sfp_api_laravel_serprati/app/Services/CityService.php

<?php

namespace App\Services;

use App\Models\City;
use Illuminate\Database\Eloquent\Collection;

class CityService
{
    public function getAll(): Collection
    {
        return City::with(["state:id,name", "country:id,name"])
            ->orderBy("name", "asc")
            ->get();
    }

    public function findById(int $id): ?City
    {
        return City::find($id);
    }

    public function create(array $data): City
    {
        return City::create($data);
    }

    public function update(int $id, array $data): ?City
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        $model->update($data);
        return $model->fresh();
    }

    public function delete(int $id): bool
    {
        $model = $this->findById($id);

        if (!$model) {
            return false;
        }

        return $model->delete();
    }

    public function getAllByStateId(int $stateId): Collection
    {
        return City::with(["state:id,name", "country:id,name"])
            ->where('state_id', $stateId)
            ->orderBy('name', 'asc')
            ->get();
    }

    public function getAllByCountryId(int $countryId): Collection
    {
        return City::with(["state:id,name", "country:id,name"])
            ->where('country_id', $countryId)
            ->orderBy('name', 'asc')
            ->get();
    }
}