Merge pull request #147 from RedCarpetUp/ananth_ledger

Changed the reversal method.

Author: transhapHigsn

src/rush/create_card_swipe.py

@@ -5,7 +5,10 @@
     Optional,
 )
 
-from pendulum import DateTime
+from pendulum import (
+    DateTime,
+    datetime,
+)
 from sqlalchemy.orm.session import Session
 
 from rush.card.base_card import BaseLoan
@@ -16,10 +19,10 @@
     card_transaction_event,
     disburse_money_to_card,
 )
+from rush.ledger_utils import reverse_event
 from rush.models import (
     CardTransaction,
     LedgerTriggerEvent,
-    Loan,
     LoanData,
 )
 
@@ -80,23 +83,32 @@ def create_card_swipe(
     return {"result": "success", "data": swipe}
 
 
-def refund_card_swipe(
-    session: Session, loan: Loan, txn_ref_no: str, trace_no: str, transaction_id: Optional[int]
-) -> None:
-    card_transaction = (
-        session.query(CardTransaction)
-        .join(LoanData, LoanData.id == CardTransaction.loan_id)
+def reverse_card_swipe(
+    session: Session, user_loan: BaseLoan, card_transaction: CardTransaction, post_date: datetime
+) -> Dict:
+
+    bill = session.query(LoanData).filter(LoanData.id == card_transaction.loan_id).one()
+    if bill.is_generated:  # Can't reverse if already generated. # TODO what to do?
+        return {"result": "error", "message": "Bill is already generated."}
+
+    original_event = (
+        session.query(LedgerTriggerEvent)
         .filter(
-            LoanData.loan_id == loan.id,
-            LoanData.user_id == loan.user_id,
-            CardTransaction.status == "CONFIRMED",
-            CardTransaction.txn_ref_no == txn_ref_no,
-            CardTransaction.trace_no == trace_no,
+            LedgerTriggerEvent.loan_id == user_loan.loan_id,
+            LedgerTriggerEvent.extra_details["swipe_id"].astext == str(card_transaction.id),
         )
+        .one()
     )
 
-    if transaction_id:
-        card_transaction = card_transaction.filter(CardTransaction.id == transaction_id)
-
-    card_transaction = card_transaction.one()
-    card_transaction.status == "REFUNDED"
+    reversal_event = LedgerTriggerEvent.new(
+        session,
+        performed_by=user_loan.user_id,
+        name="transaction_reversal",
+        loan_id=user_loan.loan_id,
+        post_date=post_date,
+        amount=card_transaction.amount,
+        extra_details={"swipe_id": card_transaction.id},
+    )
+    reverse_event(session=session, event_to_reverse=original_event, event=reversal_event)
+    card_transaction.status = "REVERSED"
+    return {"result": "success"}

src/rush/ledger_utils.py

@@ -15,6 +15,7 @@
 from rush.models import (
     BookAccount,
     LedgerEntry,
+    LedgerTriggerEvent,
     LoanData,
     get_or_create,
 )
@@ -126,3 +127,15 @@ def is_bill_closed(session: Session, bill: LoanData, to_date: Optional[DateTime]
     if max_balance != 0:
         return False
     return True
+
+
+def reverse_event(session: Session, event_to_reverse: LedgerTriggerEvent, event: LedgerTriggerEvent):
+    ledger_entries = session.query(LedgerEntry).filter(LedgerEntry.event_id == event_to_reverse.id).all()
+    for entry in ledger_entries:
+        create_ledger_entry(
+            session,
+            event_id=event.id,
+            debit_book_id=entry.credit_account,
+            credit_book_id=entry.debit_account,
+            amount=entry.amount,
+        )

src/rush/payments.py

@@ -9,7 +9,6 @@
 from rush.anomaly_detection import run_anomaly
 from rush.card import BaseLoan
 from rush.card.base_card import BaseBill
-from rush.create_card_swipe import refund_card_swipe
 from rush.create_emi import update_event_with_dpd
 from rush.ledger_events import (
     _adjust_bill,
@@ -94,30 +93,20 @@ def refund_payment(
     user_loan: BaseLoan,
     payment_amount: Decimal,
     payment_date: DateTime,
-    payment_request_id: Optional[str] = None,
-    trace_no: Optional[str] = None,
-    txn_ref_no: Optional[str] = None,
+    payment_request_id: str,
 ) -> None:
-
-    assert payment_request_id is not None or (trace_no is not None and txn_ref_no is not None)
-
     lt = LedgerTriggerEvent(
         name="transaction_refund",
         loan_id=user_loan.loan_id,
         amount=payment_amount,
         post_date=payment_date,
         extra_details={
             "payment_request_id": payment_request_id,
-            "trace_no": trace_no,
-            "txn_ref_no": txn_ref_no,
         },
     )
     session.add(lt)
     session.flush()
 
-    if trace_no and txn_ref_no:
-        refund_card_swipe(session=session, loan=user_loan, txn_ref_no=txn_ref_no, trace_no=trace_no)
-
     # Checking if bill is generated or not. if not then reduce from unbilled else treat as payment.
     transaction_refund_event(session=session, user_loan=user_loan, event=lt)
     run_anomaly(session=session, user_loan=user_loan, event_date=payment_date)

src/test/test_current.py

@@ -30,7 +30,10 @@
     get_weekly_spend,
 )
 from rush.create_bill import bill_generate
-from rush.create_card_swipe import create_card_swipe
+from rush.create_card_swipe import (
+    create_card_swipe,
+    reverse_card_swipe,
+)
 from rush.create_emi import (
     daily_dpd_update,
     update_event_with_dpd,
@@ -170,7 +173,7 @@ def test_m2p_transfer(session: Session) -> None:
     # assert lender_pool_balance == Decimal(50000)
 
 
-def test_card_swipe(session: Session) -> None:
+def test_card_swipe_and_reversal(session: Session) -> None:
     test_lenders(session)
     card_db_updates(session)
     uc = create_user_product(
@@ -215,6 +218,29 @@ def test_card_swipe(session: Session) -> None:
     _, lender_payable = get_account_balance_from_str(session, f"{uc.loan_id}/loan/lender_payable/l")
     assert lender_payable == 900
 
+    resp = reverse_card_swipe(session, uc, swipe2, parse_date("2020-05-02 13:22:11"))
+    assert resp["result"] == "success"
+
+    _, unbilled_balance = get_account_balance_from_str(session, f"{bill_id}/bill/unbilled/a")
+    assert unbilled_balance == 700
+    # remaining card balance should be -900 because we've not loaded it yet and it's going in negative.
+    _, card_balance = get_account_balance_from_str(session, f"{uc.loan_id}/card/available_limit/l")
+    assert card_balance == -700
+
+    _, lender_payable = get_account_balance_from_str(session, f"{uc.loan_id}/loan/lender_payable/l")
+    assert lender_payable == 700
+
+    swipe3 = create_card_swipe(
+        session=session,
+        user_loan=uc,
+        txn_time=parse_date("2020-05-02 17:22:11"),
+        amount=Decimal(200),
+        description="Flipkart.com",
+        txn_ref_no="dummy_txn_ref_no_2",
+        trace_no="123452",
+    )
+    swipe3 = swipe3["data"]
+
 
 def test_closing_bill(session: Session) -> None:
     # Replicating nishant's case upto June
@@ -3123,7 +3149,7 @@ def test_reducing_interest_with_extension(session: Session) -> None:
 
 
 def test_intermediate_bill_generation(session: Session) -> None:
-    test_card_swipe(session)
+    test_card_swipe_and_reversal(session)
     user_loan = get_user_product(session, 2)
     bill_1 = bill_generate(user_loan)