#!/bin/bash
#                          |\_
# B A C K U P N I N J A   /()/
#                         `\|
#
# Copyright (C) 2004 riseup.net -- property is theft.
#
# 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 2 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.
#

#####################################################
## DEFAULTS

DEBUG=${DEBUG:=0}
CONFFILE="/etc/backupninja.conf"
USECOLOURS=1

#####################################################
## FUNCTIONS

function setupcolors() {
	if [  "$USECOLOURS" == 1 ]
	then
		BLUE="\033[34;01m"
		GREEN="\033[32;01m"
		YELLOW="\033[33;01m"
		PURPLE="\033[35;01m"
		RED="\033[31;01m"
		OFF="\033[0m"
		CYAN="\033[36;01m"
	fi
}

function run() {
	RUNERROR=0
	debug 0 "$@"
	returnstring=`$@ 2>&1`
	RUNERROR=$?
	RUNERRORS=$[RUNERRORS+RUNERROR]
	if [ "$RUNERROR" != 0 ]; then
		debug 3 "Exitcode $RUNERROR returned when running: $@"
		debug 3 "$returnstring"
	else
		debug 0 "$returnstring"
	fi
	return $RUNERROR
}

# We have the following debug levels:
# 0 - debug - blue
# 1 - normal messages - green
# 2 - warnings - yellow
# 3 - errors - orange
# 4 - fatal - red
# First variable passed is the error level, all others are printed

# if 1, echo out all warnings, errors, or fatal
# used to capture output from handlers
echo_debug_msg=0

function debug() {

	[ ${#@} -gt 1 ] || return
	 
	TYPES=(Debug Info Warning Error Fatal)
	COLOURS=($BLUE $GREEN $YELLOW $RED $PURPLE)
	type=$1
	colour=${COLOURS[$type]}
	shift
	print=$[4-type]
	if [ "$print" -lt "$loglevel" -o "$DEBUG" == 1 ]; then
		if [ -z "$logfile" ]; then
			echo -e "${colour}${TYPES[$type]}: $@${OFF}" >&2
		else
			if [ "$DEBUG" == 1 -o "$type" == 4 ]; then
				echo -e "${colour}${TYPES[$type]}: $@${OFF}" >&2
			fi
			echo -e "${colour}${TYPES[$type]}: $@${OFF}" >> $logfile
		fi
	fi
	if [ "$echo_debug_msg" != "0" -a "$type" -gt "1" ]; then
		echo -e "${TYPES[$type]}: $@"
	fi
}

function fatal() {
	debug 4 "$@"
	exit 2
}

msgcount=0
function msg {
	messages[$msgcount]=$1
	let "msgcount += 1"
}

function setfile() {
	CURRENT_CONF_FILE=$1
}

function setsection() {
	CURRENT_SECTION=$1
}

#
# sets a global var with name equal to $1
# to the value of the configuration parameter $1
# $2 is the default.
# 

function getconf() {
	CURRENT_PARAM=$1
	ret=`awk -f $scriptdir/parseini S=$CURRENT_SECTION P=$CURRENT_PARAM $CURRENT_CONF_FILE`
	# if nothing is returned, set the default
	if [ "$ret" == "" -a "$2" != "" ]; then
		ret="$2"
	fi

	# replace * with %, so that it is not globbed.
	ret="${ret//\\*/__star__}"

	# this is weird, but single quotes are needed to 
	# allow for returned values with spaces. $ret is still expanded
	# because it is in an 'eval' statement.
	eval $1='$ret'
}

#
# enforces very strict permissions on configuration file $file.
#

function check_perms() {
	local file=$1
	local perms=`ls -ld $file`
	perms=${perms:4:6}
	if [ "$perms" != "------" ]; then
		fatal "Configuration files must not be group or world readable! Dying on file $file"
	fi
	if [ `ls -ld $file | awk '{print $3}'` != "root" ]; then
		fatal "Configuration files must be owned by root! Dying on file $file"
	fi
}

# simple lowercase function
function tolower() {
	echo "$1" | tr [:upper:] [:lower:]
}

# simple to integer function
function toint() {
	echo "$1" | tr [:alpha:] -d 
}

#
# function isnow(): returns 1 if the time/day passed as $1 matches
# the current time/day.
#
# format is <day> at <time>:
#   sunday at 16
#   8th at 01
#   everyday at 22
#

# we grab the current time once, since processing
# all the configs might take more than an hour.
nowtime=`date +%H`
nowday=`date +%d`
nowdayofweek=`date +%A`
nowdayofweek=`tolower "$nowdayofweek"`

function isnow() {
	local when="$1"
	set -- $when
	whendayofweek=$1; at=$2; whentime=$3;
	whenday=`toint "$whendayofweek"`
	whendayofweek=`tolower "$whendayofweek"`
	whentime=`echo "$whentime" | sed 's/:[0-9][0-9]$//'`

	if [ "$whendayofweek" == "everyday" ]; then
		whendayofweek=$nowdayofweek
	fi

	if [ "$whenday" == "" ]; then
		if [ "$whendayofweek" != "$nowdayofweek" ]; then
			whendayofweek=${whendayofweek%s}
			if [ "$whendayofweek" != "$nowdayofweek" ]; then
				return 0
			fi
		fi
	elif [ "$whenday" != "$nowday" ]; then
		return 0
	fi

	[ "$at" == "at" ] || return 0
	[ "$whentime" == "$nowtime" ] || return 0

	return 1
}

#####################################################
## MAIN

## process command line options

if [ "$1" == "--help" ]; then
	HELP=1;DEBUG=1;loglevel=4
else
	while getopts h,f:,d,t option
	do
		case "$option" in
			h) HELP=1;DEBUG=1;loglevel=4;;
			d) DEBUG=1;loglevel=4;;
			f) CONFFILE="$OPTARG";;
			t) test=1;DEBUG=1;;
		esac
	done
fi
	
setupcolors

## Print help

if [ "$HELP" == 1 ]; then
cat << EOF
$0 usage:
This script allows you to coordinate system backup by dropping a few
simple configuration files into /etc/backup.d/. In general, this script
is run from a cron job late at night. 

The following options are available:
-h         This help message
-d         Run in debug mode, where all log messages are output to the current shell.
-f <file>  Use <file> for the main configuration instead of /etc/backupninja.conf
-t         Run in test mode, no actions are actually taken.

When using colored output, there are:
EOF
debug 0 "Debugging info (when run with -d)"
debug 1 "Informational messages (verbosity level 4)"
debug 2 "Warnings (verbosity level 3 and up)"
debug 3 "Errors (verbosity level 2 and up)"
debug 4 "Fatal, halting errors (always shown)"
exit 0
fi

## Load and confirm basic configuration values

# bootstrap
[ -r "$CONFFILE" ] || fatal "Configuration file $CONFFILE not found."
scriptdir=`grep scriptdirectory $CONFFILE | awk '{print $3}'`
[ -n "$scriptdir" ] || fatal "Cound not find entry 'scriptdirectory' in $CONFFILE."
[ -d "$scriptdir" ] || fatal "Script directory $scriptdir not found."
setfile $CONFFILE

# get global config options (second param is the default)
getconf configdirectory /etc/backup.d
getconf reportemail
getconf reportsuccess yes
getconf reportwarning yes
getconf loglevel 3
getconf when "Everyday at 01:00"
defaultwhen=$when
getconf logfile /var/log/backupninja.log
getconf SLAPCAT /usr/sbin/slapcat
getconf RDIFFBACKUP /usr/bin/rdiff-backup
getconf MYSQL /usr/bin/mysql
getconf MYSQLHOTCOPY /usr/bin/mysqlhotcopy
getconf MYSQLDUMP /usr/bin/mysqldump
getconf GZIP /bin/gzip

[ -d "$configdirectory" ] || fatal "Configuration directory '$configdirectory' not found."
[ `id -u` == "0" ] || fatal "Can only be run as root"

## Process each configuration file

debug 1 "====== starting at "`date`" ======"

# by default, don't make files which are world or group readable.
umask 077

errors=0

for file in $configdirectory/*; do
	[ -f $file ] || continue;

	check_perms $file
	suffix="${file##*.}"
	base=`basename $file`
	if [ "${base:0:1}" == "0" ]; then
		debug 1 "Skipping $file"
		continue
	else
		debug 1 "Processing $file"
	fi

	if [ -e "$scriptdir/$suffix" ]; then
		setfile $file

		# skip over this config if "when" option
		# is not set to the current time.
		getconf when "$defaultwhen"
		IFS=$'\t\n'
		for w in $when; do
			IFS=$' \t\n'
			isnow "$w"
			ret=$?
			IFS=$'\t\n'
			if [ $ret == 0 ]; then
				debug 0 "skipping $file because it is not $w"
				continue
			else
				debug 0 "running $file because it is $w"
				continue
			fi		
		done
		IFS=$' \t\n'

		echo_debug_msg=1
		# call the handler:
		ret=`( . $scriptdir/$suffix $file )`
		retcode="$?"
		warnings=`echo $ret | grep -e "^Warning: " | wc -l`
		errors=`echo $ret | grep -e "^Error: \|^Fatal: " | wc -l`
		if [ $errors != 0 ]; then
			msg "*failed* -- $file"
			errormsg="$error\n== errors from $file ==\n\n$ret\n"
		elif [ $warnings != 0 ]; then
			msg "*warning* -- $file"
			errormsg="$error\n== warnings from $file ==\n\n$ret\n"
		elif [ $retcode == 0 ]; then
			msg "success -- $file"
		else
			msg "unknown -- $file"
		fi
		echo_debug_msg=0
	else
		debug 3 "Can't process file '$file': no handler script for suffix '$suffix'"
		msg "*missing handler* -- $file"
	fi
done

## mail the messages to the report address

if [ "$reportemail" == "" ]; then doit=0
elif [ $errors != 0 ]; then doit=1
elif [ "$reportsuccess" == "yes" ]; then doit=1
elif [ "$reportwarning" == "yes" -a $warnings != 0 ]; then doit=1
else doit=0
fi

if [ $doit == 1 ]; then
	hostname=`hostname`
	{
		for ((i=0; i < ${#messages[@]} ; i++)); do
	 		echo ${messages[$i]}
		done
		echo -e "$errormsg"
	} | mail $reportemail -s "backupninja: $hostname"
fi

debug 1 "====== finished at "`date`" ======"

############################################################