#!/bin/sh
# Copyright (C) 2019 iopsys Software Solutions AB
# Author: AMIN Ben Ramdhane <amin.benramdhane@pivasoftware.com>

source /usr/share/bbfdm/bbf_uci_api

LOG_FILE="/tmp/nslookup.log"

nslookup_launch() {
	local i j time1 time2 timeresponse status AnswerType HostNameReturned address dns_server_ip ResponseTime success_count
	local address=""
	local hostname=`uci_get_bbf_dmmap dmmap_diagnostics.nslookup.HostName`
	local dnsserver=`uci_get_bbf_dmmap dmmap_diagnostics.nslookup.DNSServer`
	local cnt=`uci_get_bbf_dmmap dmmap_diagnostics.nslookup.NumberOfRepetitions 1`
	[ "$hostname" = "" ] && return
	i=0
	j=0
	success_count=0
	[ -e "${LOG_FILE}" ] && rm ${LOG_FILE}
	delete_all_results
	while [ $i -lt $cnt ]; do
		let i++
		time1=`date +%s`
		if [ -z "$dnsserver" ]; then
			nslookup $hostname >>${LOG_FILE} 2>&1
		else
			nslookup $hostname $dnsserver >>${LOG_FILE} 2>&1
		fi
		time2=`date +%s`                       
		timeresponse=$(($(($time2-$time1))*1000))
		echo "ResponseTime: $timeresponse" >>${LOG_FILE}
		echo "++++++++++++++++++++++++++++++" >>${LOG_FILE}
	done

	while IFS= read line; do
	[ -z "$line" ] && continue;
	local server=`echo "$line" | tr -d '\t' | tr -d ' ' | grep "Server:" | awk -F':' '{print $2}'`

	if [[ -n "$server" && "$server" == "0.0.0.0" ]]; then
	        status="Error_DNSServerNotAvailable"
	        continue
	elif [ -n "$server" ]; then
	        dns_server_ip=$server
	        continue
	fi

	var=`echo "$line" | tr -d '\t' | tr -d ' ' | grep "Name:" | awk -F':' '{print $2}'`
	[ -n "$var" ] && { HostNameReturned=$var; status="Success"; AnswerType="Authoritative"; let success_count++; continue; }

	var=`echo "$line" | grep "Address " | awk -F':' '{print substr($0, index($0,$2))}' | tr -d '\t' | tr -d ' '`
	[ -n "$var" ] && { [ -z "$address" ] && address="$var" || address="$address,$var"; continue; }

	var=`echo "$line" | tr -d '\t' | tr -d ' ' | grep "ResponseTime:" | awk -F':' '{print $2}'`
	[ -n "$var" ] && { ResponseTime=$var; continue; }

	echo $line | grep 'Can' >/dev/null 2>&1 && {  continue; }
	echo $line | grep 'connection timed out' >/dev/null 2>&1 && { AnswerType="None"; status="Error_Timeout"; continue; }
	echo $line | grep 'Non-authoritative' >/dev/null 2>&1 && { AnswerType="NonAuthoritative"; continue; }

	if echo $line | grep '++++++++++++++++++++++' >/dev/null 2>&1; then
		$UCI_ADD_BBF_DMMAP dmmap_diagnostics NSLookupResult
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].Status=$status
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].AnswerType=$AnswerType
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].HostNameReturned=$HostNameReturned
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].IPAddresses=$address
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].DNSServerIP=$dns_server_ip
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].ResponseTime=$ResponseTime
		let j++
		address=""
	fi
	done <${LOG_FILE}
	rm -f ${LOG_FILE}
	$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.SuccessCount=$success_count
	$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=Complete
	$UCI_COMMIT_BBF_DMMAP
}

delete_all_results() {
	local j
	for j in $($UCI_SHOW_BBF_DMMAP dmmap_diagnostics | grep "dmmap_diagnostics.@NSLookupResult.*=NSLookupResult"); do
		$UCI_DELETE_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[-1]
	done
	$UCI_COMMIT_BBF_DMMAP
}

nslookup_stop_diagnostic() {
	delete_all_results
	local pids=`ps | grep nslookup_launch | grep -v grep | awk '{print $1}'`
	if [ -n "$pids" ]; then
		kill -9 $pids &>/dev/null
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=None
		$UCI_COMMIT_BBF_DMMAP
	fi
}

if [ "$1" == "run" ]; then
	nslookup_launch
elif [ "$1" == "stop" ]; then
	nslookup_stop_diagnostic
else
	return
fi