"""Move Python's history file to "$XDG_STATE_HOME/python/history".

Python 3.13+ honors the `$PYTHON_HISTORY` environment variable,
so this file is only needed for older interpreters (e.g., via `pyenv`).

`$PYTHONSTARTUP` is executed in the REPL's own namespace
=> Everything is wrapped in a function that is deleted afterwards
   to avoid polluting the prompt with temporary names
"""

import sys


def _setup_history():
    if sys.version_info >= (3, 13):
        return  # `$PYTHON_HISTORY` handles it

    try:
        import readline  # because it is not in every build
    except ImportError:
        return

    import atexit
    import os

    state_home = os.environ.get("XDG_STATE_HOME") or os.path.join(
        os.path.expanduser("~"), ".local", "state"
    )
    history_file = os.path.join(state_home, "python", "history")

    os.makedirs(os.path.dirname(history_file), exist_ok=True)
    if os.path.isdir(history_file):
        raise OSError(history_file + " must not be a directory")

    try:
        readline.read_history_file(history_file)
    except OSError:  # `$PYTHON_HISTORY` is non-existent or unreadable
        pass

    readline.set_auto_history(True)
    readline.set_history_length(99999)

    def write_history():
        try:
            readline.write_history_file(history_file)
        except OSError:
            pass

    atexit.register(write_history)  # Keep a reference to `write_history`


_setup_history()

del _setup_history