#!/bin/sh
#
# Purpose {{{
# This script will hardlink latest Proxmox's backup with a explicit name.
#
# This script is intended to be used as a hook script for the Proxmox
# VZDump utility.
#
# In order to use it, use the configuration directive "script" of the
# vzdump utility. This can be done for scheduled backups by putting
# "script: /path/to/this/script" in /etc/vzdump.conf. Don't forget to
# set executable permission for the script file.
#
# Based on RobHost's vzdump_hook script :
# https://github.com/robhost/proxmox-scripts/blob/master/vzdump_hook.sh
# }}}
# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly ARGS="${*}"
[ -z "${DEBUG}" ] && DEBUG=0
## Export DEBUG for sub-script
export DEBUG

## Colors
readonly PURPLE='\033[1;35m'
readonly RED='\033[0;31m'
readonly RESET='\033[0m'
readonly COLOR_DEBUG="${PURPLE}"
# }}}
usage() {                                                       # {{{

	cat <<- HELP
usage: ${PROGNAME} [-h]

Hardlink latest Proxmox's backup with a explicit name.

OPTIONS :
    -h,--help
      Print this help message.
HELP

}
# }}}
debug_message() {                                               # {{{

	local_debug_message="${1}"

	## Print message if DEBUG is enable (=0)
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME} : ${local_debug_message}"

	unset local_debug_message

	return 0
}
# }}}
error_message() {                                               # {{{

	local_error_message="${1}"
	local_error_code="${2}"

	## Print message
	printf '%b\n' "ERROR − ${PROGNAME} : ${RED}${local_error_message}${RESET}"

	exit "${local_error_code:=66}"
}
# }}}

main() {                                                        # {{{

	# If backup is complete {{{
	if [ "${phase}" = "backup-end" ]; then
		## Get TARGET's file extension
		target_archive_extension="$(printf '%s' "${TARGET}" | sed -n "s/.*\.\([[:alnum:]]*\.[[:alnum:]]*\)$/\1/p")"
		## Set path for LATEST archive file
		latest_archive="${dumpdir}/vzdump-${vmtype}-${vmid}-latest.${target_archive_extension}"

		## hardlink TARGET archive to LATEST
		debug_message "hardlink TARGET archive (${target_archive}) to \
LATEST (${latest_archive})." >> "${temp_log_file}"
		ln --force "${target_archive}" "${latest_archive}"
	fi
	# }}}

	# If log is complete {{{
	if [ "${phase}" = "log-end" ]; then
		## Set path for LATEST log file
		latest_log="${dumpdir}/vzdump-${vmtype}-${vmid}-latest.log"

		## hardlink TARGET log to LATEST
		debug_message "hardlink TARGET logs (${logfile}) to \
LATEST (${latest_log})." >> "${temp_log_file}"
		ln --force "${logfile}" "${latest_log}"
	fi
	# }}}

		debug_message "main − \
ARGS=${ARGS}
env=$(env)
---"

}
# }}}

# Manage arguments                                                # {{{
# This code can't be in a function due to argument management

	phase="${1}" # (job|backup)-(start|end|abort)|log-end|pre-(stop|restart)|post-restart

	case "${phase}" in
		# set variables for the phases
		#backup-start|backup-end|backup-abort|log-end|pre-stop|pre-restart|post-restart)
			#;;
		# do work
		job-start|job-end|job-abort)
			# Available vars {{{
			# Arguments : job-start
			#LVM_SUPPRESS_FD_WARNINGS=1
			#DUMPDIR=/path/to/backup/dump
			#STOREID=backup.id.from.storage.cfg
			# }}}
			;;
		backup-start|backup-end|backup-abort)
			# Available vars {{{
			#ARGS=backup-start stop vm.id
			#HOSTNAME=hostname.domain.tld
			#TARGET=/path/to/backup/dump/vzdump-$VMTYPE_VALUE-$2_VALUE-YYYY_MM_DD-hh-mm-ss.tar.zst
			#LOGFILE=/path/to/backup/dump/vzdump-$VMTYPE_VALUE-$2_VALUE-YYYY_MM_DD-hh-mm-ss.log
			#LVM_SUPPRESS_FD_WARNINGS=1
			#DUMPDIR=/path/to/backup/dump
			#VMTYPE=lxc|qemu
			#STOREID=backup.id.from.storage.cfg
			# }}}
			vmid="${3}"
			target_archive="${TARGET}"
			dumpdir="${DUMPDIR}"
			vmtype="${VMTYPE}"
			;;
		log-end)
			# Available vars {{{
			#ARGS=log-end stop vm.id
			#HOSTNAME=hostname.domain.tld
			#TARGET=/path/to/backup/dump/vzdump-$VMTYPE_VALUE-$2_VALUE-YYYY_MM_DD-hh-mm-ss.tar.zst
			#LOGFILE=/path/to/backup/dump/vzdump-$VMTYPE_VALUE-$2_VALUE-YYYY_MM_DD-hh-mm-ss.log
			#LVM_SUPPRESS_FD_WARNINGS=1
			#DUMPDIR=/path/to/backup/dump
			#VMTYPE=lxc|qemu
			#STOREID=backup.id.from.storage.cfg
			# }}}
			vmid="${3}"
			logfile="${LOGFILE}"
			dumpdir="${DUMPDIR}"
			vmtype="${VMTYPE}"
			;;
		pre-stop)
			;;
		pre-restart)
			;;
		post-restart)
			;;
		*)
			error_message "Unknown phase ${phase}." 1
			;;
	esac

# }}}

main

exit 0