Flesh out more of the subscription infra and services using CRUD types

src/infra/db.py

@@ -1,6 +1,8 @@
-from sqlalchemy.orm import DeclarativeBase
+from typing import Callable
+from sqlalchemy.orm import DeclarativeBase, Session
 from src.config.database import Database as DatabaseConfig
-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, Engine
+import abc
 
 
 class Base(DeclarativeBase):
@@ -13,3 +15,81 @@ def get_database(config: DatabaseConfig):
     Base.metadata.create_all(engine)
 
     return engine
+
+
+class UpdateMissingEntryError(Exception):
+    def __init__(self, model_name: str, id: int):
+        super().__init__(f'Attempted to update non-existing {model_name} {id}')
+
+
+class CRUD[T, C](abc.ABC):
+    @abc.abstractmethod
+    def create(self, domain_item: C, verify: Callable[[T], None] | None) -> T:
+        pass
+
+    @abc.abstractmethod
+    def get(self, item_id: int) -> T | None:
+        pass
+
+    @abc.abstractmethod
+    def update(self, item_id: int, transform: Callable[[T], T]) -> T:
+        pass
+
+    @abc.abstractmethod
+    def delete(self, item_id: int, verify: Callable[[T], None] | None):
+        pass
+
+
+class CRUDRepo[T: Base, U, C](CRUD[U, C]):
+    def __init__(
+        self,
+        db: Engine,
+        root: type[T],
+        model_to_domain: Callable[[T], U],
+        mutate_from_domain: Callable[[T, U], None],
+        create_row: Callable[[C], T],
+    ):
+        self._db = db
+        self._root = root
+        self._model_to_domain = model_to_domain
+        self._mutate_from_domain = mutate_from_domain
+        self._create_row = create_row
+
+    def get(self, item_id: int) -> U | None:
+        with Session(self._db) as session:
+            db_item = session.get(self._root, item_id)
+            if db_item:
+                return self._model_to_domain(db_item)
+
+    def create(self, domain_item: C, verify: Callable[[U], None] | None) -> U:
+        item = self._create_row(domain_item)
+
+        with Session(self._db) as session:
+            session.add(item)
+            session.flush()
+            to_create = self._model_to_domain(item)
+            if verify:
+                verify(to_create)
+            session.commit()
+            return to_create
+
+    def update(self, item_id: int, transform: Callable[[U], U]) -> U:
+        with Session(self._db) as session:
+            db_item = session.get(self._root, item_id)
+            if db_item is None:
+                raise UpdateMissingEntryError(self._root.__tablename__, item_id)
+
+            domain_item = self._model_to_domain(db_item)
+            updated = transform(domain_item)
+            self._mutate_from_domain(db_item, updated)
+            session.commit()
+            return updated
+
+    def delete(self, item_id: int, verify: Callable[[U], None] | None):
+        with Session(self._db) as session:
+            db_item = session.get(self._root, item_id)
+            if db_item:
+                if verify:
+                    verify(self._model_to_domain(db_item))
+                session.delete(db_item)
+                session.commit()

src/infra/subscription.py

@@ -1,15 +1,17 @@
+from dataclasses import asdict
+import logging
 from src.infra.publication import model_to_order
 from typing import TYPE_CHECKING
 from datetime import datetime
-from src.infra.users import UserModel, model_to_user
+from src.infra.users import UserModel
 from sqlalchemy.orm import Mapped, mapped_column, relationship, Session, joinedload
-from src.infra.db import Base
-from sqlalchemy import Engine, ForeignKey, CheckConstraint, DateTime, func, UniqueConstraint, select
+from src.infra.db import Base, CRUDRepo
+from sqlalchemy import Engine, ForeignKey, CheckConstraint, DateTime, func, UniqueConstraint, select, delete
 from src.services.subscription import (
     SubscriptionRepo,
     Subscription,
     SubscriptionId,
-    UpdateSubscription,
+    SubscriptionCreateParams,
     AvailableSubscriptionEntry,
 )
 
@@ -46,16 +48,24 @@ class SubscriptionModel(Base):
 def model_to_subscription(db_sub: SubscriptionModel) -> Subscription:
     return Subscription(
         id=db_sub.id,
-        user=model_to_user(db_sub.user).to_profile(),
+        user_id=db_sub.user_id,
         publication_order=model_to_order(db_sub.order).to_profile(),
         sequence_seen=db_sub.sequence_seen,
         start=db_sub.start,
     )
 
 
-class SubscriptionRepoImpl(SubscriptionRepo):
+def mutate_subscription(db_sub: SubscriptionModel, sub: Subscription):
+    pass
+
+
+class SubscriptionRepoImpl(SubscriptionRepo, CRUDRepo[SubscriptionModel, Subscription, SubscriptionCreateParams]):
     def __init__(self, db: Engine):
-        self._db = db
+        super().__init__(
+            db, SubscriptionModel, model_to_subscription, mutate_subscription, lambda u: SubscriptionModel(**asdict(u))
+        )
+
+        self._logger = logging.getLogger('UserRepoImpl')
 
     def get_subscriptions_for_user(self, user_id: int) -> list[Subscription]:
         with Session(self._db) as session:
@@ -65,7 +75,6 @@ class SubscriptionRepoImpl(SubscriptionRepo):
                     .where(SubscriptionModel.user_id == user_id)
                     .options(
                         joinedload(SubscriptionModel.order),
-                        joinedload(SubscriptionModel.user),
                     )
                 )
                 .unique()
@@ -78,21 +87,12 @@ class SubscriptionRepoImpl(SubscriptionRepo):
             db_sub = session.get(
                 SubscriptionModel,
                 sub_id,
-                options=[joinedload(SubscriptionModel.order), joinedload(SubscriptionModel.user)],
+                options=[joinedload(SubscriptionModel.order)],
             )
 
         if db_sub:
             return model_to_subscription(db_sub)
 
-    def create_subscription_for_user(self, user_id: int, order_id: int) -> Subscription:
-        pass
-
-    def delete_subscription(self, subscription_id: SubscriptionId):
-        pass
-
-    def update_subscription(self, update: UpdateSubscription) -> Subscription:
-        pass
-
     def get_available_entries(self, user_id: int) -> dict[SubscriptionId, list[AvailableSubscriptionEntry]]:
         return {}
 

src/infra/users.py

@@ -6,7 +6,7 @@ from src.config.email import EmailAddress
 from sqlalchemy import String, VARCHAR, Engine, select
 from sqlalchemy.orm import mapped_column, Mapped, Session, relationship
 from argon2 import PasswordHasher
-from src.infra.db import Base
+from src.infra.db import Base, CRUDRepo
 from src.services.users.data import UserDTO, User
 from src.services.users.repo import UserRepo
 
@@ -33,42 +33,7 @@ def model_to_user(db_user: UserModel) -> User:
     )
 
 
-class UserRepoImpl(UserRepo):
-    def __init__(self, db: Engine):
-        self._db = db
-        self._hasher = PasswordHasher()
-        self._logger = logging.getLogger('UserRepoImpl')
-
-    def create_user(self, user: UserDTO) -> User:
-        pw = self._hasher.hash(user.raw_password.expose_secret())
-        db_user = UserModel(email=user.email, password_hash=pw)
-        with Session(self._db) as session:
-            session.add(db_user)
-            session.commit()
-
-        return model_to_user(db_user)
-
-    def get_user_by_id(self, user_id: int) -> User | None:
-        with Session(self._db) as session:
-            user = session.get(UserModel, user_id)
-
-        if user:
-            return model_to_user(user)
-
-    def get_user_by_email(self, email: EmailAddress) -> User | None:
-        with Session(self._db) as session:
-            user = session.scalar(select(UserModel).where(UserModel.email == email))
-
-        if user:
-            return model_to_user(user)
-
-    def update_user(self, user: User):
-        with Session(self._db) as session:
-            db_user = session.get(UserModel, user.id)
-            if db_user is None:
-                self._logger.warning(f'Attempted to update non-existing user {user.id}')
-                return
-
+def mutate_user(db_user: UserModel, user: User):
     # These fields can be set directly
     db_user.email_confirmed = user.email_confirmed
     db_user.password_hash = user.password_hash.expose_secret()
@@ -78,7 +43,28 @@ class UserRepoImpl(UserRepo):
         db_user.email = user.email
         db_user.email_confirmed = False
 
-            session.commit()
+
+def make_create_user(hasher: PasswordHasher):
+    def create_user(user: UserDTO) -> UserModel:
+        pw = hasher.hash(user.raw_password.expose_secret())
+        return UserModel(email=user.email, password_hash=pw)
+
+    return create_user
+
+
+class UserRepoImpl(CRUDRepo[UserModel, User, UserDTO], UserRepo):
+    def __init__(self, db: Engine):
+        hasher = PasswordHasher()
+        super().__init__(db, UserModel, model_to_user, mutate_user, make_create_user(hasher))
+        self._logger = logging.getLogger('UserRepoImpl')
+        self._hasher = hasher
+
+    def get_user_by_email(self, email: EmailAddress) -> User | None:
+        with Session(self._db) as session:
+            user = session.scalar(select(UserModel).where(UserModel.email == email))
+
+        if user:
+            return model_to_user(user)
 
     def auth_as_user(self, user: UserDTO) -> User | None:
         full_user = self.get_user_by_email(user.email)

src/services/subscription.py

@@ -1,3 +1,4 @@
+from src.infra.db import CRUD
 import abc
 from datetime import datetime
 from src.services.publications import (
@@ -5,7 +6,6 @@ from src.services.publications import (
     Sequence as PublicationSequence,
     Publication,
 )
-from src.services.users.data import UserProfile
 from dataclasses import dataclass
 
 SubscriptionId = int
@@ -20,7 +20,7 @@ class SubscriptionCreateParams:
 @dataclass
 class Subscription:
     id: SubscriptionId
-    user: UserProfile
+    user_id: int
     publication_order: PublicationOrderProfile
     sequence_seen: int
     start: datetime
@@ -29,8 +29,6 @@ class Subscription:
 @dataclass
 class UpdateSubscription:
     id: int
-    user_id: int
-    publication_order_id: int | None = None
     sequence_seen: int | None = None
     start: datetime | None = None
 
@@ -43,27 +41,11 @@ class AvailableSubscriptionEntry:
     sequence: PublicationSequence
 
 
-class SubscriptionRepo(abc.ABC):
+class SubscriptionRepo(CRUD[Subscription, SubscriptionCreateParams]):
     @abc.abstractmethod
     def get_subscriptions_for_user(self, user_id: int) -> list[Subscription]:
         pass
 
-    @abc.abstractmethod
-    def get_subscription_by_id(self, sub_id: SubscriptionId) -> Subscription | None:
-        pass
-
-    @abc.abstractmethod
-    def create_subscription_for_user(self, user_id: int, order_id: int) -> Subscription:
-        pass
-
-    @abc.abstractmethod
-    def delete_subscription(self, subscription_id: SubscriptionId):
-        pass
-
-    @abc.abstractmethod
-    def update_subscription(self, subscription: UpdateSubscription) -> Subscription:
-        pass
-
     @abc.abstractmethod
     def get_available_entries(self, user_id: int) -> dict[SubscriptionId, list[AvailableSubscriptionEntry]]:
         pass
@@ -91,15 +73,11 @@ class SubscriptionService:
         return self._repo.get_available_entries(user_id)
 
     def create_suscription(self, params: SubscriptionCreateParams) -> Subscription:
-        return self._repo.create_subscription_for_user(params.user_id, params.order_id)
+        return self._repo.create(params, None)
 
     def delete_subcription(self, user_id: int, subscription_id: SubscriptionId):
-        subscription = self._repo.get_subscription_by_id(subscription_id)
-        if subscription is None:
-            # TODO Domain error types
-            raise RuntimeError('not found')
-        if subscription.user.id != user_id:
-            # TODO: Domain error types
-            raise RuntimeError('Cannot delete a subscription for another user')
+        def verify(subscription: Subscription):
+            if subscription.user_id != user_id:
+                raise ValueError('Only the owning user can delete a subscription')
 
-        self._repo.delete_subscription(subscription_id)
+        self._repo.delete(subscription_id, verify)

src/services/users/repo.py

@@ -1,26 +1,15 @@
+from src.infra.db import CRUD
 import abc
 from src.config.email import EmailAddress
 
 from .data import User, UserDTO
 
 
-class UserRepo(abc.ABC):
-    @abc.abstractmethod
-    def create_user(self, user: UserDTO) -> User:
-        pass
-
-    @abc.abstractmethod
-    def get_user_by_id(self, user_id: int) -> User | None:
-        pass
-
+class UserRepo(CRUD[User, UserDTO]):
     @abc.abstractmethod
     def get_user_by_email(self, email: EmailAddress) -> User | None:
         pass
 
-    @abc.abstractmethod
-    def update_user(self, user: User):
-        pass
-
     @abc.abstractmethod
     def auth_as_user(self, user: UserDTO) -> User | None:
         pass

src/services/users/service.py

@@ -65,14 +65,20 @@ class UserService:
         if not claim or claim.sub != user_id:
             raise EmailConfirmationTokenInvalid
 
-        user = self._repo.get_user_by_id(user_id)
+        user = self._repo.get(user_id)
         # If there is no user or the users emails don't match or the user is already confirmed then consider
         # the token invalid for this request.
         if not user or user.email != claim.email or user.email_confirmed:
             raise EmailConfirmationTokenInvalid
 
+        def update(user: User) -> User:
             user.email_confirmed = True
-        self._repo.update_user(user)
+            return user
+
+        self._repo.update(
+            user_id,
+            update,
+        )
 
     def _send_confirmation_email(self, user: User):
         env = Environment(loader=PackageLoader('src'), autoescape=select_autoescape())
@@ -96,13 +102,13 @@ class UserService:
             raise SignupError('The given password was not acceptable')
 
         # Create a user in persistence
-        created_user = self._repo.create_user(user)
+        created_user = self._repo.create(user, None)
         # send a confirmation email
         self._send_confirmation_email(created_user)
 
         return created_user.to_profile()
 
     def get_user_by_id(self, user_id: int) -> UserProfile | None:
-        user = self._repo.get_user_by_id(user_id)
+        user = self._repo.get(user_id)
         if user:
             return user.to_profile()