BookStack/app/Exports/ZipExportModels/ZipExportAttachment.php

<?php

namespace BookStack\Exports\ZipExportModels;

use BookStack\Exports\ZipExportFiles;
use BookStack\Uploads\Attachment;

class ZipExportAttachment implements ZipExportModel
{
    public ?int $id = null;
    public string $name;
    public ?int $order = null;
    public ?string $link = null;
    public ?string $file = null;

    public static function fromModel(Attachment $model, ZipExportFiles $files): self
    {
        $instance = new self();
        $instance->id = $model->id;
        $instance->name = $model->name;

        if ($model->external) {
            $instance->link = $model->path;
        } else {
            $instance->file = $files->referenceForAttachment($model);
        }

        return $instance;
    }

    public static function fromModelArray(array $attachmentArray, ZipExportFiles $files): array
    {
        return array_values(array_map(function (Attachment $attachment) use ($files) {
            return self::fromModel($attachment, $files);
        }, $attachmentArray));
    }
}