package main

import (
	"context"
	"fmt"
	"os/exec"
	"strings"
	"time"
)

// ProbeTimeout bounds `node --version`.
const ProbeTimeout = 15 * time.Second

// ProbeNode reads the installed Node version: what `node --version` prints ("v26.10.0"), as the toolchains state holds it.
func ProbeNode(ctx context.Context) (string, error) {
	ctx, cancel := context.WithTimeout(ctx, ProbeTimeout)
	defer cancel()
	out, err := exec.CommandContext(ctx, "node", "--version").Output()
	if err != nil {
		return "", err
	}
	return parseNodeVersion(string(out))
}

func parseNodeVersion(out string) (string, error) {
	v := strings.TrimSpace(out)
	if len(v) < 2 || v[0] != 'v' || v[1] < '0' || v[1] > '9' || strings.ContainsAny(v, " \n\t") {
		return "", fmt.Errorf("`node --version` answered %q", v)
	}
	return v, nil
}