TenantAtlas/app/Services/Auth/PostLoginRedirectResolver.php

<?php

declare(strict_types=1);

namespace App\Services\Auth;

use App\Filament\Pages\TenantDashboard;
use App\Models\Tenant;
use App\Models\User;
use Illuminate\Support\Collection;

class PostLoginRedirectResolver
{
    public function resolve(User $user): string
    {
        $tenants = $this->getActiveTenants($user);

        if ($tenants->isEmpty()) {
            return '/admin/no-access';
        }

        if ($tenants->count() === 1) {
            /** @var Tenant $tenant */
            $tenant = $tenants->first();

            return TenantDashboard::getUrl(tenant: $tenant);
        }

        return '/admin/choose-tenant';
    }

    /**
     * @return Collection<int, Tenant>
     */
    private function getActiveTenants(User $user): Collection
    {
        if ($user->isPlatformSuperadmin()) {
            return Tenant::query()
                ->where('status', 'active')
                ->orderBy('name')
                ->get();
        }

        return $user->tenants()
            ->where('status', 'active')
            ->orderBy('name')
            ->get();
    }
}