############################################################################
# 
# Copyright (c) 2002 Zope Foundation and Contributors.
#
# 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
#
############################################################################
import binascii
from cgi import escape
import logging
import random
import re
import string
import sys
import time
from urllib import quote
from urlparse import urlparse
from urlparse import urlunparse

from AccessControl.class_init import InitializeClass
from AccessControl.SecurityInfo import ClassSecurityInfo
from Acquisition import Implicit
from Acquisition import aq_parent
from Acquisition import aq_inner
from App.Management import Tabs
from App.special_dtml import DTMLFile
from Persistence import Persistent
from persistent import TimeStamp
from OFS.owner import Owned
from OFS.role import RoleManager
from OFS.SimpleItem import Item
from ZPublisher.BeforeTraverse import registerBeforeTraverse
from ZPublisher.BeforeTraverse import unregisterBeforeTraverse
from ZPublisher.BeforeTraverse import queryBeforeTraverse
from zope.interface import implements

from Products.Sessions.interfaces import IBrowserIdManager
from Products.Sessions.interfaces import BrowserIdManagerErr
from Products.Sessions.SessionPermissions import ACCESS_CONTENTS_PERM
from Products.Sessions.SessionPermissions import CHANGE_IDMGR_PERM
from Products.Sessions.SessionPermissions import MGMT_SCREEN_PERM

b64_trans = string.maketrans('+/', '-.')
b64_untrans = string.maketrans('-.', '+/')

badidnamecharsin = re.compile('[\?&;,<> ]').search
badcookiecharsin = re.compile('[;,<>& ]').search
twodotsin = re.compile('(\w*\.){2,}').search

_marker = []

constructBrowserIdManagerForm = DTMLFile('dtml/addIdManager', globals())

BROWSERID_MANAGER_NAME = 'browser_id_manager'# imported by SessionDataManager
ALLOWED_BID_NAMESPACES = ('form', 'cookies', 'url')
ADD_BROWSER_ID_MANAGER_PERM="Add Browser Id Manager"
TRAVERSAL_APPHANDLE = 'BrowserIdManager'

LOG = logging.getLogger('Zope.BrowserIdManager')

def constructBrowserIdManager(
    self, id=BROWSERID_MANAGER_NAME, title='', idname='_ZopeId',
    location=('cookies', 'form'), cookiepath='/', cookiedomain='',
    cookielifedays=0, cookiesecure=0, cookiehttponly=0, auto_url_encoding=0,
    REQUEST=None
    ):
    """ """
    ob = BrowserIdManager(id, title, idname, location, cookiepath,
                          cookiedomain, cookielifedays, cookiesecure,
                          cookiehttponly, auto_url_encoding)
    self._setObject(id, ob)
    ob = self._getOb(id)
    if REQUEST is not None:
        return self.manage_main(self, REQUEST, update_menu=1)
    
class BrowserIdManager(Item, Persistent, Implicit, RoleManager, Owned, Tabs):
    """ browser id management class
    """
    implements(IBrowserIdManager)
    meta_type = 'Browser Id Manager'

    security = ClassSecurityInfo()
    security.declareObjectPublic()
    ok = {'meta_type':1, 'id':1, 'title': 1, 'icon':1,
          'bobobase_modification_time':1, 'title_or_id':1 }
    security.setDefaultAccess(ok)
    security.setPermissionDefault(MGMT_SCREEN_PERM, ['Manager'])
    security.setPermissionDefault(ACCESS_CONTENTS_PERM,['Manager','Anonymous'])
    security.setPermissionDefault(CHANGE_IDMGR_PERM, ['Manager'])

    # BBB
    auto_url_encoding = 0
    cookie_http_only = 0

    def __init__(self, id, title='', idname='_ZopeId',
                 location=('cookies', 'form'), cookiepath=('/'),
                 cookiedomain='', cookielifedays=0, cookiesecure=0,
                 cookiehttponly=0, auto_url_encoding=0):
        self.id = str(id)
        self.title = str(title)
        self.setBrowserIdName(idname)
        self.setBrowserIdNamespaces(location)
        self.setCookiePath(cookiepath)
        self.setCookieDomain(cookiedomain)
        self.setCookieLifeDays(cookielifedays)
        self.setCookieSecure(cookiesecure)
        self.setCookieHTTPOnly(cookiehttponly)
        self.setAutoUrlEncoding(auto_url_encoding)

    # IBrowserIdManager
    security.declareProtected(ACCESS_CONTENTS_PERM, 'hasBrowserId')
    def hasBrowserId(self):
        """ See IBrowserIdManager.
        """
        try:
            return self.getBrowserId(create=0) is not None
        except BrowserIdManagerErr:
            return False
                
    security.declareProtected(ACCESS_CONTENTS_PERM, 'getBrowserId')
    def getBrowserId(self, create=1):
        """ See IBrowserIdManager.
        """
        REQUEST = self.REQUEST
        # let's see if bid has already been attached to request
        bid = getattr(REQUEST, 'browser_id_', None)
        if bid is not None:
            # it's already set in this request so we can just return it
            # if it's well-formed
            if not isAWellFormedBrowserId(bid):
                # somebody screwed with the REQUEST instance during
                # this request.
                raise BrowserIdManagerErr(
                                'Ill-formed browserid in '
                                'REQUEST.browser_id_:  %s' % escape(bid))
            return bid
        # fall through & ck form/cookie namespaces if bid is not in request.
        tk = self.browserid_name
        ns = self.browserid_namespaces
        for name in ns:
            if name == 'url':
                continue # browser ids in url are checked by Traverser class
            current_ns = getattr(REQUEST, name, None)
            if current_ns is None:
                continue
            bid = current_ns.get(tk, None)
            if bid is not None:
                # hey, we got a browser id!
                if isAWellFormedBrowserId(bid):
                    # bid is not "plain old broken"
                    REQUEST.browser_id_ = bid
                    REQUEST.browser_id_ns_ = name
                    return bid
        # fall through if bid is invalid or not in namespaces
        if create:
            # create a brand new bid
            bid = getNewBrowserId()
            if 'cookies' in ns:
                self._setCookie(bid, REQUEST)
            REQUEST.browser_id_ = bid
            REQUEST.browser_id_ns_ = None
            return bid
        # implies a return of None if:
        # (not create=1) and (invalid or ((not in req) and (not in ns)))

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getBrowserIdName')
    def getBrowserIdName(self):
        """ See IBrowserIdManager.
        """
        return self.browserid_name

    security.declareProtected(ACCESS_CONTENTS_PERM, 'isBrowserIdNew')
    def isBrowserIdNew(self):
        """ See IBrowserIdManager.
        """
        if not self.getBrowserId(create=False):
            raise BrowserIdManagerErr('There is no current browser id.')
        # ns will be None if new
        return getattr(self.REQUEST, 'browser_id_ns_', None) is None

    security.declareProtected(ACCESS_CONTENTS_PERM, 'isBrowserIdFromCookie')
    def isBrowserIdFromCookie(self):
        """ See IBrowserIdManager.
        """
        if not self.getBrowserId(create=False):
            raise BrowserIdManagerErr('There is no current browser id.')
        if getattr(self.REQUEST, 'browser_id_ns_') == 'cookies':
            return 1

    security.declareProtected(ACCESS_CONTENTS_PERM, 'isBrowserIdFromForm')
    def isBrowserIdFromForm(self):
        """ See IBrowserIdManager.
        """
        if not self.getBrowserId(create=False):
            raise BrowserIdManagerErr('There is no current browser id.')
        if getattr(self.REQUEST, 'browser_id_ns_') == 'form':
            return 1

    security.declareProtected(ACCESS_CONTENTS_PERM, 'isBrowserIdFromUrl')
    def isBrowserIdFromUrl(self):
        """ See IBrowserIdManager.
        """
        if not self.getBrowserId(create=False):
            raise BrowserIdManagerErr('There is no current browser id.')
        if getattr(self.REQUEST, 'browser_id_ns_') == 'url':
            return 1

    security.declareProtected(ACCESS_CONTENTS_PERM, 'flushBrowserIdCookie')
    def flushBrowserIdCookie(self):
        """ See IBrowserIdManager.
        """
        if 'cookies' not in self.browserid_namespaces:
            raise BrowserIdManagerErr(
                            'Cookies are not now being used as a '
                            'browser id namespace, thus the '
                            'browserid cookie cannot be flushed.')
        self._setCookie('deleted', self.REQUEST, remove=1)

    security.declareProtected(ACCESS_CONTENTS_PERM,'setBrowserIdCookieByForce')
    def setBrowserIdCookieByForce(self, bid):
        """ See IBrowserIdManager.
        """
        if 'cookies' not in self.browserid_namespaces:
            raise BrowserIdManagerErr(
                            'Cookies are not now being used as a '
                            'browser id namespace, thus the '
                            'browserid cookie cannot be forced.')
        self._setCookie(bid, self.REQUEST)

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getHiddenFormField')
    def getHiddenFormField(self):
        """ See IBrowserIdManager.
        """
        s = '<input type="hidden" name="%s" value="%s" />'
        return s % (self.getBrowserIdName(), self.getBrowserId())
    
    security.declareProtected(ACCESS_CONTENTS_PERM, 'encodeUrl')
    def encodeUrl(self, url, style='querystring', create=1):
        """ See IBrowserIdManager.
        """
        bid = self.getBrowserId(create)
        if bid is None:
            raise BrowserIdManagerErr('There is no current browser id.')
        name = self.getBrowserIdName()
        if style == 'querystring': # encode bid in querystring
            if '?' in url:
                return '%s&amp;%s=%s' % (url, name, bid)
            else:
                return '%s?%s=%s' % (url, name, bid)
        else: # encode bid as first two URL path segments
            proto, host, path, params, query, frag = urlparse(url)
            path = '/%s/%s%s' % (name, bid, path)
            return urlunparse((proto, host, path, params, query, frag))

    # Non-IBrowserIdManager accessors / mutators.
    security.declareProtected(CHANGE_IDMGR_PERM, 'setBrowserIdName')
    def setBrowserIdName(self, k):
        """ Set browser id name string

        o Enforce "valid" values.
        """
        if not (type(k) is type('') and k and not badidnamecharsin(k)):
            raise BrowserIdManagerErr(
                            'Bad id name string %s' % escape(repr(k)))
        self.browserid_name = k

    security.declareProtected(CHANGE_IDMGR_PERM, 'setBrowserIdNamespaces')
    def setBrowserIdNamespaces(self, ns):
        """
        accepts list of allowable browser id namespaces 
        """
        for name in ns:
            if name not in ALLOWED_BID_NAMESPACES:
                raise BrowserIdManagerErr(
                            'Bad browser id namespace %s' % repr(name))
        self.browserid_namespaces = tuple(ns)

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getBrowserIdNamespaces')
    def getBrowserIdNamespaces(self):
        """ """
        return self.browserid_namespaces

    security.declareProtected(CHANGE_IDMGR_PERM, 'setCookiePath')
    def setCookiePath(self, path=''):
        """ sets cookie 'path' element for id cookie """
        if not (type(path) is type('') and not badcookiecharsin(path)):
            raise BrowserIdManagerErr(
                            'Bad cookie path %s' % escape(repr(path)))
        self.cookie_path = path

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getCookiePath')
    def getCookiePath(self):
        """ """
        return self.cookie_path

    security.declareProtected(CHANGE_IDMGR_PERM, 'setCookieLifeDays')
    def setCookieLifeDays(self, days):
        """ offset for id cookie 'expires' element """
        if type(days) not in (type(1), type(1.0)):
            raise BrowserIdManagerErr(
                            'Bad cookie lifetime in days %s '
                            '(requires integer value)' % escape(repr(days)))
        self.cookie_life_days = int(days)

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getCookieLifeDays')
    def getCookieLifeDays(self):
        """ """
        return self.cookie_life_days

    security.declareProtected(CHANGE_IDMGR_PERM, 'setCookieDomain')
    def setCookieDomain(self, domain):
        """ sets cookie 'domain' element for id cookie """
        if type(domain) is not type(''):
            raise BrowserIdManagerErr(
                            'Cookie domain must be string: %s'
                                % escape(repr(domain)))
        if not domain:
            self.cookie_domain = ''
            return
        if not twodotsin(domain):
            raise BrowserIdManagerErr(
                            'Cookie domain must contain at least two dots '
                            '(e.g. ".zope.org" or "www.zope.org") or it must '
                            'be left blank. : ' '%s' % escape(`domain`))
        if badcookiecharsin(domain):
            raise BrowserIdManagerErr(
                            'Bad characters in cookie domain %s'
                                % escape(`domain`))
        self.cookie_domain = domain

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getCookieDomain')
    def getCookieDomain(self):
        """ """
        return self.cookie_domain

    security.declareProtected(CHANGE_IDMGR_PERM, 'setCookieHTTPOnly')
    def setCookieHTTPOnly(self, http_only):
        """ sets cookie 'HTTPOnly' on or off """
        self.cookie_http_only = bool(http_only)

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getCookieHTTPOnly')
    def getCookieHTTPOnly(self):
        """ retrieve the 'HTTPOnly' flag """
        return self.cookie_http_only

    security.declareProtected(CHANGE_IDMGR_PERM, 'setCookieSecure')
    def setCookieSecure(self, secure):
        """ sets cookie 'secure' element for id cookie """
        self.cookie_secure = not not secure

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getCookieSecure')
    def getCookieSecure(self):
        """ """
        return self.cookie_secure

    security.declareProtected(CHANGE_IDMGR_PERM, 'setAutoUrlEncoding')
    def setAutoUrlEncoding(self, auto_url_encoding):
        """ sets 'auto url encoding' on or off """
        self.auto_url_encoding = not not auto_url_encoding

    security.declareProtected(ACCESS_CONTENTS_PERM, 'getAutoUrlEncoding')
    def getAutoUrlEncoding(self):
        """ """
        return self.auto_url_encoding

    security.declareProtected(ACCESS_CONTENTS_PERM, 'isUrlInBidNamespaces')
    def isUrlInBidNamespaces(self):
        """ Returns true if 'url' is in the browser id namespaces
        for this browser id """
        return 'url' in self.browserid_namespaces

    def _setCookie(
        self, bid, REQUEST, remove=0, now=time.time, strftime=time.strftime,
        gmtime=time.gmtime
        ):
        """ """
        expires = None
        if remove:
            expires = "Sun, 10-May-1971 11:59:00 GMT"
        elif self.cookie_life_days:
            expires = now() + self.cookie_life_days * 86400
            # Wdy, DD-Mon-YYYY HH:MM:SS GMT
            expires = strftime('%a %d-%b-%Y %H:%M:%S GMT',gmtime(expires))

        # cookie attributes managed by BrowserIdManager
        d = {'domain':self.cookie_domain,'path':self.cookie_path,
             'secure':self.cookie_secure,'http_only': self.cookie_http_only,
             'expires':expires}

        if self.cookie_secure:
            URL1 = REQUEST.get('URL1', None)
            if URL1 is None:
                return # should we raise an exception?
            if string.split(URL1,':')[0] != 'https':
                return # should we raise an exception?

        cookies = REQUEST.RESPONSE.cookies
        cookie = cookies[self.browserid_name]= {}
        for k,v in d.items():
            if v:
                cookie[k] = v #only stuff things with true values
        cookie['value'] = bid

    def _setId(self, id):
        if id != self.id:
            raise ValueError('Cannot rename a browser id manager')

    # Jukes for handling URI-munged browser IDS
    def hasTraversalHook(self, parent):
        name = TRAVERSAL_APPHANDLE
        return not not queryBeforeTraverse(parent, name)

    def updateTraversalData(self):
        if 'url' in self.browserid_namespaces:
            self.registerTraversalHook()
        else:
            self.unregisterTraversalHook()

    def unregisterTraversalHook(self):
        parent = aq_parent(aq_inner(self))
        name = TRAVERSAL_APPHANDLE
        if self.hasTraversalHook(parent):
            unregisterBeforeTraverse(parent, name)

    def registerTraversalHook(self):
        parent = aq_parent(aq_inner(self))
        if not self.hasTraversalHook(parent):
            hook = BrowserIdManagerTraverser()
            name = TRAVERSAL_APPHANDLE
            priority = 40 # "higher" priority than session data traverser
            registerBeforeTraverse(parent, hook, name, priority)

    # ZMI
    icon = 'misc_/Sessions/idmgr.gif'
    manage_options=({'label': 'Settings', 'action':'manage_browseridmgr'},
                    {'label': 'Security', 'action':'manage_access'},
                    {'label': 'Ownership', 'action':'manage_owner'},
                   )

    def manage_afterAdd(self, item, container):
        """ Maybe add our traversal hook """
        self.updateTraversalData()

    def manage_beforeDelete(self, item, container):
        """ Remove our traversal hook if it exists """
        self.unregisterTraversalHook()

    security.declareProtected(MGMT_SCREEN_PERM, 'manage_browseridmgr')
    manage_browseridmgr = DTMLFile('dtml/manageIdManager', globals())

    security.declareProtected(CHANGE_IDMGR_PERM,
                              'manage_changeBrowserIdManager')
    def manage_changeBrowserIdManager(
        self, title='', idname='_ZopeId', location=('cookies', 'form'),
        cookiepath='/', cookiedomain='', cookielifedays=0, cookiesecure=0,
        cookiehttponly=0, auto_url_encoding=0,  REQUEST=None
        ):
        """ """
        self.title = str(title)
        self.setBrowserIdName(idname)
        self.setCookiePath(cookiepath)
        self.setCookieDomain(cookiedomain)
        self.setCookieLifeDays(cookielifedays)
        self.setCookieSecure(cookiesecure)
        self.setCookieHTTPOnly(cookiehttponly)
        self.setBrowserIdNamespaces(location)
        self.setAutoUrlEncoding(auto_url_encoding)
        self.updateTraversalData()
        if REQUEST is not None:
            msg = '/manage_browseridmgr?manage_tabs_message=Changes saved'
            REQUEST.RESPONSE.redirect(self.absolute_url()+msg)

InitializeClass(BrowserIdManager)

class BrowserIdManagerTraverser(Persistent):
    def __call__(self, container, request, browser_id=None,
                 browser_id_ns=None,
                 BROWSERID_MANAGER_NAME=BROWSERID_MANAGER_NAME):
        """
        Registered hook to set and get a browser id in the URL.  If
        a browser id is found in the URL of an  incoming request, we put it
        into a place where it can be found later by the browser id manager.
        If our browser id manager's auto-url-encoding feature is on, cause
        Zope-generated URLs to contain the browser id by rewriting the
        request._script list.
        """
        browser_id_manager = getattr(container, BROWSERID_MANAGER_NAME, None)
        # fail if we cannot find a browser id manager (that means this
        # instance has been "orphaned" somehow)
        if browser_id_manager is None:
            LOG.error('Could not locate browser id manager!')
            return

        try:
            stack = request['TraversalRequestNameStack']
            request.browser_id_ns_ = browser_id_ns
            bid_name = browser_id_manager.getBrowserIdName()

            # stuff the browser id and id namespace into the request
            # if the URL has a browser id name and browser id as its first
            # two elements.  Only remove these elements from the
            # traversal stack if they are a "well-formed pair".
            if len(stack) >= 2 and stack[-1] == bid_name:
                if isAWellFormedBrowserId(stack[-2]):
                    name       = stack.pop() # pop the name off the stack
                    browser_id = stack.pop() # pop id off the stack
                    request.browser_id_    = browser_id
                    request.browser_id_ns_ = 'url'

            # if the browser id manager is set up with 'auto url encoding',
            # cause generated URLs to be encoded with the browser id name/value
            # pair by munging request._script.
            if browser_id_manager.getAutoUrlEncoding():
                if browser_id is None:
                    request.browser_id_ = browser_id = getNewBrowserId()
                request._script.append(quote(bid_name))
                request._script.append(quote(browser_id))
        except:
            LOG.error('indeterminate error', exc_info=sys.exc_info())

def getB64TStamp(
    b2a=binascii.b2a_base64,gmtime=time.gmtime, time=time.time,
    b64_trans=b64_trans, split=string.split,
    TimeStamp=TimeStamp.TimeStamp, translate=string.translate
    ):
    t=time()
    ts=split(b2a(`TimeStamp(*gmtime(t)[:5]+(t%60,))`)[:-1],'=')[0]
    return translate(ts, b64_trans)

def getB64TStampToInt(
    ts, TimeStamp=TimeStamp.TimeStamp, b64_untrans=b64_untrans,
    a2b=binascii.a2b_base64, translate=string.translate
    ):
    return TimeStamp(a2b(translate(ts+'=',b64_untrans))).timeTime()

def getBrowserIdPieces(bid):
    """ returns browser id parts in a tuple consisting of rand_id,
    timestamp
    """
    return (bid[:8], bid[8:19])


def isAWellFormedBrowserId(bid, binerr=binascii.Error):
    try:
        rnd, ts = getBrowserIdPieces(bid)
        int(rnd)
        getB64TStampToInt(ts)
        return bid
    except (TypeError, ValueError, AttributeError, IndexError, binerr):
        return None


def getNewBrowserId(randint=random.randint, maxint=99999999):
    """ Returns 19-character string browser id
    'AAAAAAAABBBBBBBB'
    where:

    A == leading-0-padded 8-char string-rep'd random integer
    B == modified base64-encoded 11-char timestamp

    To be URL-compatible, base64 encoding is modified as follows:
      '=' end-padding is stripped off
      '+' is translated to '-'
      '/' is translated to '.'

    An example is: 89972317A0C3EHnUi90w
    """
    return '%08i%s' % (randint(0, maxint-1), getB64TStamp())

