#!/usr/bin/env bash
# This script is intended to be run by a systemd timer

# Exit on failure or pipefail
set -e -o pipefail

#Set this to any location you like
BACKUP_PATHS="/"
BACKUP_EXCLUDES="/etc/restic/exclude"

BACKUP_TAG=$(hostname -s)

FEAT_NOTIFY=false

# How many backups to keep.
RETENTION_DAYS=7
RETENTION_WEEKS=4
RETENTION_MONTHS=3
RETENTION_YEARS=1

# Paths to binaries
CURL="/usr/bin/curl"
RESTIC="/usr/bin/restic"
ECHO="/usr/bin/echo"

HOST=$(hostname -s)

source /etc/restic/env

# define functions
timestamp () {
   date "+%Y-%m-%d %H:%M:%S"
}

run_checklock () {
	OUTPUT=$(${RESTIC} list locks|wc -l)
	if (( OUTPUT != 0 ));then
		return 1
	else
		return 0
	fi

}

run_backup () {
#Do the backup
	${ECHO} "Starting backup on $HOST at $(timestamp)"
	${RESTIC} backup \
		--tag "$BACKUP_TAG" \
		--exclude-file $BACKUP_EXCLUDES \
		$BACKUP_PATHS &
	wait $!
	return $?
}

run_forget (){
	# Remove old Backups
	${ECHO} "Removing old backups per retention settings"
	${RESTIC} forget \
		--tag "$BACKUP_TAG" \
		--prune \
		--keep-daily $RETENTION_DAYS \
		--keep-weekly $RETENTION_WEEKS \
		--keep-monthly $RETENTION_MONTHS \
		--keep-yearly $RETENTION_YEARS &
	wait $!
	return $?
}

run_check () {
	# Check if everything is fine
	${ECHO} "Running check"
	${RESTIC} check &
	wait $!
	return $?
}

cleanup () {
	# Remove locks in case other stale processes kept them in
	${ECHO} "Removing lockfile"
	${RESTIC} unlock
}

send_matrix () {
	${CURL} -skd "{\"body\": \"$1\"}" $MATRIX_HOOK_URL/\?key\=$MATRIX_HOOK_KEY\&room_id\=$MATRIX_HOOK_ROOMID > /dev/null
}

notify () {
	#notify works either from stdin or from $1, so you can call it as
	# notify "text to send"
	# or
	# echo "text to send" | notify
	local message=$1
	if [ -z "$message" ]; then
		read -r message
	fi
	
	# call whatever notification script/function you wish with "$message" as the part you want to show
    if $FEAT_NOTIFY; then
        send_matrix "$message"
    fi
}

# Do the actual work
ERRORS=""
STATUS_TOTAL=0

if run_checklock; then
	${ECHO} "Restic backup on $HOST starting at $(timestamp)"|notify
else
    ${ECHO} "Backup on $HOST aborted at $(timestamp) due to locks" |notify
    exit 1
fi

if ! run_backup; then
    STATUS_TOTAL=$((STATUS_TOTAL+1))
	ERRORS="$ERRORS [backup step failed]"
fi


if ! run_forget; then
    STATUS_TOTAL=$((STATUS_TOTAL+1))
	ERRORS="$ERRORS [forget step failed]"
fi

if ! run_check ; then
    STATUS_TOTAL=$((STATUS_TOTAL+1))
	ERRORS="$ERRORS [check step failed]"
fi

cleanup

if (( STATUS_TOTAL == 0 ));then
    ${ECHO} "Backup on $HOST completed successfully at $(timestamp)" |notify
else
    ${ECHO} "Backup on $HOST completed at $(timestamp) with issues: $ERRORS " |notify
fi