<?php

/**

 * API for fetching the HTML to embed remote content based on a provided URL.

 * Used internally by the {@link WP_Embed} class, but is designed to be generic.

 *

 * @link http://codex.wordpress.org/oEmbed oEmbed Codex Article

 * @link http://oembed.com/ oEmbed Homepage

 *

 * @package WordPress

 * @subpackage oEmbed

 */

/**

 * oEmbed class.

 *

 * @package WordPress

 * @subpackage oEmbed

 * @since 2.9.0

 */

class WP_oEmbed {

	var $providers = array();

	/**

	 * PHP4 constructor

	 */

	function WP_oEmbed() {

		return $this->__construct();

	}

	/**

	 * PHP5 constructor

	 *

	 * @uses apply_filters() Filters a list of pre-defined oEmbed providers.

	 */

	function __construct() {

		// List out some popular sites that support oEmbed.

		// The WP_Embed class disables discovery for non-unfiltered_html users, so only providers in this array will be used for them.

		// Add to this list using the wp_oembed_add_provider() function (see it's PHPDoc for details).

		$this->providers = apply_filters( 'oembed_providers', array(

			'#http://(www\.)?youtube.com/watch.*#i' => array( 'http://www.youtube.com/oembed',            true  ),

			'http://blip.tv/file/*'                 => array( 'http://blip.tv/oembed/',                   false ),

			'#http://(www\.)?vimeo\.com/.*#i'       => array( 'http://www.vimeo.com/api/oembed.{format}', true  ),

			'#http://(www\.)?dailymotion\.com/.*#i' => array( 'http://www.dailymotion.com/api/oembed',    true  ),

			'#http://(www\.)?flickr\.com/.*#i'      => array( 'http://www.flickr.com/services/oembed/',   true  ),

			'#http://(www\.)?hulu\.com/watch/.*#i'  => array( 'http://www.hulu.com/api/oembed.{format}',  true  ),

			'#http://(www\.)?viddler\.com/.*#i'     => array( 'http://lab.viddler.com/services/oembed/',  true  ),

			'http://qik.com/*'                      => array( 'http://qik.com/api/oembed.{format}',       false ),

			'http://revision3.com/*'                => array( 'http://revision3.com/api/oembed/',         false ),

			'http://i*.photobucket.com/albums/*'    => array( 'http://photobucket.com/oembed',            false ),

			'http://gi*.photobucket.com/groups/*'   => array( 'http://photobucket.com/oembed',            false ),

			'#http://(www\.)?scribd\.com/.*#i'      => array( 'http://www.scribd.com/services/oembed',    true  ),

			'http://wordpress.tv/*'                 => array( 'http://wordpress.tv/oembed/',              false ),

		) );

		// Fix Scribd embeds. They contain new lines in the middle of the HTML which breaks wpautop().

		add_filter( 'oembed_dataparse', array(&$this, 'strip_scribd_newlines'), 10, 3 );

	}

	/**

	 * The do-it-all function that takes a URL and attempts to return the HTML.

	 *

	 * @see WP_oEmbed::discover()

	 * @see WP_oEmbed::fetch()

	 * @see WP_oEmbed::data2html()

	 *

	 * @param string $url The URL to the content that should be attempted to be embedded.

	 * @param array $args Optional arguments. Usually passed from a shortcode.

	 * @return bool|string False on failure, otherwise the UNSANITIZED (and potentially unsafe) HTML that should be used to embed.

	 */

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

		$provider = false;

		if ( !isset($args['discover']) )

			$args['discover'] = true;

		foreach ( $this->providers as $matchmask => $data ) {

			list( $providerurl, $regex ) = $data;

			// Turn the asterisk-type provider URLs into regex

			if ( !$regex )

				$matchmask = '#' . str_replace( '___wildcard___', '(.+)', preg_quote( str_replace( '*', '___wildcard___', $matchmask ), '#' ) ) . '#i';

			if ( preg_match( $matchmask, $url ) ) {

				$provider = str_replace( '{format}', 'json', $providerurl ); // JSON is easier to deal with than XML

				break;

			}

		}

		if ( !$provider && $args['discover'] )

			$provider = $this->discover( $url );

		if ( !$provider || false === $data = $this->fetch( $provider, $url, $args ) )

			return false;

		return apply_filters( 'oembed_result', $this->data2html( $data, $url ), $url, $args );

	}

	/**

	 * Attempts to find oEmbed provider discovery <link> tags at the given URL.

	 *

	 * @param string $url The URL that should be inspected for discovery <link> tags.

	 * @return bool|string False on failure, otherwise the oEmbed provider URL.

	 */

	function discover( $url ) {

		$providers = array();

		// Fetch URL content

		if ( $html = wp_remote_retrieve_body( wp_remote_get( $url ) ) ) {

			// <link> types that contain oEmbed provider URLs

			$linktypes = apply_filters( 'oembed_linktypes', array(

				'application/json+oembed' => 'json',

				'text/xml+oembed' => 'xml',

				'application/xml+oembed' => 'xml', // Incorrect, but used by at least Vimeo

			) );

			// Strip <body>

			$html = substr( $html, 0, stripos( $html, '</head>' ) );

			// Do a quick check

			$tagfound = false;

			foreach ( $linktypes as $linktype => $format ) {

				if ( stripos($html, $linktype) ) {

					$tagfound = true;

					break;

				}

			}

			if ( $tagfound && preg_match_all( '/<link([^<>]+)>/i', $html, $links ) ) {

				foreach ( $links[1] as $link ) {

					$atts = shortcode_parse_atts( $link );

					if ( !empty($atts['type']) && !empty($linktypes[$atts['type']]) && !empty($atts['href']) ) {

						$providers[$linktypes[$atts['type']]] = $atts['href'];

						// Stop here if it's JSON (that's all we need)

						if ( 'json' == $linktypes[$atts['type']] )

							break;

					}

				}

			}

		}

		// JSON is preferred to XML

		if ( !empty($providers['json']) )

			return $providers['json'];

		elseif ( !empty($providers['xml']) )

			return $providers['xml'];

		else

			return false;

	}

	/**

	 * Connects to a oEmbed provider and returns the result.

	 *

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

	 * @param string $url The URL to the content that is desired to be embedded.

	 * @param array $args Optional arguments. Usually passed from a shortcode.

	 * @return bool|object False on failure, otherwise the result in the form of an object.

	 */

	function fetch( $provider, $url, $args = '' ) {

		$args = wp_parse_args( $args, wp_embed_defaults() );

		$provider = add_query_arg( 'format', 'json', $provider ); // JSON is easier to deal with than XML

		$provider = add_query_arg( 'maxwidth', $args['width'], $provider );

		$provider = add_query_arg( 'maxheight', $args['height'], $provider );

		$provider = add_query_arg( 'url', urlencode($url), $provider );

		if ( !$result = wp_remote_retrieve_body( wp_remote_get( $provider ) ) )

			return false;

		$result = trim( $result );

		// JSON?

		// Example content: http://vimeo.com/api/oembed.json?url=http%3A%2F%2Fvimeo.com%2F240975

		if ( $data = json_decode($result) ) {

			return $data;

		}

		// Must be XML. Only parse it if PHP5 is installed. (PHP4 isn't worth the trouble.)

		// Example content: http://vimeo.com/api/oembed.xml?url=http%3A%2F%2Fvimeo.com%2F240975

		elseif ( function_exists('simplexml_load_string') ) {

			$errors = libxml_use_internal_errors( 'true' );

			$data = simplexml_load_string( $result );

			libxml_use_internal_errors( $errors );

			if ( is_object($data) )

				return $data;

		}

		return false;

	}

	/**

	 * Converts a data object from {@link WP_oEmbed::fetch()} and returns the HTML.

	 *

	 * @param object $data A data object result from an oEmbed provider.

	 * @param string $url The URL to the content that is desired to be embedded.

	 * @return bool|string False on error, otherwise the HTML needed to embed.

	 */

	function data2html( $data, $url ) {

		if ( !is_object($data) || empty($data->type) )

			return false;

		switch ( $data->type ) {

			case 'photo':

				if ( empty($data->url) || empty($data->width) || empty($data->height) )

					return false;

				$title = ( !empty($data->title) ) ? $data->title : '';

				$return = '<img src="' . esc_attr( clean_url( $data->url ) ) . '" alt="' . esc_attr($title) . '" width="' . esc_attr($data->width) . '" height="' . esc_attr($data->height) . '" />';

				break;

			case 'video':

			case 'rich':

				$return = ( !empty($data->html) ) ? $data->html : false;

				break;

			case 'link':

				$return = ( !empty($data->title) ) ? '<a href="' . clean_url($url) . '">' . esc_html($data->title) . '</a>' : false;

				break;

			default;

				$return = false;

		}

		// You can use this filter to add support for custom data types or to filter the result

		return apply_filters( 'oembed_dataparse', $return, $data, $url );

	}

	/**

	 * Strip new lines from the HTML if it's a Scribd embed.

	 *

	 * @param string $html Existing HTML.

	 * @param object $data Data object from WP_oEmbed::data2html()

	 * @param string $url The original URL passed to oEmbed.

	 * @return string Possibly modified $html

	 */

	function strip_scribd_newlines( $html, $data, $url ) {

		if ( preg_match( '#http://(www\.)?scribd.com/.*#i', $url ) )

			$html = str_replace( array( "\r\n", "\n" ), '', $html );

		return $html;

	}

}

/**

 * Returns the initialized {@link WP_oEmbed} object

 *

 * @since 2.9.0

 * @access private

 *

 * @see WP_oEmbed

 * @uses WP_oEmbed

 *

 * @return WP_oEmbed object.

 */

function &_wp_oembed_get_object() {

	static $wp_oembed;

	if ( is_null($wp_oembed) )

		$wp_oembed = new WP_oEmbed();

	return $wp_oembed;

}

?>