#!/bin/bash
{{ ansible_managed | comment }}

set -eu

TEXTFILE_COLLECTOR_DIR=/var/lib/prometheus/node-exporter
PROM_FILE=$TEXTFILE_COLLECTOR_DIR/backup.prom
TMP_FILE=$PROM_FILE.$$
NOW=$(date +%s)
BORG_INFO=$(borgmatic --no-color info --last 1 --json)

get_field() {
    local query="$1"
    printf '%s' "$BORG_INFO" | jq -r ".[].$query"
}

borg_last_modified=$(get_field 'repository.last_modified' | xargs -I{} date -d "{}" +"%s")
borg_backup_age=$(echo "$NOW" "$borg_last_modified" | awk '{print(($1 - $2) / (24 * 60 * 60))}')

get_status_data() {
    cat <<EOF
# HELP backup_age Age of last backup in days.
# TYPE backup_age gauge
backup_age $borg_backup_age
# HELP backup_files Number of files in backup.
# TYPE backup_files gauge
backup_files $(get_field 'archives | .[] | .stats.nfiles')
# HELP backup_chunks_unique Number of unique chunks of last backup.
# TYPE backup_chunks_unique gauge
backup_chunks_unique $(get_field 'cache.stats.total_unique_chunks')
# HELP backup_chunks_total Number of chunks in all backups.
# TYPE backup_chunks_total gauge
backup_chunks_total $(get_field 'cache.stats.total_chunks')
# HELP backup_last_size Size of last backup in bytes.
# TYPE backup_last_size gauge
backup_last_size $(get_field 'archives | .[] | .stats.original_size')
# HELP backup_last_size_compressed Compressed site of last backup in bytes.
# TYPE backup_last_size_compressed gauge
backup_last_size_compressed $(get_field 'archives | .[] | .stats.compressed_size')
# HELP backup_last_size_dedup Depluplicated size of last backup in bytes.
# TYPE backup_last_size_dedup gauge
backup_last_size_dedup $(get_field 'archives | .[] | .stats.deduplicated_size')
# HELP backup_total_size Size of all backups in bytes.
# TYPE backup_total_size gauge
backup_total_size $(get_field 'cache.stats.total_size')
# HELP backup_total_size_compressed Compressed size of all backups in bytes.
# TYPE backup_total_size_compressed gauge
backup_total_size_compressed $(get_field 'cache.stats.total_csize')
# HELP backup_total_size_dedup Depluplicated size of all backups in bytes.
# TYPE backup_total_size_dedup gauge
backup_total_size_dedup $(get_field 'cache.stats.unique_csize')
EOF
}

status=$(get_status_data)

printf '%s' "$status" >"$TMP_FILE"
mv "$TMP_FILE" "$PROM_FILE"

# The textfile collector needs a newline at the end of the file
echo >> "$PROM_FILE"