#!/usr/bin/env bash
#
# Create Forgejo backups
#
# Prep
#  groupadd --system bkp
#  mkdir /var/xyzzy/backup
#  chmod 0750 /var/xyzzy/backup
#  chown git:bkp /var/xyzzy/backup
#
# SPDX-License-Identifier: MIT

_VERSION="0.0.2"

BDTS=$(date +"%Y%m%d%H%M")
BDIR="/var/xyzzy/backup"
BFILE="${BDIR}/forgejo-${BDTS}"

BDMP="${BDIR}/forgejo-${BDTS}.tar.xz"
BGRP="bkp"

GCNF="/var/xyzzy/etc/forgejo/app.ini"
GBIN="/var/xyzzy/bin/forgejo"
GDATA="/var/xyzzy/forge"

# healthchecks.io ping URL upon success, uses curl - "none" to disable
HCPING="none"

# delete backups older than
#  see 'man find'; "+3" = 3*24h ago
BDEL="-mtime +3"

# we need to chgrp/chmod to a foreign group
if [[ $(id -u) -ne 0 ]]; then
  echo "Must run as root user"
  exit 1
fi

# just to be sure
cd "${BDIR}" || (echo "Cannot cd to ${BDIR}"; exit 1)

# runuser exits with the error code of the command
_EC=1
runuser -u git -- "${GBIN}" dump --config "${GCNF}" --tempdir "${BDIR}" \
  --work-path "${GDATA}" --skip-log --type tar.xz --file "${BFILE}"
_EC=$?

# post processing
if [[ $_EC -eq 0 ]]; then
  # gitea dump writes git:git 0600
  if [[ -f "${BDMP}" ]]; then
    chgrp "${BGRP}" "${BDMP}"
    chmod 0640 "${BDMP}"
  fi
  # delete older than BDEL backups
  # shellcheck disable=SC2086
  find "${BDIR}" -type f ${BDEL} \
    -regextype egrep \
    -regex '.*/forgejo-[0-9]{12}\.tar\.xz' \
    -delete
  # ping healthchecks.io
  if [[ "${HCPING}" != "none" ]]; then
    curl -fsS -m 10 --retry 5 -o /dev/null "${HCPING}"
  fi
fi