import os

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base

config = {}
for key in ["POSTGRES_USER","POSTGRES_PASSWORD","POSTGRES_DB","POSTGRES_HOST","POSTGRES_PORT"]:
    config[key.lower().replace("postgres_","")] = os.environ.get(key,"")

if config["user"] and config["password"]:
    config["auth"] = f"{config['user']}:{config['password']}"
elif config["user"]:
    config["auth"] = config['user']
else:
    raise ValueError("Username is required.")

if not config["db"]:
    raise ValueError("Db is invalid.")

if not config["port"]:
    config["port"] = ":5432"
elif ":" not in str(config["port"]):
    config["port"] = f":{str(config["port"])}"

engine = create_engine(f"postgresql://{config['auth']}@{config['host']}{config['port']}/{config['db']}", echo=False)

SessionLocal = sessionmaker(bind=engine)

Base = declarative_base()