import os
from google.appengine.ext.webapp import template

import cgi
import datetime
import urllib
import wsgiref.handlers

from google.appengine.ext import db
from google.appengine.api import users
import webapp2

class Greeting(db.Model):
    """Models an individual Guestbook entry with an author, content, and date."""
    author      = db.UserProperty()
    content     = db.StringProperty(multiline=True)
    date        = db.DateTimeProperty(auto_now_add=True)

def guestbook_key(guestbook_name=None):
    """Contstructs a datastore key for a Guestbook entity with guestbook_name"""
    return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')

class MainPage(webapp2.RequestHandler):
    def get(self):

        guestbook_name=self.request.get('guestbook_name')
        greetings_query = Greeting.all().ancestor(guestbook_key(guestbook_name)).order('-date')
        greetings = greetings_query.fetch(10)

        if users.get_current_user():
            url = users.create_logout_url(self.request.uri)
            url_linktext = 'Logout'
        else:
            url = users.create_login_url(self.request.uri)
            url_linktext = 'Login'

        template_values= {
            'greetings': greetings,
            'url': url,
            'url_linktext': url_linktext,
        }

        path = os.path.join(os.path.dirname(__file__), 'index.html')
        self.response.out.write(template.render(path, template_values))

class Guestbook(webapp2.RequestHandler):
    def post(self):
        guestbook_name = self.request.get('guestbook_name')
        greeting = Greeting(parent=guestbook_key(guestbook_name))

        if users.get_current_user():
            greeting.author = users.get_current_user()

        greeting.content = self.request.get('content')
        greeting.put()
        self.redirect('/?' + urllib.urlencode({'guestbook_name': guestbook_name}))

app = webapp2.WSGIApplication([
    ('/', MainPage),
    ('/sign', Guestbook)
], debug=True)

def main():
    app.run()

if __name__ == "__main__":
    main()
