Perform mercilless separation of bussiness logic from request handling

solvable/src/webservice/user_ops.py

@@ -0,0 +1,28 @@
+from crypto import PasswordHasher
+from model import Session, User
+from exceptions import InvalidCredentialsError, UserExistsError
+
+
+class UserOps:
+    def __init__(self, username, password):
+        self.username = username
+        self.password = password
+
+    def authenticate(self):
+        with Session() as db:
+
+            user = db.query(User).filter(User.username == self.username).first()
+
+            if not user or not PasswordHasher.verify(self.password, user.passwordhash):
+                raise InvalidCredentialsError
+
+    def register(self):
+        with Session() as db:
+
+            if db.query(User).filter(User.username == self.username).all():
+                raise UserExistsError
+
+            user = User(username=self.username,
+                        passwordhash=PasswordHasher.hash(self.password))
+            db.add(user)
+            db.commit()