#!/usr/bin/python

"""Redirects all HTTP requests to the specified URL."""

import optparse
import sys
import tornado.ioloop
import tornado.web
import tornado.httpclient

PKI_HOSTS = set(['pki.google.com', 'clients1.google.com'])

class Redirector(tornado.web.RequestHandler):

  def initialize(self, url):
    self._url = url
    self._http_client = tornado.httpclient.HTTPClient()

  def get(self):
    if self._is_crl_request():
      # proxy CRL/OCSP requests. Workaround for b/19825798.
      url = '%s://%s%s' % (self.request.protocol, self.request.host,
                           self.request.uri)
      print 'Forwarding request to %s' % url
      response = self._http_client.fetch(url)
      for (name, value) in response.headers.get_all():
        self.set_header(name, value)
      self.write(response.body)
    else:
      self.redirect(self._url)

  def _is_crl_request(self):
    uri = self.request.uri
    return self.request.host in PKI_HOSTS and (uri.startswith('/ocsp/')
        or uri.endswith('.crl'))

if __name__ == '__main__':
  parser = optparse.OptionParser()
  parser.add_option('-p', '--port', type='int')
  parser.add_option('-u', '--url', type='string')
  options, args = parser.parse_args(sys.argv)

  if not options.port or not options.url:
    sys.stderr.write('port and url are required\n')
    sys.exit(1)

  application = tornado.web.Application([
      (r'.*', Redirector, dict(url=options.url)),
  ])
  application.listen(options.port)
  tornado.ioloop.IOLoop.instance().start()