#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - An Open Source Firewall Solution                               #
# Copyright (C) 2012 Michael Tremer                                           #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

export LC_ALL=C

SARG_CONFIG="/etc/sarg/sarg.conf"
SQUID_LOG="/var/log/squid/access.log"
REPORTS_PATH="/var/log/sarg"

function date_calc() {
	local when
	local range="false"

	case "${1}" in
		month)
			when="1 month ago"
			range="true"
			;;
		week)
			when="1 week ago"
			;;
		yesterday)
			when="1 day ago"
			;;
		today)
			when="today"
			;;
		*)
			return 1
			;;
	esac

	if [ "${range}" = "true" ]; then
		echo "$(date --date "${when}" +01/%m/%Y)-$(date --date "${when}" +31/%m/%Y)"
	else
		date --date "${when}" +%d/%m/%Y
	fi

	return 0
}

function compile_report() {
	local interval=${1}

	local date
	case "${interval}" in
		today)
			date=$(date_calc today)
			;;
		daily)
			date=$(date_calc yesterday)
			;;
		weekly)
			date="$(date_calc week)-$(date_calc yesterday)"
			;;
		monthly)
			date="$(date_calc month)"
			;;
	esac
	[ -n "${date}" ] || return 1

	# Determine max. number of archived log files to search.
	local max_logs
	case "${interval}" in
		today|daily)
			max_logs=3
			;;
		weekly)
			max_logs=14
			;;
		monthly)
			max_logs=40
			;;
	esac

	# Create reports_path, if not exists.
	local reports_path="${REPORTS_PATH}/${interval}"
	mkdir -p ${reports_path}

	# Remove already existant data on today's reports.
	case "${interval}" in
		today)
			rm -rf ${reports_path}/*
			;;
	esac

	# Run SARG.
	get_logs ${max_logs} | sarg -f ${SARG_CONFIG} -l - -d ${date} -o ${reports_path}
}

function get_logs() {
	local max=${1}

	if [ -z "${max}" ]; then
		max=10000
	fi

	local idx=0
	while [ ${idx} -le ${max} ]; do
		file=$(search_log_file ${idx})

		# If no log file could be opened, we are done.
		[ -z "${file}" ] && break

		case "${file}" in
			# Logs in plain text.
			*.log)
				cat ${file}
				;;

			# GZip compressed log files.
			*.gz)
				gzip -d < ${file}
				;;

			# XZ compressed log files.
			*.xz)
				xz -d < ${file}
				;;

			# Unhandled stuff.
			*)
				echo "Unhandled file type: ${file}" >&2
				;;
		esac

		idx=$(( ${idx} + 1 ))
	done

	return 0
}

function search_log_file() {
	local idx=${1}

	if [ "${idx}" = "0" ] && [ -e "${SQUID_LOG}" ]; then
		echo "${SQUID_LOG}"
		return 0
	fi

	local algo
	for algo in gz xz; do
		file="${SQUID_LOG}.${idx}.${algo}"

		if [ -e "${file}" ]; then
			echo "${file}"
			return 0
		fi
	done

	return 1
}

# Main.

case "${1}" in
	today|daily|weekly|monthly)
		compile_report ${1}
		;;
	*)
		echo "${0} - Squid proxy reports creation tool"
		echo
		echo "Usage: ${0} [interval]"
		echo "    interval: today, daily, weekly, monthly"
		echo
		exit 0
		;;
esac

exit 0