Naqshlarni noto'g'ri ishlatish

// "To'g'ri" yozilgan versiya
interface SalomlashuvchiInterfeysi
{
    public function salomlash(string $ism): string;
}

final class OddiySalomlashuvchi implements SalomlashuvchiInterfeysi
{
    public function salomlash(string $ism): string
    {
        return "Salom, {$ism}!";
    }
}

final class SalomlashuvchiFabrikasi
{
    public static function yarat(): SalomlashuvchiInterfeysi
    {
        return new OddiySalomlashuvchi();
    }
}

final class SalomlashuvXizmati
{
    public function __construct(
        private readonly SalomlashuvchiInterfeysi $salomlashuvchi,
    ) {}

    public function bajar(string $ism): string
    {
        return $this->salomlashuvchi->salomlash($ism);
    }
}

$xizmat = new SalomlashuvXizmati(SalomlashuvchiFabrikasi::yarat());
echo $xizmat->bajar('Husanboy'), PHP_EOL;

// Va bu - xuddi shu natija
function salomlash(string $ism): string
{
    return "Salom, {$ism}!";
}

echo salomlash('Husanboy'), PHP_EOL;

// Kodingizda shunday joylar bormi?
interface FoydalanuvchiOmboriInterfeysi
{
    public function top(int $id): ?string;
}

final class FoydalanuvchiOmbori implements FoydalanuvchiOmboriInterfeysi
{
    /** @var array<int, string> */
    private array $malumot = [1 => 'Husanboy', 2 => 'Malika'];

    public function top(int $id): ?string
    {
        return $this->malumot[$id] ?? null;
    }
}

$ombor = new FoydalanuvchiOmbori();
echo $ombor->top(1) ?? '(yoq)', PHP_EOL;
echo $ombor->top(9) ?? '(yoq)', PHP_EOL;

// Observer - lekin tartib MUHIM
final class NotogriOqim
{
    /** @var list<callable> */
    private array $qadamlar = [];

    public function qosh(callable $q): void
    {
        $this->qadamlar[] = $q;
    }

    public function ishga(array $malumot): array
    {
        foreach ($this->qadamlar as $q) {
            $malumot = $q($malumot);
        }
        return $malumot;
    }
}

$oqim = new NotogriOqim();
$oqim->qosh(static fn(array $d): array => [...$d, 'tekshirildi']);
$oqim->qosh(static fn(array $d): array => [...$d, 'saqlandi']);
$oqim->qosh(static fn(array $d): array => [...$d, 'xabar berildi']);

echo implode(' -> ', $oqim->ishga(['boshlandi'])), PHP_EOL;

// "Kelajakda kerak bo'ladi" deb yozilgan kod
abstract class HisobotAsosi
{
    abstract protected function sarlavha(): string;
    abstract protected function qatorlar(): array;
    abstract protected function altSarlavha(): string;
    abstract protected function kolontitul(): string;
    abstract protected function valyuta(): string;
    abstract protected function tilKodi(): string;

    final public function chiqar(): string
    {
        return $this->sarlavha();
    }
}

// Bir yildan keyin - yagona voris
final class OylikHisobot extends HisobotAsosi
{
    protected function sarlavha(): string { return 'Oylik hisobot'; }
    protected function qatorlar(): array { return []; }
    protected function altSarlavha(): string { return ''; }
    protected function kolontitul(): string { return ''; }
    protected function valyuta(): string { return 'UZS'; }
    protected function tilKodi(): string { return 'uz'; }
}

echo (new OylikHisobot())->chiqar(), PHP_EOL;

// Abstraksiya olib tashlangan versiya
final readonly class Salomlashuv
{
    public function __construct(private string $shablon = 'Salom, %s!') {}

    public function bajar(string $ism): string
    {
        return sprintf($this->shablon, $ism);
    }
}

$s = new Salomlashuv();
echo $s->bajar('Husanboy'), PHP_EOL;

// Kerak bo'lsa - shablonni almashtirish yetarli
echo (new Salomlashuv('Assalomu alaykum, %s!'))->bajar('Malika'), PHP_EOL;

echo '--- solishtirish', PHP_EOL;
printf('%-22s %d fayl%s', 'interfeys+fabrika+xizmat', 4, PHP_EOL);
printf('%-22s %d fayl%s', 'bitta sinf', 1, PHP_EOL);

// Har qavat "to'g'ri", lekin birgalikda - o'qib bo'lmaydi
interface Amal { public function bajar(int $x): int; }

final class Qoshuvchi implements Amal
{
    public function __construct(private readonly int $qancha) {}
    public function bajar(int $x): int { return $x + $this->qancha; }
}

final class Jurnalli implements Amal
{
    public function __construct(private readonly Amal $ichki) {}

    public function bajar(int $x): int
    {
        $n = $this->ichki->bajar($x);
        echo "    jurnal: {$x} -> {$n}", PHP_EOL;
        return $n;
    }
}

final class Keshli implements Amal
{
    /** @var array<int, int> */
    private array $kesh = [];

    public function __construct(private readonly Amal $ichki) {}

    public function bajar(int $x): int
    {
        return $this->kesh[$x] ??= $this->ichki->bajar($x);
    }
}

final class Tekshiruvchi implements Amal
{
    public function __construct(private readonly Amal $ichki) {}

    public function bajar(int $x): int
    {
        if ($x < 0) { throw new InvalidArgumentException('manfiy'); }
        return $this->ichki->bajar($x);
    }
}

$amal = new Tekshiruvchi(new Keshli(new Jurnalli(new Qoshuvchi(5))));

echo $amal->bajar(10), PHP_EOL;
echo $amal->bajar(10), PHP_EOL;   // keshdan
echo 'chuqurlik: 4 qatlam, natija: 10 + 5', PHP_EOL;

$yomon = [
    'FoydalanuvchiManager',
    'BuyurtmaHelper',
    'TolovProcessorFactoryImpl',
    'MalumotUtils',
    'AbstractBaseHisobotServiceProvider',
];

$yaxshi = [
    'Foydalanuvchi',
    'Buyurtma',
    'KartaToolovi',
    'SanaOraligi',
    'OylikHisobot',
];

printf("%-38s %s%s", 'Yomon', 'Yaxshi', PHP_EOL);
echo str_repeat('-', 58), PHP_EOL;
foreach ($yomon as $i => $n) {
    printf("%-38s %s%s", $n, $yaxshi[$i], PHP_EOL);
}

// Ma'lumot bir joyda, mantiq boshqa joyda
final class AnemikBuyurtma
{
    public int $summa = 0;
    public string $holat = 'yangi';
    public int $chegirma = 0;
}

final class BuyurtmaServis
{
    public function chegirmaQoy(AnemikBuyurtma $b, int $foiz): void
    {
        $b->chegirma = $foiz;
    }

    public function jami(AnemikBuyurtma $b): int
    {
        return $b->summa - intdiv($b->summa * $b->chegirma, 100);
    }
}

$b = new AnemikBuyurtma();
$b->summa = 500000;

$servis = new BuyurtmaServis();
$servis->chegirmaQoy($b, 15);
echo $servis->jami($b), PHP_EOL;

// Hech kim to'sqinlik qilmaydi:
$b->chegirma = 500;
echo $servis->jami($b), PHP_EOL;

final class TogriBuyurtma
{
    private int $chegirma = 0;

    public function __construct(private readonly int $summa)
    {
        if ($summa <= 0) {
            throw new InvalidArgumentException('summa musbat bolishi kerak');
        }
    }

    public function chegirmaQoy(int $foiz): void
    {
        if ($foiz < 0 || $foiz > 50) {
            throw new InvalidArgumentException(
                "chegirma 0-50% oraligida bolishi kerak, berildi: {$foiz}");
        }
        $this->chegirma = $foiz;
    }

    public function jami(): int
    {
        return $this->summa - intdiv($this->summa * $this->chegirma, 100);
    }
}

$b = new TogriBuyurtma(500000);
$b->chegirmaQoy(15);
echo $b->jami(), PHP_EOL;

try {
    $b->chegirmaQoy(500);
} catch (InvalidArgumentException $x) {
    echo 'RAD: ', $x->getMessage(), PHP_EOL;
}
echo 'jami ozgarmadi: ', $b->jami(), PHP_EOL;