<?php

namespace App\Utilities;

use App\Models\Auth\User;
use App\Models\Auth\UserAccessGroup;

class SidebarPermissions
{
    public static function settings(): array
    {
        $value = setting('system.sidebar_permissions', []);

        if (is_string($value)) {
            $value = json_decode($value, true) ?: [];
        }

        return is_array($value) ? $value : [];
    }

    public static function subjectKey(User $user): string
    {
        $userKey = 'user_' . $user->id;
        $settings = self::settings();

        if (in_array($userKey, $settings['configured'] ?? [], true)) {
            return $userKey;
        }

        return 'role_' . SystemAccess::roleName($user);
    }

    public static function allowedKeys(User $user): ?array
    {
        if (SystemAccess::isSuperAdmin($user)) {
            return null;
        }

        $settings = self::settings();
        $userSubject = 'user_' . $user->id;
        if (in_array($userSubject, $settings['configured'] ?? [], true)) {
            return array_values(array_unique((array) ($settings['subjects'][$userSubject] ?? [])));
        }

        $groups = UserAccessGroup::forUser($user);
        if ($groups->isNotEmpty()) {
            return $groups->flatMap(fn ($group) => $group->page_permissions ?? [])->unique()->values()->all();
        }

        $subject = 'role_' . SystemAccess::roleName($user);

        if (! in_array($subject, $settings['configured'] ?? [], true)) {
            return null;
        }

        return array_values(array_unique((array) ($settings['subjects'][$subject] ?? [])));
    }

    public static function navigationFor(User $user): array
    {
        $navigation = BusinessNavigation::all();
        $allowed = self::allowedKeys($user);

        if ($allowed === null) {
            return $navigation;
        }

        return array_values(array_filter(array_map(function (array $section) use ($allowed) {
            $sectionKey = $section['slug'];

            if (in_array($sectionKey, $allowed, true)) {
                return $section;
            }

            $pages = array_values(array_filter(array_map(function (array $page) use ($allowed, $sectionKey) {
                $pageKey = $sectionKey . '/' . $page['slug'];

                if (in_array($pageKey, $allowed, true)) {
                    // 若有 children，保留 children 的精确权限过滤
                    if (! empty($page['children'])) {
                        $page['children'] = array_values(array_filter($page['children'], function (array $child) use ($allowed, $sectionKey) {
                            return in_array($sectionKey . '/' . $child['slug'], $allowed, true);
                        }));
                    }
                    return $page;
                }

                // 子页面可能在 allowed 列表中（独立 URL），父级分组也允许展开
                if (! empty($page['children'])) {
                    $visibleChildren = array_values(array_filter($page['children'], function (array $child) use ($allowed, $sectionKey) {
                        return in_array($sectionKey . '/' . $child['slug'], $allowed, true);
                    }));
                    if (! empty($visibleChildren)) {
                        $page['children'] = $visibleChildren;
                        return $page;
                    }
                }

                return null;
            }, $section['pages'] ?? [])));

            if (! empty($pages)) {
                $section['pages'] = $pages;

                return $section;
            }

            return null;
        }, $navigation)));
    }

    public static function allKeys(): array
    {
        $keys = [];

        foreach (BusinessNavigation::all() as $section) {
            $keys[] = $section['slug'];

            foreach ($section['pages'] ?? [] as $page) {
                $keys[] = $section['slug'] . '/' . $page['slug'];

                foreach ($page['children'] ?? [] as $child) {
                    $keys[] = $section['slug'] . '/' . $child['slug'];
                }
            }
        }

        return $keys;
    }
}