#!/usr/bin/env bash

# PgBackrest backup wrapper script

## FUNCTIONS

# METHOD: convert_time
# PARAMS: timestamp in seconds or with milliseconds (nnnn.nnnn)
# RETURN: formated string with human readable time (d/h/m/s)
# CALL  : var=$(convert_time $timestamp);
# DESC  : converts a timestamp or a timestamp with float milliseconds
#         to a human readable format
#         output is in days/hours/minutes/seconds
function convert_time
{
	timestamp=${1};
	# round to four digits for ms
	timestamp=$(printf "%1.4f" "$timestamp");
	# get the ms part and remove any leading 0
	ms=$(echo "${timestamp}" | cut -d "." -f 2 | sed -e 's/^0*//');
	timestamp=$(echo "${timestamp}" | cut -d "." -f 1);
	timegroups=(86400 3600 60 1); # day, hour, min, sec
	timenames=("d" "h" "m" "s"); # day, hour, min, sec
	output=( );
	time_string="";
	for timeslice in "${timegroups[@]}"; do
		# floor for the division, push to output
		output[${#output[*]}]=$(awk "BEGIN {printf \"%d\", ${timestamp}/${timeslice}}");
		timestamp=$(awk "BEGIN {printf \"%d\", ${timestamp}%${timeslice}}");
	done;

	for ((i=0; i<${#output[@]}; i++)); do
		if [ "${output[$i]}" -gt 0 ] || [ -n "$time_string" ]; then
			if [ -n "${time_string}" ]; then
				time_string=${time_string}" ";
			fi;
			time_string=${time_string}${output[$i]}${timenames[$i]};
		fi;
	done;
	if [ -n "${ms}" ] && [ "${ms}" != "nan" ] && [ "${ms}" -gt 0 ]; then
		time_string=${time_string}" ${ms}ms";
	fi;
	# just in case the time is 0
	if [ -z "${time_string}" ]; then
		time_string="0s";
	fi;
	echo -n "${time_string}";
}

## VARIABLES

REGEX_COMMENT="^[\ \t]*#";
INI_BLOCK="^\[[A-Za-z]*\]";
BASE_FOLDER=$(dirname "$(readlink -f "$0")")"/";
CONFIG="${BASE_FOLDER}../config/";
BACKUP_TYPE="";
OVERRIDE_STANZA="";
LIST_STANZA=0;
TEST=0;
config_file="${CONFIG}pgbackrest.cfg";
stanza_file="${CONFIG}stanza.cfg";
if [ -f "${config_file}" ]; then
	# shellcheck disable=SC1090
	# shellcheck disable=SC2283
	source <(grep = "${config_file}" | sed 's/ *= */=/g')
else
	echo "Missing config file ${config_file}";
	exit;
fi;
if [ -z "${sudo_user}" ]; then
	echo "sudo_user not set in the config file ${config_file}";
	exit;
fi;
if ! id "${sudo_user}" &>/dev/null; then
	echo "Sudo user ${sudo_user} does not exist, skipping stanza";
	exit
fi;
if [ -z "${pgbackrest_config}" ] ||[ ! -f "${pgbackrest_config}" ]; then
	echo "Missing pgbackrest default config file ${pgbackrest_config}";
	exit;
fi;
# stanza list file
if [ ! -f "${stanza_file}" ]; then
	echo "Missing stanza config file ${stanza_file}";
	exit;
fi;

PRINTF_BLOCK="=== [%-8s: %19s] ==[%s]===============>\n";

## OPT PARSEIN

while getopts ":b:s:lt" opt; do
	case "${opt}" in
		b)
			# backuptype
			BACKUP_TYPE="${OPTARG}";
			;;
		s)
			# stanza
			OVERRIDE_STANZA="${OPTARG}";
			;;
		l)
			# list
			LIST_STANZA=1;
			;;
		t)
			# test
			TEST=1;
			;;
		:)
			echo "Option -$OPTARG requires an argument."
			;;
		\?)
			echo -e "\n Option does not exist: ${OPTARG}\n";
			echo "-b (backuptype): full/diff";
			echo "-s (stanza): override stanza name, must be in list"
			echo "-l list available stanza"
			echo "-t test run"
			exit 1;
			;;
	esac;
done;

## check if OVERIDE_STANZA has a repo target flag set, get the name only for checks
OVERRIDE_STANZA_NAME="";
if [ -n "${OVERRIDE_STANZA}" ]; then
	OVERRIDE_STANZA_NAME=$(echo "${OVERRIDE_STANZA}" | cut -d ":" -f 1);
fi;

## SCRIPT

if [ $TEST -eq 1 ]; then
	echo "[..........] TEST RUN ONLY";
fi;

if [ $LIST_STANZA -eq 1 ]; then
	echo "+ Stanza List:";
	while read -r stanza; do
		# skip empty
		[ -z "${stanza}" ] && continue;
		# skip starting with #
		[[ "${stanza}" =~ ${REGEX_COMMENT} ]] && continue;
		# skip the ini header blocks
		[[ "${stanza}" =~ ${INI_BLOCK} ]] && continue;
		# split the stanz int stanza and stanza repo list
		stanza_name=$(echo "${stanza}" | cut -d ":" -f 1);
		stanza_repo=$(echo "${stanza}" | awk -F':' '{print (NF>1) ? $2 : ""}');
		# if override stanza matching
		if [ "${stanza_name}" = "${OVERRIDE_STANZA_NAME}" ]; then
			OVERRIDE_STANZA_REPO=$(echo "${OVERRIDE_STANZA}" | awk -F':' '{print (NF>1) ? $2 : ""}');
			if [ -n "${OVERRIDE_STANZA_REPO}" ] && [ -n "${stanza_repo}" ] && [ "${stanza_repo}" = "${OVERRIDE_STANZA_REPO}" ]; then
				echo "[*] ${stanza}";
			elif [ -z "${OVERRIDE_STANZA_REPO}" ]; then
				echo "[*] ${stanza}";
			else
				echo "[ ] ${stanza}";
			fi;
		else
			echo "[ ] ${stanza}";
		fi;
	done <<< "$(cat "${stanza_file}")";
	echo "";
	echo "Entry marked with '*' is set as override stanza, and will be the only ones backed up";
	echo "";
	exit;
fi;

if [ -z "${BACKUP_TYPE}" ]; then
	echo "[!] Backup type must be set as -b full or -b diff";
	exit;
fi;

if [ "${BACKUP_TYPE}" != "full" ] && [ "${BACKUP_TYPE}" != "diff" ]; then
	echo "[!] Backup type can only be 'full' or 'diff'";
	exit;
fi;

echo "* PgBackrest Backup run type '${BACKUP_TYPE}' on $(date +'%F')";
# run backup
while read -r stanza; do
	# skip empty
	[ -z "${stanza}" ] && continue;
	# skip starting with #
	[[ "${stanza}" =~ ${REGEX_COMMENT} ]] && continue;
	# skip the ini header blocks
	[[ "${stanza}" =~ ${INI_BLOCK} ]] && continue;
	# split into the name and repo list
	stanza_name=$(echo "${stanza}" | cut -d ":" -f 1);
	stanza_repo=$(echo "${stanza}" | awk -F':' '{print (NF>1) ? $2 : ""}');
	# if we have a config
	stanza_config=$(echo "${stanza}" | awk -F':' '{print (NF>1) ? $3 : ""}');
	# for possible override super user
	stanza_super_user=$(echo "${stanza}" | awk -F':' '{print (NF>3) ? $4 : ""}');
	# override stanza check
	if [ -n "${OVERRIDE_STANZA}" ]; then
		# skip if not matching name
		if [ "${stanza_name}" != "${OVERRIDE_STANZA_NAME}" ]; then
			continue
		fi;
		# if we have repo set, check if repo is matching
		OVERRIDE_STANZA_REPO=$(echo "${OVERRIDE_STANZA}" | awk -F':' '{print (NF>1) ? $2 : ""}');
		if [ -n "${OVERRIDE_STANZA_REPO}" ] && [ "${stanza_repo}" != "${OVERRIDE_STANZA_REPO}" ]; then
			continue
		fi;
		# set repo from override
		stanza_repo="${OVERRIDE_STANZA_REPO}";
		# config
		OVERRIDE_STANZA_CONFIG=$(echo "${OVERRIDE_STANZA}" | awk -F':' '{print (NF>2) ? $3 : ""}');
		# if we have a config set in the stanza config, but none in the override, use the one from the stanza config
		if [ -z "${OVERRIDE_STANZA_CONFIG}" ] && [ -n "${stanza_config}" ]; then
			OVERRIDE_STANZA_CONFIG="${stanza_config}";
		else
			stanza_config="${OVERRIDE_STANZA_CONFIG}";
		fi;
		# super user
		OVERRIDE_STANZA_SUPER_USER=$(echo "${OVERRIDE_STANZA}" | awk -F':' '{print (NF>3) ? $4 : ""}');
		if [ -z "${OVERRIDE_STANZA_SUPER_USER}" ] && [ -n "${stanza_super_user}" ]; then
			OVERRIDE_STANZA_SUPER_USER="${stanza_super_user}";
		else
			stanza_super_user="${OVERRIDE_STANZA_SUPER_USER}";
		fi;
	fi;
	# set override sudo user
	if [ -n "${stanza_super_user}" ]; then
		if ! id "${stanza_super_user}" &>/dev/null; then
			echo "[!] Sudo user ${stanza_super_user} for stanza ${stanza_name} does not exist, skipping stanza";
			continue;
		fi;
		sudo_user="${stanza_super_user}";
	fi;
	# build the call command
	CALL=(
		"sudo" "-u" "${sudo_user}"
		"pgbackrest" "--type=${BACKUP_TYPE}" "--stanza=${stanza_name}"
	);
	_stanza_config="${pgbackrest_config}";
	if [ -f "${stanza_config}" ]; then
		_stanza_config="${stanza_config}";
	fi;
	stanza_check=$(grep -E "^\[${stanza_name}\]$" "${_stanza_config}");
	if [ -z "${stanza_check}" ]; then
		echo "[!] Stanza ${stanza_name} not found in config file ${_stanza_config}, skipping stanza";
		continue;
	fi;
	if [ -n "${stanza_repo}" ]; then
		# check if repo exists in config file with "repo<number>-"
		repo_check=$(grep -E "^repo${stanza_repo}-" "${_stanza_config}");
		if [ -z "${repo_check}" ]; then
			echo "[!] Stanza repo ${stanza_repo} for stanza ${stanza_name} not found in config file ${_stanza_config}, skipping stanza";
			continue;
		fi;
		CALL=("${CALL[@]}" "--repo=${stanza_repo}");
	fi;
	if [ -n "${stanza_config}" ]; then
		if [ ! -f "${stanza_config}" ]; then
			echo "[!] Stanza config file ${stanza_config} for stanza ${stanza_name} not found, skipping stanza";
			continue;
		fi;
		CALL=("${CALL[@]}" "--config=${stanza_config}");
	fi;
	CALL=("${CALL[@]}" "backup");
	# main backup start
	START=$(date +'%s');
	# shellcheck disable=SC2059
	printf "${PRINTF_BLOCK}" "START" "$(date +'%F %T')" "${stanza}";
	# --log-level-console=info
	if [ $TEST -eq 1 ]; then
		echo "${CALL[@]}";
	else
		# sudo -u "${sudo_user}" pgbackrest --type="${BACKUP_TYPE}" --stanza="${stanza}" ${option_repo} backup;
		"${CALL[@]}";
	fi;
	DURATION=$(( $(date +'%s') - START ));
	# shellcheck disable=SC2059
	printf "${PRINTF_BLOCK}" "END" "$(convert_time ${DURATION})" "${stanza}";
done <<< "$(cat "${stanza_file}")";
echo "* PgBackrest Backup end";
if [ $TEST -eq 1 ]; then
	echo "[..........] TEST RUN ONLY";
fi;

## __END__