<?php
namespace FluidTYPO3\Vhs\Traits;

use FluidTYPO3\Vhs\Utility\FrontendSimulationUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface;

/*
 * 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.
 */

/**
 * This trait can be used by viewhelpers that generate image tags
 * to add srcsets based to the imagetag for better responsiveness
 */
trait SourceSetViewHelperTrait {

	/**
	 * used to attach srcset variants of a given image to the specified tag
	 *
	 * @param \TYPO3\CMS\Fluid\Core\ViewHelper\TagBuilder $tag the tag to add the srcset as argument
	 * @param string $src image path to render srcsets for
	 * @return array
	 */
	public function addSourceSet($tag, $src) {
		$srcsets = $this->getSourceSetWidths();

 		if ('BE' === TYPO3_MODE) {
			FrontendSimulationUtility::simulateFrontendEnvironment();
		}

		$format = $this->arguments['format'];
		$quality = $this->arguments['quality'];
		$treatIdAsReference = (boolean) $this->arguments['treatIdAsReference'];

		$imageSources = array();
		$srcsetVariants = array();

		foreach ($srcsets as $key => $width) {
			$srcsetVariant = $this->getImgResource($src, $width, $format, $quality, $treatIdAsReference);

			$srcsetVariantSrc = rawurldecode($srcsetVariant[3]);
			$srcsetVariantSrc = $this->preprocessSourceUri(GeneralUtility::rawUrlEncodeFP($srcsetVariantSrc));

			$imageSources[$srcsetVariant[0]] = array(
				'src' => $srcsetVariantSrc,
				'width' => $srcsetVariant[0],
				'height' => $srcsetVariant[1],
			);
			$srcsetVariants[$srcsetVariant[0]] = $srcsetVariantSrc . ' ' . $srcsetVariant[0] . 'w';
		}

		$tag->addAttribute('srcset', implode(',', $srcsetVariants));

		if ('BE' === TYPO3_MODE) {
			FrontendSimulationUtility::resetFrontendEnvironment();
		}

		return $imageSources;
	}

	/**
	 * generates a copy of a give image with a specific width
	 *
	 * @param string $src path of the image to convert
	 * @param integer $width width to convert the image to
	 * @param string $format format of the resulting copy
	 * @param string $quality quality of the resulting copy
	 * @param string $treatIdAsReference given src argument is a sys_file_reference record
	 * @param array $params additional params for the image rendering
	 * @return string
	 */
	public function getImgResource($src, $width, $format, $quality, $treatIdAsReference, $params = NULL) {

		$setup = array(
			'width' => $width,
			'treatIdAsReference' => $treatIdAsReference
		);
		if (FALSE === empty($format)) {
			$setup['ext'] = $format;
		}
		if (0 < intval($quality)) {
			$quality = MathUtility::forceIntegerInRange($quality, 10, 100, 75);
			$setup['params'] .= ' -quality ' . $quality;
		}

		if ('BE' === TYPO3_MODE && '../' === substr($src, 0, 3)) {
			$src = substr($src, 3);
		}
		return $this->contentObject->getImgResource($src, $setup);
	}

	/**
	 * returns an array of srcsets based on the mixed ViewHelper
	 * input (list, csv, array, iterator)
	 *
	 * @return array
	 */
	public function getSourceSetWidths() {
		$srcsets = $this->arguments['srcset'];
		if (TRUE === $srcsets instanceof \Traversable) {
			$srcsets = iterator_to_array($srcsets);
		} elseif (TRUE === is_string($srcsets)) {
			$srcsets = GeneralUtility::trimExplode(',', $srcsets, TRUE);
		} else {
			$srcsets = (array) $srcsets;
		}
		return $srcsets;
	}
}