# -*- Ruby -*-

require 'win32ole'

class WinShell
  # Get the path separator used by common ruby classes such as Dir and File.
  def separator()
    return File.const_get('SEPARATOR')
  end

  # My shell is the ole object "Shell" as described in the Windows SDK.
  def shell()
    # lazy initialisation, don't use @shell directly!
    @shell = WIN32OLE.new('Shell.application') if !@shell
    return @shell
  end

  # Has filename the Extension ext (e. g. ".jpg")
  def hasExtension?(filename, ext)
    raise ArgumentError, "Extension missing" if ext.empty?
    pExt = (ext[0] == '.'[0] ? ext : '.' + ext).downcase
    dcFilename = filename.downcase
    return File.basename(dcFilename, pExt) != dcFilename
  end

  # Is filename a Windows shortcut?
  def link?(filename)
    return hasExtension?(filename, '.lnk')
  end

  # Get a path string usable by Windows systems.
  def winPath(pathString)
    return pathString.gsub(separator, "\\")
  end

  # Get a path string usable by common ruby classes such as Dir and File.
  def rubyPath(pathString)
    return pathString.gsub(/\\/, separator)
  end

  # Get Directory entries as ole-objects, not as strings!
  def getFolderItems(directoryPathString)
    folder = shell.NameSpace(winPath(directoryPathString))
    raise "Folderermittlung fehlgeschlagen" if !folder
    items = folder.items
    return (0..items.Count-1).collect { |i| items.item(i) }
  end

  #Get the path stored in the Windows shortcut filename. PRE: link?(filename)
  def getLinkTarget(filename, pathString = Dir.getwd)
    raise(ArgumentError, "Kein Link") if !link?(filename)
    ext = '.' + filename.split('.')[-1]
    linkdef = File.basename(filename,  ext)
    raise ArgumentError, "Linkname leer" if linkdef.empty?
    item = getFolderItems(pathString).find { |fi|
      linkdef == (fi.Name.to_s) }
    return item ? rubyPath(item.GetLink.Path.to_s) : ''
  end
end

shell = WinShell.new
ARGV.each { | arg |
  if shell.link?(arg)
    puts "#{arg} =>\n#{shell.getLinkTarget(arg)}"
  end
}