#!/bin/sh

# Move the active window to the first empty workspace and follow it
#
# Note: This assumes that only the main monitor has workspaces enabled

set -eu


active=$(xprop -root _NET_ACTIVE_WINDOW | awk '{print $NF}')
desktop=$(xprop -id "$active" _NET_WM_DESKTOP 2>/dev/null | awk '{print $NF}')

# 4294967295 (i.e., 0xFFFFFFFF) means "on all workspaces",
# which is what `mutter` reports for windows on secondary monitors
# when "workspaces-only-on-primary" is true
if [ "$desktop" = "4294967295" ] || [ -z "$desktop" ]; then
    command -v notify-send >/dev/null \
        && notify-send 'Window Management' 'Active window is not on a workspace on the main screen'
    exit 1
fi


occupied_workspaces=$(wmctrl -l) || exit 1  # fail safe
occupied_workspaces=$(echo "$occupied_workspaces" | awk '{print $2}' | sort -u)

total=$(wmctrl -d | wc -l)


# 0-based index for the first workspace
i=0


while [ "$i" -lt "$total" ]; do

    if ! echo "$occupied_workspaces" | grep -qx "$i"; then
        wmctrl -r :ACTIVE: -t "$i"
        wmctrl -s "$i"
        exit 0
    fi

    i=$((i + 1))

done


command -v notify-send >/dev/null \
    && notify-send 'Window Management' 'No empty workspace available'

exit 1