class ActionDispatch::FileHandler

def call(env)
  @file_server.call(env)
end

def clean_path_info(path_info)
  parts = path_info.split PATH_SEPS
  clean = []
  parts.each do |part|
    next if part.empty? || part == '.'
    part == '..' ? clean.pop : clean << part
  end
  clean.unshift '/' if parts.empty? || parts.first.empty?
  ::File.join(*clean)
end

def escape_glob_chars(path)
  path.gsub(/[*?{}\[\]\\]/, "\\\\\\&")
end

def ext
  @ext ||= begin
    ext = ::ActionController::Base.default_static_extension
    "{,#{ext},/index#{ext}}"
  end
end

def initialize(root, cache_control)
  @root          = root.chomp('/')
  @compiled_root = /^#{Regexp.escape(root)}/
  headers = cache_control && { 'Cache-Control' => cache_control }
  @file_server   = ::Rack::File.new(@root, headers)
end

def match?(path)
  path = unescape_path(path)
  return false unless path.valid_encoding?
  full_path = path.empty? ? @root : File.join(@root,
    clean_path_info(escape_glob_chars(path)))
  paths = "#{full_path}#{ext}"
  matches = Dir[paths]
  match = matches.detect { |m| File.file?(m) && File.readable?(m) }
  if match
    match.sub!(@compiled_root, '')
    ::Rack::Utils.escape(match)
  end
end

def unescape_path(path)
  URI.parser.unescape(path)
end