package main

import (
	"bufio"
	"fmt"
	"os"

	"golang.org/x/term"
)

// readPassword prompts the user for a password on the given file
// descriptor. If the fd is a terminal the input is hidden; otherwise
// (piped stdin) it falls back to a plain read.
func readPassword(prompt string) ([]byte, error) {
	fd := int(os.Stdin.Fd())
	if term.IsTerminal(fd) {
		fmt.Fprint(os.Stderr, prompt)
		pw, err := term.ReadPassword(fd)
		fmt.Fprintln(os.Stderr)
		return pw, err
	}
	// Non-tty (piped): read a line without echo hiding.
	scanner := bufio.NewScanner(os.Stdin)
	if !scanner.Scan() {
		if err := scanner.Err(); err != nil {
			return nil, err
		}
		return nil, fmt.Errorf("no input on stdin")
	}
	return []byte(scanner.Text()), nil
}