# -*- mode: sh; sh-basic-offset: 3; indent-tabs-mode: nil; -*-
#
# rdiff-backup handler script for backupninja
# requires rdiff-backup
#

### FUNCTIONS ###

function test_connection() {
	# given a user and host,
	# tests the connection.
	# if user or host is missing, returns 0
	# (ie, assume it's a local connection).
	if [ $# -lt 2 ]; then
		debug "(local is assumed to be a good connection)"
		return 0
	fi
	local user=$1
	local host=$2
	debug "ssh $sshoptions -o PasswordAuthentication=no $host -l $user 'echo -n 1'"
	local ret=`ssh $sshoptions -o PasswordAuthentication=no $host -l $user 'echo -n host is alive'`
	if echo $ret | grep "host is alive"; then
		debug "Connected to $host as $user successfully"
	else
		fatal "Can't connect to $host as $user."
	fi
}

function get_version() {
	# given no arguments, returns the local version.
	# given a user and host, returns the remote version.
	# if user or host is missing, returns the local version.
	if [ "$#" -lt 2 ]; then
		debug "$RDIFFBACKUP -V"
		echo `$RDIFFBACKUP -V`
	else
		local user=$1
		local host=$2
		debug "ssh $sshoptions $host -l $user '$RDIFFBACKUP -V'"
		echo `ssh $sshoptions $host -l $user "$RDIFFBACKUP -V | grep rdiff-backup"`
	fi
}

function check_consistency() {
	local section=$1
	local type=$2
	local user=$3
	local host=$4
	if [ "$type" == "local" ]; then
		if [ "$user" != "" ]; then
			warning "User should not be specified for local $section."
		fi
		if [ "$host" != "" ]; then
			warning "Host should not be specified for local $section."
		fi
	fi
	if [ "$type" == "remote" ]; then
		if [ "$user" == "" ]; then
			fatal "User must be specified for remote $section."
		fi
		if [ "host" == "" ]; then
			fatal "Host must be specifed for remote $section."
		fi
	fi
}

### GET CONFIG ###

getconf options
getconf testconnect yes
getconf nicelevel 0

setsection source
getconf type; sourcetype=$type
getconf user; sourceuser=$user
getconf host; sourcehost=$host
check_consistency "source" "$type" "$user" "$host"
getconf label
getconf keep 60
getconf include
getconf vsnames all
getconf vsinclude
getconf exclude

setsection dest
getconf directory; destdir=$directory
# strip trailing /
destdir=${destdir%/}
getconf type; desttype=$type
getconf user; destuser=$user
getconf host; desthost=$host
getconf sshoptions
check_consistency "destination" "$type" "$user" "$host"

### CHECK CONFIG ###

# If vservers are configured, check that the ones listed in $vsnames do exist.
local usevserver=no
if [ $vservers_are_available = yes ]; then
   if [ "$vsnames" = all ]; then
      vsnames="$found_vservers"
   else
      if ! vservers_exist "$vsnames" ; then
            fatal "At least one of the vservers listed in vsnames ($vsnames) does not exist."
      fi
   fi
   if [ -n "$vsinclude" ]; then
      info "Using vservers '$vsnames'"
      usevserver=yes
   fi
else
   [ -z "$vsinclude" ] || warning 'vservers support disabled in backupninja.conf, vsincludes configuration lines will be ignored'
fi

# check the connection at the source and destination
[ -n "$test" ] || test=0
if [ "$testconnect" = "yes" ] || [ "${test}" -eq 1 ]; then
	test_connection $sourceuser $sourcehost
	test_connection $destuser $desthost
fi

# see that rdiff-backup has the same version at the source and destination
sourceversion=`get_version $sourceuser $sourcehost`
destversion=`get_version $destuser $desthost`
if [ "$sourceversion" != "$destversion" ]; then
	fatal "rdiff-backup does not have the same version at the source and at the destination."
fi

# source specific checks
[ "$include" != "" -o "$vsinclude" != "" ] || fatal "No source includes specified"
case $sourcetype in 
	remote ) execstr_sourcepart="$sourceuser@$sourcehost::/" ;;
	local  ) execstr_sourcepart="/" ;;
	*      ) fatal "sourcetype '$sourcetype' is neither local nor remote" ;;
esac

# destination specific checks
[ "$destdir" != "" ] || fatal "Destination directory not set"
case $desttype in 
	remote ) execstr_destpart="$destuser@$desthost::$destdir/$label" ;;
	local  ) execstr_destpart="$destdir/$label" ;;
	*      ) fatal "desttype '$desttype' is neither local nor remote" ;;
esac
	
### REMOVE OLD BACKUPS ###

if [ "`echo $keep | tr -d 0-9`" == "" ]; then
	# add D if no other date unit is specified
	keep="${keep}D"
fi

removestr="$RDIFFBACKUP $options --force --remove-older-than $keep "
if [ "$desttype" == "remote" ]; then
	removestr="${removestr}${destuser}@${desthost}::"
fi
removestr="${removestr}${destdir}/${label}";

debug "$removestr"
if [ $test = 0 ]; then
	output="`su -c "$removestr" 2>&1`"
	if [ $? = 0 ]; then
		debug $output
		info "Removing backups older than $keep days succeeded."
	else
		warning $output
		warning "Failed removing backups older than $keep."
	fi
fi

### EXECUTE ###

execstr="$RDIFFBACKUP $options --print-statistics "

set -o noglob

symlinks_warning="Maybe you have mixed symlinks and '*' in this statement, which is not supported."

# TODO: order the includes and excludes
# excludes
for i in $exclude; do
   str="${i//__star__/*}"
   execstr="${execstr}--exclude '$str' "
done
# includes 
for i in $include; do
   [ "$i" != "/" ] || fatal "Sorry, you cannot use 'include = /'"
   str="${i//__star__/*}"
   execstr="${execstr}--include '$str' "
done

# vsinclude
if [ $usevserver = yes ]; then
   for vserver in $vsnames; do
      for vi in $vsinclude; do
	 str="${vi//__star__/*}"
	 str="$VROOTDIR/$vserver$str"
         if [ -n "$str" ]; then
	    execstr="${execstr}--include '$str' "
         else
            warning "vsinclude statement '${vi//__star__/*}' will be ignored for VServer $vserver. $symlinks_warning"
         fi
      done
   done
fi

set +o noglob

# exclude everything else
execstr="${execstr}--exclude '/*' "
		
# include client-part and server-part
execstr="${execstr}$execstr_sourcepart $execstr_destpart"

debug "$execstr"
if [ $test = 0 ]; then
	output=`nice -n $nicelevel su -c "$execstr" 2>&1`
	if [ $? = 0 ]; then
		debug $output
		info "Successfully finished backing up source $label"
	else
		warning $output
		warning "Failed backup up source $label"
	fi
fi	

return 0