from datetime import date
import tornado.escape
import tornado.ioloop
import tornado.web
import mysql.connector
import json

class UseDatabase:
    def __init__(self, configuration):
        """ Initialisation code which executes the context manager
            is CREATED. """
        self.host = configuration['DB_HOST']
        self.user = configuration['DB_USER']
        self.passwd = configuration['DB_PASSWD']
        self.db = configuration['DB']

    def __enter__(self):
        """ Set-up code which executes BEFORE the body of the
            with statement. """
        self.conn = mysql.connector.connect(host=self.host,
                                            user=self.user,
                                            password=self.passwd,
                                            database=self.db,)
        self.cursor = self.conn.cursor()
        return(self.cursor)

    def __exit__(self, exc_type, exv_value, exc_traceback):
        """ Tear-down code with executes AFTER the body of the
            with statement.
            The three extra parameters to __exit__() contain information
            related to any exception which may have occurred while running
            the body of the with statement. """
        self.cursor.close()
        self.conn.commit()
        self.conn.close()

config = {'DB_HOST' : 'localhost','DB_USER' : 'root' , 'DB_PASSWD' : '******', 'DB' : 'db'}

class VersionHandler(tornado.web.RequestHandler):
    def get(self):
        response = { 'version': '3.5.1',
                     'last_build':  date.today().isoformat() }
        self.write(response)

class SignIn(tornado.web.RequestHandler):
    def get(self):
        username = self.get_argument('name')
        with UseDatabase(config) as cursor:
            SQL = '''select * from users where username = "%s" Limit 1'''% (username)
            cursor.execute(SQL)
            userData = cursor.fetchone()
        message = {}
        message["userData"] = userData
        json.dumps(message)
        self.write(message)
    def post(self):
        username = self.get_argument('name')
        password = self.get_argument('password')
        with UseDatabase(config) as cursor:
            SQL = '''INSERT INTO users (username , password) VALUES ( "%s" , "%s")'''% (username,password)
            cursor.execute(SQL)
        response = "{ 'create user with name : '" + username + " and password : " + password + "}"
        self.write(response)

application = tornado.web.Application([
    (r"/signin", SignIn),
    (r"/version", VersionHandler)
])

if __name__ == "__main__":
    application.listen(443)
    tornado.ioloop.IOLoop.instance().start()