#!/usr/bin/env bash

# * check we are root
# if we are not root, bail out
# if [ $(whoami) != "root" ]; then
if [[ "$EUID" -ne "0" ]]; then
	echo "Must be run as root or with sudo command";
	exit;
fi;

# base folder
BASE_FOLDER=$(dirname $(readlink -f $0))"/";
# auth log file
AUTH_LOG="${BASE_FOLDER}/../auth-log/user_auth.log";
if [ ! -f "${AUTH_LOG}" ]; then
	touch "${AUTH_LOG}";
fi;
# run full log check flag
RUN_FULL_LOG=0;
if [ ! -z "${1}" ] && [ "${1}" = "FULL" ]; then
	echo "[!!!] Run through all log files to collect data";
	RUN_FULL_LOG=1;
fi;

# Collector script for login information via journalctl
# if no systemd installed, try to get info from /var/log/secure or /var/log/auth.log
readonly init_version=$(/proc/1/exe --version | head -n 1);
if [ -z "${init_version##*systemd*}" ]; then
	LOG_TARGET="systemd";
	# for journalctl
	START_DATE=$(date +%F -d "1 day ago");
	END_DATE=$(date +%F);
	START_YEAR=$(date +%Y -d "1 day ago");
	OPT_START_DATE='';
	if [ $RUN_FULL_LOG -eq 0 ]; then
		OPT_START_DATE="-S ${START_DATE}";
		OPT_END_DATE="-U ${END_DATE}";
	fi;
	journalctl -u systemd-logind --no-pager ${OPT_START_DATE} ${OPT_END_DATE} | grep ": New session" |
	while read line; do
		# # Nov 21 14:15:46 we.are.hostname.com systemd-logind[1865]: New session 12345 of user some^user.
		# date: 5 chars
		# time: 8 chars
		# hostname
		# systemd-logind pid ...
		# " of user <username>"
		# we want date + time + username
		# prefix year with start date year

		# echo "L: $line";

		# do we have a key entry, if not add new with last log date
		# clean up date from YYYY nam dd to YYYY-MM-DD HH:II:SS
		# auth_date=$(echo "${line}" | cut -c 1-15 | date +"%F %T" -f -);
		# auth_date=$($(echo "${line}" | cut -c 1-6)" ${START_YEAR} "$(echo "${line}" | cut -c 8-15)) | date +"%F %T" -f -;
		auth_date=$(echo "${line}" | cut -c 1-6)" ${START_YEAR} "$(echo "${line}" | cut -c 8-15);
		auth_date=$(echo "${auth_date}" | date +"%F %T" -f -);
		# auth user has . at the end, remove that one
		auth_user=$(echo "${line}" | cut -d "]" -f 2 | cut -d " " -f 7 | cut -d "." -f 1);

		# echo -n "USER: $auth_user | DATE: $auth_date";

		# find auth user in current auth file
		# if not there attach, else replace date only
		found=$(grep "${auth_user};" "${AUTH_LOG}");
		if [ -z "${found}" ]; then
			# echo -n " | Write new";
			echo "${auth_user};${auth_date}" >> "${AUTH_LOG}";
		else
			# echo -n " | Replace old";
			sed -i "s/${auth_user};.*$/${auth_user};${auth_date}/" "${AUTH_LOG}";
		fi;
		# echo " [***]";
	done;
else
	LOG_TARGET="syslog";
	# for secure/auth log
	START_DATE=$(date +"%b %e" -d "1 day ago")
	cat /var/log/secure | grep "${START_DATE}" | grep ": session opened for user" |
	while read line; do
		# Nov 21 14:15:56 some.hostname.com sshd[12345]: pam_unix(sshd:session): session opened for user some-user(uid=6789) by (uid=0)
		auth_date=$($(echo "${line}" | cut -c 1-6)" ${START_YEAR} "$(echo "${line}" | cut -c 8-15) | date +"%F %T" -f -);
		auth_user=$(echo "${line}" | cut -d ")" -f 2 | cut -d " " -f 6 | cut -d "(" -f 1);
		# find auth user in current auth file
		# if not there attach, else replace date only
		if [ -z grep "${auth_user}" "${AUTH_LOG}" ]; then
			cat "${auth_user};${auth_date}"  >> "${AUTH_LOG}";
		else
			sed -i "s/${auth_user};.*$/${auth_user};${auth_date}/" "${AUTH_LOG}";
		fi;
	done;
fi;

# __END__