# -*- coding: utf-8 -*-
##############################################################################
#
# Copyright (c) 2012 Nexedi SA and Contributors. All Rights Reserved.
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsibility of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# guarantees and support are strongly advised to contract a Free Software
# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
##############################################################################

from Products.ERP5Type.Globals import InitializeClass
from AccessControl import ClassSecurityInfo

from Products.PageTemplates.PageTemplateFile import PageTemplateFile
from Products.PluggableAuthService.interfaces import plugins
from Products.PluggableAuthService.utils import classImplements
from Products.PluggableAuthService.plugins.BasePlugin import BasePlugin
from Products import ERP5Security
from Products.PluggableAuthService.PluggableAuthService import DumbHTTPExtractor
from AccessControl.SecurityManagement import getSecurityManager, \
  setSecurityManager, newSecurityManager
from Products.ERP5Type.Cache import DEFAULT_CACHE_SCOPE
import socket
from zLOG import LOG, ERROR, INFO

try:
  import facebook
except ImportError:
  facebook = None

try:
  import apiclient.discovery
  import httplib2
  import oauth2client.client
except ImportError:
  httplib2 = None

#Form for new plugin in ZMI
manage_addERP5FacebookExtractionPluginForm = PageTemplateFile(
  'www/ERP5Security_addERP5FacebookExtractionPlugin', globals(),
  __name__='manage_addERP5FacebookExtractionPluginForm')

def addERP5FacebookExtractionPlugin(dispatcher, id, title=None, REQUEST=None):
  """ Add a ERP5FacebookExtractionPlugin to a Pluggable Auth Service. """

  plugin = ERP5FacebookExtractionPlugin(id, title)
  dispatcher._setObject(plugin.getId(), plugin)

  if REQUEST is not None:
    REQUEST['RESPONSE'].redirect(
      '%s/manage_workspace'
      '?manage_tabs_message='
      'ERP5FacebookExtractionPlugin+added.'
      % dispatcher.absolute_url())

#Form for new plugin in ZMI
manage_addERP5GoogleExtractionPluginForm = PageTemplateFile(
  'www/ERP5Security_addERP5GoogleExtractionPlugin', globals(),
  __name__='manage_addERP5GoogleExtractionPluginForm')

def addERP5GoogleExtractionPlugin(dispatcher, id, title=None, REQUEST=None):
  """ Add a ERP5GoogleExtractionPlugin to a Pluggable Auth Service. """

  plugin = ERP5GoogleExtractionPlugin(id, title)
  dispatcher._setObject(plugin.getId(), plugin)

  if REQUEST is not None:
    REQUEST['RESPONSE'].redirect(
      '%s/manage_workspace'
      '?manage_tabs_message='
      'ERP5GoogleExtractionPlugin+added.'
      % dispatcher.absolute_url())

class ERP5ExternalOauth2ExtractionPlugin:

  cache_factory_name = 'extrenal_oauth2_token_cache_factory'
  security = ClassSecurityInfo()

  def __init__(self, id, title=None):
    #Register value
    self._setId(id)
    self.title = title

  #####################
  # memcached helpers #
  #####################
  def _getCacheFactory(self):
    portal = self.getPortalObject()
    cache_tool = portal.portal_caches
    cache_factory = cache_tool.getRamCacheRoot().get(self.cache_factory_name)
    #XXX This conditional statement should be remove as soon as
    #Broadcasting will be enable among all zeo clients.
    #Interaction which update portal_caches should interact with all nodes.
    if cache_factory is None \
        and getattr(cache_tool, self.cache_factory_name, None) is not None:
      #ram_cache_root is not up to date for current node
      cache_tool.updateCache()
    cache_factory = cache_tool.getRamCacheRoot().get(self.cache_factory_name)
    if cache_factory is None:
      raise KeyError
    return cache_factory

  def setToken(self, key, body):
    cache_factory = self._getCacheFactory()
    cache_duration = cache_factory.cache_duration
    for cache_plugin in cache_factory.getCachePluginList():
      cache_plugin.set(key, DEFAULT_CACHE_SCOPE,
                       body, cache_duration=cache_duration)

  def getToken(self, key):
    cache_factory = self._getCacheFactory()
    for cache_plugin in cache_factory.getCachePluginList():
      cache_entry = cache_plugin.get(key, DEFAULT_CACHE_SCOPE)
      if cache_entry is not None:
        return cache_entry.getValue()
    raise KeyError('Key %r not found' % key)

  ####################################
  #ILoginPasswordHostExtractionPlugin#
  ####################################
  security.declarePrivate('extractCredentials')
  def extractCredentials(self, request):
    """ Extract Oauth2 credentials from the request header. """
    Base_createOauth2User = getattr(self.getPortalObject(),
      'Base_createOauth2User', None)
    if Base_createOauth2User is None:
      LOG('ERP5ExternalOauth2ExtractionPlugin', INFO,
          'No Base_createOauth2User script available, install '
            'erp5_credential_oauth2, disabled authentication.')
      return DumbHTTPExtractor().extractCredentials(request)

    creds = {}
    token = None
    if request._auth is not None:
      # 1st - try to fetch from Authorization header
      if self.header_string.lower() in request._auth.lower():
        l = request._auth.split()
        if len(l) == 2:
          token = l[1]

    if token is None:
      # no token
      return DumbHTTPExtractor().extractCredentials(request)

    # token is available
    user = None
    user_entry = None
    try:
      user = self.getToken(self.prefix + token)
    except KeyError:
      user_entry = self.getUserEntry(token)
      if user_entry is not None:
        user = user_entry['reference']

    if user is None:
      # fallback to default way
      return DumbHTTPExtractor().extractCredentials(request)

    tag = '%s_user_creation_in_progress' % user.encode('hex')

    if self.getPortalObject().portal_activities.countMessageWithTag(tag) > 0:
      self.REQUEST['USER_CREATION_IN_PROGRESS'] = user
    else:
      # create the user if not found
      if not self.searchUsers(id=user, exact_match=True):
        sm = getSecurityManager()
        if sm.getUser().getId() != ERP5Security.SUPER_USER:
          newSecurityManager(self, self.getUser(ERP5Security.SUPER_USER))
        try:
          self.REQUEST['USER_CREATION_IN_PROGRESS'] = user
          if user_entry is None:
            user_entry = self.getUserEntry(token)
          try:
            self.Base_createOauth2User(tag, **user_entry)
          except Exception:
            LOG('ERP5ExternalOauth2ExtractionPlugin', ERROR,
              'Issue while calling creation script:', error=True)
            raise
        finally:
          setSecurityManager(sm)
    try:
      self.setToken(self.prefix + token, user)
    except KeyError:
      # allow to work w/o cache
      pass
    creds['external_login'] = user
    creds['remote_host'] = request.get('REMOTE_HOST', '')
    try:
      creds['remote_address'] = request.getClientAddr()
    except AttributeError:
      creds['remote_address'] = request.get('REMOTE_ADDR', '')
    return creds

class ERP5FacebookExtractionPlugin(ERP5ExternalOauth2ExtractionPlugin, BasePlugin):
  """
  Plugin to authenicate as machines.
  """

  meta_type = "ERP5 Facebook Extraction Plugin"
  prefix = 'fb_'
  header_string = 'facebook'

  def getUserEntry(self, token):
    if facebook is None:
      LOG('ERP5FacebookExtractionPlugin', INFO,
          'No facebook module, install facebook-sdk package. '
            'Authentication disabled.')
      return None
    timeout = socket.getdefaulttimeout()
    try:
      # require really fast interaction
      socket.setdefaulttimeout(5)
      facebook_entry = facebook.GraphAPI(token).get_object("me")
    except Exception:
      facebook_entry = None
    finally:
      socket.setdefaulttimeout(timeout)

    user_entry = {}
    if facebook_entry is not None:
      # sanitise value
      try:
        for k in ('first_name', 'last_name', 'id', 'email'):
          if k == 'id':
            user_entry['reference'] = self.prefix + facebook_entry[k].encode(
              'utf-8')
          else:
            user_entry[k] = facebook_entry[k].encode('utf-8')
      except KeyError:
        user_entry = None
    return user_entry

class ERP5GoogleExtractionPlugin(ERP5ExternalOauth2ExtractionPlugin, BasePlugin):
  """
  Plugin to authenicate as machines.
  """

  meta_type = "ERP5 Google Extraction Plugin"
  prefix = 'go_'
  header_string = 'google'

  def getUserEntry(self, token):
    if httplib2 is None:
      LOG('ERP5GoogleExtractionPlugin', INFO,
        'No Google modules available, please install google-api-python-client '
        'package. Authentication disabled..')
      return None
    timeout = socket.getdefaulttimeout()
    try:
      # require really fast interaction
      socket.setdefaulttimeout(5)
      http = oauth2client.client.AccessTokenCredentials(token, 'ERP5 Client'
        ).authorize(httplib2.Http())
      service = apiclient.discovery.build("oauth2", "v1", http=http)
      google_entry = service.userinfo().get().execute()
    except Exception:
      google_entry = None
    finally:
      socket.setdefaulttimeout(timeout)

    user_entry = {}
    if google_entry is not None:
      # sanitise value
      try:
        for k in (('first_name', 'given_name'),
            ('last_name', 'family_name'),
            ('reference', 'id'),
            ('email', 'email')):
          value = google_entry[k[1]].encode('utf-8')
          if k[0] == 'reference':
            value = self.prefix + value
          user_entry[k[0]] = value
      except KeyError:
        user_entry = None
    return user_entry

#List implementation of class
classImplements( ERP5FacebookExtractionPlugin,
                plugins.ILoginPasswordHostExtractionPlugin
               )
InitializeClass(ERP5FacebookExtractionPlugin)

classImplements( ERP5GoogleExtractionPlugin,
                plugins.ILoginPasswordHostExtractionPlugin
               )
InitializeClass(ERP5GoogleExtractionPlugin)

