prompt_yn.sh

# scriptlet:_common/is_noninteractive.sh

##
# Prompt user for a yes or no response
#
# Arguments:
#   --invert            Invert the response (yes becomes 0, no becomes 1)
#   --default-yes       Default to yes if no response is given
#   --default-no        Default to no if no response is given
#   -q                  Quiet mode (no output text after response)
#
# Returns:
#   1 for yes, 0 for no (or inverted if --invert is set)
#
# CHANGELOG:
#   2025.12.16 - Add text output for non-interactive and empty responses
#   2025.11.23 - Use is_noninteractive to handle non-interactive mode
#   2025.11.09 - Add -q (quiet) option to suppress output after prompt (and use return value)
#   2025.01.01 - Initial version
#
function prompt_yn() {
	local TRUE=0 # Bash convention: 0 is success/true
	local YES=1
	local FALSE=1 # Bash convention: non-zero is failure/false
	local NO=0
	local DEFAULT="n"
	local DEFAULT_CODE=1
	local PROMPT="Yes or no?"
	local RESPONSE=""
	local QUIET=0

	while [ $# -ge 1 ]; do
		case $1 in
			--invert) YES=0; NO=1 TRUE=1; FALSE=0;;
			--default-yes) DEFAULT="y";;
			--default-no) DEFAULT="n";;
			-q) QUIET=1;;
			*) PROMPT="$1";;
		esac
		shift
	done

	echo "$PROMPT" >&2
	if [ "$DEFAULT" == "y" ]; then
		DEFAULT_TEXT="yes"
		DEFAULT="$YES"
		DEFAULT_CODE=$TRUE
		echo -n "> (Y/n): " >&2
	else
		DEFAULT_TEXT="no"
		DEFAULT="$NO"
		DEFAULT_CODE=$FALSE
		echo -n "> (y/N): " >&2
	fi

	if is_noninteractive; then
		# In non-interactive mode, return the default value
		echo "$DEFAULT_TEXT (default non-interactive)" >&2
		if [ $QUIET -eq 0 ]; then
			echo $DEFAULT
		fi
		return $DEFAULT_CODE
	fi

	read RESPONSE
	case "$RESPONSE" in
		[yY]*)
			if [ $QUIET -eq 0 ]; then
				echo $YES
			fi
			return $TRUE;;
		[nN]*)
			if [ $QUIET -eq 0 ]; then
				echo $NO
			fi
			return $FALSE;;
		"")
			echo "$DEFAULT_TEXT (default choice)" >&2
			if [ $QUIET -eq 0 ]; then
				echo $DEFAULT
			fi
			return $DEFAULT_CODE;;
		*)
			if [ $QUIET -eq 0 ]; then
				echo $DEFAULT
			fi
			return $DEFAULT_CODE;;
	esac
}