public static function roles_and_permissions() {

		$instructor_role = DOZENT_INSTRUCTOR_ROLE;
		$permissions     = [
			//Manage Instructor
			'dozent_instructor',

			//Posts Type Permission
			'edit_course',
			'read_course',
			'delete_course',
			'delete_courses',
			'edit_courses',
			'edit_others_courses',
			'read_private_courses',
		];

		remove_role( $instructor_role );
		add_role( $instructor_role, DOZENT_INSTRUCTOR_ROLE_NAME, $permissions );

		$instructor = get_role( $instructor_role );
		if ( $instructor ) {

			$instructor_cap = array(
				'edit_posts',
				'read',
				'upload_files',
			);

			$instructor_cap = array_merge( $instructor_cap, $permissions );

			$can_publish_course = (bool) dozent_get_option( 'instructor_can_publish_course' );
			if ( $can_publish_course ) {
				$instructor_cap[] = 'publish_courses';
			}

			foreach ( $instructor_cap as $cap ) {
				$instructor->add_cap( $cap );
			}
		}

		$administrator = get_role( 'administrator' );
		if ( $administrator ) {

			$permissions[] = 'publish_courses';
			foreach ( $permissions as $cap ) {
				$administrator->add_cap( $cap );
			}
		}

		/**
		 * Add Instructor role to administrator
		 */
		if ( current_user_can( 'administrator' ) ) {
			dozent_instructor_approve( get_current_user_id() );
		}

	}