#!/bin/sh

# Define ask_yn, which asks a yes or no question and defaults to the specified choice.
# Outputs 1 for yes and 0 for no

ask_yn() {
    default=${2:-"y"}
    default=$(echo "$default" | tr '[:upper:]' '[:lower:]')
    if [ "$default" = "y" ]; then
        prompt="${1} (Y/n): "
        default_output=1
    else
        prompt="${1} (y/N): "
        default_output=0
    fi
    
    while true; do
        # Show prompt and get user input
        printf "%s" "$prompt"
        if [ "$(uname)" = "Darwin" ]; then
            # On macOS, use "read -n 1"
            read -n 1 -r REPLY
        else
            # On Linux and others, use "read -n 1 -s"
            read -r -n 1 -s REPLY
        fi

        # If user hits Ctrl+C or Enter, break and return default output
        if [ -z "$REPLY" ] || [ "$REPLY" = "$(printf '\003')" ]; then
            REPLY=$default
            printf "\n"
            break
        fi
        
        case "$REPLY" in
            y|Y ) printf "\n"; return 1;;
            n|N ) printf "\n"; return 0;;
            * ) printf "\nInvalid input. Please type 'y' or 'n'.";;
        esac
    done
    return $default_output
}

ask_yn "$@"