---
phase: 01-ai-ranking-backend
plan: 04
subsystem: ai-ranking
tags: [auto-trigger, notifications, ranking, evaluation, tRPC]
requirements: [RANK-09, RANK-10]
dependency_graph:
  requires: [01-01, 01-02, 01-03]
  provides: [auto-trigger-on-evaluation-complete, retroactive-scan, admin-notifications]
  affects: [evaluation-submit-mutation, ranking-router, in-app-notifications]
tech_stack:
  added: []
  patterns: [fire-and-forget async, cooldown-guard, module-level-helper-function]
key_files:
  created: []
  modified:
    - src/server/services/in-app-notification.ts
    - src/server/routers/evaluation.ts
    - src/server/routers/ranking.ts
decisions:
  - "triggerAutoRankIfComplete defined as module-level (non-exported) function in evaluation.ts — avoids circular imports and keeps the auto-trigger logic colocated with the mutation it serves"
  - "EvaluationConfig null fallback typed as {} as EvaluationConfig rather than just {} — required for TypeScript strict mode to recognize rankingCriteria and autoRankOnComplete fields"
  - "ParsedRankingRule[] cast via unknown as Prisma.InputJsonValue — Prisma InputJsonValue does not overlap with typed arrays, double-cast is the correct pattern throughout the codebase"
  - "retroactiveScan uses RETROACTIVE triggerType to distinguish from MANUAL/AUTO/QUICK — prevents duplicate re-runs on subsequent scans"
  - "triggerAutoRank procedure in ranking.ts uses MANUAL triggerType (not AUTO) because it is admin-initiated, not system-initiated"
metrics:
  duration: ~8min
  completed_date: "2026-02-27"
  tasks_completed: 2
  files_modified: 3
---

# Phase 1 Plan 04: Auto-Trigger + Retroactive Scan Summary

**One-liner:** Fire-and-forget auto-ranking on evaluation completion with 5-minute cooldown guard, plus retroactive scan procedure for rounds already complete at deploy time.

## What Was Built

### Task 1: AI_RANKING_COMPLETE + AI_RANKING_FAILED notification types

Added two new entries to `src/server/services/in-app-notification.ts`:

- `NotificationTypes.AI_RANKING_COMPLETE` — type string + `BarChart3` icon + `normal` priority
- `NotificationTypes.AI_RANKING_FAILED` — type string + `AlertTriangle` icon + `high` priority

Pattern follows existing FILTERING_COMPLETE / FILTERING_FAILED entries exactly.

### Task 2: Auto-trigger hook + new ranking procedures

**evaluation.ts — `triggerAutoRankIfComplete` function:**

```typescript
async function triggerAutoRankIfComplete(
  roundId: string,
  prisma: PrismaClient,
  userId: string,
): Promise<void>
```

Logic flow:
1. Count required assignments — skip if not all complete
2. Read `round.configJson` → check `autoRankOnComplete` + `rankingCriteria` — skip silently if not configured
3. Cooldown guard — skip if AUTO snapshot exists within last 5 minutes
4. Call `aiQuickRank()` — executes in 10-30s asynchronously
5. Create `RankingSnapshot` with `triggerType: 'AUTO'`, `triggeredById: null`
6. Notify admins via `AI_RANKING_COMPLETE` notification
7. Catch-all: any error sends `AI_RANKING_FAILED` notification, never rethrows

**Fire-and-forget call in submit mutation (line 378):**
```typescript
void triggerAutoRankIfComplete(evaluation.assignment.roundId, ctx.prisma, ctx.user.id)
```
Placed after `$transaction([evaluation.update, assignment.update])`, before `logAudit`. The submission returns immediately — ranking runs asynchronously.

**ranking.ts — 7 total procedures:**

| Procedure | Type | Trigger | Description |
|-----------|------|---------|-------------|
| `parseRankingCriteria` | mutation | admin | Preview-only parse (RANK-01, RANK-03) |
| `executeRanking` | mutation | admin | Confirmed ranking with pre-parsed rules (RANK-05, RANK-06, RANK-08) |
| `quickRank` | mutation | admin | Parse + execute in one step (RANK-04) |
| `listSnapshots` | query | admin | List snapshots for round, most recent first |
| `getSnapshot` | query | admin | Retrieve single snapshot by ID |
| `triggerAutoRank` | mutation | admin | Manual trigger from round config (RANK-09) |
| `retroactiveScan` | mutation | admin | Scan all active/closed rounds (RANK-10) |

**retroactiveScan logic:**
- Finds all `ROUND_ACTIVE` and `ROUND_CLOSED` rounds
- Checks each for `autoRankOnComplete + rankingCriteria` config
- Checks if all required assignments are complete
- Skips rounds that already have a `RETROACTIVE` snapshot
- Executes ranking sequentially (not parallel) to avoid OpenAI rate limits
- Returns `{ results[], total, triggered }` summary

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] TypeScript strict mode: `?? {}` loses EvaluationConfig type**
- **Found during:** Task 2 typecheck
- **Issue:** `(configJson as EvaluationConfig | null) ?? {}` — the `{}` fallback widens the type to `{}` which doesn't have `rankingCriteria` / `autoRankOnComplete` fields, causing TS2339 errors
- **Fix:** Changed to `?? ({} as EvaluationConfig)` in all three locations (evaluation.ts + two in ranking.ts)
- **Files modified:** `src/server/routers/evaluation.ts`, `src/server/routers/ranking.ts`
- **Commit:** c310631

**2. [Rule 1 - Bug] TypeScript: ParsedRankingRule[] requires double-cast to InputJsonValue**
- **Found during:** Task 2 typecheck
- **Issue:** `result.parsedRules as Prisma.InputJsonValue` produces TS2352 — neither type overlaps
- **Fix:** Changed to `result.parsedRules as unknown as Prisma.InputJsonValue` (matching the pattern already used for `rankedProjects` arrays)
- **Files modified:** `src/server/routers/ranking.ts` (triggerAutoRank + retroactiveScan)
- **Commit:** c310631

## Build Status

- `npm run typecheck` — PASSED (0 errors)
- `npm run build` — PASSED (full production build)

## Key Links Implemented

| From | To | Via |
|------|----|-----|
| `evaluation.ts submit` | `triggerAutoRankIfComplete` | `void` fire-and-forget after `isCompleted: true` |
| `triggerAutoRankIfComplete` | `ai-ranking.ts quickRank` | `aiQuickRank(criteriaText, roundId, prisma, userId)` |
| `triggerAutoRankIfComplete` | `in-app-notification.ts` | `notifyAdmins({ type: AI_RANKING_COMPLETE })` |
| `ranking.ts triggerAutoRank` | `ai-ranking.ts quickRank` | admin-initiated, creates MANUAL snapshot |
| `ranking.ts retroactiveScan` | `ai-ranking.ts quickRank` | sequential per-round, creates RETROACTIVE snapshot |

## Self-Check: PASSED

- `src/server/routers/evaluation.ts` — modified, contains `void triggerAutoRankIfComplete(...)`
- `src/server/routers/ranking.ts` — modified, contains `triggerAutoRank` and `retroactiveScan`
- `src/server/services/in-app-notification.ts` — modified, contains `AI_RANKING_COMPLETE` and `AI_RANKING_FAILED`
- Commits: 4683bb8 (Task 1), c310631 (Task 2)
- Build: PASSED