Repository: batch-insert RPC adapter integration
epic-bulk-and-proxy-registration-services-task-005 — Integrate the Batch Insert RPC Adapter into ProxyActivityRepository to support bulk proxy insertions. Implement insertBatch(List<ProxyActivityRecord>) that delegates to the Supabase RPC function for atomic multi-row inserts. Ensure each row in the batch carries its own recorded_by_user_id and peer_mentor_id. Handle partial failures by returning a BatchInsertResult with per-row success/failure flags.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 2 - 518 tasks
Can start after Tier 1 completes
Implementation Notes
The Supabase RPC function should be defined as `insert_proxy_activity_batch(records jsonb[])` in Postgres using `INSERT INTO activities SELECT * FROM jsonb_populate_recordset(null::activities, $1)`. Wrap in a transaction with EXCEPTION handling to capture per-row errors if the DB function supports it. On the Dart side, serialize each `ProxyActivityRecord` to a `Map
Consider a 30-second timeout for large batches. Coordinate with the RPC function author (task-002 scope) to align on the function name and parameter schema.
Testing Requirements
Unit tests with flutter_test and mocked Supabase RPC client: (1) valid batch of 5 returns all-success result, (2) batch exceeding 100 items rejected before RPC call, (3) one invalid record excluded and rest submitted successfully, (4) RPC network failure maps to typed domain failure, (5) duplicate within batch flagged correctly, (6) each record in result carries correct index, (7) empty batch returns ValidationFailure. Integration test against local Supabase: seed a coordinator with 3 mentors, submit a 3-record batch, verify all rows persisted with correct dual-identity fields.
The Proxy Registration Service must verify that the coordinator has a legitimate assignment relationship with the target peer mentor before creating a record. If this check is implemented only in application code and not enforced at the DB/RLS level, a compromised or buggy client could bypass it by calling the Supabase endpoint directly, creating fraudulent proxy records for arbitrary peer mentors.
Mitigation & Contingency
Mitigation: Implement permission validation at two levels: (1) application-layer check in Proxy Registration Service that queries the assignments table before constructing the payload, and (2) RLS policy on the activities table that restricts INSERT to rows where recorded_by_user_id matches the authenticated user AND peer_mentor_id is in the set of peer mentors assigned to that coordinator. The RLS policy is the authoritative guard; the service-layer check provides early user-facing feedback.
Contingency: If RLS policy implementation is blocked by Supabase plan constraints, implement a Supabase Edge Function as a proxy endpoint that enforces the permission check server-side before forwarding to the DB. Disable direct client inserts entirely for proxy activities.
For a bulk session with 30 selected peer mentors, the Proxy Duplicate Detector must query existing activities for each mentor. If implemented as 30 sequential Supabase queries, round-trip latency could make the bulk confirmation screen feel slow (>3s), degrading coordinator experience and potentially causing timeouts.
Mitigation & Contingency
Mitigation: Implement the duplicate check as a single Supabase query using an IN clause on peer_mentor_id combined with the activity_type and date filters, returning all potential duplicates for the entire batch in one network round-trip. Group results client-side by mentor ID to produce the per-mentor warning structure.
Contingency: If the single-query approach returns too much data for very large chapters, add a database index on (peer_mentor_id, activity_type, date) and profile query time. If still insufficient, accept a short loading state on the confirmation screen with a progress indicator rather than pre-loading duplicates before navigation.