Useful.psm1

function Find-MaybeChocolateyProgram($Path, $Name, $ChocolateyPackageName) {
  if (!$Path) {
    $commandFromEnvPath = Get-Command $Name
    if ($commandFromEnvPath -ne $null) {
      return $commandFromEnvPath.Definition
    }
    
    if (!(Test-Path env:ChocolateyInstall)) {
      throw "Chocolately not installed. Please tell me where $Name is."
    }
    
    $Path = Join-Path $env:ChocolateyInstall "bin\$Name"
    if (!(Test-Path $Path)) {
      throw "$Name not installed or not installed via chocolatey. " `
        + "Please ``choco install $ChocolateyPackageName`` or tell me where $Name is."
    }
  } elseif (!(Test-Path $Path)) {
    throw "$Name not found at $Path. Please check path or install $Name."
  } else {
    $Path
  }
}

function Install-EmacsExplorerIntegration(
  $EmacsPath,
  $Extensions=('.asm',
               '.c', '.clj', '.cljs', '.cljx', '.config', '.cpp', '.cs', '.csproj',
               '.d',
               '.el',
               '.fs', '.fsi',
               '.h', '.hpp', '.hs',
               '.java',
               '.log', '.lisp',
               '.markdown', '.md', '.ml',
               '.org',
               '.pl', '.proj', '.ps1', '.psd1', '.psm1', '.py',
               '.rb',
               '.tex', '.txt',
               '.xml'),
  [switch] $NoDiredHere)
{
  $EmacsPath = Find-MaybeChocolateyProgram $EmacsPath 'emacsclient.exe' 'emacs'

  if (!$NoDiredHere) {
    $diredHerePath = 'Registry::HKEY_CLASSES_ROOT\Directory\shell\DiredHere'
    New-Item $diredHerePath -Force
    Set-Item $diredHerePath 'Open Emacs Dired Here'

    $commandPath = Join-Path $diredHerePath 'command'
    New-Item $commandPath -Force
    Set-Item $commandPath -Value "$EmacsPath '%L'"
  }

  foreach ($ext in $Extensions) {
    $diredHerePath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\$ext\UserChoice"
    #  [HKEY_CLASSES_ROOT\*\Shell\Open In Emacs\Command]
    #@="\"C:\\bin\\Emacs-23.1\\bin\\emacsclientw.exe\" -a \"C:\\bin\\Emacs-23.1\\bin\\runemacs.exe\" \"%1\""
  }
}