#!/bin/sh
# Entry point for the `backup` sidecar container's periodic loop. Runs
# db-backup.sh on a fixed interval (default: daily) -- a sleep loop instead of
# a cron daemon, kept deliberately simple so it works in a bare
# postgres:16-alpine image.
#
# Resolves db-backup.sh the same way entrypoint.sh resolves this file: prefer
# the live bind-mounted copy at /scripts (so edits don't need a rebuild), fall
# back to the copy baked into the image at build time if the mount is
# missing, empty, or stale. Resolving fresh on every loop iteration also means
# that if the mount comes back healthy later (e.g. someone fixes the host
# directory) this container picks it up on the very next run, with no
# restart needed.
set -eu

resolve() {
  # $1 = script filename, e.g. db-backup.sh
  if [ -f "/scripts/$1" ]; then
    echo "/scripts/$1"
  else
    echo "/app/scripts-default/$1"
  fi
}

INTERVAL="${BACKUP_INTERVAL_SECONDS:-86400}"   # 86400 = once a day
echo "[backup] sidecar started; interval=${INTERVAL}s, keep=${BACKUP_KEEP:-14}, dir=${BACKUP_DIR:-/backups}"

# Take one backup shortly after start so a freshly-deployed stack has an
# immediate restore point instead of waiting a whole interval.
sleep 20
while true; do
  DB_BACKUP="$(resolve db-backup.sh)"
  sh "$DB_BACKUP" || echo "[backup] run failed; will retry next interval" >&2
  sleep "$INTERVAL"
done