Define RegistrationDefaults data model and interfaces
epic-quick-activity-registration-business-logic-task-001 — Define the Dart data classes and interfaces for RegistrationDefaults, including today's date, 30-minute default duration, and last-used activity type. Establish the abstract interface for RegistrationDefaultsManager so dependent components can program against a contract rather than a concrete class.
Acceptance Criteria
Technical Requirements
Implementation Notes
Keep this purely a domain layer definition — no Flutter framework imports, no Supabase references. Use Dart's built-in const constructors where possible. For copyWith, implement manually (no code generation required given the small field count, and it avoids a build_runner dependency at this stage). The abstract IRegistrationDefaultsManager interface should mirror the concrete class's public API exactly — this is the contract that BLoC/Cubit classes and tests will depend on, so keep it minimal and stable.
Consider placing the interface in a separate file (registration_defaults_manager.dart) from the model (registration_defaults.dart) so they can evolve independently.
Testing Requirements
Unit tests using flutter_test: verify RegistrationDefaults default duration is 30 minutes, verify lastUsedActivityTypeId is null when not provided, verify copyWith produces a new instance with only the specified fields changed, verify == and hashCode are consistent (two instances with identical field values are equal). Verify IRegistrationDefaultsManager cannot be instantiated directly (abstract). Target 100% line coverage on the data class.
The wizard Cubit manages multiple concurrent state slices (current step, each field value, submission status, error state). As the number of wizard steps grows, the state class can become unwieldy, making it difficult to reason about transitions, leading to subtle bugs where advancing a step resets a previously filled field.
Mitigation & Contingency
Mitigation: Use an immutable state model (copyWith pattern) with a separate sealed class per wizard step state. Keep the Cubit's emit calls minimal and always derive the next state from the current state to prevent accidental field resets. Document the state machine transitions explicitly in code comments.
Contingency: If state complexity becomes unmanageable, split into a parent WizardCubit (owns step navigation and submission) and per-step child Cubits (own individual field state), coordinating via a shared repository layer.
Organisation-specific compensation eligibility rules (e.g., activity type + duration thresholds) are business logic that may change independently of the app release cycle. Hardcoding these rules in ActivityRegistrationService means rule changes require a new app deployment, causing delays and potential financial errors if the deployed version uses outdated rules.
Mitigation & Contingency
Mitigation: Model compensation rules as configuration fetched from Supabase (stored per organisation), cached locally. ActivityRegistrationService reads from cache with a fallback to hardcoded defaults for offline scenarios. Design the rule schema to be extensible without code changes.
Contingency: If dynamic rules are not ready for initial release, ship with hardcoded rules and a feature flag that enables the remote-config path. Document the rule structure clearly so coordinators can trigger a rule update via a Supabase dashboard entry rather than a code deployment.
The last-used activity type stored in RegistrationPreferencesStore may become invalid if the organisation administrator deactivates that activity type between sessions. The Cubit would pre-populate a deleted type, and either the UI would show a missing item or submission would fail with a foreign-key constraint error.
Mitigation & Contingency
Mitigation: In RegistrationDefaultsManager, validate the retrieved last-used activity type ID against the current list of active types fetched from the activity type repository. If the stored ID is not in the active list, fall back to the first active type alphabetically.
Contingency: If validation cannot be performed offline, surface a non-blocking warning in the activity type step ('Your previously used activity type is no longer available') and require the user to make a new selection before advancing.