<?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(

);

/**

* 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 ) {

}

/**

* 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 wtih 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 ) {

// Should've called extract( $blog_id, $post_id ) if you want images

return new WP_Error( 'media-extraction-error', "IMAGES extraction not supported in extract_from_content()" );

}

// ----------------------------------- 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

if ( 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-java/blob/master/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 );

// 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 );

$extracted['link'] = $links;

if ( $link_count ) {

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_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 );

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 theh 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;

}

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;

}

}