#!/bin/sh
# PostgreSQL-Backup für ATM10 Stats.
#   backup.sh once   – ein Backup jetzt erstellen
#   backup.sh loop   – täglich ein Backup, ältere als BACKUP_KEEP_DAYS (Standard 14) löschen
# Erwartet PGHOST, PGUSER, PGDATABASE, PGPASSWORD (im Compose-Service gesetzt).
set -u

DIR=/backups
KEEP="${BACKUP_KEEP_DAYS:-14}"

# Each step checks its own result: inside "backup_once || …" the shell ignores set -e.
backup_once() {
  file="$DIR/atm-$(date -u +%Y%m%dT%H%M%SZ).dump"
  if ! pg_dump --format=custom --file="$file.partial"; then
    rm -f "$file.partial"
    echo "backup: FAILED (pg_dump)" >&2
    return 1
  fi
  mv "$file.partial" "$file" || { echo "backup: FAILED (mv)" >&2; return 1; }
  find "$DIR" -name 'atm-*.dump' -mtime +"$KEEP" -delete
  echo "backup: $file ($(du -h "$file" | cut -f1))"
}

mkdir -p "$DIR"
case "${1:-once}" in
  once) backup_once ;;
  loop)
    while true; do
      backup_once
      sleep 86400
    done
    ;;
  *) echo "usage: backup.sh once|loop" >&2; exit 2 ;;
esac