<?php

class SerialGenerator
{
    public function generate()
    {
        $serial = array();
        $key = array_merge(
            range('a', 'z'),
            range(0, 9)
        );

        do {
            $serial[] = $key[array_rand($key, 1)];
        } while (count($serial) < 12);

        return implode('', $serial);
    }

    public function start($amount = 100)
    {
        $results = array();

        for ($i = 0; $i < $amount; $i++) {
            $gen = $this->generate();

            do {
                $gen = $this->generate();
                srand(microtime() * 10000000);
            } while (in_array($gen, $results) === true);

            $results[] = $gen;

            var_dump("{$i} " . $this->colorize($gen));
        }
    }

    public function colorize($text, $status = 'SUCCESS') {
        $out = '';

        switch($status) {
            case 'SUCCESS':
                $out = '[42m'; //Green background
                break;
            case 'FAILURE':
                $out = '[41m'; //Red background
                break;
            case 'WARNING':
                $out = '[43m'; //Yellow background
                break;
            case 'NOTE':
                $out = '[44m'; //Blue background
                break;
        }

        return chr(27) . "$out" . "$text" . chr(27) . "[0m";
    }
}