Feature: A logged-in, unverified user cancels their pending registration

  As the maintainer of RenewCMS
  I want a logged-in user who has not yet verified their account to be able to delete that
    account and clear their session in one call, while a user who is already verified cannot use
    this route to delete their own account, and a token that carries no usable user_id is answered
    with 401 instead of a panic
  So that someone who registered by mistake, or changed their mind before verifying, can free their
    username and email immediately (features/unverified_users_and_reregistration.feature), without
    exposing a general self-delete for verified accounts

  Background:
    Given this slice adds DELETE /v1/auth/register, mounted in api/router.go inside the same
      protected group NewAuthRouter already applies to POST /v1/auth/verify: jwtauth.Verifier then
      jwtauth.Authenticator, so a request with no jwt cookie, an expired jwt, or a jwt with a bad
      signature never reaches the handler and is answered 401 by jwtauth.Authenticator itself
    And the handler extracts user_id from the already-verified token's claims using the same safe
      pattern auth.Handler.Verify already established (features/account_verification.feature):
      401 with apperr.UnauthorizedErrorMessage whenever the "user_id" claim is missing, is not a
      number, or does not match any user in the repository, never a panic and never trusting the
      raw claim value
    And a new use case, CancelRegistrationUseCase (internal/infrastructure/useCases/CancelRegistration.go),
      is injected into auth.Handler as CancelRegistrationUseCase; it depends only on user.Repository
      and exposes CancelRegistration(userId uint32) error
    And CancelRegistrationUseCase.CancelRegistration loads the user by id, returns the existing
      sentinel user.ErrUserNotFound when no such user exists, refuses with a new sentinel
      user.ErrAlreadyVerified when the loaded user's IsVerified is already true, and otherwise calls
      user.Repository.Delete(userId), whose GORM implementation removes the row entirely rather than
      soft-deleting it (features/unverified_users_and_reregistration.feature), so the same username
      and email are immediately free for a new registration
    And the handler maps user.ErrUserNotFound to 401 with apperr.UnauthorizedErrorMessage, the same
      status and body Verify already uses for an unresolvable user_id, and maps
      user.ErrAlreadyVerified to 403 with a new apperr.AlreadyVerifiedErrorMessage constant
    And on success the handler clears the "jwt" cookie exactly the way auth.Handler.Logout already
      does (Max-Age -1, empty value, Path "/") and responds 200 with {"message": "..."}
    And on any error path the handler returns before touching the "jwt" cookie, so an unresolved or
      already-verified request leaves the caller's existing session untouched

  Scenario: An unverified user cancels their pending registration
    Given a user repository containing user id 7, username "alice", email "alice@example.com",
      is_verified false
    And a valid jwt cookie for user id 7
    When the client sends DELETE /v1/auth/register with that cookie
    Then the response status is 200
    And the response body is {"message": "..."}
    And the response clears the "jwt" cookie
    And the user repository no longer contains user id 7; Get(7) returns user.ErrUserNotFound

  Scenario: Cancelling frees the username and email for a new registration
    Given a user repository containing user id 7, username "alice", email "alice@example.com",
      is_verified false
    And a valid jwt cookie for user id 7
    When the client sends DELETE /v1/auth/register with that cookie
    Then the response status is 200
    When the client sends POST /v1/auth/register with username "alice", password
      "hunter2example12", email "alice@example.com"
    Then the response status is 200
    And a jwt cookie is set
    And the newly created user's id is different from 7

  Scenario: An already-verified user cannot cancel their account this way
    Given a user repository containing user id 7, username "alice", email "alice@example.com",
      is_verified true
    And a valid jwt cookie for user id 7
    When the client sends DELETE /v1/auth/register with that cookie
    Then the response status is 403
    And the response body is the new apperr.AlreadyVerifiedErrorMessage text
    And the response does not clear the "jwt" cookie
    And the user repository's record for id 7 is unchanged: is_verified true, the row still exists

  Scenario Outline: A token without a valid user_id returns 401 instead of crashing
    Given a user repository containing user id 7, username "alice", is_verified false
    And <token description>
    When the client sends DELETE /v1/auth/register with that cookie
    Then the response status is 401
    And the response body is the apperr.UnauthorizedErrorMessage text
    And the handler does not panic
    And the response does not clear the "jwt" cookie
    And the user repository's record for id 7 still exists

    Examples:
      | token description                                                             |
      | a validly signed jwt cookie whose claims carry no "user_id" key at all        |
      | a validly signed jwt cookie whose "user_id" claim is the string "seven"       |
      | a validly signed jwt cookie whose "user_id" claim is the number 999, which does not match any user |

  Scenario: A request with no jwt cookie never reaches the handler
    Given a user repository containing user id 7, username "alice", is_verified false
    And no jwt cookie is sent
    When the client sends DELETE /v1/auth/register without a cookie
    Then the response status is 401
    And the user repository's record for id 7 still exists

  Scenario: The use case deletes an unverified user, independently of any handler
    Given a user.Repository fake containing user id 3, is_verified false
    And a CancelRegistrationUseCase built directly over that fake
    When CancelRegistration is called with userId 3
    Then the call returns nil
    And the fake repository no longer contains user id 3

  Scenario: The use case refuses to delete an already-verified user, independently of any handler
    Given a user.Repository fake containing user id 3, is_verified true
    And a CancelRegistrationUseCase built directly over that fake
    When CancelRegistration is called with userId 3
    Then the call returns user.ErrAlreadyVerified, asserted with errors.Is
    And the fake repository still contains user id 3

  Scenario: The use case reports an unknown user, independently of any handler
    Given a user.Repository fake containing no user with id 42
    And a CancelRegistrationUseCase built directly over that fake
    When CancelRegistration is called with userId 42
    Then the call returns user.ErrUserNotFound, asserted with errors.Is