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

# INIT
printf '%s' "$$" > "$XDG_CACHE_HOME/pidofbar"
sec=0

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="$(mullvad status | awk '{print $3}' | bool)"
}

update_vol () { 
	vol="$(amixer get Master | awk -F'[][]' 'END{printf"%d %s",($4=="on")?1:0,$2}')"
}

update_mic () { 
	mic="$(amixer get Capture | awk -F'[][]' 'END{print $4}' | 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=""
#}

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

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

# 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

while true; do
	# next line of code seems make hotkeys that send kill signals more responsive? not fully understood
	sleep 1 & wait && { 
		# to update item ever n seconds with a offset of m
		## [ $((sec % n)) -eq m ] && udpate_item
		[ $((sec % 5 )) -eq 0 ] && update_time 	# update time every 5 seconds
		[ $((sec % 5 )) -eq 0 ] && update_net
		[ $((sec % 5 )) -eq 0 ] && update_vpn
		[ $((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