<?php
namespace AccessNow\SimpleLMS;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Capabilities {

	/**
	 * Each post type's capability_type (singular, plural). With map_meta_cap, WordPress then checks
	 * edit_slms_courses, edit_others_slms_courses, publish_slms_courses... instead of the post ones,
	 * so a role can be given courses without posts (an instructor) or posts without courses.
	 */
	const POST_TYPES = array(
		'slms_course' => array( 'slms_course', 'slms_courses' ),
		'slms_unit'   => array( 'slms_unit', 'slms_units' ),
		'slms_lesson' => array( 'slms_lesson', 'slms_lessons' ),
		'slms_quiz'   => array( 'slms_quiz', 'slms_quizzes' ),
	);

	/**
	 * Post capability => the same capability for a post type (%s is its plural).
	 * These are every primitive capability map_meta_cap() asks for.
	 */
	const FROM_POST_CAPS = array(
		'edit_posts'             => 'edit_%s',
		'edit_others_posts'      => 'edit_others_%s',
		'edit_private_posts'     => 'edit_private_%s',
		'edit_published_posts'   => 'edit_published_%s',
		'publish_posts'          => 'publish_%s',
		'read_private_posts'     => 'read_private_%s',
		'delete_posts'           => 'delete_%s',
		'delete_others_posts'    => 'delete_others_%s',
		'delete_private_posts'   => 'delete_private_%s',
		'delete_published_posts' => 'delete_published_%s',
	);

	public static function create_roles() {
		add_role(
			'slms_student',
			__( 'Student', 'accessnow-lms' ),
			array(
				'read' => true,
			)
		);

		$admin = get_role( 'administrator' );
		if ( $admin ) {
			$admin->add_cap( 'manage_slms' );
			$admin->add_cap( 'manage_slms_enrollments' );
			$admin->add_cap( 'manage_slms_reports' );
			foreach ( self::post_type_caps() as $cap ) {
				$admin->add_cap( $cap );
			}
		}
	}

	public static function remove_roles() {
		remove_role( 'slms_student' );

		$admin = get_role( 'administrator' );
		if ( $admin ) {
			$admin->remove_cap( 'manage_slms' );
			$admin->remove_cap( 'manage_slms_enrollments' );
			$admin->remove_cap( 'manage_slms_reports' );
		}
		self::remove_post_type_caps();
	}

	/**
	 * The arguments that give a post type its own capabilities.
	 *
	 * @param string $post_type One of POST_TYPES.
	 * @return array
	 */
	public static function post_type_args( $post_type ) {
		return array(
			'capability_type' => self::POST_TYPES[ $post_type ],
			'map_meta_cap'    => true,
		);
	}

	/**
	 * Every primitive capability of the four post types.
	 *
	 * @return string[]
	 */
	public static function post_type_caps() {
		$caps = array();
		foreach ( self::POST_TYPES as $names ) {
			foreach ( self::FROM_POST_CAPS as $template ) {
				$caps[] = sprintf( $template, $names[1] );
			}
		}
		return $caps;
	}

	/**
	 * Give the roles that run the site's content (those that can edit others' posts: administrators,
	 * editors) the course, unit, lesson and quiz capabilities matching their post capabilities (5.1.0).
	 *
	 * Until 5.1.0 the post types used the post capabilities, so authors and contributors could reach a
	 * course's editor through "+ New" although the LMS menu never showed them anything (Martin,
	 * 2026-10-18: LMS content stays with admins and editors). They get nothing now; an instructor role
	 * is given course capabilities explicitly.
	 *
	 * Only adds: a capability a role was explicitly denied (false) is neither copied nor overwritten,
	 * and running it twice changes nothing. Roles created later get none until they are given them.
	 */
	public static function grant_matching_post_caps() {
		foreach ( array_keys( wp_roles()->roles ) as $role_name ) {
			$role = get_role( $role_name );
			if ( ! $role || empty( $role->capabilities['edit_others_posts'] ) ) {
				continue;
			}
			foreach ( self::FROM_POST_CAPS as $post_cap => $template ) {
				if ( empty( $role->capabilities[ $post_cap ] ) ) {
					continue;
				}
				foreach ( self::POST_TYPES as $names ) {
					$cap = sprintf( $template, $names[1] );
					if ( ! array_key_exists( $cap, $role->capabilities ) ) {
						$role->add_cap( $cap );
					}
				}
			}
		}
	}

	/**
	 * Remove the post type capabilities from every role (uninstall).
	 */
	public static function remove_post_type_caps() {
		foreach ( array_keys( wp_roles()->roles ) as $role_name ) {
			$role = get_role( $role_name );
			if ( ! $role ) {
				continue;
			}
			foreach ( self::post_type_caps() as $cap ) {
				if ( array_key_exists( $cap, $role->capabilities ) ) {
					$role->remove_cap( $cap );
				}
			}
		}
	}

	/**
	 * Whether the current user may see a lesson or quiz without being enrolled: LMS managers, and
	 * anyone who can edit it (its author, an editor), so they can preview their own work.
	 *
	 * @param int $post_id Lesson or quiz ID.
	 * @return bool
	 */
	public static function can_preview( $post_id ) {
		return current_user_can( 'manage_slms' ) || ( $post_id && current_user_can( 'edit_post', $post_id ) );
	}

	/**
	 * Whether the current user may make a post its parent (a lesson's unit, a quiz's lesson): they must
	 * be able to edit it. The parent it already has is always kept, and 0 (no parent) is always allowed.
	 *
	 * @param int $new_parent Submitted parent ID.
	 * @param int $current    The parent stored now.
	 * @return bool
	 */
	public static function can_use_parent( $new_parent, $current ) {
		$new_parent = (int) $new_parent;
		return 0 === $new_parent || (int) $current === $new_parent || current_user_can( 'edit_post', $new_parent );
	}

	/**
	 * Parent options for a meta box select: the posts the current user can edit, plus the current one.
	 *
	 * @param \WP_Post[] $posts   Candidate parents.
	 * @param int        $current The parent stored now.
	 * @return \WP_Post[]
	 */
	public static function filter_parent_options( $posts, $current ) {
		return array_values(
			array_filter(
				$posts,
				function ( $post ) use ( $current ) {
					return (int) $post->ID === (int) $current || current_user_can( 'edit_post', $post->ID );
				}
			)
		);
	}
}