#!/usr/bin/env bash

ENVFIILE=/etc/prometheus/node_exporter/borg_exporter.env
[[ -f "$ENVFIILE" ]] && source "$ENVFIILE"

REPO_BASE=${REPO_BASE:-/home/backup/borg}
TEXTFILE_COLLECTOR_DIR=${TEXTFILE_COLLECTOR_DIR:-/var/lib/node_exporter/}

PROM_FILE=$TEXTFILE_COLLECTOR_DIR/backup.prom
TMP_FILE=$PROM_FILE.$$

mapfile -t REPOS < <(find "$REPO_BASE" -type d -name data -print0 | xargs --null -n1 dirname)

if [[ -n "${REPOS[*]}" ]] ; then
  echo "# TYPE backup_age_seconds gauge"
  echo "# TYPE backup_total_size_bytes gauge"
fi >> "$TMP_FILE"

for repository in "${REPOS[@]}" ; do
  hostname=${HOSTNAMES[$repository]:-$repository}
  if [[ "$hostname" == "$repository" ]] ; then
    hostname=${hostname/"${REPO_BASE}/"//}
    hostname=${hostname/"/backup"//}
  fi
  index_base="$repository/index"
  age_seconds="$(( $(date +%s) - $(date +%s -r "$index_base".*) ))"
  size="$(du -s "$repository" | cut -f1)"
  echo backup_age_seconds\{host=\""$hostname"\",repository=\""$repository"\"\} "$age_seconds"
  echo backup_total_size_bytes\{host=\""$hostname"\",repository=\""$repository"\"\} "$size"
done >> "$TMP_FILE"

mv "$TMP_FILE" "$PROM_FILE"