#!/bin/sh
# vim: set noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 :

name=$0
basename="$(basename $0)"

_log() {
	logger -p daemon.info -t "${basename}" "$@"
}

_ping_server() {
	local host=$1
	ret=$(ping \
	    -w "$OMR_TRACKER_TIMEOUT" \
	    -c 1 \
	    -q \
	    "${host}"
	) && echo "$ret" | grep -sq " 0% packet loss" && {
		server_ping=true
	}
}

_check_server() {
	local host=$1
	local port=$2
	local k=0
	while [ "$server_ping" = false ] && [ "$k" -le "$retry" ]; do
		ret=$(curl \
		    --max-time "$OMR_TRACKER_TIMEOUT" \
		    -s \
		    -k \
		    "https://${host}:${port}/"
		)
		[ -n "$ret" ] && server_ping=true
		k=$((k+1))
		sleep "${intervaltries}"
	done
}

_check_server_intf() {
	local host=$1
	local port=$2
	local k=0
	for intf in $(multipath | awk '/default/ {print $1}'); do
		while [ "$server_ping" = false ] && [ "$k" -le "$retry" ]; do
			ret=$(curl \
			    --max-time "$OMR_TRACKER_TIMEOUT" \
			    -s \
			    -k \
			    --interface $intf
			    "https://${host}:${port}/"
			)
			[ -n "$ret" ] && {
				server_ping=true
				return
			}
			k=$((k+1))
			sleep "${intervaltries}"
		done
	done
}

_disable_current() {
	local serv=$1
	config_set $serv current "0"
}

_disable_redir() {
	local redir=$1
	config_get server $redir server
	if [ "$server" = "sss${count}" ]; then
		config_set $redir disabled "1"
	fi
}

_enable_redir() {
	local redir=$1
	config_get server $redir server
	if [ "$server" = "sss${count}" ]; then
		config_set $redir disabled "0"
	fi
}

_check_master() {
	local name=$1
	local count=0
	local countips=0
	local changes="0"
	config_get master $1 master
	config_get ip $1 ip
	config_get port $1 port "65500"
	config_get disabled $1 disabled
	[ "$master" = "1" ] && [ -n "$ip" ] && [ "$disabled" != "1" ] && {
		set_ip() {
			local ipd=$1
			local ip=""
			ipresolve="$(resolveip -4 $ipd | head -n 1)"
			if [ -n "$ipresolve" ]; then
				ip="$ipresolve"
			else
				ip6resolve="$(resolveip -6 $ipd | head -n 1)"
				[ -n "$ip6resolve" ] && ip="$ip6resolve"
			fi
			[ -z "$ip" ] && return
			#_ping_server $ip
			#_check_server $ip $port
			_check_server_intf $ip $port
			if [ "$server_ping" = true ]; then
				if [ "$(uci -q get shadowsocks-libev.sss${count}.server | tr -d '\n')" != "$ip" ]; then
					logger -t "OMR-Tracker-Server" "Master server ${name} up ($ip), set it back"
					changes="1"
					#logger -t "OMR-Tracker-Server" "$(uci -q get shadowsocks-libev.sss${count}.server | tr -d '\n') - $ip"
					uci -q batch <<-EOF >/dev/null
						set shadowsocks-libev.sss${count}.server=$ip
						set shadowsocks-rust.sss${count}.server=$ip
					EOF
					if [ "$count" -eq "0" ]; then
						config_load openmptcprouter
						config_foreach _disable_current server
						uci -q batch <<-EOF >/dev/null
							set xray.omrout.s_vmess_address=$ip
							set xray.omrout.s_vless_address=$ip
							set xray.omrout.s_vless_reality_address=$ip
							set xray.omrout.s_trojan_address=$ip
							set xray.omrout.s_socks_address=$ip
							set xray.omrout.s_shadowsocks_address=$ip
							set v2ray.omrout.s_vmess_address=$ip
							set v2ray.omrout.s_vless_address=$ip
							set v2ray.omrout.s_trojan_address=$ip
							set v2ray.omrout.s_socks_address=$ip
							commit v2ray
							commit xray
							set glorytun.vpn.host=$ip
							commit glorytun
							glorytun-udp.vpn.host=$ip
							commit glorytun
							set dsvpn.vpn.host=$ip
							commit dsvpn
							set mlvpn.general.host=$ip
							commit mlvpn
							del openvpn.omr.remote
							add_list openvpn.omr.remote=$ip
							commit openvpn
							set openmptcprouter.${name}.current='1'
							commit openmptcprouter
						EOF
						/etc/init.d/openmptcprouter-vps get_openvpn_key $name >/dev/null 2>/dev/null
						/etc/init.d/v2ray restart >/dev/null 2>/dev/null
						/etc/init.d/xray restart >/dev/null 2>/dev/null
						/etc/init.d/glorytun restart >/dev/null 2>/dev/null
						/etc/init.d/glorytun-udp restart >/dev/null 2>/dev/null
						/etc/init.d/mlvpn restart >/dev/null 2>/dev/null
						/etc/init.d/openvpn restart >/dev/null 2>/dev/null
						/etc/init.d/dsvpn restart >/dev/null 2>/dev/null
						/etc/init.d/mptcpovervpn restart >/dev/null 2>/dev/null
					fi
				fi
				config_load shadowsocks-libev
				config_foreach _enable_redir ss_redir
				config_load shadowsocks-rust
				config_foreach _enable_redir ss_redir
				OMR_TRACKER_STATUS_MSG="Answer to ping and to API check"
				mail_alert="$(uci -q get omr-tracker.server.mail_alert)"
				#[ -z "$mail_alert" ] && mail_alert="$(uci -q get omr-tracker.defaults.mail_alert)"
				[ "$mail_alert" = "1" ] && [ -n "$(uci -q get mail.default.to)" ] && {
					OMR_SYSNAME="$(uci -q get system.@system[0].hostname)"
					if [ "$(uci -q get omr-tracker.defaults.mail_up_subject)" != "" ] && [ "$(uci -q get omr-tracker.defaults.mail_up_message)" != "" ]; then
						mail_subject="$(uci -q get omr-tracker.defaults.mail_up_subject)"
						mail_subject=`echo $mail_subject | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						mail_message="$(uci -q get omr-tracker.defaults.mail_up_message)"
						mail_message=`echo $mail_message | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						echo -e "Subject: ${mail_subject}\n\n${mail_message}" | sendmail $(uci -q get mail.default.to)
					else
						echo -e "Subject: $OMR_SYSNAME: Server ${name} (${ip}) is UP\n. The reason is \"$OMR_TRACKER_STATUS_MSG\"." | sendmail $(uci -q get mail.default.to)
					fi
				}
				script_alert_down="$(uci -q get omr-tracker.proxy.script_alert_up)"
				[ -n "$script_alert_down" ] && eval $script_alert_up
				count=$((count+1))
			else
				logger -t "OMR-Tracker-Server" "Master server ${name} down ($ip)"
				OMR_TRACKER_STATUS_MSG="No answer to ping and API check"
				uci -q batch <<-EOF >/dev/null
					set openmptcprouter.${name}.current='0'
					commit openmptcprouter
				EOF
				config_load shadowsocks-libev
				config_foreach _disable_redir ss_redir
				config_load shadowsocks-rust
				config_foreach _disable_redir ss_redir
				mail_alert="$(uci -q get omr-tracker.server.mail_alert)"
				#[ -z "$mail_alert" ] && mail_alert="$(uci -q get omr-tracker.defaults.mail_alert)"
				[ "$mail_alert" = "1" ] && [ -n "$(uci -q get mail.default.to)" ] && {
					OMR_SYSNAME="$(uci -q get system.@system[0].hostname)"
					if [ "$(uci -q get omr-tracker.defaults.mail_down_subject)" != "" ] && [ "$(uci -q get omr-tracker.defaults.mail_down_message)" != "" ]; then
						mail_subject="$(uci -q get omr-tracker.defaults.mail_down_subject)"
						mail_subject=`echo $mail_subject | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						mail_message="$(uci -q get omr-tracker.defaults.mail_down_message)"
						mail_message=`echo $mail_message | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						echo -e "Subject: ${mail_subject}\n\n${mail_message}" | sendmail $(uci -q get mail.default.to)
					else
						echo -e "Subject: $OMR_SYSNAME: Server ${name} (${ip}) is down\n. The reason is \"$OMR_TRACKER_STATUS_MSG\"." | sendmail $(uci -q get mail.default.to)
					fi
				}
				script_alert_down="$(uci -q get omr-tracker.proxy.script_alert_down)"
				[ -n "$script_alert_down" ] && eval $script_alert_down
			fi
			countips=$((countips+1))
		}
		config_load openmptcprouter
		config_list_foreach $1 ip set_ip
		#if [ "$server_ping" = true ] && [ "$countips" = "1" ]; then
		#	uci -q batch <<-EOF >/dev/null
		#		set shadowsocks-libev.sss${count}.server=$ip
		#	EOF
		#	config_foreach _enable_redir ss_redir
		#fi
		uci -q commit shadowsocks-libev
		uci -q commit shadowsocks-rust
		[ "$changes" = "1" ] && {
			/etc/init.d/shadowsocks-libev restart >/dev/null 2>/dev/null
			/etc/init.d/shadowsocks-rust restart >/dev/null 2>/dev/null
		}
		break
	}
}

_check_backup() {
	local name=$1
	local count=0
	local countips=0
	local changes="0"
	config_get backup $1 backup
	config_get ip $1 ip
	config_get port $1 port
	config_get disabled $1 disabled
	[ "$backup" = "1" ] && [ -n "$ip" ] && [ "$disabled" != "1" ] && {
		set_ip() {
			local ip=$1
			ipresolve="$(resolveip -4 $ip | head -n 1)"
			if [ -n "$ipresolve" ]; then
				ip="$ipresolve"
			else
				ip6resolve="$(resolveip -6 $ip | head -n 1)"
				[ -n "$ip6resolve" ] && ip="$ip6resolve"
			fi
			#_ping_server $ip
			#_check_server $ip $port
			_check_server_intf $ip $port
			#[ "$server_ping" = true ] && [ "$(uci -q get shadowsocks-libev.sss${count}.server | tr -d '\n')" = "$ip" ] && break
			if [ "$server_ping" = true ]; then
				if [ "$(uci -q get shadowsocks-libev.sss${count}.server | tr -d '\n')" != "$ip" ]; then
					logger -t "OMR-Tracker-Server" "Use backup server $1 ($ip)"
					changes="1"
					uci -q batch <<-EOF >/dev/null
						set shadowsocks-libev.sss${count}.server=$ip
						set shadowsocks-rust.sss${count}.server=$ip
					EOF
					if [ "$count" -eq "0" ]; then
						config_load openmptcprouter
						config_foreach _disable_current server
						uci -q batch <<-EOF >/dev/null
							set xray.omrout.s_vmess_address=$ip
							set xray.omrout.s_vless_address=$ip
							set xray.omrout.s_vless_reality_address=$ip
							set xray.omrout.s_trojan_address=$ip
							set xray.omrout.s_socks_address=$ip
							set xray.omrout.s_shadowsocks_address=$ip
							set v2ray.omrout.s_vmess_address=$ip
							set v2ray.omrout.s_vless_address=$ip
							set v2ray.omrout.s_trojan_address=$ip
							set v2ray.omrout.s_socks_address=$ip
							commit v2ray
							commit xray
							set glorytun.vpn.host=$ip
							commit glorytun
							glorytun-udp.vpn.host=$ip
							commit glorytun
							set dsvpn.vpn.host=$ip
							commit dsvpn
							set mlvpn.general.host=$ip
							commit mlvpn
							del openvpn.omr.remote
							add_list openvpn.omr.remote=$ip
							commit openvpn
							set openmptcprouter.${name}.current='1'
							commit openmptcprouter
						EOF
						/etc/init.d/openmptcprouter-vps get_openvpn_key $name >/dev/null 2>/dev/null
						/etc/init.d/v2ray restart >/dev/null 2>/dev/null
						/etc/init.d/xray restart >/dev/null 2>/dev/null
						/etc/init.d/glorytun restart >/dev/null 2>/dev/null
						/etc/init.d/glorytun-udp restart >/dev/null 2>/dev/null
						/etc/init.d/mlvpn restart >/dev/null 2>/dev/null
						/etc/init.d/openvpn restart >/dev/null 2>/dev/null
						/etc/init.d/dsvpn restart >/dev/null 2>/dev/null
						/etc/init.d/mptcpovervpn restart >/dev/null 2>/dev/null
					fi
					sleep $waittest
				fi
				config_load shadowsocks-libev
				config_foreach _enable_redir ss_redir
				config_load shadowsocks-rust
				config_foreach _enable_redir ss_redir
				OMR_TRACKER_STATUS_MSG="Answer to ping and to API check"
				mail_alert="$(uci -q get omr-tracker.server.mail_alert)"
				#[ -z "$mail_alert" ] && mail_alert="$(uci -q get omr-tracker.defaults.mail_alert)"
				[ "$mail_alert" = "1" ] && [ -n "$(uci -q get mail.default.to)" ] && {
					OMR_SYSNAME="$(uci -q get system.@system[0].hostname)"
					if [ "$(uci -q get omr-tracker.defaults.mail_up_subject)" != "" ] && [ "$(uci -q get omr-tracker.defaults.mail_up_message)" != "" ]; then
						mail_subject="$(uci -q get omr-tracker.defaults.mail_up_subject)"
						mail_subject=`echo $mail_subject | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						mail_message="$(uci -q get omr-tracker.defaults.mail_up_message)"
						mail_message=`echo $mail_message | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						echo -e "Subject: ${mail_subject}\n\n${mail_message}" | sendmail $(uci -q get mail.default.to)
					else
						echo -e "Subject: $OMR_SYSNAME: Server ${name} (${ip}) is UP\n. The reason is \"$OMR_TRACKER_STATUS_MSG\"." | sendmail $(uci -q get mail.default.to)
					fi
				}
				script_alert_down="$(uci -q get omr-tracker.proxy.script_alert_up)"
				[ -n "$script_alert_down" ] && eval $script_alert_up
				count=$((count+1))
			else
				uci -q batch <<-EOF >/dev/null
					set openmptcprouter.${name}.current='0'
					commit openmptcprouter
				EOF
				config_load shadowsocks-libev
				config_foreach _disable_redir ss_redir
				config_load shadowsocks-rust
				config_foreach _disable_redir ss_redir
				OMR_TRACKER_STATUS_MSG="No answer to ping and to API check"
				mail_alert="$(uci -q get omr-tracker.server.mail_alert)"
				#[ -z "$mail_alert" ] && mail_alert="$(uci -q get omr-tracker.defaults.mail_alert)"
				[ "$mail_alert" = "1" ] && [ -n "$(uci -q get mail.default.to)" ] && {
					OMR_SYSNAME="$(uci -q get system.@system[0].hostname)"
					if [ "$(uci -q get omr-tracker.defaults.mail_down_subject)" != "" ] && [ "$(uci -q get omr-tracker.defaults.mail_down_message)" != "" ]; then
						mail_subject="$(uci -q get omr-tracker.defaults.mail_down_subject)"
						mail_subject=`echo $mail_subject | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						mail_message="$(uci -q get omr-tracker.defaults.mail_down_message)"
						mail_message=`echo $mail_message | sed -e "s/%SYSNAME%/$OMR_SYSNAME/g" -e "s/%INTERFACE%/Server ${name}/g" -e "s/%DEVICE%/${ip}/g" -e "s/%MESSAGE%/$OMR_TRACKER_STATUS_MSG/g"`
						echo -e "Subject: ${mail_subject}\n\n${mail_message}" | sendmail $(uci -q get mail.default.to)
					else
						echo -e "Subject: $OMR_SYSNAME: Server ${name} (${ip}) is down\n. The reason is \"$OMR_TRACKER_STATUS_MSG\"." | sendmail $(uci -q get mail.default.to)
					fi
				}
				script_alert_down="$(uci -q get omr-tracker.proxy.script_alert_down)"
				[ -n "$script_alert_down" ] && eval $script_alert_down
			fi
			countips=$((countips+1))
		}
		config_load openmptcprouter
		config_list_foreach $1 ip set_ip
		#if [ "$server_ping" = true ] && [ "$countips" = "1" ]; then
		#	uci -q batch <<-EOF >/dev/null
		#		set shadowsocks-libev.sss${count}.server=$ip
		#	EOF
		#	config_foreach _enable_redir ss_redir
		#fi
		uci -q commit shadowsocks-libev
		uci -q commit shadowsocks-rust
		[ "$changes" = "1" ] && {
			/etc/init.d/shadowsocks-libev restart >/dev/null 2>/dev/null
			/etc/init.d/shadowsocks-rust restart >/dev/null 2>/dev/null
		}
		[ "$server_ping" = true ] && break
	}
}

. /lib/functions.sh

timeout=${OMR_TRACKER_TIMEOUT:-5}
interval=${OMR_TRACKER_INTERVAL:-10}
intervaltries=${OMR_TRACKER_INTERVAL_TRIES:-2}
retry=${OMR_TRACKER_TRIES:-4}
waittest=${OMR_TRACKER_WAIT_TEST:-0}

while true; do
	server_ping=false
	config_load openmptcprouter
	config_foreach _check_master server
	[ "$server_ping" = false ] && {
		config_load openmptcprouter
		config_foreach _check_backup server
	}
	sleep "${interval}"
done