Adapt activity wizard routing for proxy mode
epic-bulk-and-proxy-registration-bulk-ui-task-003 — Extend the existing activity wizard step router to support a proxy mode flag. When proxy mode is active, skip the peer mentor selection step (mentor is pre-selected from the proxy mode selector) and inject the attribution banner widget into each wizard step's scaffold. Reuse the existing type, date, duration, and notes steps without modification.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 2 - 518 tasks
Can start after Tier 1 completes
Implementation Notes
Introduce a `WizardConfig` value object that encapsulates the step list and optional banner widget. Pass this config to the wizard scaffold at construction time based on the isProxyMode flag. This avoids conditional logic scattered throughout the scaffold. To inject the banner without modifying step widgets, wrap each step's body in a `Column` inside the scaffold that prepends the banner when `WizardConfig.attributionBanner != null`.
For step count in the progress indicator, derive it from `WizardConfig.steps.length` rather than a hardcoded constant. Ensure the route parameter contract is documented (which fields are required for proxy mode entry) so the proxy mode selector (upstream) can pass the correct data.
Testing Requirements
Write flutter_test widget tests covering: (1) proxy mode skips peer mentor step — verify by asserting the step widget is never found in the widget tree, (2) attribution banner is present on step 1, step 2, and final step in proxy mode, (3) non-proxy mode renders all original steps in original order, (4) back navigation on step 1 in proxy mode pops to the correct parent route. Use a fake GoRouter or NavigatorObserver to assert navigation events without relying on real routing.
If the batch insert RPC returns a mix of successes and failures (e.g., 3 of 10 mentors fail due to constraint violations that slipped through application-level duplicate detection), the confirmation screen result state becomes ambiguous. A coordinator who sees '7 of 10 succeeded' may not know whether to manually register the 3 failures, retry, or escalate — leading to either duplicate registrations or silent underreporting.
Mitigation & Contingency
Mitigation: Design the Bulk Registration Service to return a strongly typed BulkRegistrationResult with per-mentor RegistrationOutcome (success | duplicate_detected | constraint_violation | permission_denied). Design the result screen to list each failed mentor with a specific, plain-language reason and a one-tap 'Retry for this mentor' action that pre-fills the activity wizard with the batch template for that individual.
Contingency: If per-mentor retry UI is too complex to deliver within the epic scope, fall back to displaying failed mentors with their error codes and instructing coordinators to use single-proxy mode for the failures. Document this as a known limitation in release notes and create a follow-up ticket for per-mentor retry in the next sprint.
The Proxy Activity Wizard must reuse the existing activity wizard step widgets (type, date, duration, notes) while injecting a proxy attribution banner and a different submission payload builder. If the existing wizard is not designed for composability, the proxy variant may require forking the widget tree, creating two maintenance-diverging codebases that will drift out of sync when the base wizard is updated (e.g., new activity types added, new mandatory fields).
Mitigation & Contingency
Mitigation: Before implementing the Proxy Activity Wizard, audit the existing activity wizard's architecture. If steps are already extracted as independent StatelessWidget/ConsumerWidget classes, compose them directly with a wrapping Column that injects the attribution banner. If they are tightly coupled inside a parent widget, refactor the existing wizard to accept a nullable ProxyContext parameter before starting the proxy variant — this refactor should be a prerequisite task in this epic.
Contingency: If refactoring the base wizard is blocked by unrelated in-flight work on that component, implement the proxy wizard as a full fork but create a shared StepWidgets library file that both the base wizard and proxy wizard import. Schedule a deduplication refactor as a tech-debt ticket in the next planning cycle.
The bulk registration flow spans three sequential screens (multi-select → activity form → confirmation → result) with shared mutable state: the selected mentor list, the activity template, the per-mentor duplicate warnings, and the final submission result. Managing this state across screens without a well-designed Bloc risks state leaks, stale duplicate warning data after mentor removal, and confirmation screen inconsistencies if the user navigates back and changes the mentor selection.
Mitigation & Contingency
Mitigation: Define a single BulkRegistrationBloc (or Cubit) with explicit state transitions covering: MentorsSelected → ActivityTemplateCompleted → DuplicatesChecked → ConfirmationReady → Submitting → SubmissionResult. Each backward navigation event (e.g., 'Back' from confirmation to mentor selection) dispatches a ResetToMentorSelection event that clears downstream state. Unit test every state transition with edge cases including empty mentor list, all mentors having duplicates, and network failure during submission.
Contingency: If state management complexity causes persistent bugs in testing, simplify by passing state explicitly through Navigator arguments (immutable snapshots per screen) rather than a shared Bloc. This reduces flexibility but eliminates cross-screen state mutation bugs.