# Task 014: Assets And Media Library

Development description: Implement asset specifications, generated or uploaded asset records, object-storage file handling, approval/rejection, replacement, and a media library view.

## Implementation Details

- Backend endpoints:
  - `POST /api/articles/{article_id}/assets/generate-specs`
  - `GET /api/articles/{article_id}/assets`
  - `PATCH /api/articles/{article_id}/assets/{asset_id}`
  - `POST /api/articles/{article_id}/assets/{asset_id}/approve`
  - Upload/replacement endpoint for asset files.
- Asset types:
  - Hero image.
  - Inline diagram.
  - Table.
  - Flowchart.
  - Comparison matrix.
  - Architecture diagram.
  - Inline image.
- Asset record fields:
  - Title.
  - Type.
  - Prompt or diagram/table code.
  - File URL/object key.
  - Alt text.
  - Caption.
  - Status.
  - Linked section/article.
- Frontend:
  - Asset review page.
  - Media library.
  - Replacement upload.
  - Approval/rejection controls.

## Public Interface

- Editor reviews generated asset specs.
- Editor approves, rejects, or replaces assets.
- Approved assets are included in draft/publish bundle.

## Acceptance Criteria

- [x] TDD pre-requirement: before implementation, write one failing public API test for approving an asset and seeing it become available to the article; proceed one asset behavior at a time and record evidence in `Result`.
- [x] Asset specs are generated and linked to article or section.
- [x] File uploads store objects in object storage and persist object keys.
- [x] Asset approval writes workflow event.
- [x] Rejected assets are excluded from publish bundle.
- [x] Replacement preserves audit history.
- [x] Media library lists article assets with status, type, title, preview/file link, alt text, and caption.
- [x] Draft preview uses approved asset references where available.

## Verification

- Run asset API tests.
- Run object-storage upload integration tests.
- Run frontend media library tests.
- Run smoke flow approving and replacing an asset.

## Result

- Status: Implementation completed, acceptance criteria closed.
- TDD plan:
  1. Keep RED pre-requirement test that calls approve API and asserts asset visibility in article context.
  2. Expand integration tests to cover full assets lifecycle: specs generation, upload, approve/reject, replacement audit, and draft-facing inclusion/exclusion behavior.
  3. Implement API contracts + persistence + routes + object storage integration.
  4. Add frontend media library model/UI and draft preview asset reference resolution.
- Red evidence:
  - Initial pre-requirement failure: `POST /api/articles/{article_id}/assets/{asset_id}/approve` returned `404 Not Found`.
  - During implementation hardening: transient runtime bug `NameError: name 'approved' is not defined` in `approve_asset` (fixed), confirmed by rerun to green.
- Green evidence:
  - Backend assets suite now green with 7 integration tests, including:
    - specs linked to sections,
    - upload persists `object_key` and writes object file,
    - approval writes workflow event,
    - rejected asset excluded from assembled draft publish-facing data,
    - replacement keeps full audit history.
  - Draft assembly and parallel production suites remain green after assets integration.
  - Frontend media-library model tests and typecheck are green.
- Refactor notes:
  - Added dedicated assets application module and routes.
  - Extended object storage adapter with `put_bytes`.
  - Added persistent `asset_revisions` history table and API-visible history payload.
  - Updated shared OpenAPI contracts and generated TS types.
- Verification output:
  - `PYTHONPATH=/private/tmp/pupline-backend-deps python3 -m unittest apps/backend/tests/integration/test_assets_media_library_public_api.py`
    - `Ran 7 tests ... OK`
  - `PYTHONPATH=/private/tmp/pupline-backend-deps python3 -m unittest apps/backend/tests/integration/test_draft_assembly_public_api.py`
    - `Ran 5 tests ... OK`
  - `PYTHONPATH=/private/tmp/pupline-backend-deps python3 -m unittest apps/backend/tests/integration/test_parallel_production_public_api.py`
    - `Ran 6 tests ... OK`
  - `node apps/frontend/tests/article_assets.model.test.mjs`
    - `OK` (exit code `0`)
  - `node apps/frontend/tests/draft_editor.model.test.mjs`
    - `OK` (exit code `0`)
  - `pnpm --dir apps/frontend typecheck`
    - `tsc --noEmit` completed successfully.