fix nkode api; username should be specified at the beginning of the enrollment

src/nkode_api.py

@@ -15,6 +15,9 @@ class NKodeAPI:
     customers: dict[UUID, Customer] = field(default_factory=dict)
     signup_sessions: dict[UUID, UserSignupSession] = field(default_factory=dict)
 
+    def get_customer(self, customer_id: UUID) -> Customer:
+        return self.customers[customer_id]
+
     def create_new_customer(self, keypad_size: KeypadSize, nkode_policy: NKodePolicy) -> UUID:
         new_customer = Customer.create(
             cipher=CustomerCipher.create(keypad_size),
@@ -23,13 +26,17 @@ class NKodeAPI:
         self.customers[new_customer.customer_id] = new_customer
         return new_customer.customer_id
 
-    def generate_signup_keypad(self, customer_id: UUID) -> tuple[UUID, np.ndarray]:
+    def generate_signup_keypad(self, customer_id: UUID, username: str) -> tuple[UUID, np.ndarray]:
         if customer_id not in self.customers.keys():
             raise ValueError(f"Customer with ID '{customer_id}' does not exist")
         customer = self.customers[customer_id]
+        if username in customer.users.keys():
+            raise ValueError(f"Username '{username}' already exists for this customer")
+        customer = self.customers[customer_id]
         login_keypad = UserKeypad.create(customer.cipher.keypad_size)
         set_keypad = login_keypad.sign_up_keypad()
         new_session = UserSignupSession(
+            username=username,
             session_id=uuid4(),
             login_keypad=login_keypad,
             set_keypad=set_keypad.keypad,
@@ -41,24 +48,20 @@ class NKodeAPI:
 
     def set_nkode(
             self,
-            username: str,
             customer_id: UUID,
             key_selection: list[int],
             session_id: UUID
     ) -> np.ndarray:
         if customer_id not in self.customers.keys():
             raise ValueError(f"Customer ID {customer_id} not found")
-        customer = self.customers[customer_id]
-        if username in customer.users.keys():
-            raise ValueError(f"Username '{username}' already exists for this customer")
         if session_id not in self.signup_sessions.keys():
             raise ValueError(f"Session ID {session_id} not found")
-        self.signup_sessions[session_id].set_user_nkode(username, key_selection)
+        session = self.signup_sessions[session_id]
+        self.signup_sessions[session_id].set_user_nkode(session.username, key_selection)
         return self.signup_sessions[session_id].confirm_keypad
 
     def confirm_nkode(
             self,
-            username: str,
             customer_id: UUID,
             confirm_key_entry: list[int],
             session_id: UUID
@@ -68,8 +71,6 @@ class NKodeAPI:
         session = self.signup_sessions[session_id]
         if customer_id != session.customer_id:
             raise AssertionError(f"Customer ID mismatch: {customer_id} vs {session.customer_id}")
-        if username != session.username:
-            raise AssertionError(f"Username mismatch: {username} vs {session.username}")
         customer = self.customers[customer_id]
         passcode = self.signup_sessions[session_id].deduce_passcode(confirm_key_entry)
         new_user_keys = UserCipher.create(
@@ -79,7 +80,7 @@ class NKodeAPI:
         )
         enciphered_passcode = new_user_keys.encipher_nkode(passcode, customer.cipher)
         new_user = User(
-            username=username,
+            username=session.username,
             enciphered_passcode=enciphered_passcode,
             cipher=new_user_keys,
             user_keypad=self.signup_sessions[session_id].login_keypad,