statement([self.gst_accounts.sgst_account], "camt"),
+                get_tax_case_statement(
+                    [
+                        self.gst_accounts.cess_account,
+                        self.gst_accounts.cess_non_advol_account,
+                    ],
+                    "csamt",
+                ),
+            )
+            .where(taxes.account_head.isin(list(self.gst_accounts.values())))
+            .where(
+                IfNull(pi.ineligibility_reason, "") == "ITC restricted due to PoS rules"
+            )
+            .where(pi.name.isin(ineligible_transactions))
+            .groupby(pi[group_by])
+            .run(as_dict=True)
+        )
+
+        return ineligible_credit
+
     def get_for_bill_of_entry(self, group_by="name"):
         ineligible_transactions = self.get_vouchers_with_gst_expense("Bill of Entry")