private function get_engagements( $trigger_type, $related_post_id = '' ) {

		global $wpdb;

		$related_select = '';
		$related_join   = '';
		$related_where  = '';

		if ( $related_post_id ) {

			$related_select = ', relation_meta.meta_value AS related_post_id';
			$related_join   = "LEFT JOIN $wpdb->postmeta AS relation_meta ON triggers.ID = relation_meta.post_id";
			$related_where  = $wpdb->prepare( "AND relation_meta.meta_key = '_llms_engagement_trigger_post' AND relation_meta.meta_value = %d", $related_post_id );

		}

		// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$results = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT
				  DISTINCT triggers.ID AS trigger_id
				, triggers_meta.meta_value AS engagement_id
				, engagements_meta.meta_value AS trigger_event
				, event_meta.meta_value AS event_type
				, delay.meta_value AS delay
				$related_select

			FROM $wpdb->postmeta AS engagements_meta

			LEFT JOIN $wpdb->posts AS triggers ON triggers.ID = engagements_meta.post_id
			LEFT JOIN $wpdb->postmeta AS triggers_meta ON triggers.ID = triggers_meta.post_id
			LEFT JOIN $wpdb->posts AS engagements ON engagements.ID = triggers_meta.meta_value
			LEFT JOIN $wpdb->postmeta AS event_meta ON triggers.ID = event_meta.post_id
			LEFT JOIN $wpdb->postmeta AS delay ON triggers.ID = delay.post_id
			$related_join

			WHERE
				    triggers.post_type = 'llms_engagement'
				AND triggers.post_status = 'publish'
				AND triggers_meta.meta_key = '_llms_engagement'

				AND engagements_meta.meta_key = '_llms_trigger_type'
				AND engagements_meta.meta_value = %s
				AND engagements.post_status = 'publish'

				AND event_meta.meta_key = '_llms_engagement_type'

				AND delay.meta_key = '_llms_engagement_delay'

				$related_where
			",
				// Prepare variables.
				$trigger_type
			),
			OBJECT
		); // no-cache ok.
		// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared

		/**
		 * Filters the list of engagements to be triggered for a given trigger type and related post.
		 *
		 * @since 6.0.0
		 *
		 * @param object[] $results         Array of engagement objects.
		 * @param string   $trigger_type    Name of the engagement trigger.
		 * @param int      $related_post_id WP_Post ID of the related post.
		 */
		return apply_filters( 'lifterlms_get_engagements', $results, $trigger_type, $related_post_id );

	}