<?php

if (class_exists('SplFixedArray')) {

    return;

}

/**

 * The SplFixedArray class provides the main functionalities of array. The

 * main differences between a SplFixedArray and a normal PHP array is that

 * the SplFixedArray is of fixed length and allows only integers within

 * the range as indexes. The advantage is that it allows a faster array

 * implementation.

 */

class SplFixedArray implements Iterator, ArrayAccess, Countable

{

    /** @var array<int, mixed> */

    private $internalArray = array();

    /** @var int $size */

    private $size = 0;

    /**

     * SplFixedArray constructor.

     * @param int $size

     */

    public function __construct($size = 0)

    {

        $this->size = $size;

        $this->internalArray = array();

    }

    /**

     * @return int

     */

    public function count()

    {

        return count($this->internalArray);

    }

    /**

     * @return array

     */

    public function toArray()

    {

        ksort($this->internalArray);

        return (array) $this->internalArray;

    }

    /**

     * @param array $array

     * @param bool $save_indexes

     * @return SplFixedArray

     * @psalm-suppress MixedAssignment

     */

    public static function fromArray(array $array, $save_indexes = true)

    {

        $self = new SplFixedArray(count($array));

        if($save_indexes) {

            foreach($array as $key => $value) {

                $self[(int) $key] = $value;

            }

        } else {

            $i = 0;

            foreach (array_values($array) as $value) {

                $self[$i] = $value;

                $i++;

            }

        }

        return $self;

    }

    /**

     * @return int

     */

    public function getSize()

    {

        return $this->size;

    }

    /**

     * @param int $size

     * @return bool

     */

    public function setSize($size)

    {

        $this->size = $size;

        return true;

    }

    /**

     * @param string|int $index

     * @return bool

     */

    public function offsetExists($index)

    {

        return array_key_exists((int) $index, $this->internalArray);

    }

    /**

     * @param string|int $index

     * @return mixed

     */

    public function offsetGet($index)

    {

        /** @psalm-suppress MixedReturnStatement */

        return $this->internalArray[(int) $index];

    }

    /**

     * @param string|int $index

     * @param mixed $newval

     * @psalm-suppress MixedAssignment

     */

    public function offsetSet($index, $newval)

    {

        $this->internalArray[(int) $index] = $newval;

    }

    /**

     * @param string|int $index

     */

    public function offsetUnset($index)

    {

        unset($this->internalArray[(int) $index]);

    }

    /**

     * Rewind iterator back to the start

     * @link https://php.net/manual/en/splfixedarray.rewind.php

     * @return void

     * @since 5.3.0

     */

    public function rewind()

    {

        reset($this->internalArray);

    }

    /**

     * Return current array entry

     * @link https://php.net/manual/en/splfixedarray.current.php

     * @return mixed The current element value.

     * @since 5.3.0

     */

    public function current()

    {

        /** @psalm-suppress MixedReturnStatement */

        return current($this->internalArray);

    }

    /**

     * Return current array index

     * @return int The current array index.

     */

    public function key()

    {

        return key($this->internalArray);

    }

    /**

     * @return void

     */

    public function next()

    {

        next($this->internalArray);

    }

    /**

     * Check whether the array contains more elements

     * @link https://php.net/manual/en/splfixedarray.valid.php

     * @return bool true if the array contains any more elements, false otherwise.

     */

    public function valid()

    {

        if (empty($this->internalArray)) {

            return false;

        }

        $result = next($this->internalArray) !== false;

        prev($this->internalArray);

        return $result;

    }

    /**

     * Do nothing.

     */

    public function __wakeup()

    {

        // NOP

    }

}