#!/bin/sh

API_TOKEN=""      # Your API Token
ZONE_ID=""        # Your zone id, hex16 string
RECORD_NAME=""    # Your DNS record name, e.g. sub.example.com
RECORD_TTL="1"    # TTL in seconds (1=auto)
UPDATE_IPv6=false # Set to true if you want to also update IPv6
IP_QUERY_SITE="https://myip.dnsomatic.com/"    # Site used to get external DNS if router isn't able to pull it due to double NAT

get_dns_record_ids() {
  local record_name=$1
  local type=$2
  local api_token=$3
  local zone_id=$4

  RESPONSE="$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/${zone_id}/dns_records?type=${type}&name=${record_name}" \
    -H "Authorization: Bearer ${api_token}" \
    -H "Content-Type:application/json")"

  echo $RESPONSE | python -c "
import sys, json

data = json.load(sys.stdin)
for record in data['result']:
    print (record['id'])"
}

update_dns_record() {
  local record_name=$1
  local record_id=$2
  local type=$3
  local ip=$4
  local record_ttl=$5
  local api_token=$6
  local zone_id=$7

  curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/${zone_id}/dns_records/${record_id}" \
    -H "Authorization: Bearer ${api_token}" \
    -H "Content-Type: application/json" \
    --data "{\"type\":\"${type}\",\"name\":\"${record_name}\",\"content\":\"${ip}\",\"ttl\":${record_ttl},\"proxied\":false}"
}

RESULT=true

# Update IPv4
#Get IPv4 from Router otherwise from external source
IPv4=${1}
if [ -z "$IPv4" ]; then
  IPv4="$(curl -fs4 $IP_QUERY_SITE)"
  logger "IP ${IPv4} obtained external source $IP_QUERY_SITE"
else
  logger "IP ${IPv4} obtained by router"
fi

A_RECORD_IDS=$(get_dns_record_ids $RECORD_NAME A $API_TOKEN $ZONE_ID)

for A_RECORD_ID in $A_RECORD_IDS; do
  RESPONSE="$(update_dns_record $RECORD_NAME $A_RECORD_ID A $IPv4 $RECORD_TTL $API_TOKEN $ZONE_ID)"
  echo $RESPONSE | grep '"success":\ *true' >/dev/null

  if [ $? -eq 0 ]; then
    logger "Updated A record for ${RECORD_NAME} to ${IPv4}"
  else
    logger "Unable to update A record for ${RECORD_NAME} with ${IPv4}"
    RESULT=false
  fi
done

if [ "$UPDATE_IPv6" == true ]; then
  # Update IPv6
  IPv6=$(ip -6 addr list scope global $device | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)
  AAAA_RECORD_IDS=$(get_dns_record_ids $RECORD_NAME AAAA $API_TOKEN $ZONE_ID)

  for AAAA_RECORD_ID in $AAAA_RECORD_IDS; do
    RESPONSE="$(update_dns_record $RECORD_NAME $AAAA_RECORD_ID AAAA $IPv6 $RECORD_TTL $API_TOKEN $ZONE_ID)"
    echo $RESPONSE | grep '"success":\ *true' >/dev/null

    if [ $? -eq 0 ]; then
      logger "Updated AAAA record for ${RECORD_NAME} to ${IPv6}"
    else
      logger "Unable to update AAAA record for ${RECORD_NAME}"
      RESULT=false
    fi
  done
fi

if [ "$RESULT" == true ]; then
  /sbin/ddns_custom_updated 1
else
  /sbin/ddns_custom_updated 0
fi