"""
Persistence (Postgresql) configuration
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2022 Concordia CERC group
Project Coder Peter Yefi peteryefi@gmail.com
"""

import os
from dotenv import load_dotenv
from sqlalchemy.ext.declarative import declarative_base


Base = declarative_base()

# load environmental variables
load_dotenv()


class BaseConfiguration(object):
    """
    Base configuration class to hold common persistence configuration
    """
    def __init__(self):
      self._db_name = os.getenv('DB_NAME')
      self._db_host = os.getenv('DB_HOST')
      self._db_user = os.getenv('DB_USER')
      self._db_pass = os.getenv('DB_PASSWORD')
      self._db_port = os.getenv('DB_PORT')

    def conn_string(self):
      """
      Returns a connection string postgresql
      :return: connection string
      """
      if self._db_pass:
        return f'postgresql://{self._db_user}:{self._db_pass}@{self._db_host}:{self._db_port}/{self._db_name}'
      return f'postgresql://{self._db_user}@{self._db_host}:{self._db_port}/{self._db_name}'