"""
Demo of login/logout and saving some user-specific data.

From boodebr.appspot.com. May be freely used and modified for any purpose.
"""
from google.appengine.api import users
from google.appengine.ext import db
from random import random
from logging import info

class DemoUser(db.Model):
	# the user - this is the recommended way to save a reference to
	# a specific user. Do NOT save by the user's email address, as it
	# can change. (See GAE docs for more.)
	user = db.UserProperty(required=True)
	# some data to associate with the user
	value = db.FloatProperty(required=True)

def getpage(environ):
	h = u'<h3>Login demo</h3>'
	# get logged in user, or None
	user = users.get_current_user()
	if not user:
		# give 'login' link
		h += 'You are <b>not</b> logged in '
		h += '<p><a href="%s">Login</a>' % users.create_login_url('/logindemo')
	else:
		# load/create DemoUser. Really, I should do this in a transaction, but
		# keeping things simple for now.
		q = db.GqlQuery('select * from DemoUser where user = :1', user)
		uobj = q.fetch(1)
		if not len(uobj):
			# create new DemoUser
			uobj = DemoUser(user=user, value=random())
			db.put(uobj)
			h += "I've picked a random number for you of <b>%f</b>. " % uobj.value
			h += "Each time you login, I will remember this number.<p>"
		else:
			# loaded existing DemoUser
			uobj = uobj[0]
			
		# show the user their info
		h += 'You are logged in as <b>%s</b> (<b>%s</b>) ' % (user.nickname(), user.email())
		h += '<br>Your random value is <b>%f</b><br>' % uobj.value
		h += '<br>Your database key is <b>%s</b> ' % uobj.key()
		h += '<br>The app that created this key is <b>%s</b> ' % uobj.key().app()
		h += '<br>The type of the data entity is <b>%s</b> ' % uobj.key().kind()
		h += '<br>The id of the data entity is <b>%s</b> ' % uobj.key().id()
		h += '<br>The name of the data entity is <b>%s</b> ' % uobj.key().name()
		h += '<br>The parent of this data entity is <b>%s</b> ' % uobj.key().parent()
		
		h += '<p><a href="%s">Logout</a>' % users.create_logout_url('/logindemo')
		
	# show headers so user can see them change as they login/logout
	h += '<hr><h3>Headers</h3>'
	
	keys = environ.keys()
	keys.sort()
	for k in keys:
		h += '%s: %s<br>' % (k,environ[k])

	return h.encode('utf-8')
	
def login_demo(environ, start_response):
	path = environ['PATH_INFO']
	if path == '/logindemo':
		status = '200 OK'
		response_headers = [('Content-type','text/html')]
		start_response(status, response_headers)
		return [getpage(environ)]
	elif path == '/logindemo/source':
		status = '200 OK'
		response_headers = [('Content-type','text/plain')]
		start_response(status, response_headers)
		return [open(__file__).read()]
		
# does not know nor care that it is running under AppEngine!
from wsgiref.handlers import CGIHandler
CGIHandler().run(login_demo)