#!/bin/bash

me="$(readlink -f "$0")"
timeout=240
notify=10

case "$1" in
    start)
        xset s $(($timeout - $notify)) $notify
        xset dpms $(($timeout * 2)) $(($timeout * 3)) $(($timeout * 4))
        exec xss-lock -n "$me dim" -l $me lock
        ;;
    dim)
        echo "$me: dim: start"
        trap 'exit 0' TERM INT
        trap "kill %% ; wait ; xbacklight -steps 1 -set $(xbacklight -get)" EXIT
        min_brightness=0
        fade_time=$(($notify * 1000))
        fade_steps=100
        xbacklight -time $fade_time -steps $fade_steps -set $min_brightness &
        wait
        echo "$me: dim: end"
        sleep 2147483647 &
        wait
        ;;
    lock)
        i3lock_options="-e -i $HOME/.cache/awesome/current-wallpaper.png"
        echo "$me: lock: lock screen"
        if [ -e /proc/self/fd/${XSS_SLEEP_LOCK_FD:--1} ]; then
            trap 'kill %%' TERM INT
            i3lock -n $i3lock_options {XSS_SLEEP_LOCK_FD}<&- &
            sleep 0.3           # Slight race condition, better than an active loop
            exec {XSS_SLEEP_LOCK_FD}<&-
            wait
        else
            trap 'kill %%' TERM INT
            i3lock -n $i3lock_options &
            wait
        fi
        echo "$me: lock: unlock screen"
        ;;
esac