sfp_api_laravel_ginastica_cerebro/app/Http/Resources/GroupResource.php

<?php

namespace App\Http\Resources;

use Carbon\Carbon;
use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
use Illuminate\Http\Resources\Json\JsonResource;

class GroupResource extends JsonResource
{
    public function toArray(Request $request): array
    {
        return [
            'id'           => $this->id,
            'name'         => $this->name,
            'status'       => $this->status,
            'active_units' => $this->whenLoaded('units', fn() => $this->units->count()),
            'unit_ids'     => $this->whenLoaded('units', fn() => $this->units->pluck('id')),
            'units'        => $this->whenLoaded('units', fn() => $this->units->map(fn($unit) => [
                'id'           => $unit->id,
                'fantasy_name' => $unit->fantasy_name,
            ])),
            'created_at' => Carbon::parse($this->created_at)->format('Y-m-d'),
            'updated_at' => Carbon::parse($this->updated_at)->format('Y-m-d'),
        ];
    }

    public static function collection($resource): AnonymousResourceCollection
    {
        return parent::collection($resource);
    }
}