#!/bin/python3
from __future__ import annotations
import shutil


def ask_int(prompt: str) -> int:
    """Prompt user for a positive integer."""
    while True:
        try:
            value = int(input(prompt).strip())
            if value <= 0:
                print("Please enter a positive integer.")
                continue
            return value
        except ValueError:
            print("Please enter a valid integer.")


def ask_float(prompt: str) -> float:
    """Prompt user for a positive float."""
    while True:
        try:
            value = float(input(prompt).strip())
            if value <= 0:
                print("Please enter a positive number.")
                continue
            return value
        except ValueError:
            print("Please enter a valid number.")

def ask_optional_float(prompt: str) -> float | None:
    """Prompt user for an optional positive float."""
    while True:
        raw = input(f"{prompt} [Enter = keep default]: ").strip().replace(",", ".")
        if not raw:
            return None
        try:
            value = float(raw)
        except ValueError:
            print("Please enter a number.")
            continue
        if value <= 0:
            print("Value must be greater than 0.")
            continue
        return value

def ask_yes_no(prompt: str) -> bool:
    """Prompt the user for a yes/no answer."""
    while True:
        answer = input(prompt).strip().lower()

        if answer in {"y", "yes"}:
            return True

        if answer in {"n", "no"}:
            return False

        print("Please enter yes or no. [y/n]")

def check_openscad() -> None:
    if shutil.which("openscad") is None:
        raise SystemExit(
            "OpenSCAD was not found in PATH. "
            "Install OpenSCAD or make sure the 'openscad' command is available."
        )