#!/bin/sh

[ -z "$1" ] && exit # If $1 is left, hovers in the bottom left, if right, the bottom right
current=$(xdotool getwindowfocus)

# xrandr is quite slow in execution. displayselect will generate a new one in postrun.
# Otherwise if none exist this script will run xrandr once. Changing display setups will not be detected.
if [ -f /tmp/dims ]; then
	dims="$(cat /tmp/dims)"
else
	dims="$(xrandr --screen 0 | grep ' connected' | grep -v '^\s*$' | sed 's/ primary//' | cut -d ' ' -f3 | tee -i '/tmp/dims')"
fi
horizontal_offset="$( echo "$dims" | cut -d '+' -f2 )"
mouse_location_horizontal="$(xdotool getmouselocation | grep -Eo 'x:[0-9]{1,5}' | tr -d 'x:')"
# var passed is an accumulator for screens that fit the current mouse location or less
for screen in $horizontal_offset; do
	[ "$screen" -lt "$mouse_location_horizontal" ] && passed="$(printf '%s\n%s\n' "$passed" "$screen")"
done
# take max of all screens to the left of mouse
offset_of_screen_mouse_is_on="$(echo "$passed" | sort -n | tail -n1)"
dim="$( echo "$dims" | grep "+$offset_of_screen_mouse_is_on+" )"
screenwidth="$( echo "$dim" | grep -Eo '^[0-9]{1,5}x' | tr -d 'x')"
screenheight="$( echo "$dim" | grep -Eo 'x[0-9]{1,5}+' | tr -d 'x+')"

# Adjust here for larger/smaller windows
newheight=$(( 2 * screenheight / 5 ))
newwidth=$(( 2 * screenwidth / 5 ))
# fit your borderwidth setup of your WM or windows could bleed over to other display
borderwidth=1

# see https://specifications.freedesktop.org/wm-spec/wm-spec-1.3.html for gravity specs
# I do not believe that gravity is being respected in dwm.
case "$1" in
	left)	horizontal=$(( borderwidth ))
		vertical=$(( screenheight - newheight - 2 * borderwidth ))
		gravity=7 #gravity of southwest
		;;
	right)	horizontal=$((  screenwidth - newwidth - 2 * borderwidth ))
		vertical=$(( screenheight - newheight  - 2 * borderwidth ))
		gravity=9 #gravity of southeast
		;;
esac

wmctrl -r :ACTIVE: -b remove,maximized_vert,maximized_horz
wmctrl -r :ACTIVE: -e $gravity,$horizontal,$vertical,$newwidth,$newheight