Get-Date
Write-Host "Installing Chocolatey"
Invoke-Expression ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))
Import-Module "$env:ProgramData\chocolatey\helpers\chocolateyProfile.psm1"
Update-SessionEnvironment
Write-Host "Installing Chocolatey packages"

# Chocolatey tries to download winflexbison from SourceForge, which is not super reliable, and has no retry
# loop of its own - so we give it a helping hand here
For ($i = 0; $i -lt 5; $i++) {
  choco install -y python3 --params="/InstallDir:C:\python3"
  $python_install = $?
  choco install --allow-empty-checksums -y cmake git git-lfs ninja pkgconfiglite winflexbison --installargs "ADD_CMAKE_TO_PATH=System"
  $other_install = $?
  $choco_installed = $other_install -and $python_install
  if ($choco_installed) {
    Break
  }
}

if (!$choco_installed) {
  Write-Host "Couldn't install dependencies from Chocolatey"
  Exit 1
}

# Add Chocolatey's native install path
Update-SessionEnvironment
# Python and CMake add themselves to the system environment path, which doesn't get refreshed
# until we start a new shell
$env:PATH = "C:\python3;C:\python3\scripts;C:\Program Files\CMake\bin;$env:PATH"

Start-Process -NoNewWindow -Wait git -ArgumentList 'config --global core.autocrlf false'

Get-Date
Write-Host "Installing Meson and Mako"
pip3 install meson mako
if (!$?) {
  Write-Host "Failed to install dependencies from pip"
  Exit 1
}

# we want more secure TLS 1.2 for most things, but it breaks SourceForge
# downloads so must be done after Chocolatey use
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12;

# VS16.x is 2019
$msvc_2019_url = 'https://aka.ms/vs/16/release/vs_buildtools.exe'

Get-Date
Write-Host "Downloading Visual Studio 2019 build tools"
Invoke-WebRequest -Uri $msvc_2019_url -OutFile C:\vs_buildtools.exe

Get-Date
Write-Host "Installing Visual Studio 2019"
Start-Process -NoNewWindow -Wait C:\vs_buildtools.exe -ArgumentList '--wait --quiet --norestart --nocache --installPath C:\BuildTools --add Microsoft.VisualStudio.Workload.VCTools --add Microsoft.VisualStudio.Workload.NativeDesktop --add Microsoft.VisualStudio.Component.VC.ATL --add Microsoft.VisualStudio.Component.VC.ATLMFC --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 --add Microsoft.VisualStudio.Component.Graphics.Tools --add Microsoft.VisualStudio.Component.Windows10SDK.18362 --includeRecommended'
if (!$?) {
  Write-Host "Failed to install Visual Studio tools"
  Exit 1
}
Remove-Item C:\vs_buildtools.exe -Force

Get-Date
Write-Host "Cloning LLVM 10.x"
git clone -b release/10.x --depth=1 https://github.com/llvm/llvm-project llvm-project
if (!$?) {
  Write-Host "Failed to clone LLVM repository"
  Exit 1
}

Get-Date
# slightly convoluted syntax but avoids the CWD being under the PS filesystem meta-path
$llvm_build = New-Item -ItemType Directory -Path ".\llvm-project" -Name "build"
Push-Location -Path $llvm_build.FullName
Write-Host "Compiling LLVM and Clang"
cmd.exe /C 'C:\BuildTools\Common7\Tools\VsDevCmd.bat -host_arch=amd64 -arch=amd64 && cmake ../llvm -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_CRT_RELEASE=MT -DCMAKE_INSTALL_PREFIX="C:\llvm-10" -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_OPTIMIZED_TABLEGEN=TRUE -DLLVM_ENABLE_ASSERTIONS=TRUE -DLLVM_INCLUDE_UTILS=OFF -DLLVM_INCLUDE_RUNTIMES=OFF -DLLVM_INCLUDE_TESTS=OFF -DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_INCLUDE_GO_TESTS=OFF -DLLVM_INCLUDE_BENCHMARKS=OFF -DLLVM_BUILD_LLVM_C_DYLIB=OFF -DLLVM_ENABLE_DIA_SDK=OFF -DCLANG_BUILD_TOOLS=ON && ninja -j4 install'
$buildstatus = $?
Pop-Location
Remove-Item -Recurse -Path $llvm_build
if (!$buildstatus) {
  Write-Host "Failed to compile LLVM"
  Exit 1
}

Get-Date
Write-Host "Complete"