require 'webrick'
require 'stringio'

module Rack
  module Handler
    class WEBrick < WEBrick::HTTPServlet::AbstractServlet
      def self.run(app, options={})
        server = ::WEBrick::HTTPServer.new(options)
        server.mount "/", Rack::Handler::WEBrick, app
        trap(:INT) { server.shutdown }
        yield server  if block_given?
        server.start
      end

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

      def service(req, res)
        env = req.meta_vars
        env.delete_if { |k, v| v.nil? }

        env.update({"rack.version" => [0,1],
                     "rack.input" => StringIO.new(req.body.to_s),
                     "rack.errors" => STDERR,

                     "rack.multithread" => true,
                     "rack.multiprocess" => false,
                     "rack.run_once" => false,

                     "rack.url_scheme" => ["yes", "on", "1"].include?(ENV["HTTPS"]) ? "https" : "http"
                   })

        env["HTTP_VERSION"] ||= env["SERVER_PROTOCOL"]
        env["QUERY_STRING"] ||= ""
        env["REQUEST_PATH"] ||= "/"
        env.delete "PATH_INFO"  if env["PATH_INFO"] == ""

        status, headers, body = @app.call(env)
        begin
          res.status = status.to_i
          headers.each { |k, vs|
            vs.each { |v|
              res[k] = v
            }
          }
          body.each { |part|
            res.body << part
          }
        ensure
          body.close  if body.respond_to? :close
        end
      end
    end
  end
end