#!/bin/sh -e

# Copyright (C) 2006-2008 David Mandelberg

# use ssh-agent
test x"$USING_SSH_AGENT" = x"yes" || USING_SSH_AGENT=yes exec ssh-agent "$0" "$@"

BASE="`dirname "$0"`"
METARELDIR="metadata"
METADIR="$BASE/$METARELDIR"
RS="_rsync -ua --delete"
SSH="_ssh"
PROXY=""
PROXY_PORT=1080
PROXY_TIMEOUT=5
QUIET=0
VERBOSE=0


REMOTE=0
NAME="`basename "$0"`"

print_help () {
	printf "$NAME [OPTION...] [COMMAND...]\n"
	printf "\tOPTIONS:\n"
	printf "\t\t-h | --help: print a help message\n"
	printf "\t\t-u | --usage: print a usage message\n"
	printf "\t\t-p | --proxy: use an ssh proxy\n"
	printf "\t\t-q | --quiet: print less\n"
	printf "\t\t-v | --verbose: print more\n"
	printf "\t\t-l KBPS | --limit KBPS: limit bandwidth usage\n"
	printf "\t\t-o host1[,host2...] | --only host1[,host2...]: only backup certain hosts\n"
	printf "\t\t-n host1[,host2...] | --not host1[,host2...]: don't backup certain hosts\n"
	printf "\tCOMMANDS:\n"
	printf "\t\t-c [SNIPPET]| --cmd [SNIPPET] | --command [SNIPPET]\n"
	printf "\t\t\truns SNIPPET as a shell snippet after all backup commands and before any upload commands\n"
}

print_usage () {
	printf "$NAME [-h|-u]\n"
	printf "$NAME [-q|-v] [-p ssh_proxy_host] [-l KBPS] [-c snippet]... [-o host1[,host2...]] [-n host1[,host2...]]\n"
}

msg () {
	test x"$QUIET" = x0 && echo " * $*" >&2
	return 0
}
verbose () {
	test x"$VERBOSE" = x1 && msg "$@"
	return 0
}
error () {
	echo " * $*" >&2
	exit 1
}

# echo and run a command
run () {
	msg "$*"
	"$@"
}
run_verbose () {
	verbose "$*"
	"$@"
}

# create a temp file
c_tmp () {
	TMP="`mktemp`"
	verbose "created temporary file: $TMP"
}

# delete a temp file
d_tmp () {
	rm -f "$TMP"
	
	verbose "removed temporary file: $TMP"
	unset TMP
}

# move a temp file
m_tmp () {
	mv "$TMP" "$1"
	verbose "moved temporary file: $TMP -> $1"
	unset TMP
}

# if passed /foo/bar/baz, create /foo and /foo/bar
mkcontdirs () {
	while true; do
		if test ! -e "$1"; then
			run_verbose mkcontdirs "`dirname "$1"`"
			run mkdir "$1"
		fi
		shift || break
		test $# -lt 1 && break
	done
}

stop_remote () {
	run_verbose ssh-add -D
	REMOTE=0
}

forced_quit () {
	msg "Quitting..."
	test $REMOTE = 1 && stop_remote
	exit 1
}
trap forced_quit 1 2 3 6 15

setup_remote () {
	REMOTE=1
	run_verbose ssh-add
}

host_in_list () {
	_HOST="$1"
	shift
	_LIST="$1"
	test x"$_LIST" = x && _LIST="$HOSTS"
	test x"$_LIST" = x && return 1
	
	_HOSTINLIST=1
	for i in $_LIST; do
		case "$i" in
			"@ALL@"|"$_HOST")
				_HOSTINLIST=0
				;;
			"-@ALL@"|"-$_HOST")
				_HOSTINLIST=1
				;;
		esac
	done
	return $_HOSTINLIST
}

_is_mounted () {
	grep -q " $_MTPT " /etc/mtab || return 1
	return 0
}
_mount () {
	_MTPT="$1"; shift

	# did this program mount it or was it already mounted?
	# 0 = already mounted; 1 = this program
	OURMOUNT=0

	if _is_mounted; then
		OURMOUNT=0
		verbose "$_MTPT already mounted."
	else
		OURMOUNT=1
		run_verbose mount "$_MTPT"
	fi
}
_umount () {
	_MTPT="$1"; shift
	if test x"$OURMOUNT" = x0; then
		verbose "Not unmounting $_MTPT."
	else
		run_verbose umount "$_MTPT"
	fi
}

bk_prep () {
	_NAME="$1"; shift
	verbose "Preparing $_NAME"
	run_verbose mkcontdirs "$BASE/$_NAME"
	for i in "$@"; do
		run_verbose mkcontdirs "$BASE/$_NAME/$i"
	done
}

# handle ssh proxy
start_proxy () {
	run_verbose ssh -fD "$PROXY_PORT" "$PROXY" sleep "$PROXY_TIMEOUT"
}
stop_proxy () {
	test -n "$PROXY" || return
	test -f "$TSOCKS_CONF_FILE" && rm "$TSOCKS_CONF_FILE"
}
_rsync () {
	if test -n "$PROXY"; then
		start_proxy
		tsocks rsync "$@"
	else
		rsync "$@"
	fi
}
_ssh () {
	if test -n "$PROXY"; then
		start_proxy
		tsocks ssh "$@"
	else
		ssh "$@"
	fi

}

bk_remote () {
	NAME="$1"; shift
	HOST="$1"; shift
	RSOPTS="$1"; shift
	DATE="`date`"
	host_in_list "$NAME" || return 0
	msg "Backing up $NAME ($HOST)"
	bk_prep "$NAME" "$@"
	c_tmp
	run_verbose "$SSH" "$HOST" "dpkg --get-selections" > "$TMP"
	m_tmp "$METADIR/$NAME.packages"
	c_tmp
	printf "%s" "$DATE" > "$TMP"
	for LOC in "$@"; do
		run_verbose $RS $RSOPTS "$HOST:/$LOC" "$BASE/$NAME/$LOC"
	done
	m_tmp "$METADIR/$NAME.time"
}

bk_local () {
	NAME="$1"; shift
	RSOPTS="$1"; shift
	DATE="`date`"
	host_in_list "$NAME" || return 0
	msg "Backing up $NAME (local machine)"
	bk_prep "$NAME" "$@"
	c_tmp
	hostname > "$TMP"
	m_tmp "$METADIR/$NAME.hostname"
	c_tmp
	run_verbose dpkg --get-selections > "$TMP"
	m_tmp "$METADIR/$NAME.packages"
	c_tmp
	printf "%s" "$DATE" > "$TMP"
	for LOC in "$@"; do
		run_verbose $RS $RSOPTS "/$LOC" "$BASE/$NAME/$LOC"
	done
	m_tmp "$METADIR/$NAME.time"
}

bk_media () {
	NAME="$1"; shift
	MTPT="$1"; shift
	RSOPTS="$1"; shift
	DATE="`date`"
	host_in_list "$NAME" || return 0
	msg "Backing up $NAME (removable media)"
	bk_prep "$NAME" "$@"
	c_tmp
	printf "%s" "$DATE" > "$TMP"
	_mount "$MTPT"
	for LOC in "$@"; do
		run_verbose $RS $RSOPTS "$MTPT/$LOC" "$BASE/$NAME/$LOC"
	done
	_umount "$MTPT"
	m_tmp "$METADIR/$NAME.time"
}

bk_upload () {
	NAME="upload-$1"; shift
	host_in_list "$NAME" || return 0
	LOC="$1"; shift
	msg "Uploading backup to $LOC ($NAME)"
	c_tmp
	printf "%s" "$DATE" > "$TMP"
	run_verbose $RS "$BASE/" "$LOC/"
	m_tmp "$METADIR/$NAME.time"
	run $RS "$METADIR/$NAME.time" "$LOC/$METARELDIR/$NAME.time"
}



# parse options
TMP="`getopt -o c:huqo:n:vp:l: -l cmd:,command:,help,usage,quiet,only:,not:,verbose,proxy:,limit: -n "$NAME" -- "$@"`"
eval set -- "$TMP"
CMDS="true"
HOSTS="@ALL@"
while true; do
	case "$1" in
		-c|--cmd|--command)
			CMDS="$CMDS; $2"
			shift 2
			;;
		-o|--only)
			HOSTS="`printf "%s" "$2" | sed 's/,/ /g'`"
			shift 2
			;;
		-n|--not)
			HOSTS="$HOSTS -`printf "%s" "$2" | sed 's/,/ -/g'`"
			shift 2
			;;
		-p|--proxy)
			PROXY="$2"
			shift 2
			export TSOCKS_CONF_FILE="`mktemp`"
			echo "server = 127.0.0.1" >> "$TSOCKS_CONF_FILE"
			echo "server_port = $PROXY_PORT" >> "$TSOCKS_CONF_FILE"
			;;
		-l|--limit)
			RS="$RS --bwlimit=$2"
			shift 2
			;;
		-h|--help)
			print_help
			exit
			;;
		-u|--usage)
			print_usage
			exit
			;;
		-q|--quiet)
			QUIET=1
			SSH="$SSH -q"
			RS="$RS -q"
			shift
			;;
		-v|--verbose)
			VERBOSE=1
			RS="$RS -v --progress"
			shift
			;;
		--)
			shift
			break
			;;
		*)
			error "Error parsing options."
	esac
done



setup_remote

bk_remote www-server www.foo.example.com \
	"" \
	etc/ \
	root/ \
	home/ \
	var/spool/cron/crontabs/ \
	var/www/

bk_remote workstation1 workstation1.example.com \
	"--delete-excluded
	--exclude /*/.mozilla/firefox/*/Cache/*" \
	etc/ \
	root/ \
	home/ \
	var/spool/cron/crontabs/

bk_local desktop \
	"--delete-excluded
	--exclude /*/.cache/*/**
	--exclude /*/.mozilla/firefox/*/Cache/*" \
	etc/ \
	root/ \
	home/ \
	var/www/ \
	var/spool/cron/crontabs/

bk_media ipod /media/IPOD \
	"" \
	./

$CMDS

bk_upload backup-server backups.example.com:/media/backup

stop_remote
stop_proxy


msg "Backup complete!"