#!/usr/bin/env python
'''
   cookies.py
   Jeff Ondich, 28 May 2012

   A simple illustration of setting and retrieving cookies in HTTP server-side scripts.

   If the server-side script wants to store a small amount of data on the client, it
   can do so by sending a "Set-cookie: name=value" header along with the HTTP response.
   If the client (typically a web browser) accepts this cookie, then it will always
   send the cookie back to this server when making more queries.

   In this example, the first time the client visits cookies.py, we generate a new
   cookie with name "moose" and value "bullwinkle [time]" where "[time]" is the current
   time on the server's machine. We could just print "Set-cookie: moose=bullwinkle 09:35:12"
   after the Content-type line and before the blank line at the end of the HTTP response
   headers. But instead, we'll use Python's Cookie module to assemble the appropriate
   header.

   When the client visits cookies.py for a second time, the client's HTTP request headers
   will include a "Cookie: moose=bullwinkle 09:35:12" line. Python's Cookie module can
   be used to parse this line, as shown below.

   In this example, I added one extra feature. If you include "action=reset" as a
   GET or POST argument, this script tells the client to delete the moose cookie by
   setting its expiration time to now.
'''

import os
import cgi
import Cookie
import datetime

def deleteMooseCookie():
    cookie = Cookie.SimpleCookie()
    cookie['moose'] = ''
    cookie['moose']['expires'] = 0
    print cookie.output()
    print 'Content-type: text/plain'
    print
    print 'Deleted the moose cookie'

def getMooseCookieValue():
    try:
        cookie = Cookie.SimpleCookie(os.environ["HTTP_COOKIE"])
        return cookie['moose'].value
    except:
        return None

def reportExistingMooseCookie(cookieValue):
    print 'Content-type: text/plain'
    print
    print 'The moose cookie already existed on the client, with value: ' + cookieValue

def createMooseCookie():
    dateString = datetime.datetime.now().strftime("%H:%M:%S")
    cookieValue = 'bullwinkle ' + dateString
    message = 'Created a new moose cookie: ' + cookieValue
    cookie = Cookie.SimpleCookie()
    cookie['moose'] = cookieValue

    print cookie.output()
    print 'Content-type: text/plain'
    print 
    print 'The cookie has been created, with value: ' + cookieValue

if __name__ == '__main__':
    cookieValue = getMooseCookieValue()
    arguments = cgi.FieldStorage()
    if 'action' in arguments and arguments['action'].value == 'reset':
        deleteMooseCookie()
    elif cookieValue is not None:
        reportExistingMooseCookie(cookieValue)
    else:
        createMooseCookie()