Build bulk confirmation screen layout and activity summary
epic-bulk-and-proxy-registration-bulk-ui-task-010 — Implement the BulkConfirmationScreen scaffold with a mandatory review gate. Render a non-dismissible activity summary card showing type, date, duration, and notes from the activity template. Display a scrollable mentor list below the summary. Use design system card components and ensure the screen is only reachable from the bulk registration flow, not as a standalone route.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 1 - 540 tasks
Can start after Tier 0 completes
Implementation Notes
Implement the scroll-to-bottom gate using a ScrollController with a listener: when _scrollController.position.pixels >= _scrollController.position.maxScrollExtent - 20 (20px tolerance), set a state flag _hasScrolledToBottom = true and call setState to enable the confirm button. Use ListView.builder for the mentor list with itemCount = mentorIds.length for O(1) rendering regardless of list size. Resolve the activity_type name using a FutureProvider (Riverpod) or FutureBuilder that queries Supabase for the activity_type record by ID — display a shimmer placeholder while loading. The cancel confirmation dialog should use Flutter's AlertDialog with 'Keep editing' and 'Cancel registration' options; pop the screen only on the latter.
Ensure all text content (type name, notes) goes through Flutter's standard Text widget — no HTML or raw string injection. For accessibility, wrap summary card fields in Semantics widgets with explicit labels (e.g., Semantics(label: 'Activity type: ${type.name}', child: ...)).
Testing Requirements
Widget tests: verify activity summary card renders all four fields (type, date, duration, notes). Verify 'No notes' fallback when notes is null. Verify confirm button is disabled on initial render. Verify confirm button enables after simulated scroll to bottom.
Verify back gesture triggers confirmation dialog. Verify ListView.builder is used (not ListView) by checking that only visible items are built. Accessibility tests: verify all summary card fields have Semantics labels. Verify the screen passes flutter_test's SemanticsHandle checks.
Golden tests: capture the initial layout with a 5-mentor list and a 50-mentor list to catch future regressions. Coverage target: ≥80% on BulkConfirmationScreen widget.
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.