<?php

/**

 * API for easily embedding rich media such as videos and images into content.

 *

 * @package WordPress

 * @subpackage Embed

 * @since 2.9.0

 */

class WP_Embed {

	public $handlers = array();

	public $post_ID;

	public $linkifunknown = true;

	/**

	 * 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 );

		// 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 );

		// 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' ) );

	}

	/**

	 * Process 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();

			return;

<script type="text/javascript">

	jQuery(document).ready(function($){

		$.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post->ID, 'relative' ); ?>");

	});

</script>

	}

	/**

	 * 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 (default: 10). 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.

	 */

	public function register_handler( $id, $regex, $callback, $priority = 10 ) {

			'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 ] );

	}

	/**

	 * 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;

		$this->last_attr = $attr;

		// kses converts & into & and we need to undo this

		// See https://core.trac.wordpress.org/ticket/11311

		$url = str_replace( '&', '&', $url );

		// Look for known internal handlers

		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'] ) ) {

						/**

						 * Filters the returned embed handler.

						 *

						 * @since 2.9.0

						 *

						 * @see WP_Embed::shortcode()

						 *

						 * @param mixed  $return The shortcode callback function to call.

						 * @param string $url    The attempted embed URL.

						 * @param array  $attr   An array of shortcode attributes.

						 */

						return apply_filters( 'embed_handler_html', $return, $url, $attr );

				}

			}

		}

		$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_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 mixed  $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_status' => 'publish',

			);

			if ( $html ) {

				if ( $cached_post_id ) {

				} else {

						)

				}

			} elseif ( ! $cache ) {

					)

			}

			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 );

	}

	/**

	 * Delete 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 );

			return;

		foreach ( $post_metas as $post_meta_key ) {

				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

		 *

		 */

			return;

		}

		// Trigger a caching

		if ( ! empty( $post->post_content ) ) {

			$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 );

	}

	/**