#!/bin/sh
# SPDX-License-Identifier: GPL-3.0
#
# freifunk-franken dns-scipts (c) 2021-2023 Blackyfff


. ./dns-functions.sh

HoodZoneFile="$1"
Domain="$2"
Subnets="$3"
View="$4"
ZoneTempFolder="$5"
ZoneFilesFolder="$6"

DomainReg=".""$Domain"
DomainReg="$(echo "$DomainReg" | sed -e 's/\./\\\./g')"

GetLeaseEntriesInSubnet() {
	echo "$1" | while read -r LeaseLine; do
		if IPv4IsInSubnet "${LeaseLine##*	}" "$2";then
			echo "$LeaseLine"
		fi
	done
}

ZoneTempFolder="$ZoneTempFolder""$Domain""/"

OldSerial="$(GetZoneFileSerial "$ZoneTempFolder""db.""$Domain"".bkp")"
NewSerial="$(GetZoneFileSerial "$HoodZoneFile")"
ForceUpdate=""
[ $((OldSerial)) -gt 0 ] && [ $((OldSerial)) -lt $((NewSerial)) ] && ForceUpdate="1"

OldLeases="$(sed -e '/^;### Leases ###/,$!d;/^\s*\S\+\.\s\+\([0-9]*\s\)\?\s*[Ii][Nn]\s\+[Dd][Ss]\s/d' "$HoodZoneFile" | sed 1d)"

if [ -f "/tmp/dhcp.leases" ]; then
	DnsmasqLeases="$(sed -ne 's/^\s*\(\S\+\s\+\)\{2\}\(\S\+\)\s\+\([_0-9a-zA-Z-]\+\)\s\+.*/\3	IN A	\2/p' "/tmp/dhcp.leases")"
	for Subnet in $Subnets; do
		IsValidIPv4Subnet "$Subnet" && NewLeases="$(echo "$NewLeases"; GetLeaseEntriesInSubnet "$DnsmasqLeases" "$Subnet")"
	done
fi

for Leasefile in /tmp/hosts/*; do
	if [ -n "${Leasefile##*/tmp/hosts/\*}" ] && [ -n "${Leasefile##*fffmanage}" ]; then
		NewLeases="$(echo "$NewLeases"; sed -ne 's/^\s*\([0-9.]*\)\s\+\([_0-9a-zA-Z-]\+\)'"$DomainReg"'.*/\2	IN A	\1/p' "$Leasefile")"
		NewLeases="$(echo "$NewLeases"; sed -ne 's/^\s*\([0-9a-fA-F:]*\)\s\+\([_0-9a-zA-Z-]\+\)'"$DomainReg"'.*/\2	IN AAAA	\1/p' "$Leasefile")"
	fi
done

NewLeases="$(echo "$NewLeases" |
			sed -ne 's/^\(\(\(\S\+\)'"$DomainReg"'\)\|\(\S\+\)\)\(.*\)$/\3\4\5/p' |
			awk '!a[$0]++' |
# uncomment and duplicate to secure static DNS-Entries
#			sed -e '/^dns\s\+.*/d' |
#			sed -e '/^gw01\s\+.*/d' |
			NormalizeZoneFileFormatting; \
			echo "_dnsscript_version	IN TXT	""$DNSSCRIPT_VERSION" | NormalizeZoneFileFormatting)"

UpdateZone="$(UpdateDNSSECEntryCache "$Domain" "$ZoneTempFolder" "$HoodZoneFile")"

if [ "$NewLeases" != "$OldLeases" ] || [ -n "$UpdateZone" ] || [ -n "$ForceUpdate" ]; then
	NewSerial=$((NewSerial+1))
	sed -i -e 's/^\(\s*\)\(\S\+\)\(\s*;\s*Serial.*\)/\1'"$NewSerial"'\3/g' "$HoodZoneFile"
	sed -i -e '/^;### Leases ###/,$d' "$HoodZoneFile"
	{
		echo ";### Leases ###"
		echo "$NewLeases"
	} >> "$HoodZoneFile"
	for KeyFile in "$ZoneTempFolder"*; do
		[ "$KeyFile" = "$ZoneTempFolder""*" ] || \
		cat "$KeyFile" >> "$HoodZoneFile"
	done
	ReloadZone "$Domain" "$View" "$ZoneFilesFolder"
fi
cp -f "$HoodZoneFile" "$ZoneTempFolder""db.""$Domain"".bkp"