init

app/domain/shared/base_entity.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Generic, TypeVar
+
+TId = TypeVar("TId")
+
+
+@dataclass(eq=False)
+class Entity(Generic[TId]):
+    id: TId
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, Entity):
+            return False
+        return self.id == other.id and self.__class__ is other.__class__
+
+    def __hash__(self) -> int:
+        return hash((self.__class__, self.id))

app/domain/shared/base_value_object.py

@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class ValueObject:
+    """Marker base class for value objects."""
+
+    pass

app/domain/users/entities.py

@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from uuid import UUID
+
+from app.domain.shared.base_entity import Entity
+from app.domain.users.events import UserRegistered
+from app.domain.users.value_objects import Email
+
+
+@dataclass(eq=False)
+class User(Entity[UUID]):
+    email: Email
+    full_name: str
+    is_active: bool = True
+    created_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
+    _events: list[object] = field(default_factory=list, init=False, repr=False)
+
+    @property
+    def events(self) -> list[object]:
+        return list(self._events)
+
+    def pull_events(self) -> list[object]:
+        ev, self._events = self._events, []
+        return ev
+
+    @classmethod
+    def register(cls, *, user_id: UUID, email: Email, full_name: str) -> "User":
+        user = cls(id=user_id, email=email, full_name=full_name)
+        user._events.append(
+            UserRegistered(
+                user_id=user_id,
+                email=str(email),
+                occurred_at=datetime.now(timezone.utc),
+            )
+        )
+        return user

app/domain/users/events.py

@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import datetime
+from uuid import UUID
+
+
+@dataclass(frozen=True)
+class UserRegistered:
+    user_id: UUID
+    email: str
+    occurred_at: datetime

app/domain/users/exceptions.py

@@ -0,0 +1,14 @@
+class DomainError(Exception):
+    pass
+
+
+class InvalidEmail(Exception):
+    pass
+
+
+class UserAlreadyExists(Exception):
+    pass
+
+
+class UserNotFound(Exception):
+    pass

app/domain/users/services.py

@@ -0,0 +1,9 @@
+from __future__ import annotations
+
+from app.domain.users.entities import User
+from app.domain.users.exceptions import UserAlreadyExists
+
+
+def ensure_unique_email(*, existing_user: User | None) -> None:
+    if existing_user is not None:
+        raise UserAlreadyExists("User with this email already exists.")

app/domain/users/value_objects.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+
+from app.domain.shared.base_value_object import ValueObject
+from app.domain.users.exceptions import InvalidEmail
+
+_EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")
+
+
+@dataclass(frozen=True)
+class Email(ValueObject):
+    value: str
+
+    def __post_init__(self) -> None:
+        if not _EMAIL_RE.match(self.value):
+            raise InvalidEmail(f"Invalid email: {self.value}")
+
+    def __str__(self) -> str:
+        return self.value