<?php

/**

 * oEmbed API: Top-level oEmbed functionality

 *

 * @package WordPress

 * @subpackage oEmbed

 * @since 4.4.0

 */

/**

 * Registers an embed handler.

 *

 * Should probably only be used for sites that do not support oEmbed.

 *

 * @since 2.9.0

 *

 * @global WP_Embed $wp_embed

 *

 * @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.

 */

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

	global $wp_embed;

	$wp_embed->register_handler( $id, $regex, $callback, $priority );

}

/**

 * Unregisters a previously-registered embed handler.

 *

 * @since 2.9.0

 *

 * @global WP_Embed $wp_embed

 *

 * @param string $id       The handler ID that should be removed.

 * @param int    $priority Optional. The priority of the handler to be removed. Default 10.

 */

function wp_embed_unregister_handler( $id, $priority = 10 ) {

	global $wp_embed;

	$wp_embed->unregister_handler( $id, $priority );

}

/**

 * Creates default array of embed parameters.

 *

 * The width defaults to the content width as specified by the theme. If the

 * theme does not specify a content width, then 500px is used.

 *

 * The default height is 1.5 times the width, or 1000px, whichever is smaller.

 *

 * The {@see 'embed_defaults'} filter can be used to adjust either of these values.

 *

 * @since 2.9.0

 *

 * @global int $content_width

 *

 * @param string $url Optional. The URL that should be embedded. Default empty.

 *

 */

function wp_embed_defaults( $url = '' ) {

	if ( ! empty( $GLOBALS['content_width'] ) ) {

		$width = (int) $GLOBALS['content_width'];

	}

	if ( empty( $width ) ) {

		$width = 500;

	}

	$height = min( ceil( $width * 1.5 ), 1000 );

	/**

	 * Filters the default array of embed dimensions.

	 *

	 * @since 2.9.0

	 *

	 * @param string $url  The URL that should be embedded.

	 */

	return apply_filters( 'embed_defaults', compact( 'width', 'height' ), $url );

}

/**

 * Attempts to fetch the embed HTML for a provided URL using oEmbed.

 *

 * @since 2.9.0

 *

 * @see WP_oEmbed

 *

 * @param string $url  The URL that should be embedded.

 * @param array  $args Optional. Additional arguments and parameters for retrieving embed HTML.

 *                     Default empty.

 */

function wp_oembed_get( $url, $args = '' ) {

	$oembed = _wp_oembed_get_object();

	return $oembed->get_html( $url, $args );

}

/**

 * Returns the initialized WP_oEmbed object.

 *

 * @since 2.9.0

 * @access private

 *

 * @return WP_oEmbed object.

 */

function _wp_oembed_get_object() {

	static $wp_oembed = null;

	if ( is_null( $wp_oembed ) ) {

		$wp_oembed = new WP_oEmbed();

	}

	return $wp_oembed;

}

/**

 * Adds a URL format and oEmbed provider URL pair.

 *

 * @since 2.9.0

 *

 * @see WP_oEmbed

 *

 */

function wp_oembed_add_provider( $format, $provider, $regex = false ) {

	if ( did_action( 'plugins_loaded' ) ) {

		$oembed                       = _wp_oembed_get_object();

		$oembed->providers[ $format ] = array( $provider, $regex );

	} else {

		WP_oEmbed::_add_provider_early( $format, $provider, $regex );

	}

}

/**

 * Removes an oEmbed provider.

 *

 * @since 3.5.0

 *

 * @see WP_oEmbed

 *

 * @param string $format The URL format for the oEmbed provider to remove.

 * @return bool Was the provider removed successfully?

 */

function wp_oembed_remove_provider( $format ) {

	if ( did_action( 'plugins_loaded' ) ) {

		$oembed = _wp_oembed_get_object();

		if ( isset( $oembed->providers[ $format ] ) ) {

			unset( $oembed->providers[ $format ] );

			return true;

		}

	} else {

		WP_oEmbed::_remove_provider_early( $format );

	}

	return false;

}

/**

 * Determines if default embed handlers should be loaded.

 *

 * Checks to make sure that the embeds library hasn't already been loaded. If

 * it hasn't, then it will load the embeds library.

 *

 * @since 2.9.0

 *

 * @see wp_embed_register_handler()

 */

function wp_maybe_load_embeds() {

	/**

	 * Filters whether to load the default embed handlers.

	 *

	 * Returning a falsey value will prevent loading the default embed handlers.

	 *

	 * @since 2.9.0

	 *

	 * @param bool $maybe_load_embeds Whether to load the embeds library. Default true.

	 */

	if ( ! apply_filters( 'load_default_embeds', true ) ) {

		return;

	}

	wp_embed_register_handler( 'youtube_embed_url', '#https?://(www.)?youtube\.com/(?:v|embed)/([^/]+)#i', 'wp_embed_handler_youtube' );

	/**

	 * Filters the audio embed handler callback.

	 *

	 * @since 3.6.0

	 *

	 * @param callable $handler Audio embed handler callback function.

	 */

	wp_embed_register_handler( 'audio', '#^https?://.+?\.(' . join( '|', wp_get_audio_extensions() ) . ')$#i', apply_filters( 'wp_audio_embed_handler', 'wp_embed_handler_audio' ), 9999 );

	/**

	 * Filters the video embed handler callback.

	 *

	 * @since 3.6.0

	 *

	 * @param callable $handler Video embed handler callback function.

	 */

	wp_embed_register_handler( 'video', '#^https?://.+?\.(' . join( '|', wp_get_video_extensions() ) . ')$#i', apply_filters( 'wp_video_embed_handler', 'wp_embed_handler_video' ), 9999 );

}

/**

 * YouTube iframe embed handler callback.

 *

 * Catches YouTube iframe embed URLs that are not parsable by oEmbed but can be translated into a URL that is.

 *

 * @since 4.0.0

 *

 * @global WP_Embed $wp_embed

 *

 * @param array  $matches The RegEx matches from the provided regex when calling

 *                        wp_embed_register_handler().

 * @param array  $attr    Embed attributes.

 * @param string $url     The original URL that was matched by the regex.

 * @param array  $rawattr The original unmodified attributes.

 * @return string The embed HTML.

 */

function wp_embed_handler_youtube( $matches, $attr, $url, $rawattr ) {

	global $wp_embed;

	$embed = $wp_embed->autoembed( sprintf( 'https://youtube.com/watch?v=%s', urlencode( $matches[2] ) ) );

	/**

	 * Filters the YoutTube embed output.

	 *

	 * @since 4.0.0

	 *

	 * @see wp_embed_handler_youtube()

	 *

	 * @param string $embed   YouTube embed output.

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

	 * @param string $url     The original URL that was matched by the regex.

	 * @param array  $rawattr The original unmodified attributes.

	 */

	return apply_filters( 'wp_embed_handler_youtube', $embed, $attr, $url, $rawattr );

}

/**

 * Audio embed handler callback.

 *

 * @since 3.6.0

 *

 * @param array  $matches The RegEx matches from the provided regex when calling wp_embed_register_handler().

 * @param array  $attr Embed attributes.

 * @param string $url The original URL that was matched by the regex.

 * @param array  $rawattr The original unmodified attributes.

 * @return string The embed HTML.

 */

function wp_embed_handler_audio( $matches, $attr, $url, $rawattr ) {

	$audio = sprintf( '[audio src="%s" /]', esc_url( $url ) );

	/**

	 * Filters the audio embed output.

	 *

	 * @since 3.6.0

	 *

	 * @param string $audio   Audio embed output.

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

	 * @param string $url     The original URL that was matched by the regex.

	 * @param array  $rawattr The original unmodified attributes.

	 */

	return apply_filters( 'wp_embed_handler_audio', $audio, $attr, $url, $rawattr );

}

/**

 * Video embed handler callback.

 *

 * @since 3.6.0

 *

 * @param array  $matches The RegEx matches from the provided regex when calling wp_embed_register_handler().

 * @param array  $attr    Embed attributes.

 * @param string $url     The original URL that was matched by the regex.

 * @param array  $rawattr The original unmodified attributes.

 * @return string The embed HTML.

 */

function wp_embed_handler_video( $matches, $attr, $url, $rawattr ) {

	$dimensions = '';

	if ( ! empty( $rawattr['width'] ) && ! empty( $rawattr['height'] ) ) {

		$dimensions .= sprintf( 'width="%d" ', (int) $rawattr['width'] );

		$dimensions .= sprintf( 'height="%d" ', (int) $rawattr['height'] );

	}

	$video = sprintf( '[video %s src="%s" /]', $dimensions, esc_url( $url ) );

	/**

	 * Filters the video embed output.

	 *

	 * @since 3.6.0

	 *

	 * @param string $video   Video embed output.

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

	 * @param string $url     The original URL that was matched by the regex.

	 * @param array  $rawattr The original unmodified attributes.

	 */

	return apply_filters( 'wp_embed_handler_video', $video, $attr, $url, $rawattr );

}

/**

 * Registers the oEmbed REST API route.

 *

 * @since 4.4.0

 */

function wp_oembed_register_route() {

	$controller = new WP_oEmbed_Controller();

	$controller->register_routes();

}

/**

 * Adds oEmbed discovery links in the website <head>.

 *

 * @since 4.4.0

 */

function wp_oembed_add_discovery_links() {

	$output = '';

	if ( is_singular() ) {

		$output .= '<link rel="alternate" type="application/json+oembed" href="' . esc_url( get_oembed_endpoint_url( get_permalink() ) ) . '" />' . "\n";

		if ( class_exists( 'SimpleXMLElement' ) ) {

			$output .= '<link rel="alternate" type="text/xml+oembed" href="' . esc_url( get_oembed_endpoint_url( get_permalink(), 'xml' ) ) . '" />' . "\n";

		}

	}

	/**

	 * Filters the oEmbed discovery links HTML.

	 *

	 * @since 4.4.0

	 *

	 * @param string $output HTML of the discovery links.

	 */

	echo apply_filters( 'oembed_discovery_links', $output );

}

/**

 * Adds the necessary JavaScript to communicate with the embedded iframes.

 *

 * @since 4.4.0

 */

function wp_oembed_add_host_js() {

	wp_enqueue_script( 'wp-embed' );

}

/**

 * Retrieves the URL to embed a specific post in an iframe.

 *

 * @since 4.4.0

 *

 * @param int|WP_Post $post Optional. Post ID or object. Defaults to the current post.

 * @return string|false The post embed URL on success, false if the post doesn't exist.

 */

function get_post_embed_url( $post = null ) {

	$post = get_post( $post );

	if ( ! $post ) {

		return false;

	}

	$embed_url     = trailingslashit( get_permalink( $post ) ) . user_trailingslashit( 'embed' );

	$path_conflict = get_page_by_path( str_replace( home_url(), '', $embed_url ), OBJECT, get_post_types( array( 'public' => true ) ) );

	if ( ! get_option( 'permalink_structure' ) || $path_conflict ) {

		$embed_url = add_query_arg( array( 'embed' => 'true' ), get_permalink( $post ) );

	}

	/**

	 * Filters the URL to embed a specific post.

	 *

	 * @since 4.4.0

	 *

	 * @param string  $embed_url The post embed URL.

	 * @param WP_Post $post      The corresponding post object.

	 */

	return esc_url_raw( apply_filters( 'post_embed_url', $embed_url, $post ) );

}

/**

 * Retrieves the oEmbed endpoint URL for a given permalink.

 *

 * Pass an empty string as the first argument to get the endpoint base URL.

 *

 * @since 4.4.0

 *

 * @param string $permalink Optional. The permalink used for the `url` query arg. Default empty.

 * @param string $format    Optional. The requested response format. Default 'json'.

 * @return string The oEmbed endpoint URL.

 */

function get_oembed_endpoint_url( $permalink = '', $format = 'json' ) {

	$url = rest_url( 'oembed/1.0/embed' );

	if ( '' !== $permalink ) {

		$url = add_query_arg(

			array(

				'url'    => urlencode( $permalink ),

				'format' => ( 'json' !== $format ) ? $format : false,

			),

			$url

		);

	}

	/**

	 * Filters the oEmbed endpoint URL.

	 *

	 * @since 4.4.0

	 *

	 * @param string $url       The URL to the oEmbed endpoint.

	 * @param string $permalink The permalink used for the `url` query arg.

	 * @param string $format    The requested response format.

	 */

	return apply_filters( 'oembed_endpoint_url', $url, $permalink, $format );

}

/**

 * Retrieves the embed code for a specific post.

 *

 * @since 4.4.0

 *

 * @param int         $width  The width for the response.

 * @param int         $height The height for the response.

 * @param int|WP_Post $post   Optional. Post ID or object. Default is global `$post`.

 * @return string|false Embed code on success, false if post doesn't exist.

 */

function get_post_embed_html( $width, $height, $post = null ) {

	$post = get_post( $post );

	if ( ! $post ) {

		return false;

	}

	$embed_url = get_post_embed_url( $post );

	$output = '<blockquote class="wp-embedded-content"><a href="' . esc_url( get_permalink( $post ) ) . '">' . get_the_title( $post ) . "</a></blockquote>\n";

	$output .= "<script type='text/javascript'>\n";

	$output .= "<!--//--><![CDATA[//><!--\n";