llery data and srcs parsed from the expanded shortcode.
 */
function get_post_gallery( $post = 0, $html = true ) {
	$galleries = get_post_galleries( $post, $html );
	$gallery = reset( $galleries );

	/**
	 * Filters the first-found post gallery.
	 *
	 * @since 3.6.0
	 *
	 * @param array       $gallery   The first-found post gallery.
	 * @param int|WP_Post $post      Post ID or object.
	 * @param array       $galleries Associative array of all found post galleries.
	 */
	return apply_filters( 'get_post_gallery', $gallery, $post, $galleries );
}

/**
 * Retrieve the image srcs from galleries from a post's content, if present
 *
 * @since 3.6.0
 *
 * @see get_post_galleries()
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global `$post`.
 * @return array A list of lists, each containing image srcs parsed.
 *               from an expanded shortcode
 */
function get_post_galleries_images( $post = 0 ) {
	$galleries = get_post_galleries( $post, false );
	return wp_list_pluck( $galleries, 'src' );
}

/**
 * Checks a post's content for galleries and return the image srcs for the first found gallery
 *
 * @since 3.6.0
 *
 * @see get_post_gallery()
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global `$post`.
 * @return array A list of a gallery's image srcs in order.
 */
function get_post_gallery_images( $post = 0 ) {
	$gallery = get_post_gallery( $post, false );
	return empty( $gallery['src'] ) ? array() : $gallery['src'];
}

/**
 * Maybe attempts to generate attachment metadata, if missing.
 *
 * @since 3.9.0
 *
 * @param WP_Post $attachment Attachment object.
 */
function wp_maybe_generate_attachment_metadata( $attachment ) {
	if ( empty( $attachment ) || ( empty( $attachment->ID ) || ! $attachment_id = (int) $attachment->ID ) ) {
		return;
	}

	$file = get_attached_file( $attachment_id );
	$meta = wp_get_attachment_metadata( $attachment_id );
	if ( empty( $meta ) && file_exists( $file ) ) {
		$_meta = get_post_meta( $attachment_id );
		$regeneration_lock = 'wp_generating_att_' . $attachment_id;
		if ( ! array_key_exists( '_wp_attachment_metadata', $_meta ) && ! get_transient( $regeneration_lock ) ) {
			set_transient( $regeneration_lock, $file );
			wp_update_attachment_metadata( $attachment_id, wp_generate_attachment_metadata( $attachment_id, $file ) );
			delete_transient( $regeneration_lock );
		}
	}
}

/**
 * Tries to convert an attachment URL into a post ID.
 *
 * @since 4.0.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $url The URL to resolve.
 * @return int The found post ID, or 0 on failure.
 */
function attachment_url_to_postid( $url ) {
	global $wpdb;

	$dir = wp_get_upload_dir();
	$path = $url;

	$site_url = parse_url( $dir['url'] );
	$image_path = parse_url( $path );

	//force the protocols to match if needed
	if ( isset( $image_path['scheme'] ) && ( $image_path['scheme'] !== $site_url['scheme'] ) ) {
		$path = str_replace( $image_path['scheme'], $site_url['scheme'], $path );
	}

	if ( 0 === strpos( $path, $dir['baseurl'] . '/' ) ) {
		$path = substr( $path, strlen( $dir['baseurl'] . '/' ) );
	}

	$sql = $wpdb->prepare(
		"SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attached_file' AND meta_value = %s",
		$path
	);
	$post_id = $wpdb->get_var( $sql );

	/**
	 * Filters an attachment id found by URL.
	 *
	 * @since 4.2.0
	 *
	 * @param int|null $post_id The post_id (if any) found by the function.
	 * @param string   $url     The URL being looked up.
	 */
	return (int) apply_filters( 'attachment_url_to_postid', $post_id, $url );
}

/**
 * Returns the URLs for CSS files used in an iframe-sandbox'd TinyMCE media view.
 *
 * @since 4.0.0
 *
 * @return array The relevant CSS file URLs.
 */
function wpview_media_sandbox_styles() {
 	$version = 'ver=' . get_bloginfo( 'version' );
 	$mediaelement = includes_url( "js/mediaelement/mediaelementplayer-legacy.min.css?$version" );
 	$wpmediaelement = includes_url( "js/mediaelement/wp-mediaelement.css?$version" );

	return array( $mediaelement, $wpmediaelement );
}

/**
 * Registers the personal data exporter for media
 *
 * @param array   $exporters   An array of personal data exporters.
 * @return array  An array of personal data exporters.
 */
function wp_register_media_personal_data_exporter( $exporters ) {
	$exporters['wordpress-media'] = array(
		'exporter_friendly_name' => __( 'WordPress Media' ),
		'callback'               => 'wp_media_personal_data_exporter',
	);

	return $exporters;
}

/**
 * Finds and exports attachments associated with an email address.
 *
 * @since 4.9.6
 *
 * @param  string $email_address The attachment owner email address.
 * @param  int    $page          Attachment page.
 * @return array  $return        An array of personal data.
 */
function wp_media_personal_data_exporter( $email_address, $page = 1 ) {
	// Limit us to 50 attachments at a time to avoid timing out.
	$number = 50;
	$page   = (int) $page;

	$data_to_export = array();

	$user = get_user_by( 'email' , $email_address );
	if ( false === $user ) {
		return array(
			'data' => $data_to_export,
			'done' => true,
		);
	}

	$post_query = new WP_Query(
		array(
			'author'         => $user->ID,
			'posts_per_page' => $number,
			'paged'          => $page,
			'post_type'      => 'attachment',
			'post_status'    => 'any',
			'orderby'        => 'ID',
			'order'          => 'ASC',
		)
	);

	foreach ( (array) $post_query->posts as $post ) {
		$attachment_url = wp_get_attachment_url( $post->ID );

		if ( $attachment_url ) {
			$post_data_to_export = array(
				array( 'name'  => __( 'URL' ), 'value' => $attachment_url ),
			);

			$data_to_export[] = array(
				'group_id'    => 'media',
				'group_label' => __( 'Media' ),
				'item_id'     => "post-{$post->ID}",
				'data'        => $post_data_to_export,
			);
		}
	}

	$done = $post_query->max_num_pages <= $page;

	return array(
		'data' => $data_to_export,
		'done' => $done,
	);
}