sstent
b9cc50f69a
Defines the user stories, functional requirements, and success criteria for implementing a persistent authentication mechanism. This feature aims to eliminate repeated user logins for background synchronization tasks by securely storing and reusing the Garmin Connect session state.
6.2 KiB
Feature Specification: Persist Garmin Authentication for Stateless Sync
Feature Branch: 010-specification-overview-the
Created: 2025-12-22
Status: Draft
User Scenarios & Testing (mandatory)
User Story 1 - Seamless Background Sync (Priority: P1)
A user's Garmin data (activities, health metrics) is synced automatically in the background without requiring them to log in repeatedly.
Why this priority: This is the core value proposition of the feature, directly addressing the pain point of frequent manual logins and enabling reliable, automated data synchronization.
Independent Test: Can be tested by triggering a background sync job for a user with a persisted session and verifying that new activities from Garmin Connect appear in the system without any manual user interaction.
Acceptance Scenarios:
- Given a user has a valid, persisted Garmin session in the database, When a background sync job is triggered, Then the system successfully fetches new data from Garmin Connect.
- Given a user's persisted session token has expired but is refreshable, When a background sync job is triggered, Then the system automatically refreshes the session, saves the new session state, and successfully completes the sync.
User Story 2 - Initial Login with MFA (Priority: P2)
A user performs a one-time login through the system. If Garmin requires Multi-Factor Authentication (MFA), the user is prompted to enter the code to complete the login, and the session is then persisted.
Why this priority: This handles the necessary onboarding and authentication path for users, including the common MFA challenge, which is critical for establishing the initial persistent session.
Independent Test: Can be tested by a new user logging in with credentials known to trigger an MFA prompt. The test is successful if the system prompts for the MFA code and, upon submission of a valid code, successfully establishes and persists the session.
Acceptance Scenarios:
- Given a user is performing an initial login and their account requires MFA, When they submit their username and password, Then the system indicates that an MFA code is required.
- Given the system is waiting for an MFA code, When the user submits the correct MFA code, Then the system completes the authentication, persists the session, and confirms a successful login.
User Story 3 - Session Invalidation and Re-authentication (Priority: P3)
If a persisted Garmin session becomes invalid (e.g., user revoked access from Garmin's side) and cannot be refreshed, the system gracefully handles the failure and notifies the user that they need to re-authenticate.
Why this priority: This ensures system resilience and clear communication with the user when the authentication link is broken, preventing silent failures.
Independent Test: Can be tested by manually invalidating a user's session (e.g., revoking app permissions in Garmin Connect), then triggering a background sync. The test is successful if the sync job fails with a clear "authentication expired" status and the persisted session data is cleared.
Acceptance Scenarios:
- Given a user's persisted session is invalid and not refreshable, When a background sync is attempted, Then the sync job's status is marked as
AUTH_EXPIRED. - Given a sync job has failed due to an unrecoverable authentication error, Then the invalid session data is cleared from the database to prevent further failed attempts.
Edge Cases
- What happens if a user enters the wrong MFA code multiple times?
- How does the system handle network errors during session validation or refresh?
- What if the database is unavailable when the system tries to load or save the session state?
- How does the system behave if the session data in the database is corrupted or malformed?
Requirements (mandatory)
Functional Requirements
- FR-001: The system MUST allow a user to authenticate with their Garmin Connect credentials.
- FR-002: The system MUST be able to handle Multi-Factor Authentication (MFA) challenges during the login process.
- FR-003: The system MUST securely persist a user's Garmin Connect authentication state to eliminate the need for repeated logins.
- FR-004: Background data synchronization jobs MUST use the persisted authentication state to connect to Garmin Connect.
- FR-005: The system MUST automatically refresh the authentication state if it expires and a refresh is possible.
- FR-006: After a successful refresh, the system MUST update the persisted authentication state with the new details.
- FR-007: If the authentication state becomes invalid and cannot be refreshed, the system MUST record a sync failure with a clear authentication error status.
- FR-008: The system MUST clear any invalid, persisted authentication state to force a new login.
- FR-009: The system MUST provide a way to check the current status of the persisted authentication (e.g., valid, missing, expired).
Key Entities (include if feature involves data)
- GarminAuthenticationState: Represents a user's authenticated session with Garmin Connect.
- Attributes: Authentication Data (stores necessary session info), MFA Pending (flag for pending MFA), Last Validated (timestamp).
- Relationships: Associated with a single User.
Success Criteria (mandatory)
Measurable Outcomes
- SC-001: Reduce the number of user-facing login prompts by 99% for active users with valid credentials over a 30-day period.
- SC-002: 99.9% of background sync jobs for users with a valid persisted session should initiate successfully without requiring manual login.
- SC-003: The end-to-end success rate for background syncs, including session loading, execution, and potential session refresh/save, should exceed 98%.
- SC-004: System should successfully handle MFA-based logins on the first attempt for 95% of users who are required to enter an MFA code.
- SC-005: In the case of a session invalidation, the system must detect the failure, mark the sync status appropriately, and clear the session within 5 minutes.