from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session

from core import constants

engine = create_engine(f'sqlite:///{constants.DB_PATH}', echo=constants.SQL_ALCHEMY_VERBOSE)
Base = declarative_base()


def session():
    return Session(engine)


def create():
    if constants.DB_PATH.exists():
        raise FileExistsError('A db file already exists')
    Base.metadata.create_all(engine)