# Description: For DynDNS users who have their own DNS server as well
# License: GPL-2.0+
# Version: 1.0.7
#
# This function will, based on the parametere passed to it
# 1. Check for a new ip address
# 2. Update the zones defined in ~/.config/zones-to-update
# 3. List zones in ~/.config/zones-to-update
# 4. Do all of the above is no parameter is passed

function update-dynamic-ip() {

zmodload zsh/datetime
setopt extendedglob

autoload -Uz zini
zini ${HOME}/.zreprc

ZONE_PATH=/etc/named
ZONE_FILES=($(< ~/.config/zones-to-update))
IP_NEW=${1}
DATE=$(strftime "%Y%m%d" $EPOCHSECONDS)

function set_new_ip_domain() {
# Check if the domain configuration exists
if [[ -z "${config[user_tohtml_new_ip_domain]}" ]]; then
  echo "The domain for checking the new IP address is not configured."
  read "domain?Please enter the domain (e.g., kekepower.noip.me): "
  # After reading the domain from the user
  if ! [[ "${domain}" =~ ^[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ ]]; then
    echo "The input does not seem like a valid domain. Exiting..."
    exit 1
  fi
  # Optionally write the provided domain back to the configuration file
  zini ${HOME}/.zreprc user tohtml_new_ip_domain "${domain}"
  # Reload configuration to reflect the changes
  zini ${HOME}/.zreprc
fi
}

function validate_ip() {
  if [[ ${1} =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; then
    return 0
  else
    return 1
  fi
}

function find_serial() {
	SERIAL=$(grep serial ${ZONE_PATH}/${1} | awk '{print $1}' | uniq)
}

function usage() {
	echo "${ZSH_SCRIPT:t} v1.0.0"
	echo "\tUsage:"
	echo "\t${ZSH_SCRIPT:t} check"
	echo "\t${ZSH_SCRIPT:t} update"
	echo "\t${ZSH_SCRIPT:t} list"
	echo "\nWritten by kekePower 2022-2024"
	return 0
}

function get_new_ip() {
    REMOTE_IP=$(host ${config[user_tohtml_new_ip_domain]} | awk '/has address/ {print $4}')
    if [[ -z ${REMOTE_IP} ]]; then
        echo "Could not resolve IP address for ${domain_name}. Exiting..."
        return 1
    fi
}

function get_current_ip() {
	# Get the existing IP from zone files
	LOCAL_IP=$(grep www ${ZONE_PATH}/* | awk '{print $3}' | uniq)
}

function backup() {
    local file_to_backup=$1
    local date=$(date +%Y%m%d)
    local backup_dir="${HOME}/backup/named/${DATE}"

    echo "Backing up ${file_to_backup} to ${backup_dir}"
    mkdir -p ${backup_dir}
    cp -f ${file_to_backup} ${backup_dir}
}

function reload_bind() {
	get_new_ip
        echo "Reloading named zones"
        sudo systemctl reload named
        echo "Remember to update Puck, Raiola and Cloudflare with ${REMOTE_IP}"
}

function update_serial() {
	#find_serial ${1}
	SERIAL=$(grep serial ${ZONE_PATH}/${1} | awk '{print $1}' | uniq)
	sudo sed -i "s|${SERIAL}|${DATE}01|g" ${ZONE_PATH}/${1}
}

function update_zones() {

# Compare IPs
if [[ ${REMOTE_IP} != ${LOCAL_IP} ]]; then
    read "REPLY?IP address has changed. Current IP: $REMOTE_IP. Update DNS? (y/n): " 
    if [[ ${REPLY} =~ ^[Yy]$ ]]; then
	# Update Zone Files (Loop for flexibility)
	for zone in "${ZONE_FILES[@]}"; do
		backup "${ZONE_PATH}/${zone}"
		echo "Updating ${zone}"
		if ! sudo sed -i "s|${LOCAL_IP}|${REMOTE_IP}|g" ${ZONE_PATH}/${zone}; then
		echo "Error updating ${zone}. Exiting..."
		return 1
		fi
	update_serial ${zone}
	done
	reload_bind
    else
	echo "Skipping update. Consider updating manually."
    fi
else
	echo "IP address has not changed. No update needed."
fi

}

function get_active_zones() {
  active_zones=()

while read -r line; do
	echo "DEBUG: Reading a line"
	if [[ $line =~ ^zone\s+\"(.+)\"\s+IN\s+\\{ ]]; then
	    zone_name=${match[1]}
	    echo "DEBUG: zone_name is $zone_name"
	    echo "DEBUG: Match array: ${match[@]}" # Print the match array
	fi

    if [[ $line =~ ^zone\s+\"(.+)\"\s+IN\s+\\{ ]] && ! [[ $line =~ ^\s*// ]]; then 
        zone_name=${match[1]}  
        echo "DEBUG: zone_name is $zone_name" # Add this line

        if [[ ! $zone_name = (#i)(localhost.localdomain|localhost|*.arpa) ]]; then
            active_zones+=($zone_name)
        fi
    fi
done < /etc/named.rfc1912.zones  

  echo "get_active_zones: $active_zones"
}

function main() {
	set_new_ip_domain
	case "${1}" in
		help | -h | --help)
			usage
		;;
		check)
			get_current_ip
			get_new_ip
			if [[ ${LOCAL_IP} == ${REMOTE_IP} ]]; then
				echo "IP address is the same (${REMOTE_IP})."
			else
				echo "New IP address detected: ${REMOTE_IP}"
				echo "Time to update..."
			fi
			return 0
		;;
		update)
                        get_current_ip
                        get_new_ip
                        validate_ip ${REMOTE_IP}
			update_zones
		;;
		list)
			get_active_zones
			echo "Active zones: ${active_zones[@]}"
		;;
		*)
			get_current_ip
                        get_new_ip
                        validate_ip ${REMOTE_IP}
			update_zones
		;;
	esac
}

main "${@}"

}