# $kNotwork: toyproxy.rb,v 1.5 2002/01/07 15:49:10 gotoken Exp $
require "webrick"
require "net/http"

class HTTPProxyServer < WEBrick::HTTPServer
  class HTTPProxyServlet < WEBrick::HTTPServlet::AbstractServlet
    include Net
    include WEBrick
    HTTP::version_1_2 if RUBY_VERSION =~ /^1\.6/

    def service(req, res)
      res.http_version = "1.0"
      method_name = req.request_method
      scheme, host, port, path, header = preprocess(req,res)

      begin
        http = HTTP.new(host, port)

	##################################   these issues are 
	http.open_timeout = 30  # secs  #   necessary (maybe bacause
	http.read_timeout = 60  # secs  #   Ruby's bug, but why?)
	##################################

        case method_name
        when "GET"
          response = http.get(path, header)
          res.body = response.body
        when "POST"
          response = http.post(path, req.body, header)
          res.body = response.body
        when "HEAD"
          response = http.head(path, header)
        else
          raise HTTPStatus::MethodNotAllowed,
            "unsupported method `#{req.request_method}'."
        end
      rescue SocketError, Errno::ECONNREFUSED => err
        raise HTTPStatus::ServiceUnavailable, err.message
      end

      response.each do |name,value|
        res[name] = value
        @logger.debug ">#{name}: #{value}"
      end
      res['Proxy-Connection'] = 'closed'
      res.status = response.code.to_i
    end

    private

    def preprocess(req,res)
      if @config[:AuthProc]
	HTTPAuth::proxy_basic_auth(req,res,"hogehoge",&@config[:AuthProc])
      end

      req.header.delete("proxy-authorization")
      if %r!^/! =~ req.request_uri.to_s
        raise HTTPStatus::BadRequest, req.request_uri.to_s
      end

      uri = req.request_uri
      scheme = uri.scheme
      host = uri.host
      port = uri.port
      path = uri.path
      query = uri.query
      query[0,0] = "?" if query

      # create Net::HTTP compatible header
      header = Hash.new
      req.each{|k,v| header[k] = v}
      req.raw_header.each{|line| @logger.debug '<'+line.chomp}
      [scheme, host, port, "#{path}#{query}", header]
    end

    def initialize(config, *options)
      super
      @logger = @config[:Logger]
    end
  end

  def initialize(config, default = WEBrick::Config::HTTP)
    super
    mount("/", HTTPProxyServlet)
  end
end

if __FILE__ == $0
  require 'getopts'
  include WEBrick
  getopts("d", "port:8128", "logfile:")
  $-d = $OPT_d
  log = $OPT_logfile ? open($OPT_logfile, "a") : STDERR

  passwd = {"user" => "passwd"}

  config = {
    :Port => $OPT_port,
    :Logger => Log.new(log, ($OPT_d ? Log::DEBUG : Log::INFO)), 
    :AuthProc => lambda{|user,pass| user and passwd[user] == pass},
  }

  proxy = HTTPProxyServer.new(config)
  trap('INT'){ proxy.shutdown }
  trap('TERM'){ proxy.shutdown }
  proxy.start
end