from google.appengine.ext import db
from ext import sessions as sess
from ext import rotmodel as ROT

class BaseModel(ROT.ROTModel):
	created = db.DateProperty(auto_now_add=True)

class User(BaseModel):
	username = db.StringProperty(required=True)
	password = db.StringProperty(required=True)
	email = db.StringProperty(required=True)
	firstname = db.StringProperty(required=True)
	lastname = db.StringProperty(required=True)
	expertise = db.StringProperty(required=True)

	session = db.ReferenceProperty(sess._AppEngineUtilities_Session)

	@classmethod
	def login(cls, session, username, password):
		"""
		Returns user object on success, None on failure.
		"""
		query = User.all().filter("username =", username).filter("password =", password)
		result = query.get()

		if result:
			result.session = session.get_ds_entity()
			result.put()
			session['user_key'] = result.key()

		return result

	@classmethod
	def logout(cls, session):
		"""
		Clears user.session and session data.
		Returns nothing.
		"""
		if session.has_key('user_key'):
			user = User.get(session['user_key'])
			if user:
				user.session = None
				user.put()
			session.clear()

	@classmethod
	def isAuthentic(cls, session):
		"""
		Checks if this computer is logged in, and if the user object is
		set for this session.
		Returns the session instance if successful. None on failure.
		"""
		if session.has_key('user_key'):
			user = User.get_by_id(session['user_key'])
			if user and user.session == session.get_ds_entity():
				return session
			session.clear() #If the session key exists, but the user doesn't match, then clear the session.
		return None