import inspect
import logging
import os
from config import Config
from contextlib import contextmanager
from sqlalchemy import create_engine
from sqlalchemy.orm import (sessionmaker, scoped_session)
from typing import Generator

from log import log

MYSQL_CONNECT = os.environ.get('URMA_DB')
if MYSQL_CONNECT is None:
    raise ValueError("MYSQL_CONNECT is undefined")
else:
    dbname = MYSQL_CONNECT.split('/')[-1]
    log.debug(f"Database: {dbname}")

engine = create_engine(
    MYSQL_CONNECT,
    encoding='utf-8',
    echo=Config.DISPLAY_SQL,
    pool_pre_ping=True,
    future=True
)


@contextmanager
def Session() -> Generator[scoped_session, None, None]:
    frame = inspect.stack()[2]
    file = frame.filename
    function = frame.function
    lineno = frame.lineno
    Session = scoped_session(sessionmaker(bind=engine, future=True))
    log.debug(
        f"Session acquired, {file=}, {function=}, "
        f"function{lineno=}, {Session=}"
    )
    yield Session
    log.debug(" Session released")
    Session.commit()
    Session.close()