From c9af60e36c92e2b9e46e95d9d38a45387ead681c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gregor=20D=C3=BCster?= <git@gdstr.eu>
Date: Sat, 28 Sep 2024 21:39:18 +0200
Subject: [PATCH] Move FinTS client creation to seperate function

---
 pycroft/lib/finance/fints.py          | 28 ++++++++++++--------
 tests/external_services/test_fints.py | 37 +++++++++++++++++++++------
 web/blueprints/finance/__init__.py    | 15 +++++++----
 3 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/pycroft/lib/finance/fints.py b/pycroft/lib/finance/fints.py
index 7e15b75e9..e828214f4 100644
--- a/pycroft/lib/finance/fints.py
+++ b/pycroft/lib/finance/fints.py
@@ -2,6 +2,7 @@
 #  This file is part of the Pycroft project and licensed under the terms of
 #  the Apache License, Version 2.0. See the LICENSE file for details
 
+import typing as t
 from datetime import date
 
 from mt940.models import Transaction as MT940Transaction
@@ -10,15 +11,30 @@
 from pycroft.model.finance import BankAccount
 
 
-def get_fints_transactions(
+def get_fints_client(
     *,
     product_id: str,
     user_id: int,
     secret_pin: str,
     bank_account: BankAccount,
+    **kwargs: t.Any,
+) -> FinTS3Client:
+    return FinTS3Client(
+        bank_identifier=bank_account.routing_number,
+        user_id=user_id,
+        pin=secret_pin,
+        server=bank_account.fints_endpoint,
+        product_id=product_id,
+        **kwargs,
+    )
+
+
+def get_fints_transactions(
+    *,
     start_date: date,
     end_date: date,
-    FinTSClient: type[FinTS3Client] = FinTS3Client,
+    bank_account: BankAccount,
+    fints_client: FinTS3Client,
 ) -> tuple[list[MT940Transaction], list[StatementError]]:
     """Get the transactions from FinTS
 
@@ -26,14 +42,6 @@ def get_fints_transactions(
 
     - FinTS (:module:`pycroft.external_services.fints`)
     """
-    # login with fints
-    fints_client = FinTSClient(
-        bank_identifier=bank_account.routing_number,
-        user_id=user_id,
-        pin=secret_pin,
-        server=bank_account.fints_endpoint,
-        product_id=product_id,
-    )
     acc = next(
         (a for a in fints_client.get_sepa_accounts() if a.iban == bank_account.iban),
         None,
diff --git a/tests/external_services/test_fints.py b/tests/external_services/test_fints.py
index 3379eae1b..e1568897a 100644
--- a/tests/external_services/test_fints.py
+++ b/tests/external_services/test_fints.py
@@ -70,27 +70,48 @@ class BankAccountFactory(BankAccountFactory_):
 @pytest.fixture(scope="session")
 def default_transaction_args() -> dict:
     return {
-        "product_id": "1",
-        "user_id": 1,
-        "secret_pin": "123456",
         "start_date": today() - timedelta(days=30),
         "end_date": today(),
-        "FinTSClient": StubFintsClient,
     }
 
 
-def test_fints_connection(default_transaction_args):
+@pytest.fixture(scope="session")
+def default_fints_client_args() -> dict:
+    return {
+        "product_id": "1",
+        "user_id": 1,
+        "pin": "123456",
+    }
+
+
+def test_fints_connection(default_fints_client_args, default_transaction_args):
+    bank_account = BankAccountFactory.build(iban="DE61850503003120219540")
+    fints_client = StubFintsClient(
+        **default_fints_client_args,
+        bank_identifier=bank_account.routing_number,
+        server=bank_account.fints_endpoint,
+    )
+
     transactions, errors = get_fints_transactions(
         **default_transaction_args,
-        bank_account=BankAccountFactory.build(iban="DE61850503003120219540"),
+        bank_account=bank_account,
+        fints_client=fints_client,
     )
     assert transactions == []
     assert errors == []
 
 
-def test_transactions_unknown_iban(default_transaction_args):
+def test_transactions_unknown_iban(default_fints_client_args, default_transaction_args):
+    bank_account = BankAccountFactory.build()
+    fints_client = StubFintsClient(
+        **default_fints_client_args,
+        bank_identifier=bank_account.routing_number,
+        server=bank_account.fints_endpoint,
+    )
+
     with pytest.raises(KeyError, match="BankAccount with IBAN.*not found"):
         get_fints_transactions(
             **default_transaction_args,
-            bank_account=BankAccountFactory.build(),
+            bank_account=bank_account,
+            fints_client=fints_client,
         )
diff --git a/web/blueprints/finance/__init__.py b/web/blueprints/finance/__init__.py
index 3ed3865e2..0b57792b0 100644
--- a/web/blueprints/finance/__init__.py
+++ b/web/blueprints/finance/__init__.py
@@ -78,7 +78,7 @@
     get_last_import_date,
     get_last_membership_fee,
 )
-from pycroft.lib.finance.fints import get_fints_transactions
+from pycroft.lib.finance.fints import get_fints_transactions, get_fints_client
 from pycroft.lib.finance.matching import UserMatching, AccountMatching
 from pycroft.lib.mail import MemberNegativeBalance
 from pycroft.lib.user import encode_type2_user_id, user_send_mails
@@ -307,15 +307,20 @@ def display_form_response(
     if not form.validate():
         return display_form_response(imported)
 
+    fints_client = get_fints_client(
+        product_id=config.fints_product_id,
+        user_id=form.user.data,
+        secret_pin=form.secret_pin.data,
+        bank_account=bank_account,
+    )
+
     try:
         with flash_fints_errors():
             statement, errors = get_fints_transactions(
-                product_id=config.fints_product_id,
-                user_id=form.user.data,
-                secret_pin=form.secret_pin.data,
-                bank_account=bank_account,
                 start_date=form.start_date.data,
                 end_date=form.end_date.data,
+                bank_account=bank_account,
+                fints_client=fints_client,
             )
     except PycroftException:
         return display_form_response(imported)