package session

import (
	"bufio"
	"fmt"
	"io"
	"strings"
)

// ConfirmYN prints prompt to out, reads one line from in, and returns:
//   - true for "y"/"yes" (case-insensitive)
//   - false for "n"/"no" (case-insensitive)
//   - defaultYes for empty input
//   - !defaultYes for any other input (treat unrecognized as the
//     opposite of the default, i.e., the safer choice given the default)
func ConfirmYN(in io.Reader, out io.Writer, prompt string, defaultYes bool) bool {
	fmt.Fprint(out, prompt)
	reader := bufio.NewReader(in)
	line, _ := reader.ReadString('\n')
	answer := strings.TrimSpace(strings.ToLower(line))

	if answer == "" {
		return defaultYes
	}
	if answer == "y" || answer == "yes" {
		return true
	}
	if answer == "n" || answer == "no" {
		return false
	}
	return !defaultYes
}