install-python.ps1

param ($version)
$ErrorActionPreference = "Stop"
$prev_location = $pwd

if (!([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Start-Process PowerShell -Verb RunAs "-NoProfile -ExecutionPolicy Bypass -Command `"cd '$prev_location'; & '$PSCommandPath' $version;`"";
    exit;
}

# setup done

if ($null -eq $version) {
    $minor_version = "3.11.3"
}
$major_version = $minor_version.Split('.')
$major_version = $major_version[0] + $major_version[1]

$url = "https://www.python.org/ftp/python/$minor_version/python-$minor_version-amd64.exe"
$output = "C:/tmp/python-$minor_version-amd64.exe"
$install_path = "C:\Program Files\Python$major_version\python.exe"

# variables done

if (Test-Path $install_path) {
    Write-Output "python already installed at $install_path - skipping installation"
    Read-Host -Prompt "Press Enter to exit"
    return;
}

if (Test-Path $output) {
    Write-Output "python already downloaded at $output"
}
else {
    Write-Output "downloading python from $url ..."
    New-Item -ItemType Directory -Force -Path C:/tmp
    [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
    Invoke-WebRequest -Uri $url -OutFile $output
}

Write-Output "launching installer"

& $output /passive InstallAllUsers=1 PrependPath=1 Include_test=0 

Write-Output "installer launched"

# cleaning up

Set-Location $prev_location
Read-Host -Prompt "Press Enter to exit"