Function Reset-Computer {
<#
.Synopsis
    Remotely restart or shutdown a computer.
.Description
    The function will Restart, Shutdown, PowerDown, or Logoff
    a remote computer.
.Parameter Computername
    What is the name of the computer to remotely control. This
    parameter has an alias of CN.
.Parameter Force
    If specifed, force all applications to close on the remote machine.
.Parameter Operation
    What do you want to do with the remote computer. Valid choices are
    Restart, Shutdown, PowerDown, or Logoff.
    The default is Restart. This parameter has an alias of OP.
.Example
    PS C:\> reset-computer server01 -force
    
    This will restart computer server01, forcing any open applications to close.
.Example
    PS C:\> get-content fleservers.txt | reset-computer -op Logoff

    In this example, all the computers listed in fleservers.txt will be 
    piped to Restart-Computer. Each computer will be logged off.
.Example
    PS C:\> "lab01","lab02","lab03" | reset-computer -op shutdown -force -verbose
    
    Shutdown computers lab01, lab02 and lab03 forcing applications close and
    displaying verbose information about what the function is doing.
.ReturnValue
    [BOOLEAN]   
             
.Link
   Get-WMIObject
      
.Notes
 NAME:      Reset-Computer
 VERSION:   1.1
 AUTHOR:    Don Jones/Jeffery Hicks
 LASTEDIT:  4/22/2009 5:00:00 PM
#requires -version 2.0
#>
 [CmdletBinding(
  SupportsShouldProcess=$True, 
  ConfrmImpact="high"
  )] 
      
param (
    [Parameter(
     ValueFromPipeline=$True,
     Position=0,
     Mandatory=$True,
     HelpMessage="Computer name(s) to target")] 
     [Alias("CN")]
     [String[]]$computerName,
    
     [Parameter(
      Mandatory=$false,
      Position=1,
      HelpMessage="Restart,Shutdown,PowerDown, or Logoff")]
     [Alias("OP")]
     [ValidateSet("Restart","Shutdown","PowerDown","Logoff")] 
     [String]$operation="Restart",
    
     [Parameter(
      HelpMessage="Forces applications to close")] 
     [Switch]$force
    )

BEGIN {
    Write-Debug "In the BEGIN script block."
    Write-Debug "passing value of operation $Operation to switch"
    switch ($operation) {
        "Logoff"    { $opcode = 0 }
        "Restart"   { $opcode = 2 }
        "Shutdown"  { $opcode = 1 }
        "PowerDown" { $opcode = 8 }
    }
    if ($force) {
       Write-Verbose "Using Force option"
       Write-Debug "Adding 4 to opcode ($opcode)"
        $opcode += 4
    }
    Write-Debug "Win32Shutdown opcode is $opcode"
}
PROCESS {
    trap {
        Write-Debug "trap called"
        Set-Variable -Name connected -Scope 1 -Value $false
        Write-Verbose "Connection to $computername failed"
        continue
    }
    Write-Verbose "Attempting connection to $computername"
    $connected = $True
    $wmi = Get-WmiObject win32_operatingsystem -computername $computerName -enableAllPrivileges 
-ea "Stop"
    
    Write-Debug "Creating custom PSObject"
    $obj = New-Object PSObject 
    $obj | Add-Member NoteProperty ComputerName $($computerName)
    $obj | Add-Member NoteProperty Success $false
    
    if ($connected) {
        Write-Debug "Connected is True"
        foreach    ($os in $wmi) {
            Write-Verbose "Attempting operation $opcode on $computername"
            if ($pscmdlet.shouldprocess($computername)) {
                Write-Debug "Calling the Win32Shutdown() method"
                $return = $os.win32shutdown($opcode)
                Write-Debug "return is $($return.returnvalue)"
                if ($return.returnvalue -eq 0) {
                    $obj.Success = $true
                }
                else {
                    Write-Debug "Action failed. Return is $return.returnvalue"
                }
            }
        }
    }
    Write-Debug "writing custom object to the pipeline"
    Write-Output $obj
}

END {
 Write-Debug "In the End script block"
 }
} #end function