"""Serialize calls to process-global Swiss Ephemeris/PyJHora state.

PyJHora changes shared ayanamsa/node settings and patches swisseph functions.
Its temporary stdout replacement is process-global too. FastAPI runs ordinary
def routes in a thread pool, so all chart entry points must use the same lock.
Each server process owns its own library state and lock.
"""
from functools import wraps
from threading import RLock
from typing import Callable, ParamSpec, TypeVar

P = ParamSpec("P")
R = TypeVar("R")
_calculation_lock = RLock()


def serialize_calculation(function: Callable[P, R]) -> Callable[P, R]:
    @wraps(function)
    def locked(*args: P.args, **kwargs: P.kwargs) -> R:
        with _calculation_lock:
            return function(*args, **kwargs)
    return locked