# Bulk Operations

## User Perspective
Bulk operations allow users to apply a metadata change to many videos at once — without pushing to YouTube individually. Changes go through a **preview → confirm** flow.

### Supported Bulk Actions
- **Set Privacy Status** — change privacy on all/selected videos
- **Assign Template** — apply a template to multiple videos
- **Add Tags** — append tags without replacing existing ones
- **Remove Tags** — remove specific tags from videos
- **Search & Replace in Title** — find and replace text in video titles

### Push Pending Bulk Sync
The "Push Pending" feature batch-syncs all videos with pending changes to YouTube. Accessible via the Push Pending tab. Users preview field-level diffs before confirming.

### Rollback
Completed bulk jobs can be rolled back from the Bulk Jobs page (`/bulk-jobs`). Rollback restores the `beforeSnapshot` values for each affected video.

### Bulk Job Lifecycle
`PENDING → DRY_RUN → CONFIRMED → RUNNING → DONE` (or `FAILED` / `ROLLED_BACK`)

## Developer Perspective

### Backend
- **Module**: `backend/src/modules/bulk-jobs/`
- **Endpoints**: `GET /bulk-jobs`, `GET /bulk-jobs/:id`, `POST /bulk-jobs/:id/rollback`, `GET /bulk-jobs/push-pending/preview`, `POST /bulk-jobs/push-pending`
- **Header bulk change**: The Header component's "Bulk Change" modal calls `POST /bulk-jobs/preview` (via `bulkPreview()` in api.ts) and `POST /bulk-jobs/apply`

### Job Processing
The `bulk-metadata.processor.ts` processor:
1. Loads `BulkJob` with all `BulkJobItem` records
2. For each item: saves `beforeSnapshot`, applies change, saves `afterSnapshot`
3. Updates `successCount` / `errorCount` on job
4. On completion: sets `status = DONE` and `completedAt`

### Data Model
- `BulkJob` — one per operation. Has `type`, `filterSnapshot`, `rollbackData`
- `BulkJobItem` — one per video. Has `beforeSnapshot`, `afterSnapshot`, `status`

## Related
- [[11 - Bulk Jobs API]]
- [[01 - Video Management]]