# Label Hygiene Audit

- **Command:** `lore label-audit`
- **Confidence:** 82%
- **Tier:** 2
- **Status:** proposed
- **Effort:** low — straightforward aggregation queries

## What

Report on label health:
- Labels used only once (may be typos or abandoned experiments)
- Labels applied and removed within 1 hour (likely mistakes)
- Labels with no active issues/MRs (orphaned)
- Label name collisions across projects (same name, different meaning)
- Labels never used at all (defined but not applied)

## Why

Label sprawl is real and makes filtering useless over time. Teams create labels
ad-hoc and never clean them up. This simple audit surfaces maintenance tasks.

## Data Required

All exists today:
- `labels` (name, project_id)
- `issue_labels` / `mr_labels` (usage counts)
- `resource_label_events` (add/remove pairs for mistake detection)
- `issues` / `merge_requests` (state for "active" filtering)

## Implementation Sketch

```sql
-- Labels used only once
SELECT l.name, p.path_with_namespace, COUNT(*) as usage
FROM labels l
JOIN projects p ON l.project_id = p.id
LEFT JOIN issue_labels il ON il.label_id = l.id
LEFT JOIN mr_labels ml ON ml.label_id = l.id
GROUP BY l.id
HAVING COUNT(il.issue_id) + COUNT(ml.merge_request_id) = 1;

-- Flash labels (applied and removed within 1 hour)
SELECT
    rle1.label_name,
    rle1.created_at as added_at,
    rle2.created_at as removed_at,
    (rle2.created_at - rle1.created_at) / 60000 as minutes_active
FROM resource_label_events rle1
JOIN resource_label_events rle2
    ON rle1.issue_id = rle2.issue_id
    AND rle1.label_name = rle2.label_name
    AND rle1.action = 'add'
    AND rle2.action = 'remove'
    AND rle2.created_at > rle1.created_at
    AND (rle2.created_at - rle1.created_at) < 3600000;

-- Unused labels (defined but never applied)
SELECT l.name, p.path_with_namespace
FROM labels l
JOIN projects p ON l.project_id = p.id
LEFT JOIN issue_labels il ON il.label_id = l.id
LEFT JOIN mr_labels ml ON ml.label_id = l.id
WHERE il.issue_id IS NULL AND ml.merge_request_id IS NULL;
```

## Human Output

```
Label Audit

Unused Labels (4):
  group/backend:  deprecated-v1, needs-triage, wontfix-maybe
  group/frontend: old-design

Single-Use Labels (3):
  group/backend:  perf-regression (1 issue)
  group/frontend: ux-debt (1 MR), mobile-only (1 issue)

Flash Labels (applied < 1hr, 2):
  group/backend #90: +priority::critical then -priority::critical (12 min)
  group/backend #85: +blocked then -blocked (5 min)

Cross-Project Collisions (1):
  "needs-review" used in group/backend (32 uses) AND group/frontend (8 uses)
```

## Downsides

- Low glamour; this is janitorial work
- Single-use labels may be legitimate (one-off categorization)
- Cross-project collisions may be intentional (shared vocabulary)

## Extensions

- `lore label-audit --fix` — suggest deletions for unused labels
- Trend: label count over time (is sprawl increasing?)