# 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
