generateUniquePathName.php

<?php

use Illuminate\Support\Facades\File;

function generateUniquePathName(string $filePath): string
{
    $path = File::dirname($filePath);
    $name = File::name($filePath);
    $extension = File::extension($filePath);

    $suffix = '';
    $counter = 1;

    // $this->disk = Storage::disk('local'); // for example
    while ($this->disk->exists("{$path}/{$name}{$suffix}.{$extension}")) {
        $format = '-%s'; // any - ' (%s)', '-%s'
        $suffix = sprintf($format, $counter);
        ++$counter;
    }

    return "{$path}/{$name}{$suffix}.{$extension}";
}