<?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 $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() {

		add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );

		add_filter( 'widget_text_content', array( $this, 'run_shortcode' ), 8 );

		add_shortcode( 'embed', '__return_false' );

		add_filter( 'the_content', array( $this, 'autoembed' ), 8 );

		add_filter( 'widget_text_content', array( $this, 'autoembed' ), 8 );

		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;

		$orig_shortcode_tags = $shortcode_tags;

		remove_all_shortcodes();

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

		$content = do_shortcode( $content, true );

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

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

	});

</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 callable $callback The callback function that will be called if the regex is matched.

	 */

	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.

	 *

	 */

	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.

	 *

	 *     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;

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

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

		}

		$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()

				 *

				 */

				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 );

		}

		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;

		}

		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

		 *

		 * @param string[] $post_types Array of post type names to cache oEmbed results for. Defaults to post types with `show_ui` set to true.

		 */

			return;

		}