#!/usr/bin/env sh

# This magical spell captures and processes key presses.
# Use it to capture key presses from the terminal and determine which key was pressed.
# todo: Tab key not distinguished from Enter (\t case does not work) 

# Define the function to handle key presses
handle_key() {
  # Read a single character from the terminal
  read -s -n1 key

	#echo $key > ./invisible_character # debug

  # Check the value of the key
  case "$key" in
    # Enter key
    $'\t')
    	echo "tab"
    	;;
    $'\n')
    	echo "enter"
    	;;
    '') # also fires for Tab key
      echo "enter"
      ;;
    '')
    	echo "backspace"
    	;;
    $'\b')
    	echo "backspace"
    	;;
    # Escape sequence, could be any number of keys depending on next character
    $'\e')
    	read -rsn2 -t 0.1 key
		  case "$key" in
		  	'')
		  		echo 'escape'
		  		;;
				# Up arrow key
				$'[A')
					echo "up"
					;;
				# Down arrow key
				$'[B')
					echo "down"
					;;
				# Right arrow key
				$'[C')
					echo "right"
					;;
				# Left arrow key
				$'[D')
					echo "left"
					;;
				$'[3')
					echo "delete"
					;;
				*)
					echo "escaped key: $key"
					;;
			esac
			;;
    # Any other key
    *)
      echo "$key"
      # od -c <<< $key # debug
      ;;
  esac
}

# Check if the script is being executed or sourced, if executed then call the function
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
  handle_key
fi