[CmdletBinding(SupportsShouldProcess = $true)]
param(
    [string]$ServiceName = "ScreenJobBackend"
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

function Test-IsAdministrator {
    $identity = [Security.Principal.WindowsIdentity]::GetCurrent()
    $principal = New-Object Security.Principal.WindowsPrincipal($identity)
    return $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
}

if (-not (Test-IsAdministrator)) {
    throw "Run this script from an elevated PowerShell session (Run as Administrator)."
}

$service = Get-Service -Name $ServiceName -ErrorAction SilentlyContinue
if ($null -eq $service) {
    Write-Host "Service '$ServiceName' is not installed."
    exit 0
}

if ($PSCmdlet.ShouldProcess($ServiceName, "Uninstall service")) {
    if ($service.Status -ne "Stopped") {
        Stop-Service -Name $ServiceName -Force -ErrorAction Stop
    }

    & sc.exe delete $ServiceName | Out-Null
    if ($LASTEXITCODE -ne 0) {
        throw "Failed to delete service '$ServiceName' (sc.exe exit code $LASTEXITCODE)."
    }
}

Write-Host "Service '$ServiceName' uninstalled successfully." -ForegroundColor Green