autocde2.0/app/Http/Requests/API/Project/UpdateLinkAssetsRequest.php

<?php

namespace App\Http\Requests\API\Project;

use App\Models\Asset;
use App\Models\Enums\AssetStatus;
use App\Models\Plan;
use App\Models\User;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Support\Facades\Auth;
use Illuminate\Validation\Rule;
use Illuminate\Validation\Rules\Enum;

class UpdateLinkAssetsRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     */
    public function authorize(): bool
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
     */
    public function rules(): array
    {
        return [
            'project_id' =>[
                'email'
            ],
            'assets' => [
                'array',
                function ($attribute, $value, $fail) {
                    $assetIds = Asset::query()->whereIn('id', $value)->pluck('id')->toArray();

                    if (count(array_diff($value, $assetIds)) > 0) {
                        $fail('The selected asset is invalid.');
                    }
                }
            ],
        ];
    }
}