#!/bin/sh
# Copyright (C) 2022 iopsys Software Solutions AB
# Author: AMIN Ben Ramdhane <amin.benramdhane@pivasoftware.com>

. /usr/share/libubox/jshn.sh

ROOT="$(dirname $0)"
. ${ROOT}/bbf_api

get_nslookup_log_file() {
	IDX=1
	LOG_FILE="/tmp/nslookup_$IDX.log"
	
	while [ -e ${LOG_FILE} ]; do
		IDX=$((IDX+1))
		LOG_FILE="/tmp/nslookup_$IDX.log";
	done

	echo ${LOG_FILE}
}

nslookup_error() {
	json_init
	json_add_string "Status" "$1"
	json_add_int "SuccessCount" "0"
	json_dump

	# Store data in dmmap_diagnostics for both protocols (cwmp/usp)
	[ "$3" == "both_proto" ] && {
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState="$1"
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.SuccessCount=0
		$UCI_COMMIT_BBF_DMMAP
	}
}

nslookup_launch() {
	input="$1"

	json_load "${input}"
	
	json_get_var hostname host
	json_get_var dnsserver dns_serevr
	json_get_var iface iface
	json_get_var cnt nbr_of_rep
	json_get_var proto proto
	
	LOG_FILE=$(get_nslookup_log_file)

	# Assign default value
	[ -z "${cnt}" ] && cnt=1

	# Fail if hostname is empty
	[ -z "${hostname}" ] && {
		nslookup_error "Error_Internal" "${cnt}" "${proto}"
		return
	}

	i=0

	while [ $i -lt "${cnt}" ]; do
		i=$((i+1))
		
		nslookup -debug $hostname $dnsserver >>${LOG_FILE} 2>&1
		error_code="$?"
		
		nxd=$(cat ${LOG_FILE} | grep "NXDOMAIN")
		[ -n "$nxd" ] && {
			nslookup_error "Error_DNSServerNotResolved" "${cnt}" "${proto}"
			return;
		}

		[ "$error_code" != "0" ] && {
			nslookup_error "Error_Other" "${cnt}" "${proto}"
			return;
		}

		echo "++++++++++++++++++++++++++++++" >>${LOG_FILE}
	done

	AnswerType="Authoritative"
	success_count=0
	address=""
	j=0
	json_init
	json_add_array "NSLookupResult"
	
	while IFS= read line; do
		[ -z "$line" ] && continue;
		server=$(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=$var; status="Success"; success_count=$((success_count+1)); continue; }

		var=$(echo "$line" | tr -d '\t' | tr -d ' ' | grep "name=" | awk -F'=' '{print $2}')
		[ -n "$var" ] && { HostNameReturned=$var; status="Success"; address="$hostname"; success_count=$((success_count+1)); 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" | grep "completed" | awk -F'in' '{print $2}' | tr -d 'ms:\t ')
		[ -n "$var" ] && { ResponseTime=$var; 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

			json_add_object ""
			json_add_string "Status" "${status}"
			json_add_string "AnswerType" "${AnswerType}"
			json_add_string "HostNameReturned" "${HostNameReturned}"
			json_add_string "IPAddresses" "${address}"
			json_add_string "DNSServerIP" "${dns_server_ip}"
			json_add_string "ResponseTime" "${ResponseTime}"
			json_close_object
		
			# Store data in dmmap_diagnostics for both protocols (cwmp/usp)
			[ "$proto" == "both_proto" ] && {
				$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="${ResponseTime}"
				j=$((j+1))
			}
			
			address=""
			AnswerType="Authoritative"
		fi

	done <${LOG_FILE}
	rm -f ${LOG_FILE}

	json_close_array
	json_add_string "Status" "Complete"
	json_add_int "SuccessCount" "${success_count}"
	json_dump

	# Store data in dmmap_diagnostics for both protocols (cwmp/usp)
	[ "$proto" == "both_proto" ] && {
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState="Complete"
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.SuccessCount="${success_count}"
		$UCI_COMMIT_BBF_DMMAP
	}
}


if [ -n "$1" ]; then
	nslookup_launch "$1"
else
	nslookup_error "Error_Internal" "1"
fi