gizmoduck/tests/finance/test_constraints.py

"""Synthetic direct-ORM checks for the PostgreSQL persistence boundary."""

from datetime import date
from decimal import Decimal

import pytest
from django.db import IntegrityError
from django.db.models.deletion import ProtectedError

from finance.models import (
    Account, AuditEvent, CardStatement, Category, CategoryGroup, InstallmentPlan, Payee,
    SourceRecord, Transaction, Transfer,
)

pytestmark = pytest.mark.django_db(transaction=True)


@pytest.fixture
def account():
    return Account.objects.create(name="Synthetic bank", kind="BANK")


def post(account, **changes):
    values = dict(account=account, amount=Decimal("-10.00"),
                  posting_date=date(2026, 9, 1), kind="EXPENSE")
    values.update(changes)
    return Transaction.objects.create(**values)


@pytest.mark.parametrize("kind,amount", [
    ("EXPENSE", "0"), ("EXPENSE", "1"), ("INCOME", "-1"),
    ("REFUND", "-1"), ("TRANSFER", "0"), ("OPENING", "0"),
    ("INVALID", "-1"),
])
def test_database_rejects_invalid_transaction_signs(account, kind, amount):
    with pytest.raises(IntegrityError):
        post(account, kind=kind, amount=Decimal(amount))


@pytest.mark.parametrize("currency", ["brl", "B1L", "BR", "ÁBC"])
def test_database_rejects_invalid_currency(currency):
    with pytest.raises(IntegrityError):
        Account.objects.create(name="Synthetic account", kind="BANK", currency=currency)


def test_database_rejects_invalid_reference_choices():
    with pytest.raises(IntegrityError):
        Account.objects.create(name="Synthetic account", kind="INVALID")
    with pytest.raises(IntegrityError):
        Category.objects.create(name="Synthetic category", kind="INVALID")


def test_opening_is_unique_and_cannot_have_associations(account):
    post(account, kind="OPENING")
    with pytest.raises(IntegrityError):
        post(account, kind="OPENING")
    payee = Payee.objects.create(name="Synthetic shop")
    other = Account.objects.create(name="Other synthetic bank", kind="BANK")
    with pytest.raises(IntegrityError):
        post(other, kind="OPENING", payee=payee)


def test_refund_reference_only_allowed_on_refund(account):
    expense = post(account)
    with pytest.raises(IntegrityError):
        post(account, refund_of=expense)
    with pytest.raises(IntegrityError):
        Transaction.objects.filter(pk=expense.pk).update(
            kind="REFUND", amount=Decimal("10"), refund_of=expense)


def test_transfer_cannot_have_category(account):
    category = Category.objects.create(name="Synthetic expense", kind="EXPENSE")
    with pytest.raises(IntegrityError):
        post(account, kind="TRANSFER", category=category)


def test_category_name_is_unique_within_each_group(account):
    home = CategoryGroup.objects.create(name="Synthetic Home")
    travel = CategoryGroup.objects.create(name="Synthetic Travel")
    Category.objects.create(name="Synthetic Fees", kind="EXPENSE", group=home)
    Category.objects.create(name="Synthetic Fees", kind="EXPENSE", group=travel)
    with pytest.raises(IntegrityError):
        Category.objects.create(name="Synthetic Fees", kind="EXPENSE", group=home)


def test_installment_pair_number_kind_and_uniqueness(account):
    plan = InstallmentPlan.objects.create(account=account, total_installments=10)
    for changes in [dict(installment_plan=plan), dict(installment_number=3),
                    dict(installment_plan=plan, installment_number=0),
                    dict(installment_plan=plan, installment_number=3,
                         kind="REFUND", amount=Decimal("10"))]:
        with pytest.raises(IntegrityError):
            post(account, **changes)
    post(account, installment_plan=plan, installment_number=3)
    with pytest.raises(IntegrityError):
        post(account, installment_plan=plan, installment_number=3)
    with pytest.raises(IntegrityError):
        InstallmentPlan.objects.create(account=account, total_installments=0)


def test_statement_date_order_and_identity(account):
    values = dict(account=account, period_start=date(2026, 8, 1),
                  period_end=date(2026, 8, 31), due_date=date(2026, 9, 10))
    with pytest.raises(IntegrityError):
        CardStatement.objects.create(**{**values, "period_end": date(2026, 7, 31)})
    with pytest.raises(IntegrityError):
        CardStatement.objects.create(**{**values, "due_date": date(2026, 8, 30)})
    CardStatement.objects.create(**values)
    with pytest.raises(IntegrityError):
        CardStatement.objects.create(**values)


def test_source_identity_format_and_protected_history(account):
    activity = post(account)
    values = dict(transaction=activity, document_hash="a" * 64,
                  source_format="BANK_CSV", parser_version="synthetic-v1",
                  item_locator="row:1")
    for changes in [dict(document_hash="bad"), dict(source_format="OFX")]:
        with pytest.raises(IntegrityError):
            SourceRecord.objects.create(**{**values, **changes})
    SourceRecord.objects.create(**values)
    with pytest.raises(IntegrityError):
        SourceRecord.objects.create(**values)
    with pytest.raises(ProtectedError):
        activity.delete()
    with pytest.raises(ProtectedError):
        account.delete()


def test_transfer_distinct_and_unique_roles(account):
    outgoing = post(account, kind="TRANSFER")
    incoming = post(account, kind="TRANSFER", amount=Decimal("10"))
    with pytest.raises(IntegrityError):
        Transfer.objects.create(outgoing=outgoing, incoming=outgoing)
    Transfer.objects.create(outgoing=outgoing, incoming=incoming)
    with pytest.raises(IntegrityError):
        Transfer.objects.create(outgoing=outgoing, incoming=post(account, amount=Decimal("10"), kind="TRANSFER"))
    with pytest.raises(IntegrityError):
        Transfer.objects.create(outgoing=post(account, kind="TRANSFER"), incoming=incoming)


def test_audit_actor_and_outcome_choices():
    values = dict(actor_kind="HUMAN", actor_identifier="synthetic-owner",
                  operation="create_account", outcome="SUCCESS")
    for changes in [dict(actor_kind="INVALID"), dict(outcome="INVALID")]:
        with pytest.raises(IntegrityError):
            AuditEvent.objects.create(**{**values, **changes})