Implement PersonalStatsView widget
epic-coordinator-statistics-dashboard-ui-task-008 — Build the PersonalStatsView widget for individual peer mentor contribution display. Include a personal summary card row, a personal monthly bar chart reusing MonthlyActivityBarChart with a personal data source, and a period selector. The view is shown via a tab or toggle on the dashboard. Support loading skeleton and error state. Accessible throughout with correct semantic labels.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
Place in `lib/features/statistics/widgets/personal_stats_view.dart`. Keep PersonalStatsView purely presentational — it accepts all data as constructor parameters. The parent screen (CoordinatorStatsDashboardScreen) or a dedicated PersonalStatsCubit owns the Supabase fetch and feeds data down. Reuse existing StatSummaryCard and StatsPeriodFilterBar widgets without modification; if their constructors need adjustment for reuse, make the change in those widgets' tasks, not here.
The streak metric calculation logic (consecutive weeks) belongs in a StatsCalculatorService, not in the widget — receive the pre-calculated value as personalSummary.currentStreak. For the heading semantics, wrap the peerName Text in Semantics(header: true) for screen reader h2 announcement. To prevent the personal period selector from affecting the coordinator-level charts, ensure state is scoped to PersonalStatsView's own Cubit/StateNotifier, not shared with the parent BLoC.
Testing Requirements
Widget tests (flutter_test): (1) Displays peerName heading correctly. (2) isLoading=true shows skeletons for both summary row and chart. (3) error non-null shows ErrorCard, hides all other content. (4) Empty summary shows EmptyState widget.
(5) StatsPeriodFilterBar emits onPeriodChanged when a period is selected. (6) MonthlyActivityBarChart receives personalMonthlyData prop (not coordinator-level data) — verify via a spy/mock adapter. (7) Summary cards show correct totalActivities, totalHours, and currentStreak values. (8) Semantics heading level for peerName is h2.
Integration test: mount PersonalStatsView with a mocked Supabase client returning fixture data; assert correct card values appear after async load. Accessibility: SemanticsController confirms focus order matches spec.
PeerMentorStatsList must handle rosters of 40+ mentors efficiently. A naive ListView implementation that re-renders all rows on filter change may cause frame drops on mid-range devices, degrading the experience for coordinators managing large chapters.
Mitigation & Contingency
Mitigation: Use ListView.builder with const constructors for row widgets. Profile the list with Flutter DevTools on a release build against a 60-mentor dataset before submitting for review. Implement sort in the BLoC layer, not in the widget.
Contingency: If frame drops persist, introduce pagination (load 20 mentors, scroll to load more) and add a search filter to reduce visible row count in practice.
The ActivityTypeDonutChart must render org-configured activity type labels from the org-labels system. If the terminology provider is not available or returns stale labels, chart segments will display raw key strings instead of human-readable organisation-specific names, confusing coordinators.
Mitigation & Contingency
Mitigation: Always resolve labels through the OrganizationLabelsProvider before passing data to the donut chart widget. Implement a fallback that formats the raw key as a readable string (e.g., 'peer_support' → 'Peer Support') if the provider returns null.
Contingency: If the org-labels system is unavailable, display the formatted fallback label and log a warning. Do not block chart rendering on label resolution — render with fallbacks immediately.
fl_chart widgets do not natively expose semantic labels for individual bars and donut segments. Without explicit Semantics wrappers, VoiceOver and TalkBack users will receive no meaningful chart information, failing accessibility requirements critical for Blindeforbundet and NHF deployments.
Mitigation & Contingency
Mitigation: Wrap each fl_chart widget in a Semantics widget with a descriptive label summarising the chart data. Implement the data table fallback toggle from the start, not as an afterthought. Validate with VoiceOver on iOS and TalkBack on Android during development.
Contingency: If fl_chart's rendering pipeline prevents semantic overlay from working reliably, replace chart widgets with a custom Canvas-based implementation that has full semantic control, or use a different charting library with better accessibility support.
The period filter state must be preserved when navigating away from the dashboard (e.g., drilling into a mentor's detail screen and pressing back). If the BLoC is re-created on navigation, the filter resets to default, forcing coordinators to re-select their period every time they drill down, degrading operational workflow efficiency.
Mitigation & Contingency
Mitigation: Provide the StatsBloc at a route level above the dashboard screen using a BlocProvider scoped to the statistics navigation shell, not inside the screen widget itself. Verify persistence with a widget integration test that navigates away and back.
Contingency: If route-level scoping is not achievable within the current navigation architecture, persist the last-used filter to a local session store and restore it on screen re-entry.