#!/bin/sh
# steal from pystardust, GPL3 license: https://github.com/pystardust/sbar
# modified to fit my own need

# INIT
pid_file="$XDG_CACHE_HOME/pidofbar"
vpn_fifo="$XDG_CACHE_HOME/sbar_vpn_fifo"
sec=0

# exit if sbar is already running, fix when startx in another tty, the other tty sbar not working
# maybe try dwmblocks's approach of using `kill $(pidof -x sbar)`, so can run different sbar in different tty
# but then vpn_fifo becomes a problem too, not sure how to solve
if ! [ -e "$pid_file" ] || ! pidof -qsx sbar -o "$$"; then
	printf '%s' "$$" > "$pid_file"
else
	exit
fi
if ! [ -e "$vpn_fifo" ]; then
	mkfifo "$vpn_fifo"
elif ! [ -p "$vpn_fifo" ]; then
	exit 1
fi

bool () {
	read str
	if [ "$str" = "on" ] || [ "$str" = "up" ] || [ "$str" = "Connected" ]; then
		echo 1
	else
		echo 0
	fi
}

# MODULES
update_time () { 
	time="$(date '+%a %m/%d %H:%M') $(TZ=Asia/Shanghai date '+/%d %H:')"
}

update_cap () { 
	cap="$(if xset q | grep -q "Caps Lock: *on"; then echo A; else echo a; fi)"
}

update_net () { 
	net="$(bool < /sys/class/net/wlp6s0/operstate)"
}

update_vpn () {
	vpn="$(awk '{print $3}' "$vpn_fifo" | bool)"
}

update_vol () { 
	# $(NF-1) for both alsa and pulseaudio
	vol="$(amixer get Master | awk -F'[][]' 'END{printf("%d %s",($(NF-1)=="on")?1:0,$2)}')"
}

update_mic () { 
	# $(NF-1) for both alsa and pulseaudio
	mic="$(amixer get Capture | awk -F'[][]' 'END{print $(NF-1)}' | bool)"
}

update_bat () { 
	bat="$(cat /sys/class/power_supply/BAT1/capacity)%"
}

# For calcurse users, refer https://github.com/pystardust/automeet
#update_event () { 
#	event="$(calcurse -n | sed 1d | \
#		sed -E "s_^ *\[(.*):(.*)\] ([^\t]*)\t?.*_[\1h \2m->\3]_")" 
#	[ "[]" = "$event" ] && event=""
#}

display () {
	xsetroot -name "$time | N $net V $vpn | M $vol C $mic | $cap | $bat"
}

# modules that don't update on their own need to be run at the start for getting their initial value
update_vol
update_mic

# SIGNALLING
# trap	"<function>;display"	"RTMIN+n"
trap	"update_mic;display" 	"RTMIN"
trap	"update_vol;display"	"RTMIN+1"
# xev can't read my toggle internet keyboard key, don't know what key to use in sxhkd to send signal
#trap	"update_net;display"	"RTMIN+2"
trap	"update_cap;display"	"RTMIN+3"
trap	"update_vpn;display"	"RTMIN+4"
# to update it from external commands
## kill -m "$(cat "$XDG_CACHE_HOME/pidofbar")"
# where m = 34 + n

# `mullvad status` write logs everytime it is called
# so I use `mullvad status listen`, this implementation is kinda bloat, maybe there's better way
# should be put after trap?
sh -c '
	mullvad status listen | while read -r line; do
		kill -RTMIN+4 "$(cat "$1")"
		echo "$line" > "$2"
	done &
' shell "$pid_file" "$vpn_fifo"

while :; do
	sleep 1 &
	wait
	[ $((sec % 5 )) -eq 0 ] && update_time 	# update time every 5 seconds
	[ $((sec % 5 )) -eq 0 ] && update_net
	update_cap
	[ $((sec % 60)) -eq 0 ] && update_bat
	#[ $((sec % 300)) -eq 1 ] && update_event
	# how often the display updates ( 5 seconds )
	[ $((sec % 5 )) -eq 0 ] && display
	sec=$((sec + 1))
done