name: Install Cygwin
description: Install Cygwin & packages

inputs:
  platform:
    description: Target platform
    required: false
    default: x64
  install-dir:
    description: Installation directory
    required: false
    default: C:\tools\cygwin
  packages:
    description: Packages to install, separated by a space
    required: false
  env:
    description: Value to set as the CYGWIN environment variable
    required: false
  symlinks-to-hardlinks:
    description: Convert symlinks in /usr/bin to hardlinks
    required: false
    default: 0

runs:
  using: composite
  steps:
    - run: |
        New-Variable os -Value ('${{ runner.os }}') -Option Constant

        New-Variable windows_host -Value ($os -eq 'Windows') -Option Constant

        New-Variable x64 -Value ('${{ inputs.platform }}' -eq 'x64') -Option Constant
        New-Variable install_dir -Value '${{ inputs.install-dir }}' -Option Constant
        New-Variable packages -Value '${{ inputs.packages }}' -Option Constant
        New-Variable symlinks_to_hardlinks -Value ('${{ inputs.symlinks-to-hardlinks }}' -eq '1') -Option Constant

        New-Variable bin_dir -Value (Join-Path $install_dir bin) -Option Constant
        New-Variable realpath -Value (Join-Path $bin_dir realpath.exe) -Option Constant
        New-Variable readlink -Value (Join-Path $bin_dir readlink.exe) -Option Constant
        New-Variable dirname -Value (Join-Path $bin_dir dirname.exe) -Option Constant
        New-Variable cygpath -Value (Join-Path $bin_dir cygpath.exe) -Option Constant
        New-Variable find -Value (Join-Path $bin_dir find.exe) -Option Constant

        function Locate-Choco {
            $path = Get-Command 'choco' -ErrorAction SilentlyContinue
            if ($path) {
                $path.Path
            } else {
                Join-Path ${env:ProgramData} 'chocolatey' 'bin' 'choco'
            }
        }

        function Convert-CygwinPath {
            # Like cygpath -wa, but don't resolve symlinks.
            param(
                [Parameter(Mandatory=$true)]
                [string] $Path
            )

            $realpath = & $script:realpath --no-symlinks -- $Path
            $dirname = & $script:dirname -- $realpath
            $dirname = & $script:cygpath -wa $dirname
            Join-Path $dirname (Split-Path $realpath -Leaf)
        }

        function Fix-CygwinLink {
            # Replace a Cygwin symlink with a hardlink.
            param(
                [Parameter(Mandatory=$true)]
                [string] $Path
            )

            $link_path = $Path
            $link_winpath = Convert-CygwinPath $link_path
            $link_ext = [System.IO.Path]::GetExtension($link_path)

            $dest_path = & $script:readlink --canonicalize-existing -- $link_path
            $dest_winpath = Convert-CygwinPath $dest_path
            $dest_ext = [System.IO.Path]::GetExtension($dest_path)

            echo "Removing symlink: $link_winpath"
            Remove-Item $link_winpath -Force

            # If target is an executable (i.e. its name contains one of the
            # PATHEXT extensions), make sure the hardlink has the same
            # extension.
            $exe_exts = $env:PATHEXT.ToLower().Split(';', [System.StringSplitOptions]::RemoveEmptyEntries)
            if ($exe_exts -contains $dest_ext.ToLower() -and $dest_ext.ToLower() -ne $link_ext.ToLower()) {
                $link_winpath += $dest_ext
            }
            echo "Creating hardlink '$link_winpath', pointing to '$dest_winpath'"
            New-Item -ItemType HardLink -Path $link_winpath -Value $dest_winpath | Out-Null
        }

        if ($windows_host) {
            echo 'CYGWIN=${{ inputs.env }}' >> $env:GITHUB_ENV

            $choco = Locate-Choco

            $choco_params = @(
                'install',
                '-y',
                '--no-progress',
                '--params', "/InstallDir:$install_dir"
            )
            if (!$x64) {
                $choco_params += '--x86'
            }
            $choco_params += 'cygwin'

            # Assuming that Cygwin is not installed when this is run.
            & $choco $choco_params

            # /usr/bin is really just /bin on Cygwin.
            echo (Join-Path $install_dir bin) >> $env:GITHUB_PATH
            echo (Join-Path $install_dir usr local bin) >> $env:GITHUB_PATH

            $pkg_list = $packages.Split(' ', [System.StringSplitOptions]::RemoveEmptyEntries)

            if ($pkg_list.Count -gt 0) {
                & $choco install -y --no-progress --source=cygwin $pkg_list
            }

            if ($symlinks_to_hardlinks) {
                & $find /usr/bin -type l | %{ Fix-CygwinLink $_ }
            }
        } else {
            throw "Sorry, installing Cygwin is unsupported on $os"
        }
      shell: pwsh

branding:
  icon: star
  color: green