Implement step advancement and per-field update methods
epic-quick-activity-registration-business-logic-task-009 — Implement field mutation methods on ActivityRegistrationCubit: updateActivityType, updateDate, updateDuration, updateNotes. Each method emits a new ActivityRegistrationStep with the updated value slice. Implement advanceStep() which validates completeness of the current step before emitting the next step state — incomplete steps must emit an inline validation error without advancing. Implement goBack() to return to the previous step without losing entered data.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
Each update method should follow the same pattern: guard (if state is not ActivityRegistrationStep return), then emit (state as ActivityRegistrationStep).copyWith(fieldName: newValue, validationErrors: updatedErrors). This pattern is safe, readable, and consistent. For advanceStep(), define a private _validateCurrentStep() method that returns a Map
Consider whether updateDuration should clamp values to 1–480 silently or emit a validation error — align with UX design, but make the behaviour explicit in tests before implementing.
Testing Requirements
Unit tests with flutter_test and bloc_test. Test each update method: (1) updateActivityType emits correct ActivityRegistrationStep with only activityTypeId changed, (2) updateDate clears date validation error when called with valid date, (3) updateDuration with value > 480 does not emit (or emits with validation error — define expected behaviour explicitly before implementing), (4) advanceStep from step 1 with null activityTypeId emits validationErrors without advancing, (5) advanceStep from step 1 with valid activityTypeId advances to step 2 and preserves date and duration, (6) goBack from step 2 returns to step 1 with all fields intact, (7) goBack from step 1 emits nothing (no state change), (8) advanceStep on final step with all fields valid triggers submit sequence and emits ActivityRegistrationSubmitting then ActivityRegistrationSuccess. Use mocked ActivityRegistrationService for test (8).
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.