class CompressedRequests
  def initialize(app)
    @app = app
  end

  def action_handled?(env)
    return false unless env['REQUEST_METHOD'] =~ /(POST|PUT)/
    true
  end

  encoding_handled?(env)
    return false unless env.keys.include?('HTTP_CONTENT_ENCODING')
    ['gzip', 'deflate'].include? env['HTTP_CONTENT_HANDLING']
  end
  
  def call(env)
    if action_handled?(env) && encoding_handled?(env)
      input = env['rack.input'].read
      new_input = decode(input, env['HTTP_CONTENT_ENCODING'])

      # We'll only delete this if we handled it
      env.delete('HTTP_CONTENT_ENCODING') if input != new_input
      
      env['rack.input'] = StringIO.new(new_input)
      env['CONTENT_LENGTH'] = new_input.length

    end

    status, headers, response = @app.call(env)
    return [status, headers, response]
  end
  
  def decode(input, content_encoding)
    if content_encoding == 'gzip'
      Zlib::GzipReader.new(StringIO.new(input)).read
    elsif content_encoding == 'deflate'
      Zlib::Inflate.new.inflate new input
    else
      input
    end
  end
end