#!/bin/bash
set -uo pipefail

# Publish latest /private/argus/etc/dns.conf to ${FTP_BASE_PATH}/share/dns.conf

SRC="/private/argus/etc/dns.conf"
FTP_BASE_PATH="${FTP_BASE_PATH:-/private/argus/ftp}"
DST_DIR="${FTP_BASE_PATH}/share"
DST="${DST_DIR}/dns.conf"
UID_VAL="${ARGUS_BUILD_UID:-2133}"
GID_VAL="${ARGUS_BUILD_GID:-2015}"
INTERVAL="${DNS_PUBLISH_INTERVAL:-10}"

log() { echo "$(date '+%Y-%m-%d %H:%M:%S') [DNS-Publish] $*"; }

mkdir -p "$DST_DIR" 2>/dev/null || true

log "service start: SRC=$SRC DST=$DST interval=${INTERVAL}s"

while true; do
  if [[ -f "$SRC" ]]; then
    # Only sync when content differs
    if ! cmp -s "$SRC" "$DST" 2>/dev/null; then
      tmp="${DST}.tmp"
      if cp "$SRC" "$tmp" 2>/dev/null; then
        mv -f "$tmp" "$DST"
        chown "$UID_VAL":"$GID_VAL" "$DST" 2>/dev/null || true
        chmod 0644 "$DST" 2>/dev/null || true
        ts_src=$(date -r "$SRC" '+%Y-%m-%dT%H:%M:%S%z' 2>/dev/null || echo "?")
        log "synced dns.conf (src mtime=$ts_src) -> $DST"
      else
        log "ERROR: copy failed $SRC -> $tmp"
      fi
    fi
  else
    log "waiting for source $SRC"
  fi
  sleep "$INTERVAL"
done