<# 
Alan Kaplan www.akaplan.com
GUI to Logoff/Shutdown remote computer using WMI
8/7/2017,9/26/19
#>

[CmdletBinding()]
param (
    [Parameter(Mandatory = $true)]
    [string]
    $Computer
)

Add-Type -assemblyname Microsoft.visualBasic

Function Get-ShutdownType() {
    #build menu
    $msg = @"
 = $Computer =

1 - Logoff
2 - Force Logoff (NO SAVE)
3 - Powerdown
4 - Force Powerdown (NO SAVE)    
5 - Reboot
6 - Force Reboot (NO SAVE)
=====================
7 - Ping test
8 - Check for logged on user(s)
9 - Send User(s) Message
0 - Quit
    
NOTE: Using force will close programs without saving changes!
"@

    $iAction = [Microsoft.VisualBasic.Interaction]::InputBox($msg, "Choose Action:", "0")
    switch ($iAction) {

        1 {
            #Logoff
            $Script:WMIArg = 0
            $script:msg = "Logoff for all users sent to $Computer"
            Break
        }
    
        2 {
            #Force Logoff   
            $Script:WMIArg = 4
            $script:msg = "Force logoff for all users sent to $Computer"
            Break
        }
    
        3 {
            #Powerdown
            $Script:WMIArg = 8
            $script:msg = "Powerdown sent to $Computer"
            Break
        }

        4 {
            #Force Powerdown
            $Script:WMIArg = 12
            $script:msg = "Force Powerdown sent to $Computer"
            Break
        }

        5 {
            #Reboot
            $Script:WMIArg = 2
            $script:msg = "Reboot sent to $Computer"
            Break
        }

        6 {
            #Force Reboot
            $Script:WMIArg = 6
            $script:msg = "Force Reboot sent to $Computer"
            Break
        }

        7 {
            #Ping
            if (Test-Connection $Computer -Count 2 -Quiet) {
                [Microsoft.VisualBasic.Interaction]::MsgBox("$Computer is online", [Microsoft.VisualBasic.MsgBoxStyle]::OkOnly, "Ping Test") |
                Out-Null
            }
            ELSE {
                [Microsoft.VisualBasic.Interaction]::MsgBox("$Computer failed to reply to ping", [Microsoft.VisualBasic.MsgBoxStyle]::Critical, "Ping Test") | 
                Out-Null
            }
            Get-ShutdownType
        }

        8 {
            #Check for logged on users   
            Get-LoggedOnUsers
            Break
        }
        9 {
            #Send logged on users a message   
            Send-Message
            Break
        }

        Default { Exit}
    }
}

Function Invoke-WMIAction () {
    Try {
        $retval = Invoke-WmiMethod -computername $Computer -Path "root\cimv2:Win32_OperatingSystem=@" -Name Win32Shutdown -ArgumentList $Script:WMIArg -ErrorAction stop
        if ($retval.ReturnValue -eq 0) {
            Write-host $script:msg
        }
        ELSE {
            $errmsg = "$script:msg, but failed with error: " + [ComponentModel.Win32Exception]$retval.ReturnValue
            Write-warning $errmsg
        }
    }
    Catch {
        #This may never be reached
        $errmsg = "$msg, but failed with error: " + $error[0].Exception.Message
        Write-warning $errmsg
    }
    Pause
}

Function Get-LoggedOnUserDetails() {
    Write-progress "Getting Logged On Users"
    $wQL = "Select * from Win32_LogonSession Where LogonType = 2 OR LogonType = 10"
    $colSessions = get-wmiobject -query $wql -computername $computer

    if ($colSessions.Count -eq 0) {
        Write-warning "No interactive users found on $computer"
        pause
    }
    ELSE {
        Write-Progress "Getting sessions on $computer"
        $QUserTxt = query User /server:$computer
  
        #loosely based on Get-ComputerUser by Boe Prox 01 Nov 2010
        $UserInfo = 1..($QUserTxt.count - 1) | 
        ForEach-Object {
            [PSCustomObject] @{
                UserName    = $QUserTxt[$_].Substring(1, 20).Trim() 
                SessionName = $QUserTxt[$_].Substring(22, 20).Trim() 
                ID          = $QUserTxt[$_].Substring(42, 3).Trim() 
                State       = $QUserTxt[$_].Substring(45, 8).Trim() 
                IdleTime    = $QUserTxt[$_].Substring(53, 12).Trim() 
                LogonTime   = $QUserTxt[$_].Substring(64).Trim()
            }
        }

        $UserInfo | Out-GridView -Title "Users on $computer" -Wait
    } 
}

Function Get-LoggedOnUsers() {
    $UserCount = (quser /server:$computer).count - 1 
    if ($UserCount -gt 0) {
        $msg = "$usercount sessions found.  Do you want to see logged on user details? (This can take a while)"
        $btn = [Microsoft.VisualBasic.MsgBoxStyle]::Question + [Microsoft.VisualBasic.MsgBoxStyle]::YesNo
        $retval = [Microsoft.VisualBasic.Interaction]::MsgBox($msg, $btn, "Sessions")
        if ($Retval -eq "Yes") { Get-LoggedOnUserDetails }
    }
    ELSE {
        $btn = [Microsoft.VisualBasic.MsgBoxStyle]::Question + [Microsoft.VisualBasic.MsgBoxStyle]::Information
        $retval = [Microsoft.VisualBasic.Interaction]::MsgBox("No users are logged onto $Computer", $btn , "No Sessions")
    }        
    Get-ShutdownType
}

Function Send-Message() {
    $msg = "Send what message to logged on users of $computer`?"
    $msg = [Microsoft.VisualBasic.Interaction]::InputBox($msg, "Message", "Please save your work.  Logoff in 1 minute!")
    $cmd = "msg * /Server:$computer /Time:30 `"$msg`""
    Invoke-Expression $cmd
    Get-ShutdownType
}

#Script Begins. Ensure admin rights

If (!([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).groups -match "S-1-5-32-544"))) {
    $title = "Permissions Issue"
    $msg = "You are not an administrator on this computer. Does $env:Username have admin rights on the remote computer?"
    $retval = [Microsoft.VisualBasic.Interaction]::MsgBox($msg, 'YesNoCancel,defaultbutton2,Question', $title)
    if ($retval -ne 'Yes') { Exit}
}

if ($null -eq $computer){
    $msg = "Enter the FQDN of the computer you wish to Shutdown / Reboot / Logoff"
    $title = "Remote Shutdown / Reboot / Logoff"

    $Computer = [Microsoft.VisualBasic.Interaction]::InputBox($msg, $title, [system.net.dns]::GetHostEntry('localhost').hostname)
}

if ($Computer -eq '' ) { Exit} Else { $Computer = $Computer.ToUpper() }
Get-ShutdownType
Invoke-WMIAction