class Rack::Multipart::Generator

def content_for_other(file, name)

LTIPART_BOUNDARY}\r
t-disposition: form-data; name="#{name}"\r
}\r
end

def content_for_tempfile(io, file, name)
  length = ::File.stat(file.path).size if file.path
  filename = "; filename=\"#{Utils.escape_path(file.original_filename)}\""

LTIPART_BOUNDARY}\r
t-disposition: form-data; name="#{name}"#{filename}\r
t-type: #{file.content_type}\r
tent-length: #{length}\r\n" if length}\r
ead}\r
end

def dump
  return nil if @first && !multipart?
  return flattened_params unless @first
  flattened_params.map do |name, file|
    if file.respond_to?(:original_filename)
      if file.path
        ::File.open(file.path, 'rb') do |f|
          f.set_encoding(Encoding::BINARY)
          content_for_tempfile(f, file, name)
        end
      else
        content_for_tempfile(file, file, name)
      end
    else
      content_for_other(file, name)
    end
  end.join << "--#{MULTIPART_BOUNDARY}--\r"
end

def flattened_params
  @flattened_params ||= begin
    h = Hash.new
    @params.each do |key, value|
      k = @first ? key.to_s : "[#{key}]"
      case value
      when Array
        value.map { |v|
          Multipart.build_multipart(v, false).each { |subkey, subvalue|
            h["#{k}[]#{subkey}"] = subvalue
          }
        }
      when Hash
        Multipart.build_multipart(value, false).each { |subkey, subvalue|
          h[k + subkey] = subvalue
        }
      else
        h[k] = value
      end
    end
    h
  end
end

def initialize(params, first = true)
  @params, @first = params, first
  if @first && !@params.is_a?(Hash)
    raise ArgumentError, "value must be a Hash"
  end
end

def multipart?
  query = lambda { |value|
    case value
    when Array
      value.any?(&query)
    when Hash
      value.values.any?(&query)
    when Rack::Multipart::UploadedFile
      true
    end
  }
  @params.values.any?(&query)
end