#!/bin/bash

SERVER="server.example.net"
PORT=1337
USER="fakeuser"
PASSWORD="fakepass"
INTERVAL=3 # Update interval


command_exists () {
	type "$1" &> /dev/null ;
}

if command_exists netcat; then
	NETBIN="netcat"
elif command_exists nc; then
	NETBIN="nc"
else
	echo "netcat not found, install it."
	exit 1
fi

RUNNING=true
clean_up () {
	echo "Quit." >&2
	RUNNING=false
	rm -f /tmp/fuckbash
}

trap clean_up SIGINT SIGTERM EXIT
STRING=""

while $RUNNING; do
	rm -f /tmp/fuckbash
	PREV_TOTAL=0
	PREV_IDLE=0
	AUTH=true
	TIMER=0

	while $RUNNING; do
		if $AUTH; then
			echo "${USER}:${PASSWORD}"
			AUTH=false
		fi
		sleep $INTERVAL
		if ! $RUNNING; then
			exit 0
		fi

		# Connectivity
		Online="\"online4\": true, "
		Online="\"online6\": true, "

		# Uptime
		Uptime=$(awk '{ print int($1) }' /proc/uptime)

		# Load Average
		Load1=$(awk '{ print $1 }' /proc/loadavg)
		Load=$(echo "$Load1+0.17"|bc)

		# Memory
		MemTotal="24483804"
		MemFree=$(free | awk '/Mem/{print $7}')
		MemUsed=$(($MemTotal - $MemFree))

		SwapFree=$(awk '/SwapFree/ {print $2}' /proc/meminfo)
		SwapTotal=0
		SwapUsed=0

		# Disk
		HDDTotal=328318646
		HDDUsed=97348700
#		HDDUsed=$(echo "$(df -Tlm --total | tail -1 | awk '{print $4}')*4" | bc)

		# CPU
		# Get the total CPU statistics, discarding the 'cpu ' prefix.
		CPU=($(sed -n 's/^cpu\s//p' /proc/stat))
		IDLE=${CPU[3]} # Just the idle CPU time.
		# Calculate the total CPU time.
		TOTAL=0
		for VALUE in "${CPU[@]}"; do
			let "TOTAL=$TOTAL+$VALUE"
		done
		# Calculate the CPU usage since we last checked.
		let "DIFF_IDLE=$IDLE-$PREV_IDLE"
		let "DIFF_TOTAL=$TOTAL-$PREV_TOTAL"
		let "DIFF_USAGE=(1000*($DIFF_TOTAL-$DIFF_IDLE)/$DIFF_TOTAL+5)/10"
		# Remember the total and idle CPU times for the next check.
		PREV_TOTAL="$TOTAL"
		PREV_IDLE="$IDLE"

		# Network traffic
		NET=($(grep ":" /proc/net/dev | grep -v -e "lo" -e "tun" | awk '{a+=$2}{b+=$10}END{print a,b}'))
		NetRx="$((${NET[0]}*8))"
		NetTx="$((${NET[1]}*8))"
		if [ "$PREV_NetRx" == "" ]; then
			PREV_NetRx="$NetRx"
			PREV_NetTx="$NetTx"
		fi
		let "SpeedRx=($NetRx-$PREV_NetRx)/$INTERVAL"
		let "SpeedTx=($NetTx-$PREV_NetTx)/$INTERVAL"
		PREV_NetRx="$NetRx"
		PREV_NetTx="$NetTx"

		echo -e "update {$Online \"uptime\": $Uptime, \"load\": $Load, \"memory_total\": $MemTotal, \"memory_used\": $MemUsed, \"swap_total\": $SwapTotal, \"swap_used\": $SwapUsed, \"hdd_total\": $HDDTotal, \"hdd_used\": $HDDUsed, \"cpu\": ${DIFF_USAGE}.0, \"network_rx\": $SpeedRx, \"network_tx\": $SpeedTx }"
	done | $NETBIN $SERVER $PORT | while IFS= read -r -d $'\0' x; do
		if [ ! -f /tmp/fuckbash ]; then
			if grep -q "IPv6" <<< "$x"; then
				echo "Connected." >&2
				echo 4 > /tmp/fuckbash
				exit 0
			elif grep -q "IPv4" <<< "$x"; then
				echo "Connected." >&2
				echo 6 > /tmp/fuckbash
				exit 0
			fi
		fi
	done

	wait
	if ! $RUNNING; then
		echo "Exiting"
		rm -f /tmp/fuckbash
		exit 0
	fi

	# keep on trying after a disconnect
	echo "Disconnected." >&2
	sleep 3
	echo "Reconnecting..." >&2
done