#!/bin/bash

set -uo pipefail

textfile_dir={{ node_exporter_textfile_dir }}
archive_dir={{ backup_archive_dir }}
raid_mount={{ backup_raid_mount }}

file=${textfile_dir}/backup_inventory.prom
tmp=${file}.$$
now=$(date +%s)

mkdir -p ${textfile_dir}

mounted=0
if mountpoint -q ${raid_mount}
then
    mounted=1
fi

emit_kind() {
    local kind=$1
    local newest
    local count=0
    local age=0
    local bytes=0
    local total=0

    if [ ${mounted} -eq 1 ]
    then
        count=$(find ${archive_dir} -maxdepth 1 -name "beeserver_${kind}_*.tar.gz.gpg" -type f 2>/dev/null | wc -l)
        newest=$(find ${archive_dir} -maxdepth 1 -name "beeserver_${kind}_*.tar.gz.gpg" -type f -printf '%T@ %p\n' 2>/dev/null | sort -rn | head -1 | cut -d' ' -f2-)
        total=$(find ${archive_dir} -maxdepth 1 -name "beeserver_${kind}_*.tar.gz.gpg" -type f -printf '%s\n' 2>/dev/null | awk '{ s += $1 } END { print s + 0 }')

        if [ -n "${newest:-}" ]
        then
            bytes=$(stat -c %s "${newest}")
            age=$((now - $(stat -c %Y "${newest}")))
        fi
    fi

    echo "backup_archive_count{kind=\"${kind}\"} ${count}"
    echo "backup_archive_newest_age_seconds{kind=\"${kind}\"} ${age}"
    echo "backup_archive_newest_bytes{kind=\"${kind}\"} ${bytes}"
    echo "backup_archive_total_bytes{kind=\"${kind}\"} ${total}"
}

{
    echo "# HELP backup_raid_mounted Whether the backup raid is mounted."
    echo "# TYPE backup_raid_mounted gauge"
    echo "backup_raid_mounted ${mounted}"
    echo "# HELP backup_archive_count Number of retained archives."
    echo "# TYPE backup_archive_count gauge"
    echo "# HELP backup_archive_newest_age_seconds Age of the newest archive."
    echo "# TYPE backup_archive_newest_age_seconds gauge"
    echo "# HELP backup_archive_newest_bytes Size of the newest archive."
    echo "# TYPE backup_archive_newest_bytes gauge"
    echo "# HELP backup_archive_total_bytes Size of all retained archives."
    echo "# TYPE backup_archive_total_bytes gauge"
    emit_kind daily
    emit_kind weekly
} > "${tmp}"

chmod 0644 "${tmp}"
mv "${tmp}" "${file}"