#!/usr/bin/env python3
# This entire thing is unnecessary post v3.13.0a3
# https://github.com/python/cpython/issues/73965

def is_vanilla() -> bool:
    """ :return: whether running "vanilla" Python """
    import sys
    return not hasattr(__builtins__, '__IPYTHON__') and 'bpython' not in sys.argv[0]


def setup_history():
    """ read and write history from state file """
    import os
    import atexit
    import readline
    from pathlib import Path

    # https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables
    if state_home := os.environ.get('XDG_STATE_HOME'):
            state_home = Path(state_home)
    else:
        state_home = Path.home() / '.local' / 'state'
    if not state_home.is_dir():
        print("Error: XDG_STATE_HOME does not exist at", state_home)

    history: Path = state_home / 'python_history'

    # https://github.com/python/cpython/issues/105694
    if not history.is_file():
        readline.write_history_file(str(history)) # breaks on macos + python3 without this.

    readline.read_history_file(history)
    atexit.register(readline.write_history_file, history)


if is_vanilla():
    setup_history()
