Build main evaluation orchestrator function
epic-achievement-badges-evaluation-engine-task-007 — Implement the main BadgeEvaluationService orchestrator that loads enabled badge definitions for the organisation, invokes the appropriate criteria evaluator for each definition, filters to badges not yet awarded to the peer mentor, and returns a list of newly satisfied badge IDs ready for award.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
The orchestrator is the composition root for the evaluation pipeline. Implement as a `BadgeEvaluationService` class with a single public method `evaluate(peerId: string, orgId: string): Promise
The awarded-badges query should use the same Supabase client passed to all sub-components. Run the awarded-badge filter as a Set difference (`new Set(qualifyingIds).difference(new Set(alreadyAwardedIds))`) for clarity. Do not write any badge award records here — this service is read-only and returns candidates only; the caller (edge function handler) handles the write.
Testing Requirements
Integration test scenarios required: (1) peer mentor with stats meeting 2 of 3 enabled badge criteria — verify exactly 2 IDs returned, (2) peer mentor already holding all qualifying badges — verify empty array, (3) org with no enabled badges — verify empty array, (4) unknown criteria_type in one definition — verify it is skipped and other badges still evaluated, (5) aggregation layer returns zero-values — verify no badges awarded. Unit tests should mock all sub-dependencies (loader, aggregator, evaluators) and verify orchestrator call sequencing and filtering logic in isolation.
Supabase Edge Functions may experience cold start latency of 500ms–2s when they have not been invoked recently. If evaluation latency consistently exceeds the 2-second UI expectation, the celebration overlay timing SLA cannot be met without the optimistic UI fallback from the UI epic.
Mitigation & Contingency
Mitigation: Keep the edge function warm by scheduling a lightweight health-check invocation every 5 minutes in production. Optimise the function size to minimise Deno module load time. Implement the optimistic UI path in badge-bloc (from the UI epic) as the primary UX path so cold start only affects server-side reconciliation, not perceived responsiveness.
Contingency: If cold starts remain problematic, migrate badge evaluation to a Supabase database function (pl/pgsql) triggered directly by a database trigger on activity insert, eliminating the Edge Function overhead entirely for the evaluation logic while keeping Edge Function only for FCM notification dispatch.
Supabase database webhooks can fail silently if the edge function returns a non-2xx response or times out. A missed webhook means a peer mentor does not receive a badge they earned, which is both a functional defect and a trust issue for organisations relying on milestone tracking.
Mitigation & Contingency
Mitigation: Implement idempotent webhook processing: the edge function reads the activity ID from the webhook payload and checks whether evaluation for this activity has already run (via an audit log query) before proceeding. Add Supabase webhook retry configuration (3 retries with exponential backoff). Monitor webhook failure rates via Supabase logs alert.
Contingency: Implement a nightly reconciliation job (Supabase scheduled function) that scans all activities from the past 24 hours, re-evaluates badge criteria for any peer mentor with no corresponding evaluation log entry, and awards any missing badges. Alert operations if reconciliation awards more than 5% of badges, indicating systematic webhook failure.
The evaluation service loads badge definitions per organisation, but a misconfigured RLS policy or incorrect organisation scoping in the edge function could cause one organisation's badge criteria to be evaluated against another organisation's peer mentor activity data, leading to incorrect or cross-contaminated badge awards.
Mitigation & Contingency
Mitigation: The edge function must extract organisation_id from the webhook payload activity record and pass it explicitly to every database query. Write a security test that seeds two organisations with distinct badge definitions and verifies that evaluating a peer mentor in org A never reads or awards org B definitions. Use Supabase service role key only within the edge function, never the anon key.
Contingency: If cross-org contamination is detected in audit logs, immediately disable the edge function webhook, run a targeted SQL query to identify and revoke incorrectly awarded badges, notify affected organisations, and perform a full security review of all RLS policies on badge-related tables before re-enabling.