#!/bin/bash

PING_COUNT=2
CHECK_INTERVAL_SEC=120
FORCE_RECONNECT_PING_NG_COUNT=2
FORCE_REBOOT_PING_NG_COUNT=$(( $FORCE_RECONNECT_PING_NG_COUNT+2 ))
CONFIG_FILE_EXT=_connection-recover.conf
CONFIG_FILE_DIR=/etc/connection-recover/

active_connection_exist() {
	nmcli -f NAME connection | sed -e 's/ *$//' | grep -x -q ${CONNECTION}
	if [ $? -eq 0 ]; then
		return 0
	fi
	return 1
}

get_connection_status() {
	nmcli -f DEVICE,STATE device | grep "$DEVICE"
}

reconnect() {
	logger -t connection-recover "$DEVICE reconnect start... "
	timetou 60 nmcli connection down ${CONNECTION} > /dev/null 2>&1
	sleep 5
	timeout 60 nmcli connection up ${CONNECTION} > /dev/null 2>&1
	if [ $? -eq 0 ]; then
		logger -t connection-recover "$DEVICE reconnect success"
	else
		logger -t connection-recover "$DEVICE reconnect fail"
		return -1
	fi
	return 0
}

check_route() {
	ip route get ${PING_DEST_IP} | grep ${NETWORK_IF} > /dev/null 2>&1
}

is_connect() {
	if ! check_route; then
		logger -t connection-recover "$DEVICE: In the route setting, the destination host can not be reached"
		return 0
	fi

	ping -s 1 -c ${PING_COUNT} -w 10 -I ${NETWORK_IF} ${PING_DEST_IP} > /dev/null 2>&1
	if [ $? -eq 0 ]; then
		return 0
	else
		logger -t connection-recover "$DEVICE ping fail"
	fi
	return 1
}

clear_config() {
	PRODUCT_NAME=""
	PING_DEST_IP=""
	DEVICE=""
	TYPE=""
	NETWORK_IF=""
}

read_config_file() {
	. ${CONFIG_FILE}

	if [ ! -n "$PRODUCT_NAME" ]; then
		logger -t connection-recover "$1 is PRODUCT_NAME not set"
		return 1
	fi
	if [ ! -n "$PING_DEST_IP" ]; then
		logger -t connection-recover "$1 is PING_DEST_IP not set"
		return 1
	fi
	if [ ! -n "$DEVICE" ]; then
		logger -t connection-recover "$1 is DEVICE not set"
		return 1
	fi
	if [ ! -n "$TYPE" ]; then
		logger -t connection-recover "$1 is TYPE not set"
		return 1
	fi
	if [ ! -n "$NETWORK_IF" ]; then
		logger -t connection-recover "$1 is NETWORK_IF not set"
		return 1
	fi
	if [ ! -n "$FORCE_REBOOT" ]; then
		logger -t connection-recover "$1 is FORCE_REBOOT not set"
		return 1
	fi
	grep ${PRODUCT_NAME} /proc/device-tree/model -q
	if [ $? -ne 0 ]; then
		return 1
	fi

	return 0
}

load_config() {
	OLD_IFS=$IFS
	IFS="
"
	for CONFIG_FILE in `find ${CONFIG_FILE_DIR} -name "*${CONFIG_FILE_EXT}"`; do
		clear_config
		if ! read_config_file; then
			continue
		else
			IFS=$OLD_IFS
			return	
		fi
	done

	logger -t connection-recover "error: config file is not found"
	exit 1
}

load_config

PING_NG_COUNT=0

while true; do

	sleep ${CHECK_INTERVAL_SEC}

	CONNECTION=`basename $CONFIG_FILE | sed -e "s/${CONFIG_FILE_EXT}//g"`
	if [ -z "$CONNECTION" ]; then
		continue
	fi

	if active_connection_exist; then

		PING_STATUS=1

		STATUS=`get_connection_status`
		case ${STATUS} in
		*disconnected*|*failed*|*unknown*|"*connection failed*")
			reconnect
			if [ $? -eq 0 ]; then
				continue
			fi ;;
		*connected*)
			is_connect
			PING_STATUS=$?
			if [ $PING_STATUS -ne 0 ]; then
				reconnect
			fi ;;
		*deactivating*|*unmanaged*|*unavailable*|*connecting*)
			continue ;;
		esac

		if [ $PING_STATUS -ne 0 ]; then
			PING_NG_COUNT=$(( $PING_NG_COUNT+1 ))
			if [ "$FORCE_REBOOT" = "TRUE" ]; then
				if [ $PING_NG_COUNT -ge $FORCE_REBOOT_PING_NG_COUNT ]; then
					logger -t connection-recover "exec system reboot"
					reboot
				fi
			fi
			if [ $PING_NG_COUNT -ge $FORCE_RECONNECT_PING_NG_COUNT ]; then
				logger -t connection-recover "exec wwan-force-restart"
				wwan-force-restart
			fi
		else
			PING_NG_COUNT=0
		fi

	fi

done