import json
from os import path

import sqlalchemy.engine.url as url
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker


class Session(object):

    engine = None

    def __init__(self):
        config = json.load(
            open(path.join(path.dirname(
                path.realpath(__file__)), '..', 'conf', 'db.json')))
        db_str = url.URL(
            drivername=config['type'],
            host=config['host'],
            username=config['user'],
            password=config['pass'],
            database=config['name'],
            query={'charset': config['cset']}
        )
        self.engine = create_engine(db_str, encoding=config['cset'])

    def get_maker(self):
        return sessionmaker(bind=self.engine)

    @staticmethod
    def create():
        session = Session()
        maker = session.get_maker()
        return maker()