<?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 $usecache = true;

	public $linkifunknown = true;

	/**

	 */

	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 );

		// 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_action( 'edit_form_advanced', 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,

	 *

	 *

	 * @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)

		// Put the original shortcodes back

		$shortcode_tags = $orig_shortcode_tags;

		return $content;

	}

	/**

	 * If a post/page was saved, then output JavaScript to make

	 */

	public function maybe_run_ajax_cache() {

		$post = get_post();

		if ( ! $post || empty( $_GET['message'] ) )

			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>

<?php

	}

	/**

	 * 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 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 ) {

		$this->handlers[$priority][$id] = array(

			'regex'    => $regex,

			'callback' => $callback,

		);

	}

	/**

	 *

	 * @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 ) {

	}

	/**

	 *

	 *

	 * @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'];

		}

			return '';

		$rawattr = $attr;

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

		// 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'] ) ) {

					if ( false !== $return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr ) )

						/**

						 *

						 * @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;

			$cache = get_post_meta( $post_ID, $cachekey, true );

			$cache_time = get_post_meta( $post_ID, $cachekey_time, true );

			if ( ! $cache_time ) {

				$cache_time = 0;

			}

			}

			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}}' );

			}

			if ( $html ) {

			}

		}

		// 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 );

		if ( empty($post_metas) )

			return;

			if ( '_oembed_' == substr( $post_meta_key, 0, 8 ) )

				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 ) );

		/**

		 *

		 * @since 2.9.0

		 *

		 * @param array $post_types Array of post types to cache oEmbed results for. Defaults to post types with `show_ui` set to true.

		 */

		if ( empty( $post->ID ) || ! in_array( $post->post_type, apply_filters( 'embed_cache_oembed_types', $post_types ) ) ){

			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;

		}

	}

	/**

	 *

	 *

	 * @param string $content The content to be searched.

	 * @return string Potentially modified $content.

	 */

	public function autoembed( $content ) {

	}

	/**

	 *

	 * @param array $match A regex match array.

	 * @return string The embed HTML on success, otherwise the original URL.

	 */

	public function autoembed_callback( $match ) {

		$oldval = $this->linkifunknown;

		$this->linkifunknown = false;

		$return = $this->shortcode( array(), $match[2] );

		$this->linkifunknown = $oldval;

		return $match[1] . $return . $match[3];

	}

	/**

	 * Conditionally makes a hyperlink based on an internal class variable.