<?php
/**
* API for easily embedding rich media such as videos and images into content.
*
* @package WordPress
* @subpackage Embed
* @since 2.9.0
*/
#[AllowDynamicProperties]
class WP_Embed {
public $handlers = array();
public $post_ID;
public $usecache = true;
public $linkifunknown = true;
public $last_attr = array();
public $last_url = '';

/**
* When a URL cannot be embedded, return false instead of returning a link
* or the URL.
*
* Bypasses the {@see 'embed_maybe_make_link'} filter.
*
* @var bool
*/
public $return_false_on_fail = false;

/**
* Constructor
*/
public function __construct() {
// Hack to get the [embed] shortcode to run before wpautop().
add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
add_filter( 'widget_text_content', array( $this, 'run_shortcode' ), 8 );
add_filter( 'widget_block_content', array( $this, 'run_shortcode' ), 8 );

// Shortcode placeholder for strip_shortcodes().
add_shortcode( 'embed', '__return_false' );

// Attempts to embed all URLs in a post.
add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
add_filter( 'widget_text_content', array( $this, 'autoembed' ), 8 );
add_filter( 'widget_block_content', array( $this, 'autoembed' ), 8 );

// After a post is saved, cache oEmbed items via Ajax.
add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );
add_action( 'edit_page_form', array( $this, 'maybe_run_ajax_cache' ) );
}

/**
* Processes the [embed] shortcode.
*
* Since the [embed] shortcode needs to be run earlier than other shortcodes,
* this function removes all existing shortcodes, registers the [embed] shortcode,
* calls do_shortcode(), and then re-registers the old shortcodes.
*
* @global array $shortcode_tags
*
* @param string $content Content to parse.
* @return string Content with shortcode parsed.
*/
public function run_shortcode( $content ) {
global $shortcode_tags;

// Back up current registered shortcodes and clear them all out.
$orig_shortcode_tags = $shortcode_tags;
remove_all_shortcodes();

add_shortcode( 'embed', array( $this, 'shortcode' ) );

// Do the shortcode (only the [embed] one is registered).
$content = do_shortcode( $content, true );

// Put the original shortcodes back.
$shortcode_tags = $orig_shortcode_tags;

return $content;
}

/**
* If a post/page was saved, then output JavaScript to make
* an Ajax request that will call WP_Embed::cache_oembed().
*/
public function maybe_run_ajax_cache() {
$post = get_post();

if ( ! $post || empty( $_GET['message'] ) ) {
return;
}
?>
<script type="text/javascript">
jQuery( function($) {
$.get("<?php echo esc_url( admin_url( 'admin-ajax.php', 'relative' ) ) . '?action=oembed-cache&post=' . $post->ID; ?>");
} );
</script>
<?php
}

/**
* Registers an embed handler.
*
* Do not use this function directly, use wp_embed_register_handler() instead.
*
* This function should probably also only be used for sites that do not support oEmbed.
*
* @param string $id An internal ID/name for the handler. Needs to be unique.
* @param string $regex The regex that will be used to see if this handler should be used for a URL.
* @param callable $callback The callback function that will be called if the regex is matched.
* @param int $priority Optional. Used to specify the order in which the registered handlers will be tested.
* Lower numbers correspond with earlier testing, and handlers with the same priority are
* tested in the order in which they were added to the action. Default 10.
*/
public function register_handler( $id, $regex, $callback, $priority = 10 ) {
$this->handlers[ $priority ][ $id ] = array(
'regex' => $regex,
'callback' => $callback,
);
}

/**
* Unregisters a previously-registered embed handler.
*
* Do not use this function directly, use wp_embed_unregister_handler() instead.
*
* @param string $id The handler ID that should be removed.
* @param int $priority Optional. The priority of the handler to be removed (default: 10).
*/
public function unregister_handler( $id, $priority = 10 ) {
unset( $this->handlers[ $priority ][ $id ] );
}

/**
* Returns embed HTML for a given URL from embed handlers.
*
* Attempts to convert a URL into embed HTML by checking the URL
* against the regex of the registered embed handlers.
*
* @since 5.5.0
*
* @param array $attr {
* Shortcode attributes. Optional.
*
* @type int $width Width of the embed in pixels.
* @type int $height Height of the embed in pixels.
* }
* @param string $url The URL attempting to be embedded.
* @return string|false The embed HTML on success, false otherwise.
*/
public function get_embed_handler_html( $attr, $url ) {
$rawattr = $attr;
$attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );

ksort( $this->handlers );
foreach ( $this->handlers as $priority => $handlers ) {
foreach ( $handlers as $id => $handler ) {
if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
$return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr );
if ( false !== $return ) {
/**
* Filters the returned embed HTML.
*
* @since 2.9.0
*
* @see WP_Embed::shortcode()
*
* @param string $return The HTML result of the shortcode.
* @param string $url The embed URL.
* @param array $attr An array of shortcode attributes.
*/
return apply_filters( 'embed_handler_html', $return, $url, $attr );
}
}
}
}

return false;
}

/**
* The do_shortcode() callback function.
*
* Attempts to convert a URL into embed HTML. Starts by checking the URL against the regex of
* the registered embed handlers. If none of the regex matches and it's enabled, then the URL
* will be given to the WP_oEmbed class.
*
* @param array $attr {
* Shortcode attributes. Optional.
*
* @type int $width Width of the embed in pixels.
* @type int $height Height of the embed in pixels.
* }
* @param string $url The URL attempting to be embedded.
* @return string|false The embed HTML on success, otherwise the original URL.
* `->maybe_make_link()` can return false on failure.
*/
public function shortcode( $attr, $url = '' ) {
$post = get_post();

if ( empty( $url ) && ! empty( $attr['src'] ) ) {
$url = $attr['src'];
}

$this->last_url = $url;

if ( empty( $url ) ) {
$this->last_attr = $attr;
return '';
}

$rawattr = $attr;
$attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );

$this->last_attr = $attr;

/*
* KSES converts & into &amp; and we need to undo this.
* See https://core.trac.wordpress.org/ticket/11311
*/
$url = str_replace( '&amp;', '&', $url );

// Look for known internal handlers.
$embed_handler_html = $this->get_embed_handler_html( $rawattr, $url );
if ( false !== $embed_handler_html ) {
return $embed_handler_html;
}

$post_id = ( ! empty( $post->ID ) ) ? $post->ID : null;

// Potentially set by WP_Embed::cache_oembed().
if ( ! empty( $this->post_ID ) ) {
$post_id = $this->post_ID;
}

// Check for a cached result (stored as custom post or in the post meta).
$key_suffix = md5( $url . serialize( $attr ) );
$cachekey = '_oembed_' . $key_suffix;
$cachekey_time = '_oembed_time_' . $key_suffix;

/**
* Filters the oEmbed TTL value (time to live).
*
* @since 4.0.0
*
* @param int $time Time to live (in seconds).
* @param string $url The attempted embed URL.
* @param array $attr An array of shortcode attributes.
* @param int $post_id Post ID.
*/
$ttl = apply_filters( 'oembed_ttl', DAY_IN_SECONDS, $url, $attr, $post_id );

$cache = '';
$cache_time = 0;

$cached_post_id = $this->find_oembed_post_id( $key_suffix );

if ( $post_id ) {
$cache = get_post_meta( $post_id, $cachekey, true );
$cache_time = get_post_meta( $post_id, $cachekey_time, true );

if ( ! $cache_time ) {
$cache_time = 0;
}
} elseif ( $cached_post_id ) {
$cached_post = get_post( $cached_post_id );

$cache = $cached_post->post_content;
$cache_time = strtotime( $cached_post->post_modified_gmt );
}

$cached_recently = ( time() - $cache_time ) < $ttl;

if ( $this->usecache || $cached_recently ) {
// Failures are cached. Serve one if we're using the cache.
if ( '{{unknown}}' === $cache ) {
return $this->maybe_make_link( $url );
}

if ( ! empty( $cache ) ) {
/**
* Filters the cached oEmbed HTML.
*
* @since 2.9.0
*
* @see WP_Embed::shortcode()
*
* @param string $cache The cached HTML result, stored in post meta.
* @param string $url The attempted embed URL.
* @param array $attr An array of shortcode attributes.
* @param int $post_id Post ID.
*/
return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_id );
}
}

/**
* Filters whether to inspect the given URL for discoverable link tags.
*
* @since 2.9.0
* @since 4.4.0 The default value changed to true.
*
* @see WP_oEmbed::discover()
*
* @param bool $enable Whether to enable `<link>` tag discovery. Default true.
*/
$attr['discover'] = apply_filters( 'embed_oembed_discover', true );

// Use oEmbed to get the HTML.
$html = wp_oembed_get( $url, $attr );

if ( $post_id ) {
if ( $html ) {
update_post_meta( $post_id, $cachekey, $html );
update_post_meta( $post_id, $cachekey_time, time() );
} elseif ( ! $cache ) {
update_post_meta( $post_id, $cachekey, '{{unknown}}' );
}
} else {
$has_kses = false !== has_filter( 'content_save_pre', 'wp_filter_post_kses' );

if ( $has_kses ) {
// Prevent KSES from corrupting JSON in post_content.
kses_remove_filters();
}

$insert_post_args = array(
'post_name' => $key_suffix,
'post_status' => 'publish',
'post_type' => 'oembed_cache',
);

if ( $html ) {
if ( $cached_post_id ) {
wp_update_post(
wp_slash(
array(
'ID' => $cached_post_id,
'post_content' => $html,
)
)
);
} else {
wp_insert_post(
wp_slash(
array_merge(
$insert_post_args,
array(
'post_content' => $html,
)
)
)
);
}
} elseif ( ! $cache ) {
wp_insert_post(
wp_slash(
array_merge(
$insert_post_args,
array(
'post_content' => '{{unknown}}',
)
)
)
);
}

if ( $has_kses ) {
kses_init_filters();
}
}

// If there was a result, return it.
if ( $html ) {
/** This filter is documented in wp-includes/class-wp-embed.php */
return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_id );
}

// Still unknown.
return $this->maybe_make_link( $url );
}

/**
* Deletes all oEmbed caches. Unused by core as of 4.0.0.
*
* @param int $post_id Post ID to delete the caches for.
*/
public function delete_oembed_caches( $post_id ) {
$post_metas = get_post_custom_keys( $post_id );
if ( empty( $post_metas ) ) {
return;
}

foreach ( $post_metas as $post_meta_key ) {
if ( str_starts_with( $post_meta_key, '_oembed_' ) ) {
delete_post_meta( $post_id, $post_meta_key );
}
}
}

/**
* Triggers a caching of all oEmbed results.
*
* @param int $post_id Post ID to do the caching for.
*/
public function cache_oembed( $post_id ) {
$post = get_post( $post_id );

$post_types = get_post_types( array( 'show_ui' => true ) );

/**
* Filters the array of post types to cache oEmbed results for.
*
* @since 2.9.0
*
* @param string[] $post_types Array of post type names to cache oEmbed results for. Defaults to post types with `show_ui` set to true.
*/
$cache_oembed_types = apply_filters( 'embed_cache_oembed_types', $post_types );

if ( empty( $post->ID ) || ! in_array( $post->post_type, $cache_oembed_types, true ) ) {
return;
}

// Trigger a caching.
if ( ! empty( $post->post_content ) ) {
$this->post_ID = $post->ID;
$this->usecache = false;

$content = $this->run_shortcode( $post->post_content );
$this->autoembed( $content );

$this->usecache = true;
}
}

/**
* Passes any unlinked URLs that are on their own line to WP_Embed::shortcode() for potential embedding.
*
* @see WP_Embed::autoembed_callback()
*
* @param string $content The content to be searched.
* @return string Potentially modified $content.
*/
public function autoembed( $content ) {
// Replace line breaks from all HTML elements with placeholders.
$content = wp_replace_in_html_tags( $content, array( "\n" => '<!-- wp-line-break -->' ) );

if ( preg_match( '#(^|\s|>)https?://#i', $content ) ) {
// Find URLs on their own line.
$content = preg_replace_callback( '|^(\s*)(https?://[^\s<>"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
// Find URLs in their own paragraph.
$content = preg_replace_callback( '|(<p(?: [^>]*)?>\s*)(https?://[^\s<>"]+)(\s*<\/p>)|i', array( $this, 'autoembed_callback' ), $content );
}

// Put the line breaks back.
return str_replace( '<!-- wp-line-break -->', "\n", $content );
}

/**
* Callback function for WP_Embed::autoembed().
*
* @param array $matches A regex match array.
* @return string The embed HTML on success, otherwise the original URL.
*/
public function autoembed_callback( $matches ) {
$oldval = $this->linkifunknown;
$this->linkifunknown = false;
$return = $this->shortcode( array(), $matches[2] );
$this->linkifunknown = $oldval;

return $matches[1] . $return . $matches[3];
}

/**
* Conditionally makes a hyperlink based on an internal class variable.
*
* @param string $url URL to potentially be linked.
* @return string|false Linked URL or the original URL. False if 'return_false_on_fail' is true.
*/
public function maybe_make_link( $url ) {
if ( $this->return_false_on_fail ) {
return false;
}

$output = ( $this->linkifunknown ) ? '<a href="' . esc_url( $url ) . '">' . esc_html( $url ) . '</a>' : $url;

/**
* Filters the returned, maybe-linked embed URL.
*
* @since 2.9.0
*
* @param string $output The linked or original URL.
* @param string $url The original URL.
*/
return apply_filters( 'embed_maybe_make_link', $output, $url );
}

/**
* Finds the oEmbed cache post ID for a given cache key.
*
* @since 4.9.0
*
* @param string $cache_key oEmbed cache key.
* @return int|null Post ID on success, null on failure.
*/
public function find_oembed_post_id( $cache_key ) {
$cache_group = 'oembed_cache_post';
$oembed_post_id = wp_cache_get( $cache_key, $cache_group );

if ( $oembed_post_id && 'oembed_cache' === get_post_type( $oembed_post_id ) ) {
return $oembed_post_id;
}

$oembed_post_query = new WP_Query(
array(
'post_type' => 'oembed_cache',
'post_status' => 'publish',
'name' => $cache_key,
'posts_per_page' => 1,
'no_found_rows' => true,
'cache_results' => true,
'update_post_meta_cache' => false,
'update_post_term_cache' => false,
'lazy_load_term_meta' => false,
)
);

if ( ! empty( $oembed_post_query->posts ) ) {
// Note: 'fields' => 'ids' is not being used in order to cache the post object as it will be needed.
$oembed_post_id = $oembed_post_query->posts[0]->ID;
wp_cache_set( $cache_key, $oembed_post_id, $cache_group );

return $oembed_post_id;
}

return null;
}
}