Implement Supabase Storage upload adapter
epic-driver-and-confidentiality-management-core-services-task-003 — Build the declaration storage adapter that accepts an encrypted blob from the encryption service and uploads it to the correct org-scoped Supabase Storage bucket path. The adapter must enforce bucket-level RLS policies, set content-type metadata, and return the stored object path for downstream use by the declaration management service.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 2 - 518 tasks
Can start after Tier 1 completes
Implementation Notes
Use the @supabase/storage-js client within the Deno Edge Function, initializing with the service-role key from environment. Construct the storage path as `declarations/${orgId}/${declarationId}.enc` — validate that both orgId and declarationId match UUID regex before constructing the path to prevent injection. Use the upsert: false option to prevent silently overwriting an existing declaration (throw duplicate_path error instead). Set cacheControl: '0' to prevent any CDN caching of encrypted blobs.
The Flutter Dart layer calls this adapter via an authenticated POST to the Edge Function endpoint, passing the serialized TamperEvidentBlob as a binary request body — it never calls Supabase Storage directly. Log the upload event (org_id, declaration_id, uploaded_at, object_path) to the bufdir_export_audit_log or a dedicated upload_audit_log table for traceability.
Testing Requirements
Unit tests (Deno test) with a mocked Supabase Storage client: assert correct path construction for a given orgId + declarationId, assert content-type and custom metadata are set, assert StorageUploadError with code=rls_denied is thrown when the mock returns a 403, assert StorageUploadError with code=duplicate_path is thrown on a 409. Integration test against a Supabase staging project: upload a real encrypted blob, assert the returned path exists, assert the object is not publicly downloadable (GET without signed URL returns 400/403), assert a cross-org upload attempt (different org JWT) is rejected with RLS error.
Org-scoped encryption key management is complex. If keys are not correctly isolated per organization, a breach in one org's key could expose another org's declarations. Additionally, key rotation is not specified but may be needed for compliance, and the current implementation may not support it.
Mitigation & Contingency
Mitigation: Use Supabase Vault or a dedicated secrets management approach for org-scoped key storage. Define the key derivation strategy (per-org master key) in a security design document reviewed before implementation begins. Include key isolation tests in the test suite.
Contingency: If a full per-org key management system cannot be safely implemented within the sprint, fall back to a single platform-level encryption key with strict RLS isolation as a temporary measure, flagging the key rotation gap as a security debt item with a defined resolution milestone.
Push notification delivery to drivers depends on FCM token availability and device connectivity. If a driver has not granted notification permissions or has an expired FCM token, the declaration delivery notification will silently fail, leaving the coordinator unaware and the declaration unacknowledged.
Mitigation & Contingency
Mitigation: Implement delivery status tracking in declaration-notification-service. Fall back to in-app notification and SMS (if configured) when push delivery fails. Expose delivery failure status in the declaration status badge so coordinators can identify and manually follow up.
Contingency: If push delivery proves unreliable, implement a polling-based in-app notification fallback where drivers see pending declarations on next app open, ensuring the workflow can complete even without push notifications.
The acknowledgement service is meant to validate that the driver has fully scrolled through the declaration before confirming. Implementing reliable scroll completion detection in Flutter across different screen sizes and font sizes is technically non-trivial and could be bypassed.
Mitigation & Contingency
Mitigation: Implement scroll position tracking using ScrollController with a threshold (e.g., 95% of content height reached) and record the validated state server-side before allowing acknowledgement submission. Document the approach in the legal sign-off checkpoint noted in the feature documentation.
Contingency: If reliable scroll detection cannot be implemented within the sprint, add a mandatory reading delay timer (e.g., estimated reading time based on word count) as an alternative validation mechanism, pending legal review of the approach.
The driver assignment service must coordinate with the threshold-based expense approval workflow for fees above configured thresholds. If the expense approval workflow interface changes or is not yet stable, the integration point could break or produce incorrect routing behavior.
Mitigation & Contingency
Mitigation: Define a clear interface contract between driver-assignment-service and the expense approval workflow before implementation. Use dependency injection so the expense workflow client can be mocked in tests. Monitor the expense approval feature for interface changes.
Contingency: If the expense approval workflow interface is not stable, implement a direct database insert to the expense records table as a temporary bypass, with a flag indicating manual review is needed, until the stable interface is available.