<?php
/**
 * Get post formats media
 *
 * @package    Modern
 * @copyright  2015 WebMan - Oliver Juhas
 *
 * @since    1.1
 * @version  1.3
 */



	/**
	 * Post formats media
	 *
	 * WordPress audio, gallery, image and video post format media generator.
	 *
	 * @copyright  2015 WebMan - Oliver Juhas
	 * @license    GPL-2.0+, http://www.gnu.org/licenses/gpl-2.0.html
	 * @version    1.1
	 *
	 * @link  https://github.com/webmandesign/wp-post-formats
	 * @link  http://www.webmandesign.eu
	 *
	 *
	 * GENERATED MEDIA:
	 * Media generated from post content for supported post formats:
	 *
	 *   Audio post format
	 *   - first `[audio]` or `[playlist]` shortcode
	 *   - or first embed media URL
	 *
	 *   Gallery post format
	 *   - coma separeted string of image IDs from first `[gallery]` shortcode
	 *   - or coma separated string of attached images IDs
	 *
	 *   Image post format
	 *   (Only if no featured image set:)
	 *   - ID of the first image in post content (for uploaded images)
	 *   - or URL of the first image in post content
	 *
	 *   Video post format
	 *   - first `[video]`, `[playlist]` or `[wpvideo]` shortcode
	 *   - or first embed media URL
	 *
	 *
	 * CUSTOM META FIELDS
	 * If no media saved in custom meta field, these functions will attempt to
	 * generate the media and save them in a hidden custom meta field.
	 * Also, regeneration occurs on every post saving or update.
	 * You can override the generated media with a custom `post_format_media`
	 * custom meta field setup.
	 * @link  http://codex.wordpress.org/Custom_Fields
	 *
	 *
	 * IMPLEMENTATION:
	 * Copy this file into your WordPress theme's root directory and inlcude
	 * it in your theme's `funstions.php` file like so:
	 *
	 *   get_template_part( 'post-formats' );
	 *
	 * Then, use this code in your `content-audio.php` file (for example):
	 *
	 *   $post_format_media = wm_get_post_format_media();
	 *   if ( 0 === strpos( $post_format_media, '[' ) ) {
	 *     $post_format_media = do_shortcode( $post_format_media );
	 *   } else {
	 *     $post_format_media = wp_oembed_get( $post_format_media );
	 *   }
	 *   echo $post_format_media;
	 *
	 *
	 * OTHER NOTES:
	 * Please note that this file does not register post formats for your theme.
	 * Register post formats in your theme according to WordPress Codex instructions:
	 * @link  http://codex.wordpress.org/Post_Formats#Adding_Theme_Support
	 * @link  http://codex.wordpress.org/Post_Formats
	 *
	 *
	 * CONTENT:
	 * - 10) Actions and filters
	 * - 20) Post formats media functions
	 * - 30) Image IDs caching
	 */





	/**
	 * 10) Actions and filters
	 */

		/**
		 * Actions
		 */

			//Generate post format media meta field on post save
				add_action( 'save_post', 'wm_post_format_media' );
			//Flushing transients
				add_action( 'switch_theme', 'wm_image_ids_transient_flusher' );





	/**
	 * 20) Post formats media functions
	 */

		/**
		 * Get the post format media
		 *
		 * Supported post formats: audio, gallery, image, video.
		 * Must be inside the loop.
		 *
		 * @param  string $format
		 */
		if ( ! function_exists( 'wm_get_post_format_media' ) ) {
			function wm_get_post_format_media( $format = null ) {
				//Helper variables
					if ( empty( $format ) ) {
						$format = get_post_format();
					}

				//Output
					return wm_post_format_media( get_the_ID(), $format );
			}
		} // /wm_get_post_format_media



			/**
			 * Get/set the post format media
			 *
			 * If not set already, get the post media from the post content and save
			 * it in a hidden custom meta field. But, allow user to bypass by setting
			 * a 'post_format_media' custom meta field, too.
			 *
			 * The function is triggered also on every post save to refresh the hidden
			 * post media custom meta field.
			 *
			 * @param  int $post_id
			 */
			if ( ! function_exists( 'wm_post_format_media' ) ) {
				function wm_post_format_media( $post_id = null, $format = null ) {
					//Requirements check
						if ( empty( $post_id ) ) {
							$post_id = get_the_ID();
						}
						if (
								empty( $post_id )
								//Exit early for no-post_format post types
								|| ( is_admin() && isset( $_REQUEST ) && ! isset( $_REQUEST['post_format'] ) )
							) {
							return false;
						}

					//Helper variables
						$post_id   = absint( $post_id );
						$format    = ( empty( $format ) ) ? ( get_post_format( $post_id ) ) : ( $format );
						$meta_name = apply_filters( 'wmhook_wm_post_format_media_meta_name', 'post_format_media' );

						$supported_formats = apply_filters( 'wmhook_wm_post_format_media_formats', array( 'audio', 'gallery', 'image', 'video' ) );

						//Requirements check
							if ( ! in_array( $format, $supported_formats ) ) {
								return;
							}

						//Allow users to set custom field first
							$output = get_post_meta( $post_id, $meta_name, true );
						//If no user custom field set, get the previously generated one (from hidden custom field)
							if ( empty( $output ) ) {
								$output = get_post_meta( $post_id, '_' . $meta_name, true );
							}
						//Premature output filtering
							$output = apply_filters( 'wmhook_wm_post_format_media_output_pre', $output, $post_id, $format );

						//Force refresh (regenerate and resave) the post media meta field
							if (
									//when forced
									apply_filters( 'wmhook_wm_post_format_media_force_refresh', false, $post_id, $format )
									//when no media saved
									|| empty( $output )
									//when saving post (no need for checking nonce as this can be triggered anywhere...)
									|| (
											is_admin()
											&& current_user_can( 'edit_posts', $post_id )
											&& ! wp_is_post_revision( $post_id )
											&& isset( $_REQUEST )
											&& ! empty( $_REQUEST )
											&& isset( $_REQUEST['post_format'] )
											&& ! empty( $_REQUEST['post_format'] )
										)
								) {
								$output = '';
							}

						//Return if we have output
							if ( $output ) {
								return apply_filters( 'wmhook_wm_post_format_media_output', $output, $post_id, $format );
							}

					//Preparing output

						/**
						 * This is being triggered only when forced to refresh
						 */

							switch ( $format ) {
								case 'audio':
								case 'video':

										$output = wm_get_post_media_audio_video( $post_id );

								break;
								case 'gallery':

										$output = wm_get_post_media_gallery( $post_id );

								break;
								case 'image':

										$output = wm_get_post_media_image( $post_id );

								break;

								default:
								break;
							} // /switch

							//Filter the output
								$output = apply_filters( 'wmhook_wm_post_format_media_output', $output, $post_id, $format );

							//Save the post media meta field
								update_post_meta( $post_id, '_' . $meta_name, $output );

							//Custom action hook
								do_action( 'wm_post_format_media', $output, $post_id, $format, $meta_name );

					//Output
						return $output;
				}
			} // /wm_post_format_media



				/**
				 * Get the post format media: audio, video
				 *
				 * Searches for media shortcode or URL in the post content.
				 *
				 * @param  int $post_id
				 *
				 * @return  Audio/video/playlist shortcode or oembed media URL.
				 */
				if ( ! function_exists( 'wm_get_post_media_audio_video' ) ) {
					function wm_get_post_media_audio_video( $post_id ) {
						//Requirements check
							if ( empty( $post_id ) ) {
								return;
							}

						//Helper variables
							$output  = '';
							$post    = get_post( $post_id );
							$content = $post->post_content;
							$pattern = ( 'video' == get_post_format( $post_id ) ) ? ( 'video|playlist|wpvideo' ) : ( 'audio|playlist' );

						//Preparing output

							/**
							 * INFO:
							 * preg_match() sufixes:
							 * @link  http://php.net/manual/en/function.preg-match.php#102214
							 * @link  http://php.net/manual/en/function.preg-match.php#111573
							 */

							//Search for the media
								$pattern = '/\[(' . $pattern . ')(.*)\]/u';

								preg_match( $pattern, strip_tags( $content ), $matches );

								if ( isset( $matches[0] ) ) {

									$output = trim( $matches[0] );

									//If [playlist], use the first media
									/*
										if ( false !== strpos( $output, 'ids="' ) ) {
											preg_match( '/ids="(.+?)"/', $output, $matches );

											$output = explode( ',', str_replace( array( 'ids="', '"', ' ' ), '', $matches[0] ) );
											$output = '[' . get_post_format() . ' src="' . wp_get_attachment_url( absint( $output[0] ) ) . '" /]';
										}
									*/

								} elseif ( false !== strpos( $content, 'http' ) ) {

									//If no prioritized shortcode found, look for oembed media URL
										$pattern = '/(http|https)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/';

										preg_match_all( $pattern, strip_tags( $content ), $matches );

									//Return only the first URL which is actually oembed one
										if ( isset( $matches[0] ) && is_array( $matches[0] ) ) {
											$matches = array_unique( $matches[0] );

											foreach ( $matches as $url ) {
												if ( wp_oembed_get( esc_url( $url ) ) ) {
													$output = $url;
													break;
												}
											}
										}

								}

						//Output
							return apply_filters( 'wmhook_wm_get_post_media_audio_video_output', $output, $post_id );
					}
				} // /wm_get_post_media_audio_video



				/**
				 * Get the post format media: gallery
				 *
				 * Get images from the first [gallery] shortcode found in the post content
				 * or get images attached to the post.
				 *
				 * @param  int $post_id
				 *
				 * @return  Coma separated gallery images IDs string.
				 */
				if ( ! function_exists( 'wm_get_post_media_gallery' ) ) {
					function wm_get_post_media_gallery( $post_id ) {
						//Requirements check
							if ( empty( $post_id ) ) {
								return;
							}

						//Helper variables
							$output  = '';
							$post    = get_post( $post_id );
							$content = $post->post_content;

						//Preparing output

							/**
							 * INFO:
							 * preg_match() sufixes:
							 * @link  http://php.net/manual/en/function.preg-match.php#102214
							 * @link  http://php.net/manual/en/function.preg-match.php#111573
							 */

							//Search for the media
								$pattern = '/\[gallery(.*)\]/u';

								preg_match( $pattern, strip_tags( $content ), $matches );

								//Get [gallery] shortcode parameters only
									if ( isset( $matches[1] ) ) {
										$output = trim( $matches[1] );
									}

							//Get image IDs array: from shortcode attribute or attached images
								if ( false !== strpos( $output, 'ids="' ) ) {

									preg_match( '/ids="(.+?)"/u', $output, $matches );

									$output = str_replace( array( 'ids="', '"', ' ' ), '', $matches[0] );

								} else {

									$output = implode( ',', array_keys( (array) get_children( apply_filters( 'wmhook_wm_get_post_media_gallery_get_children_args', array(
											'post_parent'    => $post_id,
											'post_status'    => 'inherit',
											'post_type'      => 'attachment',
											'post_mime_type' => 'image',
											'order'          => 'ASC',
											'orderby'        => 'menu_order'
										) ) ) ) );

								}

							//Make shure we output array if we have the images
								if ( ! empty( $output ) ) {
									$output = trim( (string) $output );
								}

						//Output
							return apply_filters( 'wmhook_wm_get_post_media_gallery_output', $output, $post_id );
					}
				} // /wm_get_post_media_gallery



				/**
				 * Get the post format media: image
				 *
				 * Searches for the image in the post content only if featured image not set.
				 *
				 * @param  int $post_id
				 *
				 * @return  Image ID (for uploaded image) or image URL.
				 */
				if ( ! function_exists( 'wm_get_post_media_image' ) ) {
					function wm_get_post_media_image( $post_id ) {
						//Requirements check
							if (
									empty( $post_id )
									|| has_post_thumbnail( $post_id )
								) {
								return;
							}

						//Helper variables
							$output  = '';
							$post    = get_post( $post_id );
							$content = $post->post_content;

						//Preparing output

							/**
							 * INFO:
							 * preg_match() sufixes:
							 * @link  http://php.net/manual/en/function.preg-match.php#example-4907
							 */

							//Search for the media
								$pattern = '/<img.+src=[\'"]([^\'"]+)[\'"].*>/i';

								preg_match( $pattern, $content, $matches );

								if ( isset( $matches[1] ) ) {
									$output = trim( $matches[1] );
								}

							//Get the image ID if the image is uploaded, otherwise output the URL
								if ( $image_id = wm_get_image_id_from_url( $output ) ) {
									$output = $image_id;
								}

						//Output
							return apply_filters( 'wmhook_wm_get_post_media_image_output', $output, $post_id );
					}
				} // /wm_get_post_media_image





	/**
	 * 30) Image IDs caching
	 */

		/**
		 * Get image ID from its URL
		 *
		 * @link   http://pippinsplugins.com/retrieve-attachment-id-from-image-url/
		 * @link   http://make.wordpress.org/core/2012/12/12/php-warning-missing-argument-2-for-wpdb-prepare/
		 *
		 * @param  string $url
		 */
		if ( ! function_exists( 'wm_get_image_id_from_url' ) ) {
			function wm_get_image_id_from_url( $url ) {
				//Helper variables
					global $wpdb;

					$output = null;
					$cache  = array_filter( (array) get_transient( 'wm-image-ids' ) );

				//Returne cached result if found and relevant
					if (
							! empty( $cache )
							&& isset( $cache[ $url ] )
							&& wp_get_attachment_url( absint( $cache[ $url ] ) )
							&& $url == wp_get_attachment_url( absint( $cache[ $url ] ) )
						) {
						return absint( apply_filters( 'wmhook_wm_get_image_id_from_url_output', $cache[ $url ] ) );
					}

				//Preparing output
					if (
							is_object( $wpdb )
							&& isset( $wpdb->prefix )
						) {
						$prefix     = $wpdb->prefix;
						$attachment = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM " . $prefix . "posts" . " WHERE guid = %s", esc_url( $url ) ) );
						$output     = ( isset( $attachment[0] ) ) ? ( $attachment[0] ) : ( null );
					}

					//Cache the new record
						$cache[ $url ] = $output;

						set_transient( 'wm-image-ids', array_filter( (array) $cache ) );

				//Output
					return absint( apply_filters( 'wmhook_wm_get_image_id_from_url_output', $output ) );
			}
		} // /wm_get_image_id_from_url



			/**
			 * Flush out the transients used in wm_get_image_id_from_url
			 */
			if ( ! function_exists( 'wm_image_ids_transient_flusher' ) ) {
				function wm_image_ids_transient_flusher() {
					delete_transient( 'wm-image-ids' );
				}
			} // /wm_image_ids_transient_flusher

?>