<?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 TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper;
use TYPO3\CMS\Fluid\Core\ViewHelper\Exception;

/**
 * Base class: Math ViewHelpers operating on one number or an
 * array of numbers.
 *
 * @author Claus Due <claus@namelesscoder.net>
 * @package Vhs
 * @subpackage ViewHelpers
 */
abstract class AbstractSingleMathViewHelper extends AbstractViewHelper {

	use ArrayConsumingViewHelperTrait;

	/**
	 * @return void
	 */
	public function initializeArguments() {
		$this->registerArgument('a', 'mixed', 'First number for calculation', FALSE, NULL, TRUE);
		$this->registerArgument('fail', 'boolean', 'If TRUE, throws an Exception if argument "a" is not specified and no child content or inline argument is found. Usually okay to use a NULL value (as integer zero).', FALSE, FALSE);
	}

	/**
	 * @param mixed $subject
	 * @return boolean
	 */
	protected function assertIsArrayOrIterator($subject) {
		return (boolean) (TRUE === is_array($subject) || TRUE === $subject instanceof \Iterator);
	}

	/**
	 * @return mixed
	 * @throw Exception
	 */
	public function render() {
		$a = $this->getInlineArgument();
		return $this->calculate($a);
	}

	/**
	 * @throws Exception
	 * @return mixed
	 */
	protected function getInlineArgument() {
		$a = $this->renderChildren();
		if (NULL === $a && TRUE === isset($this->arguments['a'])) {
			$a = $this->arguments['a'];
		}
		if (NULL === $a && TRUE === (boolean) $this->arguments['fail']) {
			throw new Exception('Required argument "a" was not supplied', 1237823699);
		}
		return $a;
	}

	/**
	 * @param mixed $a
	 * @return mixed
	 */
	protected function calculate($a) {
		$aIsIterable = $this->assertIsArrayOrIterator($a);
		if (TRUE === $aIsIterable) {
			$a = $this->arrayFromArrayOrTraversableOrCSV($a);
			foreach ($a as $index => $value) {
				$a[$index] = $this->calculateAction($value);
			}
			return $a;
		}
		return $this->calculateAction($a);
	}

}