# Bulk Update Media Items

Update multiple media items at once (supports ebooks, comics, manga).

**Endpoint**: `POST /api/media-items/bulk-update`
**Auth**: Required
**Content-Type**: `application/json`

## Request Body

| Field | Type | Required | Description |
|--------|------|-----------|-------------|
| media_item_updates | array of objects | Yes | Array of update operations |
| media_item_updates[].media_item_id | string (UUID) | Yes | Media item UUID to update |
| media_item_updates[].updates | object | Yes | Fields to update |

### Update Fields

| Field | Type | Required | Description |
|--------|------|-----------|-------------|
| title | string | No | Updated title |
| author | string | No | Updated author |
| genre | string | No | Updated genre |
| language | string | No | Updated language (ISO 639-1 code) |
| tags | array of strings | No | Updated tags (auto-normalized) |

### Example Request

```json
{
  "media_item_updates": [
    {
      "media_item_id": "550e8400-e29b-41d4-a716-446655440001",
      "updates": {
        "title": "Updated Title",
        "genre": "Science Fiction",
        "tags": ["science fiction", "space opera", "ACME CORP."]
      }
    },
    {
      "media_item_id": "660e8400-e29b-41d4-a716-446655440002",
      "updates": {
        "author": "Updated Author Name",
        "language": "en"
      }
    }
  ]
}
```

## Response (200 OK)

```json
{
  "results": [
    {
      "media_item_id": "550e8400-e29b-41d4-a716-446655440001",
      "status": "success"
    },
    {
      "media_item_id": "660e8400-e29b-41d4-a716-446655440002",
      "status": "error",
      "error": "Media item not found"
    }
  ],
  "total": 2,
  "updated": 1,
  "failed": 1
}
```

## Response Fields

| Field | Type | Description |
|-------|------|-------------|
| results | array | Individual result for each media item |
| results[].media_item_id | string | UUID of the media item |
| results[].status | string | "success" or "error" |
| results[].error | string | Error message (only present if status is "error") |
| total | number | Total number of media items processed |
| updated | number | Number of media items successfully updated |
| failed | number | Number of media items that failed to update |

## Tag and Contributor Normalization

The backend automatically normalizes tags:

- **Tags**: Titlecased, punctuation preserved, deduplicated
- **Search fields**: Lowercase, no punctuation, stored in `tags_search`

## Error Responses

| Code | Description |
|------|-------------|
| 400 | Invalid request data or empty media_item_updates array |
| 401 | Invalid or expired token |
| 403 | User does not have permission |
| 404 | One or more media items not found |
| 500 | Server error during update |

## Notes

- **Partial success**: The operation continues even if some updates fail
- **Invalid UUIDs**: Invalid UUID formats are counted as failures
- **Non-existent items**: Media items that don't exist are counted as failures
- **No changes**: If updates object is empty, the item still counts as success