<?php

namespace MintyPHP\Service;

use MintyPHP\Repository\RolePermissionRepository;
use MintyPHP\Repository\UserRoleRepository;
use MintyPHP\Repository\PermissionRepository;

class PermissionService
{
    public const USERS_CREATE = 'users.create';
    public const USERS_DELETE = 'users.delete';
    public const USERS_VIEW = 'users.view';
    public const USERS_UPDATE = 'users.update';
    public const USERS_SELF_UPDATE = 'users.self_update';
    public const USERS_UPDATE_ASSIGNMENTS = 'users.update_assignments';
    public const ADDRESS_BOOK_VIEW = 'address_book.view';
    public const TENANTS_VIEW = 'tenants.view';
    public const TENANTS_CREATE = 'tenants.create';
    public const TENANTS_UPDATE = 'tenants.update';
    public const TENANTS_DELETE = 'tenants.delete';
    public const DEPARTMENTS_VIEW = 'departments.view';
    public const DEPARTMENTS_CREATE = 'departments.create';
    public const DEPARTMENTS_UPDATE = 'departments.update';
    public const DEPARTMENTS_DELETE = 'departments.delete';
    public const ROLES_VIEW = 'roles.view';
    public const ROLES_CREATE = 'roles.create';
    public const ROLES_UPDATE = 'roles.update';
    public const ROLES_DELETE = 'roles.delete';
    public const PERMISSIONS_VIEW = 'permissions.view';
    public const PERMISSIONS_CREATE = 'permissions.create';
    public const PERMISSIONS_UPDATE = 'permissions.update';
    public const PERMISSIONS_DELETE = 'permissions.delete';
    public const SETTINGS_VIEW = 'settings.view';
    public const SETTINGS_UPDATE = 'settings.update';
    public const MAIL_LOG_VIEW = 'mail_log.view';
    public const STATS_VIEW = 'stats.view';

    public static function userHas(int $userId, string $permissionKey): bool
    {
        $permissionKey = trim((string) $permissionKey);
        if ($userId <= 0 || $permissionKey === '') {
            return false;
        }
        $keys = self::getUserPermissions($userId);
        return in_array($permissionKey, $keys, true);
    }

    public static function getUserPermissions(int $userId, bool $refresh = false): array
    {
        if ($userId <= 0) {
            return [];
        }
        $cache = $_SESSION['permissions'] ?? null;
        if ($refresh) {
            $cache = null;
        }
        if (is_array($cache) && (int) ($cache['user_id'] ?? 0) === $userId) {
            $keys = $cache['keys'] ?? [];
            if (is_array($keys)) {
                return $keys;
            }
        }
        $roleIds = UserRoleRepository::listRoleIdsByUserId($userId);
        $keys = RolePermissionRepository::listPermissionKeysByRoleIds($roleIds);
        $_SESSION['permissions'] = [
            'user_id' => $userId,
            'keys' => $keys,
        ];
        return $keys;
    }

    public static function getCachedPermissions(int $userId): array
    {
        if ($userId <= 0) {
            return [];
        }
        $cache = $_SESSION['permissions'] ?? null;
        if (is_array($cache) && (int) ($cache['user_id'] ?? 0) === $userId) {
            $keys = $cache['keys'] ?? [];
            return is_array($keys) ? $keys : [];
        }
        return [];
    }

    public static function clearUserCache(int $userId): void
    {
        $cache = $_SESSION['permissions'] ?? null;
        if (is_array($cache) && (int) ($cache['user_id'] ?? 0) === $userId) {
            unset($_SESSION['permissions']);
        }
    }

    public static function list(): array
    {
        return PermissionRepository::list();
    }

    public static function listPaged(array $options): array
    {
        return PermissionRepository::listPaged($options);
    }

    public static function find(int $id): ?array
    {
        return PermissionRepository::find($id);
    }

    public static function findByKey(string $key): ?array
    {
        return PermissionRepository::findByKey($key);
    }

    public static function createFromAdmin(array $input): array
    {
        $form = self::sanitizeBase($input);
        $errors = self::validateBase($form);
        if ($errors) {
            return ['ok' => false, 'errors' => $errors, 'form' => $form];
        }
        if (PermissionRepository::findByKey($form['key'])) {
            return ['ok' => false, 'errors' => [t('Permission key already exists')], 'form' => $form];
        }
        $createdId = PermissionRepository::create($form);
        if (!$createdId) {
            return ['ok' => false, 'errors' => [t('Permission can not be created')], 'form' => $form];
        }
        return ['ok' => true, 'form' => $form, 'id' => (int) $createdId];
    }

    public static function updateFromAdmin(int $id, array $input): array
    {
        $form = self::sanitizeBase($input);
        $errors = self::validateBase($form);
        if ($errors) {
            return ['ok' => false, 'errors' => $errors, 'form' => $form];
        }
        $existing = PermissionRepository::findByKey($form['key']);
        if ($existing && (int) ($existing['id'] ?? 0) !== $id) {
            return ['ok' => false, 'errors' => [t('Permission key already exists')], 'form' => $form];
        }
        $updated = PermissionRepository::update($id, $form);
        if (!$updated) {
            return ['ok' => false, 'errors' => [t('Permission can not be updated')], 'form' => $form];
        }
        return ['ok' => true, 'form' => $form];
    }

    public static function deleteById(int $id): array
    {
        $permission = PermissionRepository::find($id);
        if (!$permission) {
            return ['ok' => false, 'status' => 404, 'error' => 'not_found'];
        }
        $deleted = PermissionRepository::delete($id);
        if (!$deleted) {
            return ['ok' => false, 'status' => 500, 'error' => 'delete_failed'];
        }
        return ['ok' => true, 'permission' => $permission];
    }

    private static function sanitizeBase(array $input): array
    {
        return [
            'key' => trim((string) ($input['key'] ?? '')),
            'description' => trim((string) ($input['description'] ?? '')),
        ];
    }

    private static function validateBase(array $form): array
    {
        $errors = [];
        if ($form['key'] === '') {
            $errors[] = t('Permission key cannot be empty');
        } elseif (!preg_match('/^[a-z0-9._-]+$/i', $form['key'])) {
            $errors[] = t('Permission key is invalid');
        }
        return $errors;
    }
}