Init project structure

app/services/user_service.py

@@ -0,0 +1,48 @@
+"""User-related business logic."""
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+from app.core.security import PasswordHasher
+from app.models.user import User, UserCreate
+from app.repositories.user_repo import UserRepository
+
+
+class UserServiceError(Exception):
+    """Base class for user service errors."""
+
+
+class UserAlreadyExistsError(UserServiceError):
+    """Raised when attempting to create a user with duplicate email."""
+
+
+class UserNotFoundError(UserServiceError):
+    """Raised when user record cannot be located."""
+
+
+class UserService:
+    """Encapsulates user-related workflows."""
+
+    def __init__(self, user_repository: UserRepository, password_hasher: PasswordHasher) -> None:
+        self._repository = user_repository
+        self._password_hasher = password_hasher
+
+    async def list_users(self) -> Sequence[User]:
+        return await self._repository.list()
+
+    async def get_user(self, user_id: int) -> User:
+        user = await self._repository.get_by_id(user_id)
+        if user is None:
+            raise UserNotFoundError(f"User {user_id} not found")
+        return user
+
+    async def create_user(self, data: UserCreate) -> User:
+        existing = await self._repository.get_by_email(data.email)
+        if existing is not None:
+            raise UserAlreadyExistsError(f"User {data.email} already exists")
+
+        hashed_password = self._password_hasher.hash(data.password)
+        user = await self._repository.create(data=data, hashed_password=hashed_password)
+        await self._repository.session.commit()
+        await self._repository.session.refresh(user)
+        return user