Obtaining items based on chance percentage-CodePudding

I am working on a Laravel project. I will explain the problem and I would be grateful if you help me. I want to add a feature to the project. First I want to explain the entities of the project:

User,Car,CarClass, Box.

each Car has a CarClass. User can buy a Box and open it.

When the user opens the box he bought, he can win a car from a certain CarClass by chance. for example:

Red box: street 45%, sport 30%, muscle 30%, hyper 0%

Yellow box: street 20%, sport 50%, muscle 10%, hyper 20%

User who buys the Red box has a 45% chance to win a car with street class car, 30% chance to win a car with sport class and so on... .

And we have different boxes with different percentages.

Should there be one method for unboxing? Should a special design pattern be used?

Whether it is a complete answer or a clue that can help me, I would be grateful.

CodePudding user response：

Interfaces:
    Item
        # getName()
    Box:
        # getItem()
Concrete:
    YellowBox(Box)
          getItem()
    RedBox(Box)
          getItem()
    Street(Item)
          getName()
    Sport(Item)
          getName()
    Muscle(Item)
          getName()
    Hyper(Item)
          getName()

Additionally, getting random item is weighted probability. In the example below, I've assumed that all the chances always add up to 100%. Laravel code:

interface Item
{

    function getName(): string;
}

interface Box
{

    function getItem(): Item;
}

class Street implements Item
{

    public function getName(): string
    {
        return get_class($this);
    }
}

class Sport implements Item
{

    public function getName(): string
    {
        return get_class($this);
    }
}

class Muscle implements Item
{

    public function getName(): string
    {
        return get_class($this);
    }
}

class Hyper implements Item
{

    public function getName(): string
    {
        return get_class($this);
    }
}

abstract class BaseBox implements Box
{

    abstract protected function chances(): Collection;

    public function getItem(): Item
    {
        $sum = 0;
        $choice = random_int(0, 100);

        return app(
            $this->chances()
                ->map(function ($value, $item) use (&$sum) {
                    $sum  = $value;
                    return $sum;
                })
                ->reduce(function ($result, $value, $key) use ($choice) {
                    if (is_string($result)) {
                        return $result;
                    }

                    if ($choice <= $value) {
                        return $key;
                    }

                    return $result   $value;
                }, 0)
        );
    }
}

class RedBox extends BaseBox
{

    public function chances(): Collection
    {
        return collect([
            Street::class => 45,
            Sport::class => 30,
            Muscle::class => 30,
        ]);
    }
}

class YellowBox extends BaseBox
{

    public function chances(): Collection
    {
        return collect([
            Street::class => 20,
            Sport::class => 50,
            Muscle::class => 10,
            Hyper::class => 20,
        ]);
    }
}