<?php
namespace FluidTYPO3\Vhs\ViewHelpers\Math;

/*
 * This file is part of the FluidTYPO3/Vhs project under GPLv2 or later.
 *
 * For the full copyright and license information, please read the
 * LICENSE.md file that was distributed with this source code.
 */

use FluidTYPO3\Vhs\Traits\ArrayConsumingViewHelperTrait;
use TYPO3Fluid\Fluid\Core\ViewHelper\Traits\CompileWithContentArgumentAndRenderStatic;

/**
 * Math: Median
 *
 * Gets the median value from an array of numbers. If there
 * is an odd number of numbers the middle value is returned.
 * If there is an even number of numbers an average of the
 * two middle numbers is returned.
 */
class MedianViewHelper extends AbstractSingleMathViewHelper
{
    use CompileWithContentArgumentAndRenderStatic;
    use ArrayConsumingViewHelperTrait;

    /**
     * @param mixed $a
     * @return mixed
     */
    protected static function calculateAction($a, array $arguments = [])
    {
        $aIsIterable = static::assertIsArrayOrIterator($a);
        if ($aIsIterable) {
            $a = static::arrayFromArrayOrTraversableOrCSVStatic($a);
            sort($a, SORT_NUMERIC);
            $size = count($a);
            $midpoint = $size / 2;
            if (1 === $size % 2) {
                /*
                 * Array indexes of float are truncated to integers,
                 * not everybody knows, let's make it explicit for everybody
                 * wondering.
                 */
                return $a[(integer) $midpoint];
            }
            $candidates = array_slice($a, (integer) (floor($midpoint) - 1), 2);
            return array_sum($candidates) / 2;
        }
        return $a;
    }
}