# -*- coding:utf-8 -*-
import os
import functools
import pprint
import base64
import json

from datetime import datetime

from tornado import gen

def session(method):
    @functools.wraps(method)
    def wrapper(self, *args, **kwargs):
        session_cookie_name = self.application.settings['session_cookie_name']
        session_id = self.get_secure_cookie(session_cookie_name)

        if session_id is not None:
            response = yield gen.Task(self.db.sys_sessions.find_one, {'session_id': session_id})
            result, error = response

            if error['error'] is not None:
                self.logger.error('Session read error: %s', pprint.pformat(error))

            session_age = datetime.utcnow() - result[0]['updated']
            if session_age.total_seconds() > self.application.settings['session_age']:
                self.session = {}
            else:
                self.session = json.loads(base64.decodestring(result[0]['data']))

            if 'user_id' in self.session:
                response = yield gen.Task(self.db.auth_users.find_one, {'_id': self.session['user_id']})
                result, error = response
                if error['error'] is not None:
                    self.logger.error('User load error: %s', pprint.pformat(error))
                self._user = result[0]
        else:
            session_id = os.urandom(32).encode('hex')
            self.set_secure_cookie(session_cookie_name, session_id)
            self.session = {}

        method(self, *args, **kwargs)

    return wrapper