#!/bin/bash

. driglibash-base

set -euo pipefail

# Working variables
debian_bind_workdir="/var/cache/bind"
debian_bind_confdir="/etc/bind"
keydir="$DATA_DIR/keys"

# Install dependencies
apt install -y bind9 &>/dev/null

# Create Directories
mkdir -p "$keydir"
chown bind:bind "$keydir" -R
chown bind:bind "$debian_bind_confdir" -R

# Empty bind dir if it is not our git repo
if [ ! -d "$debian_bind_confdir/.git" ] ; then
	echo "lets delete $debian_bind_confdir"
	rm -rf "$debian_bind_confdir/"{*,.*}
fi

# Sync the git repo
sudo -u bind git_update.sh -b main -i "$DATA_DIR/gitkey" -d "$debian_bind_confdir" 'ssh://git@git.jean-cloud.net:22529/adrian/dnszones.git'
cd /etc/bind
sudo -u bind git status

### Generate zones from service directory ###

servicefile="/docker/services.txt"

# Function that simulate a DNS resolve by reading bind zone file
# Returns all the record line:
# @ IN A X.X.X.X
fakeresolve () {
	if [ "$#" -ne 1 ] ; then
		die "Usage: fakeresolve <name>"
	fi
	name="$1"
	
	zonefile="$debian_bind_confdir/db.jean-cloud.org"
	shortname="$(echo "$name" | grep -Po '^.*(?=\.[^\.]+\.[^\.]+$)' || true)"

	grep -v -e  '^[[:space:]]*;' "$zonefile"  |grep -oP "^[[:space:]]*$shortname\K[[:space:]]*IN[[:space:]]*A{1,4}[[:space:]]*[\S;]+" | sed 's/^/@/'

}

# Function that add DNS record in the right file
addbindline () {
	if [ "$#" -ne 2 ] ; then
		die "Usage: addbindline <name> <target_cname>"
	fi

	name="$1"
	target="$2"

	# extract the truc.com part
	domain="$(echo "$name" | grep -o '[^\.]\+\.[^\.]\+$' || true)"	
	[ -z "$domain" ] && return 0

	# extract the subdomain part (www)
	shortname="$(echo "$name" | grep -Po '^.*(?=\.[^\.]+\.[^\.]+$)' || true)"

	# bind DB file
	bindfile="$debian_bind_confdir/db.$domain"

	if [ -z "$shortname" ] ; then
		# CNAME are forbiden for empty shortnames, so we must resolve the target IPs
		while read line ; do
			line_in_file "$line" "$bindfile"
		done < <(fakeresolve "$target")
	else
		line_in_file "$shortname IN CNAME $target." "$bindfile"
	fi

	#XXX Add CAA records
}


autoconf_separator=";;; Autogeneration. Do not write under this line! ;;;"

echo 'Prepare bind: Remove autogenerated part from bind conf files'
sed -i -n "/$autoconf_separator/q;p" "$debian_bind_confdir"/*

echo 'Put the separator back'
for file in $( ls "$debian_bind_confdir"/db.* | grep -v '.signed$\|.jbk$\|.jnl$') ; do
	echo "$autoconf_separator" >> "$file"
done

for file in "$debian_bind_confdir"/db.* ; do
	domain="$(basename "$file" | sed 's/db.//')"

	# TODO fill header too?

	# If no NS record in the db file
	if [ -z "$(grep '[^;].*IN.*NS' "$file")" ] ; then
		echo -e "@ IN NS ns.jean-cloud.org\n" >> "$file"
	fi

	echo -n "
zone '$domain' {
    allow-update { none; };
    type master;
    file \"$file\";
};" >> "$debian_bind_confdir/named.conf.local"
done

echo 'Find every used domain and add them to bind db'
while read line ; do
	read -r service target <<<$(echo "$line")
	addbindline "$service" "$target"
	nginxfile="/docker/$service/nginx_server.conf"
	if [ -f "$nginxfile" ] ; then
		for name in $(extract_domain_nginx_conf.sh "$nginxfile" | template.sh "/docker/$service/.env") ; do
			addbindline "$name" "$target"
		done
	fi
done <"$servicefile"


echo 'Restart bind9'
systemctl restart bind9