# safe_sympy.py
import sympy as sp


x, y,z = sp.symbols("x y z")


ALLOWED_BASE = {
    "x": x, "y": y,"z":z,
    "pi": sp.pi, "e": sp.E,
    "sin": sp.sin, "cos": sp.cos, "tan": sp.tan,
    "asin": sp.asin, "acos": sp.acos, "atan": sp.atan, "atan2": sp.atan2,
    "sinh": sp.sinh, "cosh": sp.cosh, "tanh": sp.tanh,
    "exp": sp.exp, "log": sp.log, "sqrt": sp.sqrt, "abs": sp.Abs,
    "floor": sp.floor, "ceil": sp.ceiling, "sign": sp.sign,
    "Piecewise": sp.Piecewise, "Max": sp.Max, "Min": sp.Min,
}

def get_allowed(extra: dict | None = None) -> dict:
    allowed = dict(ALLOWED_BASE)
    if extra:
        allowed.update(extra)
    return allowed