/wp-content/plugins/jetpack/class.media-extractor.php

<?php

/**

 * Class with methods to extract metadata from a post/page about videos, images, links, mentions embedded

 * in or attached to the post/page.

 *

 * @todo Additionally, have some filters on number of items in each field

 */

class Jetpack_Media_Meta_Extractor {



	// Some consts for what to extract

	const ALL = 255;

	const LINKS = 1;

	const MENTIONS = 2;

	const IMAGES = 4;

	const SHORTCODES = 8; // Only the keeper shortcodes below

	const EMBEDS = 16;

	const HASHTAGS = 32;



	// For these, we try to extract some data from the shortcode, rather than just recording its presence (which we do for all)

	// There should be a function get_{shortcode}_id( $atts ) or static method SomethingShortcode::get_{shortcode}_id( $atts ) for these.

	private static $KEEPER_SHORTCODES = array(

		'youtube',

		'vimeo',

		'hulu',

		'ted',

		'wpvideo',

		'audio',

	);



	/**

	 * Gets the specified media and meta info from the given post.

	 * NOTE: If you have the post's HTML content already and don't need image data, use extract_from_content() instead.

	 *

	 * @param $blog_id The ID of the blog

	 * @param $post_id The ID of the post

	 * @param $what_to_extract (int) A mask of things to extract, e.g. Jetpack_Media_Meta_Extractor::IMAGES | Jetpack_Media_Meta_Extractor::MENTIONS

	 * @returns a structure containing metadata about the embedded things, or empty array if nothing found, or WP_Error on error

	 */

	static public function extract( $blog_id, $post_id, $what_to_extract = self::ALL ) {



		// multisite?

		if ( function_exists( 'switch_to_blog') )

			switch_to_blog( $blog_id );



		$post = get_post( $post_id );

		$content = $post->post_title . "\n\n" . $post->post_content;

		$char_cnt = strlen( $content );



		//prevent running extraction on really huge amounts of content

		if ( $char_cnt > 100000 ) //about 20k English words

			$content = substr( $content, 0, 100000 );



		$extracted = array();



		// Get images first, we need the full post for that

		if ( self::IMAGES & $what_to_extract ) {

			$extracted = self::get_image_fields( $post );



			// Turn off images so we can safely call extract_from_content() below

			$what_to_extract = $what_to_extract - self::IMAGES;

		}



		if ( function_exists( 'switch_to_blog') )

			restore_current_blog();



		// All of the other things besides images can be extracted from just the content

		$extracted = self::extract_from_content( $content, $what_to_extract, $extracted );



		return $extracted;

	}



	/**

	 * Gets the specified meta info from the given post content.

	 * NOTE: If you want IMAGES, call extract( $blog_id, $post_id, ...) which will give you more/better image extraction

	 * This method will give you an error if you ask for IMAGES.

	 *

	 * @param $content The HTML post_content of a post

	 * @param $what_to_extract (int) A mask of things to extract, e.g. Jetpack_Media_Meta_Extractor::IMAGES | Jetpack_Media_Meta_Extractor::MENTIONS

	 * @param $already_extracted (array) Previously extracted things, e.g. images from extract(), which can be used for x-referencing here

	 * @returns a structure containing metadata about the embedded things, or empty array if nothing found, or WP_Error on error

	 */

	static public function extract_from_content( $content, $what_to_extract = self::ALL, $already_extracted = array() ) {

		$stripped_content = self::get_stripped_content( $content );



		// Maybe start with some previously extracted things (e.g. images from extract()

		$extracted = $already_extracted;



		// Embedded media objects will have already been converted to shortcodes by pre_kses hooks on save.



 		if ( self::IMAGES & $what_to_extract ) {

			$images = Jetpack_Media_Meta_Extractor::extract_images_from_content( $stripped_content, array() );

			$extracted = array_merge( $extracted, $images );

		}



		// ----------------------------------- MENTIONS ------------------------------



		if ( self::MENTIONS & $what_to_extract ) {

			if ( preg_match_all( '/(^|\s)@(\w+)/u', $stripped_content, $matches ) ) {

				$mentions = array_values( array_unique( $matches[2] ) ); //array_unique() retains the keys!

				$mentions = array_map( 'strtolower', $mentions );

				$extracted['mention'] = array( 'name' => $mentions );

				if ( !isset( $extracted['has'] ) )

					$extracted['has'] = array();

				$extracted['has']['mention'] = count( $mentions );

			}

		}



		// ----------------------------------- HASHTAGS ------------------------------

		/** Some hosts may not compile with --enable-unicode-properties and kick a warning:

		  *   Warning: preg_match_all() [function.preg-match-all]: Compilation failed: support for \P, \p, and \X has not been compiled

		  * Therefore, we only run this code block on wpcom, not in Jetpack.

		 */

		if ( ( defined( 'IS_WPCOM' ) && IS_WPCOM ) && ( self::HASHTAGS & $what_to_extract ) ) {

			//This regex does not exactly match Twitter's

			// if there are problems/complaints we should implement this:

			//   https://github.com/twitter/twitter-text/blob/master/java/src/com/twitter/Regex.java

			if ( preg_match_all( '/(?:^|\s)#(\w*\p{L}+\w*)/u', $stripped_content, $matches ) ) {

				$hashtags = array_values( array_unique( $matches[1] ) ); //array_unique() retains the keys!

				$hashtags = array_map( 'strtolower', $hashtags );

				$extracted['hashtag'] = array( 'name' => $hashtags );

				if ( !isset( $extracted['has'] ) )

					$extracted['has'] = array();

				$extracted['has']['hashtag'] = count( $hashtags );

			}

		}



		// ----------------------------------- SHORTCODES ------------------------------



		// Always look for shortcodes.

		// If we don't want them, we'll just remove them, so we don't grab them as links below

		$shortcode_pattern = '/' . get_shortcode_regex() . '/s';

 		if ( preg_match_all( $shortcode_pattern, $content, $matches ) ) {



			$shortcode_total_count = 0;

			$shortcode_type_counts = array();

			$shortcode_types = array();

			$shortcode_details = array();



			if ( self::SHORTCODES & $what_to_extract ) {



				foreach( $matches[2] as $key => $shortcode ) {

					//Elasticsearch (and probably other things) doesn't deal well with some chars as key names

					$shortcode_name = preg_replace( '/[.,*"\'\/\\\\#+ ]/', '_', $shortcode );



					$attr = shortcode_parse_atts( $matches[3][ $key ] );



					$shortcode_total_count++;

					if ( ! isset( $shortcode_type_counts[$shortcode_name] ) )

						$shortcode_type_counts[$shortcode_name] = 0;

					$shortcode_type_counts[$shortcode_name]++;



					// Store (uniquely) presence of all shortcode regardless of whether it's a keeper (for those, get ID below)

					// @todo Store number of occurrences?

					if ( ! in_array( $shortcode_name, $shortcode_types ) )

						$shortcode_types[] = $shortcode_name;



					// For keeper shortcodes, also store the id/url of the object (e.g. youtube video, TED talk, etc.)

					if ( in_array( $shortcode, self::$KEEPER_SHORTCODES ) ) {

						unset( $id ); // Clear shortcode ID data left from the last shortcode

						// We'll try to get the salient ID from the function jetpack_shortcode_get_xyz_id()

						// If the shortcode is a class, we'll call XyzShortcode::get_xyz_id()

						$shortcode_get_id_func = "jetpack_shortcode_get_{$shortcode}_id";

						$shortcode_class_name = ucfirst( $shortcode ) . 'Shortcode';

						$shortcode_get_id_method = "get_{$shortcode}_id";

						if ( function_exists( $shortcode_get_id_func ) ) {

							$id = call_user_func( $shortcode_get_id_func, $attr );

						} else if ( method_exists( $shortcode_class_name, $shortcode_get_id_method ) ) {

							$id = call_user_func( array( $shortcode_class_name, $shortcode_get_id_method ), $attr );

						}

						if ( ! empty( $id )

							&& ( ! isset( $shortcode_details[$shortcode_name] ) || ! in_array( $id, $shortcode_details[$shortcode_name] ) ) )

							$shortcode_details[$shortcode_name][] = $id;

					}

				}



				if ( $shortcode_total_count > 0 ) {

					// Add the shortcode info to the $extracted array

					if ( !isset( $extracted['has'] ) )

						$extracted['has'] = array();

					$extracted['has']['shortcode'] = $shortcode_total_count;

					$extracted['shortcode'] = array();

					foreach ( $shortcode_type_counts as $type => $count )

						$extracted['shortcode'][$type] = array( 'count' => $count );

					if ( ! empty( $shortcode_types ) )

						$extracted['shortcode_types'] = $shortcode_types;

					foreach ( $shortcode_details as $type => $id )

						$extracted['shortcode'][$type]['id'] = $id;

				}

			}



			// Remove the shortcodes form our copy of $content, so we don't count links in them as links below.

			$content = preg_replace( $shortcode_pattern, ' ', $content );

		}



		// ----------------------------------- LINKS ------------------------------



		if ( self::LINKS & $what_to_extract ) {



			// To hold the extracted stuff we find

			$links = array();



			// @todo Get the text inside the links?



			// Grab any links, whether in <a href="..." or not, but subtract those from shortcodes and images

			// (we treat embed links as just another link)

			if ( preg_match_all( '#(?:^|\s|"|\')(https?://([^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/))))#', $content, $matches ) ) {



				foreach ( $matches[1] as $link_raw ) {

					$url = parse_url( $link_raw );



					// Data URI links

					if ( isset( $url['scheme'] ) && 'data' === $url['scheme'] )

						continue;



					// Remove large (and likely invalid) links

					if ( 4096 < strlen( $link_raw ) )

						continue;



					// Build a simple form of the URL so we can compare it to ones we found in IMAGES or SHORTCODES and exclude those

					$simple_url = $url['scheme'] . '://' . $url['host'] . ( ! empty( $url['path'] ) ? $url['path'] : '' );

					if ( isset( $extracted['image']['url'] ) ) {

						if ( in_array( $simple_url, (array) $extracted['image']['url'] ) )

							continue;

					}



					list( $proto, $link_all_but_proto ) = explode( '://', $link_raw );



					// Build a reversed hostname

					$host_parts = array_reverse( explode( '.', $url['host'] ) );

					$host_reversed = '';

					foreach ( $host_parts as $part ) {

						$host_reversed .= ( ! empty( $host_reversed ) ? '.' : '' ) . $part;

					}



					$link_analyzed = '';

					if ( !empty( $url['path'] ) ) {

						// The whole path (no query args or fragments)

						$path = substr( $url['path'], 1 ); // strip the leading '/'

						$link_analyzed .= ( ! empty( $link_analyzed ) ? ' ' : '' ) . $path;



						// The path split by /

						$path_split = explode( '/', $path );

						if ( count( $path_split ) > 1 ) {

							$link_analyzed .= ' ' . implode( ' ', $path_split );

						}



						// The fragment

						if ( ! empty( $url['fragment'] ) )

							$link_analyzed .= ( ! empty( $link_analyzed ) ? ' ' : '' ) . $url['fragment'];

					}



					// @todo Check unique before adding

					$links[] = array(

						'url' => $link_all_but_proto,

						'host_reversed' => $host_reversed,

						'host' => $url['host'],

					);

				}



			}



			$link_count = count( $links );

			if ( $link_count ) {

				$extracted[ 'link' ] = $links;

				if ( !isset( $extracted['has'] ) )

					$extracted['has'] = array();

				$extracted['has']['link'] = $link_count;

			}

		}



		// ----------------------------------- EMBEDS ------------------------------



		//Embeds are just individual links on their own line

		if ( self::EMBEDS & $what_to_extract ) {



			if ( !function_exists( '_wp_oembed_get_object' ) )

				include( ABSPATH . WPINC . '/class-oembed.php' );



			// get an oembed object

			$oembed = _wp_oembed_get_object();



			// Grab any links on their own lines that may be embeds

			if ( preg_match_all( '|^\s*(https?://[^\s"]+)\s*$|im', $content, $matches ) ) {



				// To hold the extracted stuff we find

				$embeds = array();



				foreach ( $matches[1] as $link_raw ) {

					$url = parse_url( $link_raw );



					list( $proto, $link_all_but_proto ) = explode( '://', $link_raw );



					// Check whether this "link" is really an embed.

					foreach ( $oembed->providers as $matchmask => $data ) {

						list( $providerurl, $regex ) = $data;



						// Turn the asterisk-type provider URLs into regex

						if ( !$regex ) {

							$matchmask = '#' . str_replace( '___wildcard___', '(.+)', preg_quote( str_replace( '*', '___wildcard___', $matchmask ), '#' ) ) . '#i';

							$matchmask = preg_replace( '|^#http\\\://|', '#https?\://', $matchmask );

						}



						if ( preg_match( $matchmask, $link_raw ) ) {

							$provider = str_replace( '{format}', 'json', $providerurl ); // JSON is easier to deal with than XML

							$embeds[] = $link_all_but_proto; // @todo Check unique before adding



							// @todo Try to get ID's for the ones we care about (shortcode_keepers)

							break;

						}

					}

				}



				if ( ! empty( $embeds ) ) {

					if ( !isset( $extracted['has'] ) )

						$extracted['has'] = array();

					$extracted['has']['embed'] = count( $embeds );

					$extracted['embed'] = array( 'url' => array() );

					foreach ( $embeds as $e )

						$extracted['embed']['url'][] = $e;

				}

			}

		}



		return $extracted;

	}



	/**

	 * @param $post A post object

	 * @param $args (array) Optional args, see defaults list for details

	 * @returns array Returns an array of all images meeting the specified criteria in $args

	 *

	 * Uses Jetpack Post Images

	 */

	private static function get_image_fields( $post, $args = array() ) {



		$defaults = array(

			'width'               => 200, // Required minimum width (if possible to determine)

			'height'              => 200, // Required minimum height (if possible to determine)

		);



		$args = wp_parse_args( $args, $defaults );



		$image_list = array();

		$image_booleans = array();

		$image_booleans['gallery'] = 0;



		$from_featured_image = Jetpack_PostImages::from_thumbnail( $post->ID, $args['width'], $args['height'] );

		if ( !empty( $from_featured_image ) ) {

			$srcs = wp_list_pluck( $from_featured_image, 'src' );

			$image_list = array_merge( $image_list, $srcs );

		}



		$from_slideshow = Jetpack_PostImages::from_slideshow( $post->ID, $args['width'], $args['height'] );

		if ( !empty( $from_slideshow ) ) {

			$srcs = wp_list_pluck( $from_slideshow, 'src' );

			$image_list = array_merge( $image_list, $srcs );

		}



		$from_gallery = Jetpack_PostImages::from_gallery( $post->ID );

		if ( !empty( $from_gallery ) ) {

			$srcs = wp_list_pluck( $from_gallery, 'src' );

			$image_list = array_merge( $image_list, $srcs );

			$image_booleans['gallery']++; // @todo This count isn't correct, will only every count 1

		}



		// @todo Can we check width/height of these efficiently?  Could maybe use query args at least, before we strip them out

		$image_list = Jetpack_Media_Meta_Extractor::get_images_from_html( $post->post_content, $image_list );



		return Jetpack_Media_Meta_Extractor::build_image_struct( $image_list );

	}



	public static function extract_images_from_content( $content, $image_list ) {

		$image_list = Jetpack_Media_Meta_Extractor::get_images_from_html( $content, $image_list );

		return Jetpack_Media_Meta_Extractor::build_image_struct( $image_list );

	}



	public static function build_image_struct( $image_list ) {

		if ( ! empty( $image_list ) ) {

			$retval = array( 'image' => array() );

			$unique_imgs = array_unique( $image_list );

			foreach ( $image_list as $img ) {

				$retval['image'][] = array( 'url' => $img );

			}

			$image_booleans['image'] = count( $retval['image'] );

			if ( ! empty( $image_booleans ) )

				$retval['has'] = $image_booleans;

			return $retval;

		} else {

			return array();

		}

	}



	/**

	 *

	 * @param string $html Some markup, possibly containing image tags

	 * @param array $images_already_extracted (just an array of image URLs without query strings, no special structure), used for de-duplication

	 * @return array Image URLs extracted from the HTML, stripped of query params and de-duped

	 */

	public static function get_images_from_html( $html, $images_already_extracted ) {

		$image_list = $images_already_extracted;

		$from_html = Jetpack_PostImages::from_html( $html );

		if ( !empty( $from_html ) ) {

			$srcs = wp_list_pluck( $from_html, 'src' );

			foreach( $srcs as $image_url ) {

				if ( ( $src = parse_url( $image_url ) ) && isset( $src['scheme'], $src['host'], $src['path'] ) ) {

					// Rebuild the URL without the query string

					$queryless = $src['scheme'] . '://' . $src['host'] . $src['path'];

				} elseif ( $length = strpos( $image_url, '?' ) ) {

					// If parse_url() didn't work, strip off the query string the old fashioned way

					$queryless = substr( $image_url, 0, $length );

				} else {

					// Failing that, there was no spoon! Err ... query string!

					$queryless = $image_url;

				}



				// Discard URLs that are longer then 4KB, these are likely data URIs or malformed HTML.

				if ( 4096 < strlen( $queryless ) ) {

					continue;

				}



				if ( ! in_array( $queryless, $image_list ) ) {

					$image_list[] = $queryless;

				}

			}

		}

		return $image_list;

	}



	private static function get_stripped_content( $content ) {

		$clean_content = strip_tags( $content );

		$clean_content = html_entity_decode( $clean_content );

		//completely strip shortcodes and any content they enclose

		$clean_content = strip_shortcodes( $clean_content );

		return $clean_content;

	}

}