<?php

namespace MintyPHP\Service;

use MintyPHP\Repository\TenantDepartmentRepository;
use MintyPHP\Repository\UserTenantRepository;
use MintyPHP\Repository\TenantRepository;
use MintyPHP\Service\PermissionService;

class TenantScopeService
{
    public static function isStrict(): bool
    {
        return defined('TENANT_SCOPE_STRICT') ? (bool) TENANT_SCOPE_STRICT : true;
    }

    public static function getUserTenantIds(int $userId, bool $onlyActive = true): array
    {
        if ($userId <= 0) {
            return [];
        }
        if (self::canBypass($userId)) {
            $ids = TenantRepository::listIds();
        } else {
            $ids = array_values(array_unique(array_map('intval', UserTenantRepository::listTenantIdsByUserId($userId))));
        }
        if ($onlyActive) {
            return self::filterActiveTenantIds($ids);
        }
        return $ids;
    }

    public static function canAccess(string $resource, int $resourceId, int $userId): bool
    {
        if ($resourceId <= 0 || $userId <= 0) {
            return false;
        }
        if (self::canBypass($userId)) {
            return true;
        }
        $resourceTenantIdsRaw = self::getResourceTenantIds($resource, $resourceId);
        $userTenantIdsRaw = self::getUserTenantIds($userId, false);
        $resourceTenantIds = self::filterActiveTenantIds($resourceTenantIdsRaw);
        $userTenantIds = self::filterActiveTenantIds($userTenantIdsRaw);

        if ($resourceTenantIdsRaw && !$resourceTenantIds) {
            return false;
        }
        if (!$resourceTenantIds) {
            return self::isStrict() ? false : true;
        }
        if (!$userTenantIds) {
            return false;
        }
        return (bool) array_intersect($resourceTenantIds, $userTenantIds);
    }

    public static function filterTenantIdsForUser(array $tenantIds, int $userId): array
    {
        $tenantIds = array_values(array_unique(array_map('intval', $tenantIds)));
        $userTenantIds = self::getUserTenantIds($userId);
        if (!$userTenantIds) {
            return [];
        }
        return array_values(array_intersect($tenantIds, $userTenantIds));
    }

    public static function mergeTenantIdsPreservingOutOfScope(array $requestedTenantIds, array $existingTenantIds, array $allowedTenantIds): array
    {
        $requestedTenantIds = array_values(array_unique(array_map('intval', $requestedTenantIds)));
        $existingTenantIds = array_values(array_unique(array_map('intval', $existingTenantIds)));
        $allowedTenantIds = array_values(array_unique(array_map('intval', $allowedTenantIds)));

        if (!$allowedTenantIds) {
            return $existingTenantIds;
        }
        $outOfScope = array_values(array_diff($existingTenantIds, $allowedTenantIds));
        return array_values(array_unique(array_merge($requestedTenantIds, $outOfScope)));
    }

    public static function hasGlobalAccess(int $userId): bool
    {
        return self::canBypass($userId);
    }

    private static function getResourceTenantIds(string $resource, int $resourceId): array
    {
        $resource = strtolower(trim($resource));
        if ($resource === 'tenants') {
            return $resourceId > 0 ? [$resourceId] : [];
        }
        if ($resource === 'users') {
            return array_values(array_unique(array_map('intval', UserTenantRepository::listTenantIdsByUserId($resourceId))));
        }
        if ($resource === 'departments') {
            return array_values(array_unique(array_map('intval', TenantDepartmentRepository::listTenantIdsByDepartmentId($resourceId))));
        }
        return [];
    }

    private static function filterActiveTenantIds(array $tenantIds): array
    {
        $tenantIds = array_values(array_unique(array_map('intval', $tenantIds)));
        if (!$tenantIds) {
            return [];
        }
        return TenantRepository::listActiveIdsByIds($tenantIds);
    }

    private static function canBypass(int $userId): bool
    {
        if ($userId <= 0) {
            return false;
        }
        return PermissionService::userHas($userId, PermissionService::TENANTS_UPDATE)
            || PermissionService::userHas($userId, PermissionService::SETTINGS_UPDATE);
    }
}