# Agent: worker-media

**Model:** `github-copilot/claude-sonnet-4.5`

## Mission
Implement the media processing worker: scanning, metadata extraction, thumbnail/poster generation, canonical copy logic, and safe CronJobs.

## Primary Responsibilities
- BullMQ worker jobs:
  - `scan_minio_prefix` (list objects under allowlisted prefix `originals/`).
  - `process_asset` (extract metadata + generate derived assets).
  - `copy_to_canonical` (copy-only into date-based canonical layout).
- Metadata extraction policy:
  - Photos: EXIF DateTimeOriginal-first.
  - Videos: camera-like tags first (ExifTool), fallback to universal container `creation_time` (ffprobe).
- Derived assets:
  - Images: `thumbs/{assetId}/image_256.jpg` and `image_768.jpg` using `sharp`.
  - Videos: `thumbs/{assetId}/poster_256.jpg` using ffmpeg frame extraction.
- Robustness:
  - Never crash the worker loop due to a single bad file.
  - Write `assets.status=failed` + `error_message` on failures.
- Resource constraints:
  - Keep concurrency low (1–2) for Raspberry Pi.

## Inputs
- `PLAN.md` (job semantics, key layout)
- MinIO credentials + endpoints
- DB access + Redis queue
- Docker image must include required tools:
  - ExifTool
  - ffprobe/ffmpeg

## Outputs / Deliverables
- Worker runnable in k8s.
- Repeatable job behavior with idempotency considerations.
- Derived outputs in MinIO, referenced from DB.

## Idempotency & Safety Rules
- External archive policy: never delete/mutate objects under `originals/`.
- `copy_to_canonical` is copy-only:
  - If canonical object exists, verify cheaply (HEAD/size) and treat as success.
- Staging cleanup CronJob may safely delete old `staging/` objects.

## Definition of Done
- Mixed media set (images + videos) processed end-to-end.
- Poster + thumbs appear in MinIO for ready assets.
- Worker handles unsupported codecs and corrupt files without stopping.
- Copies to canonical work for uploads, and can be enabled later for scans.