<?php
/**
 * Course Options meta box
 *
 * @package LifterLMS/Admin/PostTypes/MetaBoxes/Classes
 *
 * @since 1.0.0
 * @version 7.2.0
 */

defined( 'ABSPATH' ) || exit;

/**
 * LLMS_Meta_Box_Course_Options class.
 *
 * Course Options meta box.
 *
 * @since 1.0.0
 * @since 3.35.0 Verify nonces and sanitize `$_POST` data.
 * @since 3.36.0 Allow some fields to store values with quotes.
 */
class LLMS_Meta_Box_Course_Options extends LLMS_Admin_Metabox {

	/**
	 * Configure the metabox settings
	 *
	 * @return void
	 * @since  3.0.0
	 */
	public function configure() {

		$this->id       = 'lifterlms-course-options';
		$this->title    = __( 'Course Options', 'lifterlms' );
		$this->screens  = 'course';
		$this->priority = 'high';
	}

	/**
	 * Setup fields.
	 *
	 * @since 1.0.0
	 * @since 3.36.0 Allow some fields to store values with quotes.
	 * @since 7.1.3 Fixed condition for unsetting fields when using Gutenberg.
	 *              Replaced outdated URLs to WordPress' documentation about the list of sites you can embed from.
	 * @since 7.1.4 Fixed issue that prevented the correct saving of the course length when using the block editor.
	 * @since 7.2.0 Add function exists check for `llms_blocks_is_post_migrated`.
	 *
	 * @return array
	 */
	public function get_fields() {

		global $post;

		$course = new LLMS_Course( $this->post );

		$course_tracks_options = get_terms( 'course_track', 'hide_empty=0' );
		$course_tracks         = array();
		foreach ( (array) $course_tracks_options as $term ) {
			$course_tracks[] = array(
				'key'   => $term->term_id,
				'title' => $term->name,
			);
		}

		// Setup course difficulty select options.
		$difficulty_terms   = get_terms( 'course_difficulty', 'hide_empty=0' );
		$difficulty_options = array();
		foreach ( $difficulty_terms as $term ) {
			$difficulty_options[] = array(
				'key'   => $term->slug,
				'title' => $term->name,
			);
		}

		$sales_page_content_type = 'none';
		if ( $post && 'auto-draft' !== $post->post_status && $post->post_excerpt ) {
			$sales_page_content_type = 'content';
		}

		$instructor_defaults = llms_get_instructors_defaults();

		$fields = array(
			array(
				'title'  => __( 'Sales Page', 'lifterlms' ),
				'fields' => array(
					array(
						'allow_null'    => false,
						'class'         => 'llms-select2',
						'desc'          => __( 'Customize the content displayed to visitors and students who are not enrolled in the course.', 'lifterlms' ),
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
						'default'       => $sales_page_content_type,
						'id'            => $this->prefix . 'sales_page_content_type',
						'is_controller' => true,
						'label'         => __( 'Sales Page Content', 'lifterlms' ),
						'type'          => 'select',
						'value'         => llms_get_sales_page_types(),
					),
					array(
						'controller'       => '#' . $this->prefix . 'sales_page_content_type',
						'controller_value' => 'content',
						'desc'             => __( 'This content will only be shown to visitors who are not enrolled in this course.', 'lifterlms' ),
						'id'               => '',
						'label'            => __( 'Sales Page Custom Content', 'lifterlms' ),
						'type'             => 'post-excerpt',
					),
					array(
						'controller'       => '#' . $this->prefix . 'sales_page_content_type',
						'controller_value' => 'page',
						'data_attributes'  => array(
							'post-type'   => 'page',
							'placeholder' => __( 'Select a page', 'lifterlms' ),
						),
						'class'            => 'llms-select2-post',
						'id'               => $this->prefix . 'sales_page_content_page_id',
						'type'             => 'select',
						'label'            => __( 'Select a Page', 'lifterlms' ),
						'value'            => $course->get( 'sales_page_content_page_id' ) ? llms_make_select2_post_array( array( $course->get( 'sales_page_content_page_id' ) ) ) : array(),
					),
					array(
						'controller'       => '#' . $this->prefix . 'sales_page_content_type',
						'controller_value' => 'url',
						'type'             => 'text',
						'label'            => __( 'Sales Page Redirect URL', 'lifterlms' ),
						'id'               => $this->prefix . 'sales_page_content_url',
						'class'            => 'input-full',
						'value'            => '',
						'desc_class'       => 'd-all',
						'group'            => 'top',
					),

				),
			),
			array(
				'title'  => __( 'General', 'lifterlms' ),
				'fields' => array(
					array(
						'type'       => 'text',
						'label'      => __( 'Course Length', 'lifterlms' ),
						'desc'       => __( 'Enter a description of the estimated length. IE: 3 days', 'lifterlms' ),
						'id'         => $this->prefix . 'length',
						'class'      => 'input-full',
						'value'      => '',
						'desc_class' => 'd-all',
						'group'      => 'top',
					),
					array(
						'class'      => 'llms-select2',
						'id'         => $this->prefix . 'post_course_difficulty',
						'desc'       => sprintf( __( 'Choose a course difficulty level. New difficulties can be added via %1$sCourses -> Difficulties%2$s.', 'lifterlms' ), '<a href="' . admin_url( 'edit-tags.php?taxonomy=course_difficulty&post_type=course' ) . '">', '</a>' ),
						'desc_class' => 'd-all',
						'group'      => 'bottom',
						'label'      => __( 'Course Difficulty Category', 'lifterlms' ),
						'selected'   => $course->get_difficulty( 'slug' ),
						'type'       => 'select',
						'value'      => $difficulty_options,
					),
					array(
						'allow_null'    => false,
						'class'         => 'llms-select2',
						'id'            => $this->prefix . 'focus_mode',
						'desc'          => __( 'Enable or disable Focus Mode for lessons in this course.', 'lifterlms' ),
						'desc_class'    => 'd-all',
						'group'         => 'bottom',
						'is_controller' => true,
						'label'         => __( 'Focus Mode', 'lifterlms' ),
						'selected'      => $course->get( 'focus_mode' ) ? $course->get( 'focus_mode' ) : 'inherit',
						'type'          => 'select',
						'value'         => array(
							array(
								'key'   => 'inherit',
								'title' => sprintf(
									/* translators: %s: current global setting label */
									__( 'Inherit Global Setting (%s)', 'lifterlms' ),
									'yes' === get_option( 'lifterlms_enable_focus_mode', 'no' )
										? __( 'Enabled', 'lifterlms' )
										: __( 'Disabled', 'lifterlms' )
								),
							),
							array(
								'key'   => 'enable',
								'title' => __( 'Enable', 'lifterlms' ),
							),
							array(
								'key'   => 'disable',
								'title' => __( 'Disable', 'lifterlms' ),
							),
						),
					),
					array(
						'allow_null'       => false,
						'class'            => 'llms-select2',
						'controller'       => '#' . $this->prefix . 'focus_mode',
						'controller_value' => 'enable,inherit',
						'id'               => $this->prefix . 'focus_mode_content_width',
						'desc'             => __( 'Set the maximum width of the lesson content area in focus mode.', 'lifterlms' ),
						'desc_class'       => 'd-all',
						'group'            => 'bottom',
						'label'            => __( 'Focus Mode Content Width', 'lifterlms' ),
						'selected'         => $course->get( 'focus_mode_content_width' ) ? $course->get( 'focus_mode_content_width' ) : 'inherit',
						'type'             => 'select',
						'value'            => llms_get_focus_mode_content_width_options( true ),
					),
					array(
						'allow_null'       => false,
						'class'            => 'llms-select2',
						'controller'       => '#' . $this->prefix . 'focus_mode',
						'controller_value' => 'enable,inherit',
						'id'               => $this->prefix . 'focus_mode_sidebar_position',
						'desc'             => __( 'Choose which side the course syllabus sidebar appears on.', 'lifterlms' ),
						'desc_class'       => 'd-all',
						'group'            => 'bottom',
						'label'            => __( 'Focus Mode Sidebar Position', 'lifterlms' ),
						'selected'         => $course->get( 'focus_mode_sidebar_position' ) ? $course->get( 'focus_mode_sidebar_position' ) : 'inherit',
						'type'             => 'select',
						'value'            => llms_get_focus_mode_sidebar_position_options( true ),
					),
					array(
						'type'  => 'text',
						'label' => __( 'Featured Video', 'lifterlms' ),
						'desc'  => sprintf( __( 'Paste the url for a Wistia, Vimeo or Youtube video or a hosted video file. For a full list of supported providers see %s.', 'lifterlms' ), '<a href="https://wordpress.org/documentation/article/embeds/#list-of-sites-you-can-embed-from" target="_blank">WordPress oEmbeds</a>' ),
						'id'    => $this->prefix . 'video_embed',
						'class' => 'code input-full',
					),
					array(
						'desc'       => __( 'When enabled, the featured video will be displayed on the course tile in addition to the course page.', 'lifterlms' ),
						'desc_class' => 'd-3of4 t-3of4 m-1of2',
						'id'         => $this->prefix . 'tile_featured_video',
						'label'      => __( 'Display Featured Video on Course Tile', 'lifterlms' ),
						'type'       => 'checkbox',
						'value'      => 'yes',
					),
					array(
						'type'  => 'text',
						'label' => __( 'Featured Audio', 'lifterlms' ),
						'desc'  => sprintf( __( 'Paste the url for a SoundCloud or Spotify song or a hosted audio file. For a full list of supported providers see %s.', 'lifterlms' ), '<a href="https://wordpress.org/documentation/article/embeds/#list-of-sites-you-can-embed-from" target="_blank">WordPress oEmbeds</a>' ),
						'id'    => $this->prefix . 'audio_embed',
						'class' => 'code input-full',
					),
					array(
						'type'  => 'basic-editor',
						'label' => __( 'Featured Pricing Information', 'lifterlms' ),
						'desc'  => __( 'Enter information on pricing for this course, to be displayed on the catalog page.', 'lifterlms' ),
						'id'    => $this->prefix . 'featured_pricing',
						'class' => 'code input-full',
						'value' => 'test',
					),
					array(
						'label'           => __( 'Course Completion Page', 'lifterlms' ),
						'class'           => 'llms-select2-post',
						'data_attributes' => array(
							'allow-clear' => true,
							'post-type'   => 'page',
							'placeholder' => get_option( 'lifterlms_course_completion_page_id', '' ) ?
								sprintf( __( 'Global setting (%s)', 'lifterlms' ), get_the_title( get_option( 'lifterlms_course_completion_page_id' ) ) ) :
								__( 'Global setting (none)', 'lifterlms' ),
						),
						'desc'            => sprintf( __( 'This page will be shown to students when they complete the course. %1$sMore Information%2$s', 'lifterlms' ), '<a href="https://lifterlms.com/docs/course-completion-page/" target="_blank">', '</a>' ),
						'id'              => $this->prefix . 'completion_page_id',
						'value'           => llms_make_select2_post_array( array( $course->get( 'completion_page_id' ) ) ),
						'type'            => 'select',
					),
				),
			),
			array(
				'title'  => __( 'Restrictions', 'lifterlms' ),
				'fields' => array(

					array(
						'class'   => 'input-full',
						'default' => __( 'You must enroll in this course to access course content.', 'lifterlms' ),
						'desc'    => __( 'This message will be displayed when non-enrolled visitors attempt to access course content directly without enrolling first', 'lifterlms' ),
						'id'      => $this->prefix . 'content_restricted_message',
						'label'   => __( 'Content Restricted Message', 'lifterlms' ),
						'type'    => 'text',
					),

					array(
						'type'          => 'checkbox',
						'label'         => __( 'Enable Enrollment Period', 'lifterlms' ),
						'desc'          => __( 'Set registration start and end dates for this course', 'lifterlms' ),
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
						'id'            => $this->prefix . 'enrollment_period',
						'is_controller' => true,
						'value'         => 'yes',
					),
					array(
						'class'            => 'llms-datepicker input-full',
						'controller'       => '#' . $this->prefix . 'enrollment_period',
						'controller_value' => 'yes',
						'desc'             => __( 'Registration opens on this date.', 'lifterlms' ),
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'enrollment_start_date',
						'label'            => __( 'Enrollment Start Date', 'lifterlms' ),
						'type'             => 'date',
					),
					array(
						'class'            => 'llms-datepicker input-full',
						'controller'       => '#' . $this->prefix . 'enrollment_period',
						'controller_value' => 'yes',
						'desc'             => __( 'Registration closes on this date.', 'lifterlms' ),
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'enrollment_end_date',
						'label'            => __( 'Enrollment End Date', 'lifterlms' ),
						'type'             => 'date',
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'enrollment_period',
						'controller_value' => 'yes',
						'default'          => sprintf( __( 'Enrollment in this course opens on [lifterlms_course_info id="%d" key="enrollment_start_date"].', 'lifterlms' ), $this->post->ID ),
						'desc'             => sprintf( __( 'This message will be displayed to non-enrolled visitors before the Enrollment Start Date. You may use shortcodes like [lifterlms_course_info id="%d" key="enrollment_start_date"] in this message.', 'lifterlms' ), $this->post->ID ),
						'id'               => $this->prefix . 'enrollment_opens_message',
						'label'            => __( 'Enrollment Opens Message', 'lifterlms' ),
						'type'             => 'text',
						'sanitize'         => 'shortcode',
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'enrollment_period',
						'controller_value' => 'yes',
						'default'          => sprintf( __( 'Enrollment in this course closed on [lifterlms_course_info id="%d" key="enrollment_end_date"].', 'lifterlms' ), $this->post->ID ),
						'desc'             => sprintf( __( 'This message will be displayed to non-enrolled visitors once the Enrollment End Date has passed. You may use shortcodes like [lifterlms_course_info id="%d" key="enrollment_end_date"] in this message.', 'lifterlms' ), $this->post->ID ),
						'id'               => $this->prefix . 'enrollment_closed_message',
						'label'            => __( 'Enrollment Closed Message', 'lifterlms' ),
						'type'             => 'text',
						'sanitize'         => 'shortcode',
					),

					array(
						'type'          => 'checkbox',
						'label'         => __( 'Enable Course Time Period', 'lifterlms' ),
						'desc'          => __( 'Set start and end dates for this course. Content can only be viewed and completed within the selected range.', 'lifterlms' ),
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
						'id'            => $this->prefix . 'time_period',
						'is_controller' => true,
						'value'         => 'yes',
					),
					array(
						'class'            => 'llms-datepicker input-full',
						'controller'       => '#' . $this->prefix . 'time_period',
						'controller_value' => 'yes',
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'start_date',
						'label'            => __( 'Course Start Date', 'lifterlms' ),
						'type'             => 'date',
					),
					array(
						'class'            => 'llms-datepicker input-full',
						'controller'       => '#' . $this->prefix . 'time_period',
						'controller_value' => 'yes',
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'end_date',
						'label'            => __( 'Course End Date', 'lifterlms' ),
						'type'             => 'date',
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'time_period',
						'controller_value' => 'yes',
						'default'          => sprintf( __( 'This course opens on [lifterlms_course_info id="%d" key="start_date"].', 'lifterlms' ), $this->post->ID ),
						'desc'             => sprintf( __( 'This message will be displayed to non-enrolled visitors before the Course Start Date. You may use shortcodes like [lifterlms_course_info id="%d" key="start_date"] in this message.', 'lifterlms' ), $this->post->ID ),
						'id'               => $this->prefix . 'course_opens_message',
						'label'            => __( 'Course Opens Message', 'lifterlms' ),
						'type'             => 'text',
						'sanitize'         => 'shortcode',
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'time_period',
						'controller_value' => 'yes',
						'default'          => sprintf( __( 'This course closed on [lifterlms_course_info id="%d" key="end_date"].', 'lifterlms' ), $this->post->ID ),
						'desc'             => sprintf( __( 'This message will be displayed to non-enrolled visitors once the Course End Date has passed. You may use shortcodes like [lifterlms_course_info id="%d" key="end_date"] in this message.', 'lifterlms' ), $this->post->ID ),
						'id'               => $this->prefix . 'course_closed_message',
						'label'            => __( 'Course Closed Message', 'lifterlms' ),
						'type'             => 'text',
						'sanitize'         => 'shortcode',
					),

					array(
						'is_controller' => true,
						'type'          => 'checkbox',
						'label'         => __( 'Enable Prerequisite', 'lifterlms' ),
						'desc'          => __( 'Enable to choose a prerequisite course or course track', 'lifterlms' ),
						'id'            => $this->prefix . 'has_prerequisite',
						'class'         => '',
						'value'         => 'yes',
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
					),
					array(
						'controller'       => '#' . $this->prefix . 'has_prerequisite',
						'controller_value' => 'yes',
						'data_attributes'  => array(
							'post-type'   => 'course',
							'allow-clear' => true,
							'placeholder' => __( 'Select a course', 'lifterlms' ),
						),
						'class'            => 'llms-select2-post',
						'desc'             => __( 'Select a prerequisite course. Students must have completed the selected course before they can view or complete content in this course.', 'lifterlms' ),
						'id'               => $this->prefix . 'prerequisite',
						'type'             => 'select',
						'label'            => __( 'Choose Prerequisite Course', 'lifterlms' ),
						'value'            => llms_make_select2_post_array( array( $course->get( 'prerequisite' ) ) ),
					),
					array(
						'class'            => 'llms-select2',
						'controller'       => '#' . $this->prefix . 'has_prerequisite',
						'controller_value' => 'yes',
						'desc'             => __( 'Select the prerequisite course track. Students must have completed the select track before they can view or complete content in this course.', 'lifterlms' ),
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'prerequisite_track',
						'type'             => 'select',
						'label'            => __( 'Choose Prerequisite Course Track', 'lifterlms' ),
						'value'            => $course_tracks,
					),
					array(
						'type'          => 'checkbox',
						'label'         => __( 'Enable Lesson Drip', 'lifterlms' ),
						'desc'          => __( 'Set global drip restrictions so lesson content becomes available at an interval you define for the course.', 'lifterlms' ),
						'id'            => $this->prefix . 'lesson_drip',
						'is_controller' => true,
						'value'         => 'yes',
						'class'         => '',
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
					),
					array(
						'class'            => 'llms-select2',
						'controller'       => '#' . $this->prefix . 'lesson_drip',
						'controller_value' => 'yes',
						'is_controller'    => true,
						'type'             => 'select',
						'id'               => $this->prefix . 'drip_method',
						'label'            => __( 'Drip Method', 'lifterlms' ),
						'value'            => array(
							array(
								'key'   => 'start',
								'title' => __( 'After course start or enrollment', 'lifterlms' ),
							),
						),
					),
					array(
						'controller'       => '#' . $this->prefix . 'lesson_drip',
						'controller_value' => 'yes',
						'class'            => 'input-full',
						'id'               => $this->prefix . 'ignore_lessons',
						'label'            => __( 'Number of lessons to make immediately available on course start', 'lifterlms' ),
						'type'             => 'number',
						'step'             => 1,
						'min'              => 1,
					),
					array(
						'controller'       => '#' . $this->prefix . 'lesson_drip',
						'controller_value' => 'yes',
						'class'            => 'input-full',
						'id'               => $this->prefix . 'days_before_available',
						'label'            => __( 'Delay (in days) ', 'lifterlms' ),
						'type'             => 'number',
						'step'             => 1,
						'min'              => 1,
					),
					array(
						'is_controller' => true,
						'type'          => 'checkbox',
						'label'         => __( 'Enable Course Capacity', 'lifterlms' ),
						'desc'          => __( 'Limit the number of users that can enroll in this course.', 'lifterlms' ),
						'id'            => $this->prefix . 'enable_capacity',
						'class'         => '',
						'value'         => 'yes',
						'desc_class'    => 'd-3of4 t-3of4 m-1of2',
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'enable_capacity',
						'controller_value' => 'yes',
						'desc_class'       => 'd-all',
						'id'               => $this->prefix . 'capacity',
						'type'             => 'number',
						'label'            => __( 'Course Capacity', 'lifterlms' ),
					),
					array(
						'class'            => 'input-full',
						'controller'       => '#' . $this->prefix . 'enable_capacity',
						'controller_value' => 'yes',
						'default'          => __( 'Enrollment has closed because the maximum number of allowed students has been reached.', 'lifterlms' ),
						'desc'             => __( 'This message will be displayed to non-enrolled visitors once the Course Capacity has been reached. ', 'lifterlms' ),
						'id'               => $this->prefix . 'capacity_message',
						'label'            => __( 'Capacity Reached Message', 'lifterlms' ),
						'type'             => 'text',
					),
				),
			),
			array(
				'title'  => __( 'Instructors', 'lifterlms' ),
				'fields' => array(
					array(
						'button'  => array(
							'text' => __( 'Add Instructor', 'lifterlms' ),
						),
						'handler' => 'instructors_mb_store',
						'header'  => array(
							'default' => __( 'New Instructor', 'lifterlms' ),
						),
						'id'      => $this->prefix . 'instructors_data',
						'label'   => '',
						'type'    => 'repeater',
						'fields'  => array(
							array(
								'allow_null'      => false,
								'data_attributes' => array(
									'placeholder' => esc_attr__( 'Select an Instructor', 'lifterlms' ),
									'roles'       => 'administrator,lms_manager,instructor,instructors_assistant',
								),
								'class'           => 'llms-select2-student',
								'group'           => 'd-2of3',
								'id'              => $this->prefix . 'id',
								'type'            => 'select',
								'label'           => __( 'Instructor', 'lifterlms' ),
							),
							array(
								'group'   => 'd-1of6',
								'class'   => 'input-full',
								'default' => $instructor_defaults['label'],
								'id'      => $this->prefix . 'label',
								'type'    => 'text',
								'label'   => __( 'Label', 'lifterlms' ),
							),
							array(
								'allow_null' => false,
								'class'      => 'llms-select2',
								'default'    => $instructor_defaults['visibility'],
								'group'      => 'd-1of6',
								'id'         => $this->prefix . 'visibility',
								'type'       => 'select',
								'label'      => __( 'Visibility', 'lifterlms' ),
								'value'      => array(
									'visible' => esc_html__( 'Visible', 'lifterlms' ),
									'hidden'  => esc_html__( 'Hidden', 'lifterlms' ),
								),
							),
						),
					),
				),
			),
		);

		$current_screen = get_current_screen();
		$is_gutenberg   = is_object( $current_screen ) && method_exists( $current_screen, 'is_block_editor' ) && $current_screen->is_block_editor();

		/**
		 * Remove length and difficulty fields if
		 * - the course is a new post and the editor is Gutenberg.
		 * or
		 * - the course is migrated to blocks used in the Gutenberg editor.
		 */
		if (
			( $is_gutenberg && 'auto-draft' === get_post_status( $this->post->ID ) ) ||
			function_exists( 'llms_blocks_is_post_migrated' ) && llms_blocks_is_post_migrated( $this->post->ID )
		) {
			unset( $fields[1]['fields'][1] ); // difficulty.
		}

		return $fields;
	}

	/**
	 * Update course difficulty on save
	 *
	 * @since 3.0.0
	 * @since 3.26.3 Only save when using the classic editor.
	 * @since 3.35.0 Verify nonces and sanitize `$_POST` data.
	 * @since 5.9.0 Stop using deprecated `FILTER_SANITIZE_STRING`.
	 *
	 * @param int $post_id  WP Post ID of the course
	 * @return void
	 */
	protected function save_before( $post_id ) {

		if ( ! isset( $_REQUEST['lifterlms_meta_nonce'] ) ) {
			return;
		}
		if ( ! wp_verify_nonce( sanitize_text_field( wp_unslash( $_REQUEST['lifterlms_meta_nonce'] ) ), 'lifterlms_save_data' ) ) {
			return;
		}

		if ( ! function_exists( 'register_block_type' ) || ! llms_blocks_is_post_migrated( $this->post->ID ) ) {

			wp_set_object_terms( $post_id, llms_filter_input_sanitize_string( INPUT_POST, '_llms_post_course_difficulty' ), 'course_difficulty', false );
			unset( $_POST['_llms_post_course_difficulty'] ); // Don't save this to the postmeta table.

		}
	}
}
