<?php
/**
 * Hybrid Media Grabber - A script for grabbing media related to a post.
 *
 * Hybrid Media Grabber is a script for pulling media either from the post content or attached to the
 * post.  It's an attempt to consolidate the various methods that users have used over the years to
 * embed media into their posts.  This script was written so that theme developers could grab that
 * media and use it in interesting ways within their themes.  For example, a theme could get a video
 * and display it on archive pages alongside the post excerpt or pull it out of the content to display
 * it above the post on single post views.
 *
 * @package    Hybrid
 * @subpackage Includes
 * @author     Justin Tadlock <justin@justintadlock.com>
 * @copyright  Copyright (c) 2008 - 2015, Justin Tadlock
 * @link       http://themehybrid.com/hybrid-core
 * @license    http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

if ( ! function_exists( 'hybrid_media_grabber' ) ) {
	/**
	 * Wrapper function for the Hybrid_Media_Grabber class.  Returns the HTML output for the found media.
	 *
	 * @param array
	 *
	 * @return string
	 * @since  1.6.0
	 * @access public
	 */
	function hybrid_media_grabber( $args = array() ) {

		$media = new Hybrid_Media_Grabber( $args );

		return $media->get_media();
	}
}

if ( ! class_exists( 'Hybrid_Media_Grabber' ) ) {
	/**
	 * Grabs media related to the post.
	 *
	 * @return void
	 * @since  1.6.0
	 * @access public
	 */
	class Hybrid_Media_Grabber {

		/**
		 * The HTML version of the media to return.
		 *
		 * @since  1.6.0
		 * @access public
		 * @var    string
		 */
		public $media = '';

		/**
		 * The original media taken from the post content.
		 *
		 * @since  1.6.0
		 * @access public
		 * @var    string
		 */
		public $original_media = '';

		/**
		 * The type of media to get.  Current supported types are 'audio' and 'video'.
		 *
		 * @since  1.6.0
		 * @access public
		 * @var    string
		 */
		public $type = 'video';

		/**
		 * Arguments passed into the class and parsed with the defaults.
		 *
		 * @since  1.6.0
		 * @access public
		 * @var    array
		 */
		public $args = array();

		/**
		 * The content to search for embedded media within.
		 *
		 * @since  1.6.0
		 * @access public
		 * @var    string
		 */
		public $content = '';

		/**
		 * Constructor method.  Sets up the media grabber.
		 *
		 * @return void
		 * @global object $wp_embed
		 * @global int    $content_width
		 * @since  1.6.0
		 * @access public
		 */
		public function __construct( $args = array() ) {
			global $wp_embed, $content_width;

			// Use WP's embed functionality to handle the [embed] shortcode and autoembeds.
			add_filter( 'hybrid_media_grabber_embed_shortcode_media', array( $wp_embed, 'run_shortcode' ) );
			add_filter( 'hybrid_media_grabber_autoembed_media', array( $wp_embed, 'autoembed' ) );

			// Don't return a link if embeds don't work. Need media or nothing at all.
			add_filter( 'embed_maybe_make_link', '__return_false' );

			// Set up the default arguments.
			$defaults = array(
				'post_id'     => get_the_ID(),   // post ID (assumes within The Loop by default)
				'type'        => 'video',        // audio|video
				'before'      => '',             // HTML before the output
				'after'       => '',             // HTML after the output
				'split_media' => false,          // Splits the media from the post content
				'width'       => $content_width, // Custom width. Defaults to the theme's content width.
			);

			// Set the object properties.
			$this->args    = apply_filters( 'hybrid_media_grabber_args', wp_parse_args( $args, $defaults ) );
			$this->content = get_post_field( 'post_content', $this->args['post_id'], 'raw' );
			$this->type    = isset( $this->args['type'] ) && in_array( $this->args['type'], array(
				'audio',
				'video'
			) ) ? $this->args['type'] : 'video';

			// Find the media related to the post.
			$this->set_media();
		}

		/**
		 * Destructor method.  Removes filters we needed to add.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function __destruct() {
			remove_filter( 'embed_maybe_make_link', '__return_false' );
			remove_filter( 'the_content', array( $this, 'split_media' ), 5 );
		}


		/**
		 * Basic method for returning the media found.
		 *
		 * @return string
		 * @since  1.6.0
		 * @access public
		 */
		public function get_media() {
			return apply_filters( 'hybrid_media_grabber_media', $this->media, $this );
		}

		/**
		 * Tries several methods to find media related to the post.  Returns the found media.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function set_media() {

			// Get the media if the post type is an attachment.
			if ( 'attachment' === get_post_type( $this->args['post_id'] ) ) {
				$this->do_attachment_media();
			}

			// Find media in the post content based on WordPress' media-related shortcodes.
			if ( empty( $this->media ) ) {
				$this->do_shortcode_media();
			}

			// If no media is found and autoembeds are enabled, check for autoembeds.
			if ( empty( $this->media ) && get_option( 'embed_autourls' ) ) {
				$this->do_autoembed_media();
			}

			// If no media is found, check for media HTML within the post content.
			if ( empty( $this->media ) ) {
				$this->do_embedded_media();
			}

			// If no media is found, check for media attached to the post.
			if ( empty( $this->media ) ) {
				$this->do_attached_media();
			}

			// If media is found, let's run a few things.
			if ( ! empty( $this->media ) ) {

				// Add the before HTML.
				if ( isset( $this->args['before'] ) ) {
					$this->media = $this->args['before'] . $this->media;
				}

				// Add the after HTML.
				if ( isset( $this->args['after'] ) ) {
					$this->media .= $this->args['after'];
				}

				// Split the media from the content.
				if ( true === $this->args['split_media'] && ! empty( $this->original_media ) ) {
					add_filter( 'the_content', array( $this, 'split_media' ), 5 );
				}

				// Filter the media dimensions.
				$this->media = $this->filter_dimensions( $this->media );
			}
		}

		/**
		 * WordPress has a few shortcodes for handling embedding media:  [audio], [video], and [embed].  This
		 * method figures out the shortcode used in the content.  Once it's found, the appropriate method for
		 * the shortcode is executed.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_shortcode_media() {

			// Finds matches for shortcodes in the content.
			preg_match_all( '/' . get_shortcode_regex() . '/s', $this->content, $matches, PREG_SET_ORDER );

			// If matches are found, loop through them and check if they match one of WP's media shortcodes.
			if ( ! empty( $matches ) ) {

				foreach ( $matches as $shortcode ) {

					// Call the method related to the specific shortcode found and break out of the loop.
					if ( in_array( $shortcode[2], array( 'playlist', 'embed', $this->type ) ) ) {
						call_user_func( array( $this, "do_{$shortcode[2]}_shortcode_media" ), $shortcode );
						break;
					} // Check for Jetpack audio/video shortcodes.
					elseif ( in_array( $shortcode[2], array(
						'blip.tv',
						'dailymotion',
						'flickr',
						'ted',
						'vimeo',
						'vine',
						'youtube',
						'wpvideo',
						'soundcloud',
						'bandcamp'
					) ) ) {
						$this->do_jetpack_shortcode_media( $shortcode );
						break;
					}
				}
			}
		}

		/**
		 * Handles the output of the WordPress playlist feature.  This searches for the [playlist] shortcode
		 * if it's used in the content.
		 *
		 * @return void
		 * @since  2.0.0
		 * @access public
		 */
		public function do_playlist_shortcode_media( $shortcode ) {

			$this->original_media = array_shift( $shortcode );

			$this->media = do_shortcode( $this->original_media );
		}

		/**
		 * Handles the HTML when the [embed] shortcode is used.
		 *
		 * @param array $shortcode
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_embed_shortcode_media( $shortcode ) {

			$this->original_media = array_shift( $shortcode );

			$this->media = apply_filters(
				'hybrid_media_grabber_embed_shortcode_media',
				$this->original_media
			);
		}

		/**
		 * Handles the HTML when the [audio] shortcode is used.
		 *
		 * @param array $shortcode
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_audio_shortcode_media( $shortcode ) {

			$this->original_media = array_shift( $shortcode );

			$this->media = do_shortcode( $this->original_media );
		}

		/**
		 * Handles the HTML when the [video] shortcode is used.
		 *
		 * @param array $shortcode
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_video_shortcode_media( $shortcode ) {

			$this->original_media = array_shift( $shortcode );

			// Need to filter dimensions here to overwrite WP's <div> surrounding the [video] shortcode.
			$this->media = do_shortcode( $this->filter_dimensions( $this->original_media ) );
		}

		/**
		 * Handles the output of audio/video shortcodes included with the Jetpack plugin (or Jetpack
		 * Slim) via the Shortcode Embeds feature.
		 *
		 * @return void
		 * @since  2.0.0
		 * @access public
		 */
		public function do_jetpack_shortcode_media( $shortcode ) {

			$this->original_media = array_shift( $shortcode );

			$this->media = do_shortcode( $this->original_media );
		}

		/**
		 * Uses WordPress' autoembed feature to automatically to handle media that's just input as a URL.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_autoembed_media() {

			preg_match_all( '|^\s*(https?://[^\s"]+)\s*$|im', $this->content, $matches, PREG_SET_ORDER );

			// If URL matches are found, loop through them to see if we can get an embed.
			if ( is_array( $matches ) ) {

				foreach ( $matches as $value ) {

					// Let WP work its magic with the 'autoembed' method.
					$embed = trim( apply_filters( 'hybrid_media_grabber_autoembed_media', $value[0] ) );

					if ( ! empty( $embed ) ) {
						$this->original_media = $value[0];
						$this->media          = $embed;
						break;
					}
				}
			}
		}

		/**
		 * Grabs media embbeded into the content within <iframe>, <object>, <embed>, and other HTML methods for
		 * embedding media.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_embedded_media() {

			$embedded_media = get_media_embedded_in_content( $this->content );

			if ( ! empty( $embedded_media ) ) {
				$this->media = $this->original_media = array_shift( $embedded_media );
			}
		}

		/**
		 * Gets media attached to the post.  Then, uses the WordPress [audio] or [video] shortcode to handle
		 * the HTML output of the media.
		 *
		 * @return void
		 * @since  1.6.0
		 * @access public
		 */
		public function do_attached_media() {

			// Gets media attached to the post by mime type.
			$attached_media = get_attached_media( $this->type, $this->args['post_id'] );

			// If media is found.
			if ( ! empty( $attached_media ) ) {

				// Get the first attachment/post object found for the post.
				$post = array_shift( $attached_media );

				// Gets the URI for the attachment (the media file).
				$url = esc_url( wp_get_attachment_url( $post->ID ) );

				// Run the media as a shortcode using WordPress' built-in [audio] and [video] shortcodes.
				$this->media = do_shortcode( "[{$this->type} src='{$url}']" );
			}
		}

		/**
		 * If the post type itself is an attachment, run the shortcode for the media type.
		 *
		 * @return void
		 * @since  2.0.0
		 * @access public
		 */
		public function do_attachment_media() {

			// Gets the URI for the attachment (the media file).
			$url = esc_url( wp_get_attachment_url( $this->args['post_id'] ) );

			// Run the media as a shortcode using WordPress' built-in [audio] and [video] shortcodes.
			$this->media = do_shortcode( "[{$this->type} src='{$url}']" );
		}

		/**
		 * Removes the found media from the content.  The purpose of this is so that themes can retrieve the
		 * media from the content and display it elsewhere on the page based on its design.
		 *
		 * @param string $content
		 *
		 * @return string
		 * @since  1.6.0
		 * @access public
		 */
		public function split_media( $content ) {

			if ( get_the_ID() === (int) $this->args['post_id'] ) {
				$content = str_replace( $this->original_media, '', $content );
				$content = wp_kses_post( $content );
			}

			return $content;
		}

		/**
		 * Method for filtering the media's 'width' and 'height' attributes so that the theme can handle the
		 * dimensions how it sees fit.
		 *
		 * @param string $html
		 *
		 * @return string
		 * @since  1.6.0
		 * @access public
		 */
		public function filter_dimensions( $html ) {

			$_html = strip_tags( $html, '<object><embed><iframe><video>' );

			// Find the attributes of the media.
			$atts = wp_kses_hair( $_html, array( 'http', 'https' ) );

			// Loop through the media attributes and add them in key/value pairs.
			foreach ( $atts as $att ) {
				$media_atts[ $att['name'] ] = $att['value'];
			}

			// If no dimensions are found, just return the HTML.
			if ( empty( $media_atts ) || ! isset( $media_atts['width'] ) || ! isset( $media_atts['height'] ) ) {
				return $html;
			}

			// Set the max width.
			$max_width = $this->args['width'];

			// Set the max height based on the max width and original width/height ratio.
			$max_height = round( $max_width / ( $media_atts['width'] / $media_atts['height'] ) );

			// Fix for Spotify embeds.
			if ( ! empty( $media_atts['src'] ) && preg_match( '#https?://(embed)\.spotify\.com/.*#i', $media_atts['src'], $matches ) ) {
				list( $max_width, $max_height ) = $this->spotify_dimensions( $media_atts );
			}

			// Calculate new media dimensions.
			$dimensions = wp_expand_dimensions(
				$media_atts['width'],
				$media_atts['height'],
				$max_width,
				$max_height
			);

			// Allow devs to filter the final width and height of the media.
			list( $width, $height ) = apply_filters(
				'hybrid_media_grabber_dimensions',
				$dimensions,                       // width/height array
				$media_atts,                       // media HTML attributes
				$this                              // media grabber object
			);

			// Set up the patterns for the 'width' and 'height' attributes.
			$patterns = array(
				'/(width=[\'"]).+?([\'"])/i',
				'/(height=[\'"]).+?([\'"])/i',
				'/(<div.+?style=[\'"].*?width:.+?).+?(px;.+?[\'"].*?>)/i',
				'/(<div.+?style=[\'"].*?height:.+?).+?(px;.+?[\'"].*?>)/i'
			);

			// Set up the replacements for the 'width' and 'height' attributes.
			$replacements = array(
				'${1}' . $width . '${2}',
				'${1}' . $height . '${2}',
				'${1}' . $width . '${2}',
				'${1}' . $height . '${2}',
			);

			// Filter the dimensions and return the media HTML.
			return preg_replace( $patterns, $replacements, $html );
		}

		/**
		 * Fix for Spotify embeds because they're the only embeddable service that doesn't work that well
		 * with custom-sized embeds.  So, we need to adjust this the best we can.  Right now, the only
		 * embed size that works for full-width embeds is the "compact" player (height of 80).
		 *
		 * @param array $media_atts
		 *
		 * @return array
		 * @since  1.6.0
		 * @access public
		 */
		public function spotify_dimensions( $media_atts ) {

			$max_width  = $media_atts['width'];
			$max_height = $media_atts['height'];

			if ( 80 == $media_atts['height'] ) {
				$max_width = $this->args['width'];
			}

			return array( $max_width, $max_height );
		}
	}
}