Subversion-Projekte lars-tiefland.laravel_shop

<?php

namespace Illuminate\Support;

use RuntimeException;

class Lottery

{

    /**

     * The number of expected wins.

     *

     * @var int|float

     */

    protected $chances;

    /**

     * The number of potential opportunities to win.

     *

     * @var int|null

     */

    protected $outOf;

    /**

     * The winning callback.

     *

     * @var null|callable

     */

    protected $winner;

    /**

     * The losing callback.

     *

     * @var null|callable

     */

    protected $loser;

    /**

     * The factory that should be used to generate results.

     *

     * @var callable|null

     */

    protected static $resultFactory;

    /**

     * Create a new Lottery instance.

     *

     * @param  int|float  $chances

     * @param  ?int  $outOf

     */

    public function __construct($chances, $outOf = null)

    {

        if ($outOf === null && is_float($chances) && $chances > 1) {

            throw new RuntimeException('Float must not be greater than 1.');

        }

        $this->chances = $chances;

        $this->outOf = $outOf;

    }

    /**

     * Create a new Lottery instance.

     *

     * @param  int|float  $chances

     * @param  ?int  $outOf

     * @return static

     */

    public static function odds($chances, $outOf = null)

    {

        return new static($chances, $outOf);

    }

    /**

     * Set the winner callback.

     *

     * @param  callable  $callback

     * @return $this

     */

    public function winner($callback)

    {

        $this->winner = $callback;

        return $this;

    }

    /**

     * Set the loser callback.

     *

     * @param  callable  $callback

     * @return $this

     */

    public function loser($callback)

    {

        $this->loser = $callback;

        return $this;

    }

    /**

     * Run the lottery.

     *

     * @param  mixed  ...$args

     * @return mixed

     */

    public function __invoke(...$args)

    {

        return $this->runCallback(...$args);

    }

    /**

     * Run the lottery.

     *

     * @param  null|int  $times

     * @return mixed

     */

    public function choose($times = null)

    {

        if ($times === null) {

            return $this->runCallback();

        }

        $results = [];

        for ($i = 0; $i < $times; $i++) {

            $results[] = $this->runCallback();

        }

        return $results;

    }

    /**

     * Run the winner or loser callback, randomly.

     *

     * @param  mixed  ...$args

     * @return callable

     */

    protected function runCallback(...$args)

    {

        return $this->wins()

            ? ($this->winner ?? fn () => true)(...$args)

            : ($this->loser ?? fn () => false)(...$args);

    }

    /**

     * Determine if the lottery "wins" or "loses".

     *

     * @return bool

     */

    protected function wins()

    {

        return static::resultFactory()($this->chances, $this->outOf);

    }

    /**

     * The factory that determines the lottery result.

     *

     * @return callable

     */

    protected static function resultFactory()

    {

        return static::$resultFactory ?? fn ($chances, $outOf) => $outOf === null

            ? random_int(0, PHP_INT_MAX) / PHP_INT_MAX <= $chances

            : random_int(1, $outOf) <= $chances;

    }

    /**

     * Force the lottery to always result in a win.

     *

     * @param  callable|null  $callback

     * @return void

     */

    public static function alwaysWin($callback = null)

    {

        self::setResultFactory(fn () => true);

        if ($callback === null) {

            return;

        }

        $callback();

        static::determineResultNormally();

    }

    /**

     * Force the lottery to always result in a lose.

     *

     * @param  callable|null  $callback

     * @return void

     */

    public static function alwaysLose($callback = null)

    {

        self::setResultFactory(fn () => false);

        if ($callback === null) {

            return;

        }

        $callback();

        static::determineResultNormally();

    }

    /**

     * Set the sequence that will be used to determine lottery results.

     *

     * @param  array  $sequence

     * @param  callable|null  $whenMissing

     * @return void

     */

    public static function fix($sequence, $whenMissing = null)

    {

        return static::forceResultWithSequence($sequence, $whenMissing);

    }

    /**

     * Set the sequence that will be used to determine lottery results.

     *

     * @param  array  $sequence

     * @param  callable|null  $whenMissing

     * @return void

     */

    public static function forceResultWithSequence($sequence, $whenMissing = null)

    {

        $next = 0;

        $whenMissing ??= function ($chances, $outOf) use (&$next) {

            $factoryCache = static::$resultFactory;

            static::$resultFactory = null;

            $result = static::resultFactory()($chances, $outOf);

            static::$resultFactory = $factoryCache;

            $next++;

            return $result;

        };

        static::setResultFactory(function ($chances, $outOf) use (&$next, $sequence, $whenMissing) {

            if (array_key_exists($next, $sequence)) {

                return $sequence[$next++];

            }

            return $whenMissing($chances, $outOf);

        });

    }

    /**

     * Indicate that the lottery results should be determined normally.

     *

     * @return void

     */

    public static function determineResultNormally()

    {

        static::$resultFactory = null;

    }

    /**

     * Set the factory that should be used to deterine the lottery results.

     *

     * @param  callable  $factory

     * @return void

     */

    public static function setResultFactory($factory)

    {

        self::$resultFactory = $factory;

    }

}