import os

from dotenv import load_dotenv

from sqlalchemy import create_engine

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy.orm import sessionmaker

from sqlalchemy.exc import ProgrammingError

load_dotenv("../credentials.env")

DB_USERNAME = os.getenv("DB_USERNAME")

DB_PASSWORD = os.getenv("DB_PASSWORD")

DB_NAME = os.getenv("DB_NAME")

DB_BASE_URL = f"postgresql+psycopg2://{DB_USERNAME}:{DB_PASSWORD}@localhost:5432/"

DB_FINAL_URL = DB_BASE_URL + DB_NAME

base_engine = create_engine(DB_BASE_URL)

# create database if it doesn't exist

try:

conn = base_engine.connect()

# commit empty statement as a sqlalchemy workaround

conn.execute("commit")

# create database

conn.execute(f"CREATE DATABASE {DB_NAME};")

conn.close()

except ProgrammingError:

pass

# final engine, Base, and Session used in other scripts

engine = create_engine(DB_FINAL_URL)

Session = sessionmaker(bind=engine)

Base = declarative_base()