<?php
/**
 * Accessibility Checker pluign file.
 *
 * @package Accessibility_Checker
 */

/**
 * EDAC DOM Class
 */
class EDAC_Dom extends simple_html_dom {

	/**
	 * Array of supported video extensions.
	 *
	 * @var array $video_ext Video extensions.
	 */
	protected $video_ext = [
		'.3gp',
		'.asf',
		'.asx',
		'.avi',
		'.flv',
		'.m4p',
		'.mov',
		'.mpeg',
		'.mpeg2',
		'.mpg',
		'.mpv',
		'.ogg',
		'.ogv',
		'.qtl',
		'.smi',
		'.smil',
		'.wax',
		'.webm',
		'.wmv',
		'.wmp',
		'.wmx',
	];

	/**
	 * List of supported audio file extensions.
	 *
	 * @var array $audio_ext Audio extensions.
	 */
	protected $audio_ext = [
		'.aif',
		'.aiff',
		'.m4a',
		'.mp2',
		'.mp3',
		'.mp4',
		'.mpa',
		'.ra',
		'.ram',
		'.wav',
		'.wma',
	];

	/**
	 * Array containing URLs of embed sources.
	 *
	 * @var array $embed_sources Embed source URLs.
	 */
	protected $embed_sources = [
		'mixcloud.com',
		'reverbnation.com',
		'screencast.com',
		'soundcloud.com',
		'spotify.com',
		'ted.com',
		'tiktok.com',
		'youtube.com',
		'youtu.be',
		'videopress.com',
		'vimeo.com',
	];

	/**
	 * Convert Tag to Marker
	 *
	 * @param array $tags array of tags.
	 * @return void
	 */
	public function convert_tag_to_marker( $tags ) {
		$elements = [];

		foreach ( $tags as $tag ) {
			$elements = array_merge( $elements, $this->find( $tag ) );
		}

		foreach ( $elements as $element ) {
			$element->innertext = '[' . $element->tag_start . '_ac_element]';
		}
	}

	/**
	 * Text around element contains
	 *
	 * @param obj     $element object for element.
	 * @param string  $contains value contains.
	 * @param integer $distance_after_element number.
	 * @return int
	 */
	public function text_around_element_contains( $element, $contains, $distance_after_element = 25 ) {
		// to account for the start of the search term getting cut off add the length of the search to the distance.
		$total_distance       = $distance_after_element + strlen( $contains );
		$marker               = $element->plaintext;
		$tag_end              = stripos( $this->plaintext, $marker ) + strlen( $marker );
		$next_marker_position = stripos( $this->plaintext, 'ac_element', $tag_end ) !== false ? stripos( $this->plaintext, 'ac_element', $tag_end ) : strlen( $this->plaintext );
		$found_position       = stripos( $this->plaintext, $contains, $tag_end );

		if ( false === $found_position || $found_position > $next_marker_position ) {
			return false;
		}

		$distance = $found_position - $tag_end;

		return $distance < $total_distance;
	}

	/**
	 * Find Media Embeds
	 *
	 * @param boolean $include_audio boolean to include audio.
	 * @return array
	 */
	public function find_media_embeds( $include_audio = true ) {
		// all elements with sources.
		$elements_with_src = $this->find( '[src]' );
		$elements          = [];
		$audio             = $include_audio ? $this->audio_ext : [];
		$extensions        = array_merge( $this->video_ext, $this->embed_sources, $audio );
		if ( $elements_with_src ) {
			$elements = array_filter(
				$elements_with_src,
				function ( $element ) use ( $extensions ) {
					return edac_is_item_using_matching_extension( $element->getAttribute( 'href' ), $extensions );
				}
			);
		}

		return array_merge( $elements, $this->find( '.is-type-video' ) );
	}

	/**
	 * Find Linked Media
	 *
	 * @param boolean $include_audio boolean to include audio.
	 * @return array
	 */
	public function find_linked_media( $include_audio = true ) {
		$elements_with_href = $this->find( '[href]' );
		$elements           = [];
		$audio              = $include_audio ? $this->audio_ext : [];
		$extensions         = array_merge( $this->video_ext, $audio );
		if ( $elements_with_href ) {
			$elements = array_filter(
				$elements_with_href,
				function ( $element ) use ( $extensions ) {
					return edac_is_item_using_matching_extension( $element->getAttribute( 'href' ), $extensions );
				}
			);
		}

		return $elements;
	}
}