# Configuration Variables
$CompanyPrefix = "ABC" # Abbreviation for the company name
$LogFilePath = "C:\ComputerRenameLog.txt"

# Function to append log to the log file
function Write-Log {
    Param ([string]$message)
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    Add-Content -Path $LogFilePath -Value "$timestamp - $message"
}

# Check if running on Server OS
$os = Get-WmiObject -Class Win32_OperatingSystem
if ($os.ProductType -ne 1) {
    $logMessage = "This script is not designed to run on Server OS. Aborting."
    Write-Log -message $logMessage
    Write-Output $logMessage
    exit
}

# Automatic Device Type Detection for Laptop or Desktop
if (Get-WmiObject -Class Win32_Battery) {
    $deviceType = "L" # Assuming devices with a battery are laptops
} else {
    $deviceType = "D" # Everything else will be considered a desktop
}

# Main Script
$upn = whoami.exe /upn
$userNamePrefix = $upn.Split('@')[0].ToUpper()
$userNamePrefix = $userNamePrefix.Substring(0, [Math]::Min(5, $userNamePrefix.Length))
$randomNumber = Get-Random -Minimum 10 -Maximum 99
$newName = "$CompanyPrefix-$userNamePrefix-$deviceType$randomNumber"

$currentComputerName = $env:COMPUTERNAME
$pendingRenameKeyPath = "HKLM:\SYSTEM\CurrentControlSet\Control\ComputerName"
$activeComputerName = (Get-ItemProperty -Path "$pendingRenameKeyPath\ActiveComputerName").ComputerName
$pendingComputerName = (Get-ItemProperty -Path "$pendingRenameKeyPath\ComputerName").ComputerName

if ($activeComputerName -ne $pendingComputerName) {
    $logMessage = "A computer rename is pending. Exiting script."
    Write-Log -message $logMessage
    exit
}

Rename-Computer -NewName $newName -Force

$logMessage = "The device has been renamed to $newName"
Write-Log -message $logMessage
Write-Output $logMessage