Syncro TASK - Restart Windows if updates are pending

Import-Module $env:SyncroModule -DisableNameChecking -ErrorAction Stop

<#
Syncro TASK - Restart Windows if updates are pending.ps1
v1.1 2024-09-13 by David Sirrine @ CNS  https://cnsroanoke.com

FUNCTION.
    Syncro script to check for pending Windows updates using platform variable,
    notify all logged in users, log the reason for the reboot to activity feed
    of the Asset, then reboot the system after 60 seconds.

PURPOSE.
    Broadcast messages can only be used when scripts are RunAs "Logged In User",
    but not all users have permissions to run the "shutdown" command.

PREREQUISITES.
    Relies on Syncro's platform variable {{asset_pending_reboot}} ;
    Fails without this variable.

USAGE.
    Run scheduled or realtime in Syncro. No parameters needed in this version.

PROPOSED REVISIONS.
    1. integrate more extensive reboot checks to supplement platform variable,
       e.g. https://github.com/adbertram/Random-PowerShell-Work/blob/master/Random%20Stuff/Test-PendingReboot.ps1
    2. allow users to "snooze" the reboot a set amount of time and/or a certain number of times.
    3. add option to schedule outside of "office hours".
#>

#source of function: https://www.reddit.com/r/syncro/comments/kyqt91/broadcast_message_when_running_script_as_system/
function MessageAsSystem ([string]$Title,[string]$Message,[int]$sDelay = 15) {

    $when = (Get-Date).AddSeconds($sDelay)
    $argument = "--broadcast-message `"$Message`" --broadcast-title `"$Title`""

    # find logged-in users via running explorer.exe processes
    $explorerProcesses = Get-CimInstance -ClassName Win32_Process -Filter "Name='explorer.exe'" -ErrorAction SilentlyContinue
    $dUN = @($explorerProcesses | ForEach-Object { Invoke-CimMethod -InputObject $_ -MethodName GetOwner })
    if ($dUN.Count -ne 0) {
        # de-duplicate users in case of multiple explorer.exe processes
        $LoggedInUsers = $dUN | Select-Object -Property Domain, User -Unique
        # create scheduled task to notify each user
        Foreach ($cUN in $LoggedInUsers) {
            $username = ($cUN.Domain)+"\"+($cUN.User)
            $thisuser = $cUN.User
            Write-Host "   Scheduling task to notify user $username"
            Register-ScheduledTask -TaskName "BroadcastMessage-$thisuser"  -User $username -InputObject (
              (
                New-ScheduledTask -Action (
                  New-ScheduledTaskAction -Execute "$env:ProgramFiles\RepairTech\Syncro\Syncro.App.Runner.exe" -Argument $argument
                ) -Trigger (
                  New-ScheduledTaskTrigger -Once -At ($when.TimeOfDay.ToString("hh\:mm\:ss")) # As a "TimeOfDay" to get 24Hr format
                ) -Settings (
                  New-ScheduledTaskSettingsSet -DeleteExpiredTaskAfter 00:00:05 # Delete five seconds after trigger expires
                ) -Principal (
                  New-ScheduledTaskPrincipal -UserId $username
                )
              ) | %{ $_.Triggers[0].EndBoundary = $when.AddMinutes(5).ToString('s') ; $_ } # Run through a pipe to set the end boundary of the trigger
            )
        }
        #wait for notification tasks to run
        Start-Sleep -Seconds ($sDelay)

    } else {
        Write-Host "   Interactive user(s) not detected; skipping broadcast message"
    }
}

if ($RebootPending -eq "true") {
    Write-Host "Reboot Pending"

    #messages for broadcast and logging
    $title = "Updates Notification"
    $user_message = "Your system needs to reboot to install important updates. Windows will restart in one (1) minute."
    $system_message = "Rebooting Windows via script for pending updates"

    Write-Host "Notifying any logged in users of reboot"
    MessageAsSystem -Message $user_message -Title $title -ErrorAction SilentlyContinue

    Write-Host "Logging an item on the Assets's Activity feed"
    Log-Activity -Message $system_message -EventName $title -ErrorAction SilentlyContinue

    Write-Host "Rebooting in 60 seconds"
    shutdown /g /f /t 60

} elseif ($RebootPending -eq "false") {
    Write-Host "No reboot required"

} else {
    Write-Host "Reboot status was not found; check for platform variable in script configuration."
}