back_populates option on category relationship

Due to the use of the dataclasses mixin on the SQLAlchemy types, a
back_populates creates a RecursiveError when comparing two types. This
occurs because the dataclass will overwrite the __eq__ operator, and it
doesn't know when to stop comparing relationships.

Removing the dataclasses isn't the best approach, since then __init__,
__eq__ and __repr__ methods would have to be added to all types. Thus
the solution was to remove the relationship on the child (on a
one-to-one relationship) from the __eq__ operation, with the use of the
compare parameter.

Took the opportunity to define more logical __init__ methods on the
`Rule` and child classes.
Also revised the parameter options on some DB types.

pfbudget/__main__.py

@@ -163,14 +163,14 @@ if __name__ == "__main__":
 
             params = [
                 type.CategoryRule(
-                    args["start"][0] if args["start"] else None,
-                    args["end"][0] if args["end"] else None,
-                    args["description"][0] if args["description"] else None,
-                    args["regex"][0] if args["regex"] else None,
-                    args["bank"][0] if args["bank"] else None,
-                    args["min"][0] if args["min"] else None,
-                    args["max"][0] if args["max"] else None,
                     cat,
+                    start=args["start"][0] if args["start"] else None,
+                    end=args["end"][0] if args["end"] else None,
+                    description=args["description"][0] if args["description"] else None,
+                    regex=args["regex"][0] if args["regex"] else None,
+                    bank=args["bank"][0] if args["bank"] else None,
+                    min=args["min"][0] if args["min"] else None,
+                    max=args["max"][0] if args["max"] else None,
                 )
                 for cat in args["category"]
             ]
@@ -215,14 +215,14 @@ if __name__ == "__main__":
 
             params = [
                 type.TagRule(
-                    args["start"][0] if args["start"] else None,
-                    args["end"][0] if args["end"] else None,
-                    args["description"][0] if args["description"] else None,
-                    args["regex"][0] if args["regex"] else None,
-                    args["bank"][0] if args["bank"] else None,
-                    args["min"][0] if args["min"] else None,
-                    args["max"][0] if args["max"] else None,
                     tag,
+                    start=args["start"][0] if args["start"] else None,
+                    end=args["end"][0] if args["end"] else None,
+                    description=args["description"][0] if args["description"] else None,
+                    regex=args["regex"][0] if args["regex"] else None,
+                    bank=args["bank"][0] if args["bank"] else None,
+                    min=args["min"][0] if args["min"] else None,
+                    max=args["max"][0] if args["max"] else None,
                 )
                 for tag in args["tag"]
             ]

pfbudget/db/model.py

@@ -65,7 +65,7 @@ class Bank(Base, Export):
     BIC: Mapped[str] = mapped_column(String(8))
     type: Mapped[accounttype]
 
-    nordigen: Mapped[Optional[Nordigen]] = relationship(lazy="joined", init=False)
+    nordigen: Mapped[Optional[Nordigen]] = relationship(init=False)
 
     @property
     def format(self) -> dict[str, Any]:
@@ -98,16 +98,17 @@ class Transaction(Base, Export):
     description: Mapped[Optional[str]]
     amount: Mapped[money]
 
-    split: Mapped[bool] = mapped_column(init=False, default=False)
+    split: Mapped[bool] = mapped_column(default=False)
+
+    category: Mapped[Optional[TransactionCategory]] = relationship(
+        back_populates="transaction", default=None
+    )
+    tags: Mapped[set[TransactionTag]] = relationship(default_factory=set)
+    note: Mapped[Optional[Note]] = relationship(
+        cascade="all, delete-orphan", passive_deletes=True, default=None
+    )
 
     type: Mapped[str] = mapped_column(init=False)
-
-    category: Mapped[Optional[TransactionCategory]] = relationship(init=False)
-    note: Mapped[Optional[Note]] = relationship(
-        cascade="all, delete-orphan", init=False, passive_deletes=True
-    )
-    tags: Mapped[set[TransactionTag]] = relationship(init=False)
-
     __mapper_args__ = {"polymorphic_on": "type", "polymorphic_identity": "transaction"}
 
     @property
@@ -134,7 +135,7 @@ idfk = Annotated[
 
 
 class BankTransaction(Transaction):
-    bank: Mapped[bankfk] = mapped_column(nullable=True)
+    bank: Mapped[Optional[bankfk]] = mapped_column(default=None)
 
     __mapper_args__ = {"polymorphic_identity": "bank", "polymorphic_load": "inline"}
 
@@ -148,7 +149,7 @@ class MoneyTransaction(Transaction):
 
 
 class SplitTransaction(Transaction):
-    original: Mapped[idfk] = mapped_column(nullable=True)
+    original: Mapped[Optional[idfk]] = mapped_column(default=None)
 
     __mapper_args__ = {"polymorphic_identity": "split", "polymorphic_load": "inline"}
 
@@ -204,6 +205,15 @@ catfk = Annotated[
 ]
 
 
+class Selector_T(enum.Enum):
+    unknown = enum.auto()
+    nullifier = enum.auto()
+    vacations = enum.auto()
+    rules = enum.auto()
+    algorithm = enum.auto()
+    manual = enum.auto()
+
+
 class TransactionCategory(Base, Export):
     __tablename__ = "transactions_categorized"
 
@@ -211,7 +221,11 @@ class TransactionCategory(Base, Export):
     name: Mapped[catfk]
 
     selector: Mapped[CategorySelector] = relationship(
-        cascade="all, delete-orphan", lazy="joined"
+        cascade="all, delete-orphan", default=Selector_T.unknown
+    )
+
+    transaction: Mapped[Transaction] = relationship(
+        back_populates="category", init=False, compare=False
     )
 
     @property
@@ -234,7 +248,7 @@ class Nordigen(Base, Export):
     name: Mapped[bankfk] = mapped_column(primary_key=True)
     bank_id: Mapped[Optional[str]]
     requisition_id: Mapped[Optional[str]]
-    invert: Mapped[Optional[bool]]
+    invert: Mapped[Optional[bool]] = mapped_column(default=None)
 
     @property
     def format(self) -> dict[str, Any]:
@@ -270,18 +284,9 @@ class TransactionTag(Base, Export):
         return hash(self.id)
 
 
-class Selector_T(enum.Enum):
-    unknown = enum.auto()
-    nullifier = enum.auto()
-    vacations = enum.auto()
-    rules = enum.auto()
-    algorithm = enum.auto()
-    manual = enum.auto()
-
-
 categoryselector = Annotated[
     Selector_T,
-    mapped_column(Enum(Selector_T, inherit_schema=True), default=Selector_T.unknown),
+    mapped_column(Enum(Selector_T, inherit_schema=True)),
 ]
 
 
@@ -294,7 +299,7 @@ class CategorySelector(Base, Export):
         primary_key=True,
         init=False,
     )
-    selector: Mapped[categoryselector]
+    selector: Mapped[categoryselector] = mapped_column(default=Selector_T.unknown)
 
     @property
     def format(self):
@@ -336,7 +341,7 @@ class Link(Base):
     link: Mapped[idfk] = mapped_column(primary_key=True)
 
 
-class Rule(Base, Export):
+class Rule(Base, Export, init=False):
     __tablename__ = "rules"
 
     id: Mapped[idpk] = mapped_column(init=False)
@@ -355,6 +360,10 @@ class Rule(Base, Export):
         "polymorphic_on": "type",
     }
 
+    def __init__(self, **kwargs: Any) -> None:
+        for k, v in kwargs.items():
+            setattr(self, k, v)
+
     def matches(self, t: BankTransaction) -> bool:
         valid = None
         if self.regex:
@@ -415,6 +424,10 @@ class CategoryRule(Rule):
     def format(self) -> dict[str, Any]:
         return super().format | dict(name=self.name)
 
+    def __init__(self, name: str, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+        self.name = name
+
     def __hash__(self):
         return hash(self.id)
 
@@ -438,5 +451,9 @@ class TagRule(Rule):
     def format(self) -> dict[str, Any]:
         return super().format | dict(tag=self.tag)
 
+    def __init__(self, name: str, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+        self.tag = name
+
     def __hash__(self):
         return hash(self.id)

tests/mocks/categories.py

@@ -2,14 +2,11 @@ from decimal import Decimal
 
 from pfbudget.db.model import Category, CategoryRule, Tag, TagRule
 
-category_null = Category("null", None, set())
+category_null = Category("null")
 
 category1 = Category(
     "cat#1",
-    None,
+    rules={CategoryRule("cat#1", description="desc#1", max=Decimal(0))},
-    {CategoryRule(None, None, "desc#1", None, None, None, Decimal(0), "cat#1")},
 )
 
-tag_1 = Tag(
+tag_1 = Tag("tag#1", rules={TagRule("tag#1", description="desc#1", max=Decimal(0))})
-    "tag#1", {TagRule(None, None, "desc#1", None, None, None, Decimal(0), "tag#1")}
-)

tests/test_database.py

@@ -39,12 +39,16 @@ def banks(client: Client) -> list[Bank]:
 @pytest.fixture
 def transactions(client: Client) -> list[Transaction]:
     transactions = [
-        Transaction(date(2023, 1, 1), "", Decimal("-10")),
+        Transaction(
+            date(2023, 1, 1),
+            "",
+            Decimal("-10"),
+            category=TransactionCategory(
+                "category", CategorySelector(Selector_T.algorithm)
+            ),
+        ),
         Transaction(date(2023, 1, 2), "", Decimal("-50")),
     ]
-    transactions[0].category = TransactionCategory(
-        "name", CategorySelector(Selector_T.algorithm)
-    )
 
     client.insert(transactions)
     for i, transaction in enumerate(transactions):

tests/test_load.py

@@ -31,8 +31,8 @@ class TestDatabaseLoad:
 
     def test_insert(self, loader: Loader):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), "Bank#1"),
+            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), bank="Bank#1"),
-            BankTransaction(date(2023, 1, 2), "", Decimal("500"), "Bank#2"),
+            BankTransaction(date(2023, 1, 2), "", Decimal("500"), bank="Bank#2"),
         ]
 
         loader.load(transactions)

tests/test_psd2.py

@@ -91,9 +91,9 @@ class TestExtractPSD2:
     def test_extract(self, extractor: Extractor, bank: Bank):
         assert extractor.extract(bank) == [
             BankTransaction(
-                dt.date(2023, 1, 14), "string", Decimal("328.18"), "Bank#1"
+                dt.date(2023, 1, 14), "string", Decimal("328.18"), bank="Bank#1"
             ),
             BankTransaction(
-                dt.date(2023, 2, 14), "string", Decimal("947.26"), "Bank#1"
+                dt.date(2023, 2, 14), "string", Decimal("947.26"), bank="Bank#1"
             ),
         ]

tests/test_transform.py

@@ -20,8 +20,8 @@ from pfbudget.transform.transform import Transformer
 class TestTransform:
     def test_nullifier(self):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), "Bank#1"),
+            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), bank="Bank#1"),
-            BankTransaction(date(2023, 1, 2), "", Decimal("500"), "Bank#2"),
+            BankTransaction(date(2023, 1, 2), "", Decimal("500"), bank="Bank#2"),
         ]
 
         for t in transactions:
@@ -37,8 +37,8 @@ class TestTransform:
 
     def test_nullifier_inplace(self):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), "Bank#1"),
+            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), bank="Bank#1"),
-            BankTransaction(date(2023, 1, 2), "", Decimal("500"), "Bank#2"),
+            BankTransaction(date(2023, 1, 2), "", Decimal("500"), bank="Bank#2"),
         ]
 
         for t in transactions:
@@ -54,14 +54,14 @@ class TestTransform:
 
     def test_nullifier_with_rules(self):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), "Bank#1"),
+            BankTransaction(date(2023, 1, 1), "", Decimal("-500"), bank="Bank#1"),
-            BankTransaction(date(2023, 1, 2), "", Decimal("500"), "Bank#2"),
+            BankTransaction(date(2023, 1, 2), "", Decimal("500"), bank="Bank#2"),
         ]
 
         for t in transactions:
             assert not t.category
 
-        rules = [CategoryRule(None, None, None, None, "Bank#1", None, None, "null")]
+        rules = [CategoryRule("null", bank="Bank#1")]
 
         categorizer: Transformer = Nullifier(rules)
         transactions = categorizer.transform(transactions)
@@ -69,7 +69,7 @@ class TestTransform:
         for t in transactions:
             assert not t.category
 
-        rules.append(CategoryRule(None, None, None, None, "Bank#2", None, None, "null"))
+        rules.append(CategoryRule("null", bank="Bank#2"))
         categorizer = Nullifier(rules)
         transactions = categorizer.transform(transactions)
 
@@ -80,7 +80,7 @@ class TestTransform:
 
     def test_tagger(self):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "desc#1", Decimal("-10"), "Bank#1")
+            BankTransaction(date(2023, 1, 1), "desc#1", Decimal("-10"), bank="Bank#1")
         ]
 
         for t in transactions:
@@ -94,7 +94,7 @@ class TestTransform:
 
     def test_categorize(self):
         transactions = [
-            BankTransaction(date(2023, 1, 1), "desc#1", Decimal("-10"), "Bank#1")
+            BankTransaction(date(2023, 1, 1), "desc#1", Decimal("-10"), bank="Bank#1")
         ]
 
         for t in transactions: