##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights
# Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this
# distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
""" Classes: ERP5UserManager
"""

from Products.ERP5Type.Globals import InitializeClass
from AccessControl import ClassSecurityInfo
from AccessControl.SecurityManagement import getSecurityManager,\
    setSecurityManager, newSecurityManager
from Products.PageTemplates.PageTemplateFile import PageTemplateFile
from Products.PluggableAuthService.PluggableAuthService import \
    _SWALLOWABLE_PLUGIN_EXCEPTIONS
from Products.PluggableAuthService.plugins.BasePlugin import BasePlugin
from Products.PluggableAuthService.utils import classImplements
from Products.PluggableAuthService.interfaces.plugins import IAuthenticationPlugin
from Products.PluggableAuthService.interfaces.plugins import IUserEnumerationPlugin
from Products.ERP5Type.Cache import CachingMethod
from ZODB.POSException import ConflictError
import sys
from DateTime import DateTime
from zLOG import LOG, PROBLEM

try :
  from AccessControl.AuthEncoding import pw_validate
except ImportError:
  pw_validate = lambda reference, attempt: reference == attempt

# This user is used to bypass all security checks.
SUPER_USER = '__erp5security-=__'

manage_addERP5UserManagerForm = PageTemplateFile(
    'www/ERP5Security_addERP5UserManager', globals(),
    __name__='manage_addERP5UserManagerForm' )

def addERP5UserManager(dispatcher, id, title=None, REQUEST=None):
    """ Add a ERP5UserManager to a Pluggable Auth Service. """

    eum = ERP5UserManager(id, title)
    dispatcher._setObject(eum.getId(), eum)

    if REQUEST is not None:
        REQUEST['RESPONSE'].redirect(
                                '%s/manage_workspace'
                                '?manage_tabs_message='
                                'ERP5UserManager+added.'
                            % dispatcher.absolute_url())

class _AuthenticationFailure(Exception):
  """Raised when authentication failed, to prevent caching the fact that a user
  does not exist (yet), which happens when someone try to login before the user
  account is ready (like when the indexing not finished, an assignment not open
  etc...)
  """


class ERP5UserManager(BasePlugin):
    """ PAS plugin for managing users in ERP5
    """

    meta_type = 'ERP5 User Manager'

    security = ClassSecurityInfo()

    def __init__(self, id, title=None):

        self._id = self.id = id
        self.title = title

    #
    #   IAuthenticationPlugin implementation
    #
    security.declarePrivate( 'authenticateCredentials' )
    def authenticateCredentials(self, credentials):
        """ See IAuthenticationPlugin.

        o We expect the credentials to be those returned by
            ILoginPasswordExtractionPlugin.
        """
        # Forbidden the usage of the super user.
        if credentials.get('login') == SUPER_USER:
          return None

        def _authenticateCredentials(login, password, path):
            if not login or not password:
                return None

            user_list = self.getUserByLogin(login)

            if not user_list:
              raise _AuthenticationFailure()

            user = user_list[0]

            sm = getSecurityManager()
            if sm.getUser().getId() != SUPER_USER:
              newSecurityManager(self, self.getUser(SUPER_USER))
            try:
              # get assignment
              assignment_list = [x for x in user.contentValues(portal_type="Assignment") if x.getValidationState() == "open"]
              valid_assignment_list = []
              # check dates if exist
              login_date = DateTime()
              for assignment in assignment_list:
                if assignment.getStartDate() is not None and \
                       assignment.getStartDate() > login_date:
                  continue
                if assignment.getStopDate() is not None and \
                       assignment.getStopDate() < login_date:
                  continue
                valid_assignment_list.append(assignment)
                
              if pw_validate(user.getPassword(), password) and \
                     len(valid_assignment_list): #user.getCareerRole() == 'internal':
                return login, login # use same for user_id and login
            finally:
              setSecurityManager(sm)
            raise _AuthenticationFailure()

        _authenticateCredentials = CachingMethod(_authenticateCredentials,
                                                 id='ERP5UserManager_authenticateCredentials',
                                                 cache_factory='erp5_content_short')
        try:
          return _authenticateCredentials(
                      login=credentials.get('login'),
                      password=credentials.get('password'),
                      path=self.getPhysicalPath())
        except _AuthenticationFailure:
          return None

    #
    #   IUserEnumerationPlugin implementation
    #
    security.declarePrivate( 'enumerateUsers' )
    def enumerateUsers(self, id=None, login=None, exact_match=False,
                       sort_by=None, max_results=None, **kw):
        """ See IUserEnumerationPlugin.
        """
        if id is None:
          id = login
        if isinstance(id, str):
          id = (id,)
        if isinstance(id, list):
          id = tuple(id)

        user_info = []
        plugin_id = self.getId()

        id_list = []
        for user_id in id:
          if SUPER_USER == user_id:
            info = { 'id' : SUPER_USER
                    , 'login' : SUPER_USER
                    , 'pluginid' : plugin_id
                    }
            user_info.append(info)
          else:
            id_list.append(user_id)

        if id_list:
          for user in self.getUserByLogin(tuple(id_list), exact_match=exact_match):
              info = { 'id' : user.getReference()
                     , 'login' : user.getReference()
                     , 'pluginid' : plugin_id
                     }

              user_info.append(info)

        return tuple(user_info)


    def getUserByLogin(self, login, exact_match=True):
        # Search the Catalog for login and return a list of person objects
        # login can be a string or a list of strings
        # (no docstring to prevent publishing)
        if not login:
          return []

        portal = self.getPortalObject()

        def _getUserByLogin(login, exact_match):
          # because we aren't logged in, we have to create our own
          # SecurityManager to be able to access the Catalog
          if isinstance(login, list):
            login = tuple(login)
          elif not isinstance(login, tuple):
            login = (str(login),)
          sm = getSecurityManager()
          if sm.getUser().getId() != SUPER_USER:
            newSecurityManager(self, self.getUser(SUPER_USER))
  
          try:
            try:
              if exact_match:
                reference_key = 'ExactMatch'
              else:
                reference_key = 'Keyword'

              result = portal.portal_catalog.unrestrictedSearchResults(
                                        select_expression='reference',
                                        portal_type="Person",
                                        reference=dict(query=login,
                                                       key=reference_key))
            except ConflictError:
              raise
            except:
              LOG('ERP5Security', PROBLEM, 'getUserByLogin failed', error=sys.exc_info())
              # Here we must raise an exception to prevent callers from caching
              # a result of a degraded situation.
              # The kind of exception does not matter as long as it's catched by
              # PAS and causes a lookup using another plugin or user folder.
              # As PAS does not define explicitely such exception, we must use
              # the _SWALLOWABLE_PLUGIN_EXCEPTIONS list.
              raise _SWALLOWABLE_PLUGIN_EXCEPTIONS[0]
          finally:
            setSecurityManager(sm)
          # XXX: Here, we filter catalog result list ALTHOUGH we did pass
          # parameters to unrestrictedSearchResults to restrict result set.
          # This is done because the following values can match person with
          # reference "foo":
          # "foo " because of MySQL (feature, PADSPACE collation):
          #  mysql> SELECT reference as r FROM catalog
          #      -> WHERE reference="foo      ";
          #  +-----+
          #  | r   |
          #  +-----+
          #  | foo |
          #  +-----+
          #  1 row in set (0.01 sec)
          # "bar OR foo" because of ZSQLCatalog tokenizing searched strings
          #  by default (feature).
          result = [x.path for x in result if (not exact_match)
                          or x['reference'] in login]
          if not result:
            raise _AuthenticationFailure()
          return result

        _getUserByLogin = CachingMethod(_getUserByLogin,
                                        id='ERP5UserManager_getUserByLogin',
                                        cache_factory='erp5_content_short')
        try:
          return [portal.unrestrictedTraverse(x) for x in
                              _getUserByLogin(login, exact_match)]
        except _AuthenticationFailure:
          return []

classImplements( ERP5UserManager
               , IAuthenticationPlugin
               , IUserEnumerationPlugin
               )

InitializeClass(ERP5UserManager)