class Rack::Handler::WEBrick

def self.run(app, **options)
  environment  = ENV['RACK_ENV'] || 'development'
  default_host = environment == 'development' ? 'localhost' : nil
  if !options[:BindAddress] || options[:Host]
    options[:BindAddress] = options.delete(:Host) || default_host
  end
  options[:Port] ||= 8080
  if options[:SSLEnable]
    require 'webrick/https'
  end
  @server = ::WEBrick::HTTPServer.new(options)
  @server.mount "/", Rack::Handler::WEBrick, app
  yield @server  if block_given?
  @server.start
end

def self.shutdown
  if @server
    @server.shutdown
    @server = nil
  end
end

def self.valid_options
  environment  = ENV['RACK_ENV'] || 'development'
  default_host = environment == 'development' ? 'localhost' : '0.0.0.0'
  {
    "Host=HOST" => "Hostname to listen on (default: #{default_host})",
    "Port=PORT" => "Port to listen on (default: 8080)",
  }
end

def initialize(server, app)
  super server
  @app = app
end

def service(req, res)
  res.rack = true
  env = req.meta_vars
  env.delete_if { |k, v| v.nil? }
  rack_input = StringIO.new(req.body.to_s)
  rack_input.set_encoding(Encoding::BINARY)
  env.update(
    RACK_VERSION      => Rack::VERSION,
    RACK_INPUT        => rack_input,
    RACK_ERRORS       => $stderr,
    RACK_MULTITHREAD  => true,
    RACK_MULTIPROCESS => false,
    RACK_RUNONCE      => false,
    RACK_URL_SCHEME   => ["yes", "on", "1"].include?(env[HTTPS]) ? "https" : "http",
    RACK_IS_HIJACK    => true,
    RACK_HIJACK       => lambda { raise NotImplementedError, "only partial hijack is supported."},
    RACK_HIJACK_IO    => nil
  )
  env[HTTP_VERSION] ||= env[SERVER_PROTOCOL]
  env[QUERY_STRING] ||= ""
  unless env[PATH_INFO] == ""
    path, n = req.request_uri.path, env[SCRIPT_NAME].length
    env[PATH_INFO] = path[n, path.length - n]
  end
  env[REQUEST_PATH] ||= [env[SCRIPT_NAME], env[PATH_INFO]].join
  status, headers, body = @app.call(env)
  begin
    res.status = status.to_i
    io_lambda = nil
    headers.each { |k, vs|
      if k == RACK_HIJACK
        io_lambda = vs
      elsif k.downcase == "set-cookie"
        res.cookies.concat vs.split("\n")
      else
        # Since WEBrick won't accept repeated headers,
        # merge the values per RFC 1945 section 4.2.
        res[k] = vs.split("\n").join(", ")
      end
    }
    if io_lambda
      rd, wr = IO.pipe
      res.body = rd
      res.chunked = true
      io_lambda.call wr
    elsif body.respond_to?(:to_path)
      res.body = ::File.open(body.to_path, 'rb')
    else
      body.each { |part|
        res.body << part
      }
    end
  ensure
    body.close  if body.respond_to? :close
  end
end