if(!$args[0])
{
    Write-Output "Year - NULL in argument"
    exit 1
}
$year = $args[0]

if($args[0] -ne "1" -and $args[0] -ne "2" -and $args[0] -ne "3")
{
    Write-Output "Invalid Year : $year"
    exit 1
}

if(!$args[1])
{
    Write-Output "ESU Key - NULL in argument"
    exit 1
}

$esukey = $args[1]
$osname = (Get-WmiObject Win32_OperatingSystem).Caption
Write-Output "OSName : $osname"
$activationid = ""

if($osname -ilike "*Server 2008*")
{
    Write-Output "Server OS"
    if($year -eq "1")
    {
        Write-Output "Checking for Year 1"
        $activationid = "553673ed-6ddf-419c-a153-b760283472fd"
    }
    elseif($year -eq "2")
    {
        Write-Output "Checking for Year 2"
        $activationid = "04fa0286-fa74-401e-bbe9-fbfbb158010d"
    }
    elseif($year -eq "3")
    {
        Write-Output "Checking for Year 3"
        $activationid = "16c08c85-0c8b-4009-9b2b-f1f7319e45f9"
    }
    else
    {
        Write-Output "Invalid Year $year"
    }
}
elseif($osname -like "*Windows 7*")
{   
    Write-Output "Workstation OS"
    if($year -eq "1")
    {
        Write-Output "Checking for Year 1"
        $activationid = "77db037b-95c3-48d7-a3ab-a9c6d41093e0"
    }
    elseif($year -eq "2")
    {
        Write-Output "Checking for Year 2"
        $activationid = "0e00c25d-8795-4fb7-9572-3803d91b6880"
    }
    elseif($year -eq "3")
    {
        Write-Output "Checking for Year 3"
        $activationid = "4220f546-f522-46df-8202-4d07afd26454"
    }
    else
    {
        Write-Output "Invalid Year $year"
        exit 1
    }   
}
else
{
    Write-Output "Not applicable for OS : $osname"
    exit 1
}

$LicenseStatus = (Get-WmiObject -query "SELECT * FROM SoftwareLicensingProduct WHERE ID like '$activationid'").LicenseStatus
if($LicenseStatus -eq "1")
{
    Write-Output "ESU Installed and Licensed"
    exit 0
}
elseif($LicenseStatus -eq "0")
{
    Write-Output "ESU Installed but Unlicensed, will help you to activate ESU key"
    cscript.exe C:\windows\system32\slmgr.vbs /ato $activationid
}
else
{
    Write-Output "Can’t find this ESU key, will help you to add and activate ESU key"
    cscript.exe C:\windows\system32\slmgr.vbs /ipk $esukey
    cscript.exe C:\windows\system32\slmgr.vbs /ato $activationid
}

$LicenseStatus = (Get-WmiObject -query "SELECT * FROM SoftwareLicensingProduct WHERE ID like '$activationid'").LicenseStatus
if($LicenseStatus -eq "1")
{
    Write-Output "ESU Installed and Licensed"
    exit 0   
}
elseif($LicenseStatus -eq "0")
{
    Write-Output "Failed to activate ESU license."   
    exit 1
}
else
{
    Write-Output "Failed to install ESU license."
    exit 1
}