Implement contact-edit-service save and optimistic update
epic-contact-detail-and-edit-supporting-ui-task-013 — Build the contact-edit-service that accepts a validated ContactEditPayload, calls the contact-detail-repository update method, and applies an optimistic local state update before the network response. On success, invalidate the contact-detail-service cache for the affected contact. On failure, revert the optimistic update and surface a typed ContactEditError.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 1 - 540 tasks
Can start after Tier 0 completes
Implementation Notes
Implement the optimistic update by capturing the current state snapshot before the first `await`, applying the new state immediately, then in a try/catch reverting to the snapshot on error. Use Riverpod StateNotifier or AsyncNotifier for the contact state. To invalidate the cache, call `ref.invalidate(contactDetailProvider(contactId))` on success. Define ContactEditError as a sealed class so callers are forced to handle all error variants exhaustively.
Coordinate with the contact-detail-repository interface to ensure the `update` method signature accepts a ContactEditPayload and returns the updated Contact or throws a typed error. Avoid putting business logic (validation) in this service — validation is the responsibility of contact-form-validator (task-012).
Testing Requirements
Unit tests with mock repository (implement ContactDetailRepository as an abstract interface and inject a fake in tests). Test scenarios: (1) successful save — assert optimistic state applied, repository.update called once, cache invalidated; (2) network failure — assert state reverted to pre-save snapshot, ContactEditError.networkError returned; (3) permission error (403 from Supabase) — assert ContactEditError.permissionError returned; (4) empty contactId — assert ContactEditError.validationError without calling repository. Use Riverpod's ProviderContainer with overrides for isolation. No real async timers needed.
The encrypted-field-display confirmation dialog adds interaction steps that may frustrate coordinators who access sensitive fields frequently, leading to requests to bypass the flow or skip read-receipt logging, which would violate Blindeforbundet's compliance requirements.
Mitigation & Contingency
Mitigation: Design the confirmation dialog to be as minimal as possible (one clear sentence, single confirm action) and ensure it does not reappear for the same field within a single screen session. Validate the UX with Blindeforbundet coordinators during the TestFlight pilot before finalising.
Contingency: If coordinators raise strong objections, escalate to Blindeforbundet's data protection officer to determine whether a lighter confirmation pattern (e.g., biometric confirmation instead of dialog) satisfies their compliance obligation.
The activity-history-list infinite scroll requires paginated Supabase queries. Contacts with hundreds of activities (e.g., an HLF peer mentor with 380 annual registrations) could cause slow page loads or memory pressure on older devices if pagination boundaries are set too large.
Mitigation & Contingency
Mitigation: Use a page size of 20 records with cursor-based pagination. Implement list item recycling using Flutter's ListView.builder. Benchmark memory usage with 400+ item simulation on a low-end test device before TestFlight release.
Contingency: If performance degrades on older devices, reduce page size to 10 and add a time-window filter (last 30 days, last 6 months, all) so the default view loads a manageable record count for most coordinators.
The cognitive load rule engine (from the Cognitive Accessibility feature) mandates no more than 7 fields per screen section. If a contact model has more than 7 editable fields, the edit-contact-screen layout must be split into sections, adding complexity not accounted for in the initial scope.
Mitigation & Contingency
Mitigation: Audit the full contact field list from all four organisations before implementation. Group fields into logical sections (personal info, contact details, affiliation) so no single section exceeds 7 fields. Use the cognitive-load-rule-engine component if it is already delivered by the Cognitive Accessibility feature.
Contingency: If the rule-engine component is not yet available, implement a simple manual section layout with accordion-style expansion for less-frequently edited fields to stay within the 7-field guideline without blocking delivery.