Param(
    [string] $Version = "12.0.0",
    [string] $InstallDestination = "C:\Program Files\LLVM"
)

$ErrorActionPreference = 'Stop'

$HOME_DIR = if ($env:HOME) { $env:HOME } else { $env:USERPROFILE }

$url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-${Version}/LLVM-${Version}-win64.exe"

$llvmTemp = "$HOME_DIR/llvm-temp"
$install = "$llvmTemp/llvm.exe"

# download
Write-Host "Downloading LLVM..."
New-Item -ItemType Directory -Force -Path "$llvmTemp" | Out-Null
(New-Object System.Net.WebClient).DownloadFile("$url", "$install")

# install
Write-Host "Installing LLVM..."
& 7z x $install -y -o"$InstallDestination"

# echo version
& "$InstallDestination\bin\clang.exe" --version

# make sure that LLVM is in LLVM_HOME
Write-Host "##vso[task.setvariable variable=LLVM_HOME;]$InstallDestination";

# TODO: update the version of `win_vcvars_version` in
#       - native\windows\build.cake
#       - native\uwp\build.cake

exit $LASTEXITCODE