#!/bin/sh

# This script cannot run without the X server (GUI)
# So exit if DISPLAY is not set
[ -z "$DISPLAY" ] && {
	notify-send remap "ERROR: DISPLAY not set"
	exit
}

timeout="${KEY_RELEASE_TIMEOUT:-500}"

help() { echo "remap - remap modifier keys for easy access

USAGE:
	remap [OPTION]...

OPTIONS:
	-x  reset keys
	-t  toggle (remap/reset)
	-s  show remap status
	-i  show info of all key remaps
	-h  show this help message"; }

key_info() { echo "
	+-----------------+-----------------------------------+
	| Before          | After                             |
	+-----------------+-----------------+-----------------+
	| Key             | On Hold         | On Tap          |
	+-----------------+-----------------+-----------------+
	| Tab             | Super           | Tab             |
	| Caps Lock       | Ctrl            | Esc             |
	| Space           | Shift           | Space           |
	| Left Ctrl       | Ctrl            | Caps Lock       |
	| Escape          | Tab             | Tab             |
	+-----------------+-----------------+-----------------+

Note:
  By default, 'On Tap' will timeout at 500 miliseconds. In other words,
  if you release a key after timeout, the key will not be generated.
  You can increase it's value by setting the \$KEY_RELEASE_TIMEOUT environment
  variable. This is useful in case you don't have a fast typing speed.

If you want to change more keys or want a different configuration, you
can edit the remap_keys() function inside this script.
	"; }

while getopts 'rxtsih' o; do case "$o" in
  x) action=x ;;
  t) action=t ;;
  s) action=s ;;
  i) key_info >&2; exit ;;
  h) help >&2; exit ;;
	*) printf "remap: invalid argument -- '%s'\n" "$OPTARG" ;;
esac; done

status_file="/tmp/.remap.lock"
keymap_file="/tmp/.xmodmap.defaults"
[ -f "$keymap_file" ] || xmodmap -pke > "$keymap_file"

msg() {
	[ "$VERBOSE_REMAP" != 1 ] && return
	printf "remap: %s\n" "$@"
	# notify-send "remap" "$*"
}

remap_keys() {
	msg "remapping keys..."
	# Fast key repeats
	xset r rate 300 50

	# New key behaviour on Hold
	# lines after ! are comments
	xmodmap - <<-EOF
	!          Hold Caps_Lock -> Control_R
	remove lock = Caps_Lock
	remove Control = Control_R
	! keysym Control_R = Caps_Lock
	keysym Caps_Lock = Control_R
	! add lock = Caps_Lock
	add Control = Control_R
	keycode any = Caps_Lock

	!          Hold space -> Shift_R
	remove shift = Shift_R
	keycode 65 = Shift_R
	add shift = Shift_R
	keycode any = space

	!          Hold Tab -> Super_L
	! !          Escape -> Tab
	remove mod4 = Super_L
	keycode 23 = Super_L
	keycode any = Tab ISO_Left_Tab Tab ISO_Left_Tab
	! keycode 133 = Tab ISO_Left_Tab Tab ISO_Left_Tab
	add mod4 = Super_L
	! keycode 230 = Escape
	! keycode 9 = Tab ISO_Left_Tab Tab ISO_Left_Tab
	EOF

	# New key behaviour on Tap
	killall xcape 2>/dev/null
	xcape -t "$timeout" -e "Super_L=Tab"
	xcape -t "$timeout" -e "Control_R=Escape"
	xcape -t "$timeout" -e "Shift_L=Caps_Lock"
	xcape -t "$timeout" -e "Shift_R=space"
	date > "$status_file"
	xset led 3
	msg "keys remapped"
}


reset_keys() {
	msg "resetting keys..."
  xset r rate
  killall xcape 2>/dev/null
  setxkbmap -layout us
  xmodmap "$keymap_file"

  [ -f "$status_file" ] && rm "$status_file"
  xset -led 3
	msg "keys reset"
}

toggle_remap() {
	if [ -f "$status_file" ]; then
		reset_keys
	else
		remap_keys
	fi
}

remap_status() {
  if [ -f "$status_file" ]; then
    printf "Keys are remapped since "
		cat "$status_file"
  else
    echo "Keys are NOT remapped"
  fi
}

case "$action" in
	s) remap_status ;;
  x) reset_keys ;;
  t) toggle_remap ;;
	*) remap_keys ;;
esac