text: # coding: utf-8
  """A tornado based IPython notebook server.
  
  Authors:
  
  * Brian Granger
  """
  #-----------------------------------------------------------------------------
  #  Copyright (C) 2008-2011  The IPython Development Team
  #
  #  Distributed under the terms of the BSD License.  The full license is in
  #  the file COPYING, distributed as part of this software.
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  # stdlib
  import errno
  import logging
  import os
  import random
  import re
  import select
  import signal
  import socket
  import sys
  import threading
  import time
  import uuid
  import webbrowser
  
  # Third party
  import zmq
  from jinja2 import Environment, FileSystemLoader
  
  # Install the pyzmq ioloop. This has to be done before anything else from
  # tornado is imported.
  from zmq.eventloop import ioloop
  ioloop.install()
  
  from tornado import httpserver
  from tornado import web
  
  # Our own libraries
  from .kernelmanager import MappingKernelManager
  from .handlers import (LoginHandler, LogoutHandler,
      ProjectDashboardHandler, NewHandler, NamedNotebookHandler,
      MainKernelHandler, KernelHandler, KernelActionHandler, IOPubHandler,
      ShellHandler, NotebookRootHandler, NotebookHandler, NotebookCopyHandler,
      RSTHandler, AuthenticatedFileHandler, PrintNotebookHandler,
      MainClusterHandler, ClusterProfileHandler, ClusterActionHandler,
      FileFindHandler,
  )
  from .nbmanager import NotebookManager
  from .filenbmanager import FileNotebookManager
  from .clustermanager import ClusterManager
  
  from IPython.config.application import catch_config_error, boolean_flag
  from IPython.core.application import BaseIPythonApplication
  from IPython.core.profiledir import ProfileDir
  from IPython.frontend.consoleapp import IPythonConsoleApp
  from IPython.lib.kernel import swallow_argv
  from IPython.zmq.session import Session, default_secure
  from IPython.zmq.zmqshell import ZMQInteractiveShell
  from IPython.zmq.ipkernel import (
      flags as ipkernel_flags,
      aliases as ipkernel_aliases,
      IPKernelApp
  )
  from IPython.utils.importstring import import_item
  from IPython.utils.traitlets import (
      Dict, Unicode, Integer, List, Enum, Bool,
      DottedObjectName
  )
  from IPython.utils import py3compat
  from IPython.utils.path import filefind
  
  #-----------------------------------------------------------------------------
  # Module globals
  #-----------------------------------------------------------------------------
  
  _kernel_id_regex = r"(?P<kernel_id>\w+-\w+-\w+-\w+-\w+)"
  _kernel_action_regex = r"(?P<action>restart|interrupt)"
  _notebook_id_regex = r"(?P<notebook_id>\w+-\w+-\w+-\w+-\w+)"
  _profile_regex = r"(?P<profile>[^\/]+)" # there is almost no text that is invalid
  _cluster_action_regex = r"(?P<action>start|stop)"
  
  
  LOCALHOST = '127.0.0.1'
  
  _examples = """
  ipython notebook                       # start the notebook
  ipython notebook --profile=sympy       # use the sympy profile
  ipython notebook --pylab=inline        # pylab in inline plotting mode
  ipython notebook --certfile=mycert.pem # use SSL/TLS certificate
  ipython notebook --port=5555 --ip=*    # Listen on port 5555, all interfaces
  """
  
  #-----------------------------------------------------------------------------
  # Helper functions
  #-----------------------------------------------------------------------------
  
  def url_path_join(a,b):
      if a.endswith('/') and b.startswith('/'):
          return a[:-1]+b
      else:
          return a+b
  
  def random_ports(port, n):
      """Generate a list of n random ports near the given port.
  
      The first 5 ports will be sequential, and the remaining n-5 will be
      randomly selected in the range [port-2*n, port+2*n].
      """
      for i in range(min(5, n)):
          yield port + i
      for i in range(n-5):
          yield port + random.randint(-2*n, 2*n)
  
  #-----------------------------------------------------------------------------
  # The Tornado web application
  #-----------------------------------------------------------------------------
  
  class NotebookWebApplication(web.Application):
  
      def __init__(self, ipython_app, kernel_manager, notebook_manager, 
                   cluster_manager, log,
                   base_project_url, settings_overrides):
          handlers = [
              (r"/", ProjectDashboardHandler),
              (r"/login", LoginHandler),
              (r"/logout", LogoutHandler),
              (r"/new", NewHandler),
              (r"/%s" % _notebook_id_regex, NamedNotebookHandler),
              (r"/%s/copy" % _notebook_id_regex, NotebookCopyHandler),
              (r"/%s/print" % _notebook_id_regex, PrintNotebookHandler),
              (r"/kernels", MainKernelHandler),
              (r"/kernels/%s" % _kernel_id_regex, KernelHandler),
              (r"/kernels/%s/%s" % (_kernel_id_regex, _kernel_action_regex), KernelActionHandler),
              (r"/kernels/%s/iopub" % _kernel_id_regex, IOPubHandler),
              (r"/kernels/%s/shell" % _kernel_id_regex, ShellHandler),
              (r"/notebooks", NotebookRootHandler),
              (r"/notebooks/%s" % _notebook_id_regex, NotebookHandler),
              (r"/rstservice/render", RSTHandler),
              (r"/files/(.*)", AuthenticatedFileHandler, {'path' : notebook_manager.notebook_dir}),
              (r"/clusters", MainClusterHandler),
              (r"/clusters/%s/%s" % (_profile_regex, _cluster_action_regex), ClusterActionHandler),
              (r"/clusters/%s" % _profile_regex, ClusterProfileHandler),
          ]
  
          # Python < 2.6.5 doesn't accept unicode keys in f(**kwargs), and
          # base_project_url will always be unicode, which will in turn
          # make the patterns unicode, and ultimately result in unicode
          # keys in kwargs to handler._execute(**kwargs) in tornado.
          # This enforces that base_project_url be ascii in that situation.
          # 
          # Note that the URLs these patterns check against are escaped,
          # and thus guaranteed to be ASCII: 'héllo' is really 'h%C3%A9llo'.
          base_project_url = py3compat.unicode_to_str(base_project_url, 'ascii')
          
          settings = dict(
              template_path=os.path.join(os.path.dirname(__file__), "templates"),
              static_path=ipython_app.static_file_path,
              static_handler_class = FileFindHandler,
              static_url_prefix = url_path_join(base_project_url,'/static/'),
              cookie_secret=os.urandom(1024),
              login_url=url_path_join(base_project_url,'/login'),
              cookie_name='username-%s' % uuid.uuid4(),
          )
  
          # allow custom overrides for the tornado web app.
          settings.update(settings_overrides)
  
          # prepend base_project_url onto the patterns that we match
          new_handlers = []
          for handler in handlers:
              pattern = url_path_join(base_project_url, handler[0])
              new_handler = tuple([pattern]+list(handler[1:]))
              new_handlers.append( new_handler )
  
          super(NotebookWebApplication, self).__init__(new_handlers, **settings)
  
          self.kernel_manager = kernel_manager
          self.notebook_manager = notebook_manager
          self.cluster_manager = cluster_manager
          self.ipython_app = ipython_app
          self.read_only = self.ipython_app.read_only
          self.log = log
          self.jinja2_env = Environment(loader=FileSystemLoader(os.path.join(os.path.dirname(__file__), "templates")))
  
  
  
  #-----------------------------------------------------------------------------
  # Aliases and Flags
  #-----------------------------------------------------------------------------
  
  flags = dict(ipkernel_flags)
  flags['no-browser']=(
      {'NotebookApp' : {'open_browser' : False}},
      "Don't open the notebook in a browser after startup."
  )
  flags['no-mathjax']=(
      {'NotebookApp' : {'enable_mathjax' : False}},
      """Disable MathJax
      
      MathJax is the javascript library IPython uses to render math/LaTeX. It is
      very large, so you may want to disable it if you have a slow internet
      connection, or for offline use of the notebook.
      
      When disabled, equations etc. will appear as their untransformed TeX source.
      """
  )
  flags['read-only'] = (
      {'NotebookApp' : {'read_only' : True}},
      """Allow read-only access to notebooks.
      
      When using a password to protect the notebook server, this flag
      allows unauthenticated clients to view the notebook list, and
      individual notebooks, but not edit them, start kernels, or run
      code.
      
      If no password is set, the server will be entirely read-only.
      """
  )
  
  # Add notebook manager flags
  flags.update(boolean_flag('script', 'FileNotebookManager.save_script',
                 'Auto-save a .py script everytime the .ipynb notebook is saved',
                 'Do not auto-save .py scripts for every notebook'))
  
  # the flags that are specific to the frontend
  # these must be scrubbed before being passed to the kernel,
  # or it will raise an error on unrecognized flags
  notebook_flags = ['no-browser', 'no-mathjax', 'read-only', 'script', 'no-script']
  
  aliases = dict(ipkernel_aliases)
  
  aliases.update({
      'ip': 'NotebookApp.ip',
      'port': 'NotebookApp.port',
      'port-retries': 'NotebookApp.port_retries',
      'keyfile': 'NotebookApp.keyfile',
      'certfile': 'NotebookApp.certfile',
      'notebook-dir': 'NotebookManager.notebook_dir',
      'browser': 'NotebookApp.browser',
  })
  
  # remove ipkernel flags that are singletons, and don't make sense in
  # multi-kernel evironment:
  aliases.pop('f', None)
  
  notebook_aliases = [u'port', u'port-retries', u'ip', u'keyfile', u'certfile',
                      u'notebook-dir']
  
  #-----------------------------------------------------------------------------
  # NotebookApp
  #-----------------------------------------------------------------------------
  
  class NotebookApp(BaseIPythonApplication):
  
      name = 'ipython-notebook'
      default_config_file_name='ipython_notebook_config.py'
      
      description = """
          The IPython HTML Notebook.
          
          This launches a Tornado based HTML Notebook Server that serves up an
          HTML5/Javascript Notebook client.
      """
      examples = _examples
      
      classes = IPythonConsoleApp.classes + [MappingKernelManager, NotebookManager,
          FileNotebookManager]
      flags = Dict(flags)
      aliases = Dict(aliases)
  
      kernel_argv = List(Unicode)
  
      log_level = Enum((0,10,20,30,40,50,'DEBUG','INFO','WARN','ERROR','CRITICAL'),
                      default_value=logging.INFO,
                      config=True,
                      help="Set the log level by value or name.")
  
      # create requested profiles by default, if they don't exist:
      auto_create = Bool(True)
  
      # file to be opened in the notebook server
      file_to_run = Unicode('')
  
      # Network related information.
  
      ip = Unicode(LOCALHOST, config=True,
          help="The IP address the notebook server will listen on."
      )
  
      def _ip_changed(self, name, old, new):
          if new == u'*': self.ip = u''
  
      port = Integer(8888, config=True,
          help="The port the notebook server will listen on."
      )
      port_retries = Integer(50, config=True,
          help="The number of additional ports to try if the specified port is not available."
      )
  
      certfile = Unicode(u'', config=True, 
          help="""The full path to an SSL/TLS certificate file."""
      )
      
      keyfile = Unicode(u'', config=True, 
          help="""The full path to a private key file for usage with SSL/TLS."""
      )
  
      password = Unicode(u'', config=True,
                        help="""Hashed password to use for web authentication.
  
                        To generate, type in a python/IPython shell:
  
                          from IPython.lib import passwd; passwd()
  
                        The string should be of the form type:salt:hashed-password.
                        """
      )
  
      open_browser = Bool(True, config=True,
                          help="""Whether to open in a browser after starting.
                          The specific browser used is platform dependent and
                          determined by the python standard library `webbrowser`
                          module, unless it is overridden using the --browser
                          (NotebookApp.browser) configuration option.
                          """)
  
      browser = Unicode(u'', config=True,
                        help="""Specify what command to use to invoke a web
                        browser when opening the notebook. If not specified, the
                        default browser will be determined by the `webbrowser`
                        standard library module, which allows setting of the
                        BROWSER environment variable to override it.
                        """)
      
      read_only = Bool(False, config=True,
          help="Whether to prevent editing/execution of notebooks."
      )
      
      webapp_settings = Dict(config=True,
              help="Supply overrides for the tornado.web.Application that the "
                   "IPython notebook uses.")
      
      enable_mathjax = Bool(True, config=True,
          help="""Whether to enable MathJax for typesetting math/TeX
  
          MathJax is the javascript library IPython uses to render math/LaTeX. It is
          very large, so you may want to disable it if you have a slow internet
          connection, or for offline use of the notebook.
  
          When disabled, equations etc. will appear as their untransformed TeX source.
          """
      )
      def _enable_mathjax_changed(self, name, old, new):
          """set mathjax url to empty if mathjax is disabled"""
          if not new:
              self.mathjax_url = u''
  
      base_project_url = Unicode('/', config=True,
                                 help='''The base URL for the notebook server.
  
                                 Leading and trailing slashes can be omitted,
                                 and will automatically be added.
                                 ''')
      def _base_project_url_changed(self, name, old, new):
          if not new.startswith('/'):
              self.base_project_url = '/'+new
          elif not new.endswith('/'):
              self.base_project_url = new+'/'
  
      base_kernel_url = Unicode('/', config=True,
                                 help='''The base URL for the kernel server
  
                                 Leading and trailing slashes can be omitted,
                                 and will automatically be added.
                                 ''')
      def _base_kernel_url_changed(self, name, old, new):
          if not new.startswith('/'):
              self.base_kernel_url = '/'+new
          elif not new.endswith('/'):
              self.base_kernel_url = new+'/'
  
      websocket_host = Unicode("", config=True,
          help="""The hostname for the websocket server."""
      )
  
      extra_static_paths = List(Unicode, config=True,
          help="""Extra paths to search for serving static files.
          
          This allows adding javascript/css to be available from the notebook server machine,
          or overriding individual files in the IPython"""
      )
      def _extra_static_paths_default(self):
          return [os.path.join(self.profile_dir.location, 'static')]
      
      @property
      def static_file_path(self):
          """return extra paths + the default location"""
          return self.extra_static_paths + [os.path.join(os.path.dirname(__file__), "static")]
  
      mathjax_url = Unicode("", config=True,
          help="""The url for MathJax.js."""
      )
      def _mathjax_url_default(self):
          if not self.enable_mathjax:
              return u''
          static_url_prefix = self.webapp_settings.get("static_url_prefix",
                                                       "/static/")
          try:
              mathjax = filefind(os.path.join('mathjax', 'MathJax.js'), self.static_file_path)
          except IOError:
              if self.certfile:
                  # HTTPS: load from Rackspace CDN, because SSL certificate requires it
                  base = u"https://c328740.ssl.cf1.rackcdn.com"
              else:
                  base = u"http://cdn.mathjax.org"
              
              url = base + u"/mathjax/latest/MathJax.js"
              self.log.info("Using MathJax from CDN: %s", url)
              return url
          else:
              self.log.info("Using local MathJax from %s" % mathjax)
              return static_url_prefix+u"mathjax/MathJax.js"
      
      def _mathjax_url_changed(self, name, old, new):
          if new and not self.enable_mathjax:
              # enable_mathjax=False overrides mathjax_url
              self.mathjax_url = u''
          else:
              self.log.info("Using MathJax: %s", new)
  
      notebook_manager_class = DottedObjectName('IPython.frontend.html.notebook.filenbmanager.FileNotebookManager',
          config=True,
          help='The notebook manager class to use.')
  
      def parse_command_line(self, argv=None):
          super(NotebookApp, self).parse_command_line(argv)
          if argv is None:
              argv = sys.argv[1:]
  
          # Scrub frontend-specific flags
          self.kernel_argv = swallow_argv(argv, notebook_aliases, notebook_flags)
          # Kernel should inherit default config file from frontend
          self.kernel_argv.append("--KernelApp.parent_appname='%s'"%self.name)
  
          if self.extra_args:
              f = os.path.abspath(self.extra_args[0])
              if os.path.isdir(f):
                  nbdir = f
              else:
                  self.file_to_run = f
                  nbdir = os.path.dirname(f)
              self.config.NotebookManager.notebook_dir = nbdir
  
      def init_configurables(self):
          # force Session default to be secure
          default_secure(self.config)
          self.kernel_manager = MappingKernelManager(
              config=self.config, log=self.log, kernel_argv=self.kernel_argv,
              connection_dir = self.profile_dir.security_dir,
          )
          kls = import_item(self.notebook_manager_class)
          self.notebook_manager = kls(config=self.config, log=self.log)
          self.notebook_manager.log_info()
          self.notebook_manager.load_notebook_names()
          self.cluster_manager = ClusterManager(config=self.config, log=self.log)
          self.cluster_manager.update_profiles()
  
      def init_logging(self):
          # This prevents double log messages because tornado use a root logger that
          # self.log is a child of. The logging module dipatches log messages to a log
          # and all of its ancenstors until propagate is set to False.
          self.log.propagate = False
      
      def init_webapp(self):
          """initialize tornado webapp and httpserver"""
          self.web_app = NotebookWebApplication(
              self, self.kernel_manager, self.notebook_manager, 
              self.cluster_manager, self.log,
              self.base_project_url, self.webapp_settings
          )
          if self.certfile:
              ssl_options = dict(certfile=self.certfile)
              if self.keyfile:
                  ssl_options['keyfile'] = self.keyfile
          else:
              ssl_options = None
          self.web_app.password = self.password
          self.http_server = httpserver.HTTPServer(self.web_app, ssl_options=ssl_options)
          if not self.ip:
              warning = "WARNING: The notebook server is listening on all IP addresses"
              if ssl_options is None:
                  self.log.critical(warning + " and not using encryption. This"
                      "is not recommended.")
              if not self.password and not self.read_only:
                  self.log.critical(warning + "and not using authentication."
                      "This is highly insecure and not recommended.")
          success = None
          for port in random_ports(self.port, self.port_retries+1):
              try:
                  self.http_server.listen(port, self.ip)
              except socket.error as e:
                  if e.errno != errno.EADDRINUSE:
                      raise
                  self.log.info('The port %i is already in use, trying another random port.' % port)
              else:
                  self.port = port
                  success = True
                  break
          if not success:
              self.log.critical('ERROR: the notebook server could not be started because '
                                'no available port could be found.')
              self.exit(1)
      
      def init_signal(self):
          # FIXME: remove this check when pyzmq dependency is >= 2.1.11
          # safely extract zmq version info:
          try:
              zmq_v = zmq.pyzmq_version_info()
          except AttributeError:
              zmq_v = [ int(n) for n in re.findall(r'\d+', zmq.__version__) ]
              if 'dev' in zmq.__version__:
                  zmq_v.append(999)
              zmq_v = tuple(zmq_v)
          if zmq_v >= (2,1,9) and not sys.platform.startswith('win'):
              # This won't work with 2.1.7 and
              # 2.1.9-10 will log ugly 'Interrupted system call' messages,
              # but it will work
              signal.signal(signal.SIGINT, self._handle_sigint)
          signal.signal(signal.SIGTERM, self._signal_stop)
      
      def _handle_sigint(self, sig, frame):
          """SIGINT handler spawns confirmation dialog"""
          # register more forceful signal handler for ^C^C case
          signal.signal(signal.SIGINT, self._signal_stop)
          # request confirmation dialog in bg thread, to avoid
          # blocking the App
          thread = threading.Thread(target=self._confirm_exit)
          thread.daemon = True
          thread.start()
      
      def _restore_sigint_handler(self):
          """callback for restoring original SIGINT handler"""
          signal.signal(signal.SIGINT, self._handle_sigint)
      
      def _confirm_exit(self):
          """confirm shutdown on ^C
          
          A second ^C, or answering 'y' within 5s will cause shutdown,
          otherwise original SIGINT handler will be restored.
          
          This doesn't work on Windows.
          """
          # FIXME: remove this delay when pyzmq dependency is >= 2.1.11
          time.sleep(0.1)
          sys.stdout.write("Shutdown Notebook Server (y/[n])? ")
          sys.stdout.flush()
          r,w,x = select.select([sys.stdin], [], [], 5)
          if r:
              line = sys.stdin.readline()
              if line.lower().startswith('y'):
                  self.log.critical("Shutdown confirmed")
                  ioloop.IOLoop.instance().stop()
                  return
          else:
              print "No answer for 5s:",
          print "resuming operation..."
          # no answer, or answer is no:
          # set it back to original SIGINT handler
          # use IOLoop.add_callback because signal.signal must be called
          # from main thread
          ioloop.IOLoop.instance().add_callback(self._restore_sigint_handler)
      
      def _signal_stop(self, sig, frame):
          self.log.critical("received signal %s, stopping", sig)
          ioloop.IOLoop.instance().stop()
      
      @catch_config_error
      def initialize(self, argv=None):
          self.init_logging()
          super(NotebookApp, self).initialize(argv)
          self.init_configurables()
          self.init_webapp()
          self.init_signal()
  
      def cleanup_kernels(self):
          """shutdown all kernels
          
          The kernels will shutdown themselves when this process no longer exists,
          but explicit shutdown allows the KernelManagers to cleanup the connection files.
          """
          self.log.info('Shutting down kernels')
          km = self.kernel_manager
          # copy list, since shutdown_kernel deletes keys
          for kid in list(km.kernel_ids):
              km.shutdown_kernel(kid)
  
      def start(self):
          ip = self.ip if self.ip else '[all ip addresses on your system]'
          proto = 'https' if self.certfile else 'http'
          info = self.log.info
          info("The IPython Notebook is running at: %s://%s:%i%s" %
               (proto, ip, self.port,self.base_project_url) )
          info("Use Control-C to stop this server and shut down all kernels.")
  
          if self.open_browser or self.file_to_run:
              ip = self.ip or '127.0.0.1'
              try:
                  browser = webbrowser.get(self.browser or None)
              except webbrowser.Error as e:
                  self.log.warn('No web browser found: %s.' % e)
                  browser = None
  
              if self.file_to_run:
                  name, _ = os.path.splitext(os.path.basename(self.file_to_run))
                  url = self.notebook_manager.rev_mapping.get(name, '')
              else:
                  url = ''
              if browser:
                  b = lambda : browser.open("%s://%s:%i%s%s" % (proto, ip,
                      self.port, self.base_project_url, url), new=2)
                  threading.Thread(target=b).start()
          try:
              ioloop.IOLoop.instance().start()
          except KeyboardInterrupt:
              info("Interrupted...")
          finally:
              self.cleanup_kernels()
      
  
  #-----------------------------------------------------------------------------
  # Main entry point
  #-----------------------------------------------------------------------------
  
  def launch_new_instance():
      app = NotebookApp.instance()
      app.initialize()
      app.start()
  
  