package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

// isTerminal reports whether f is a character device (i.e. a TTY).
func isTerminal(f *os.File) bool {
	info, err := f.Stat()
	if err != nil {
		return false
	}
	return info.Mode()&os.ModeCharDevice != 0
}

// promptDir asks the user for the parent directory to scan, defaulting to
// def when the input is empty.
func promptDir(def string) (string, error) {
	fmt.Fprintf(os.Stderr, "Parent directory to scan [%s]: ", def)
	reader := bufio.NewReader(os.Stdin)
	line, err := reader.ReadString('\n')
	if err != nil {
		return "", err
	}
	line = strings.TrimSpace(line)
	if line == "" {
		return def, nil
	}
	return line, nil
}

// promptYesNo asks a y/N question on stderr and returns the answer.
func promptYesNo(def bool, format string, args ...any) (bool, error) {
	suffix := "[y/N]"
	if def {
		suffix = "[Y/n]"
	}
	fmt.Fprintf(os.Stderr, format+" "+suffix+": ", args...)
	line, err := bufio.NewReader(os.Stdin).ReadString('\n')
	if err != nil {
		return false, err
	}
	switch strings.ToLower(strings.TrimSpace(line)) {
	case "y", "yes":
		return true, nil
	case "n", "no":
		return false, nil
	case "":
		return def, nil
	default:
		return false, nil
	}
}