#!/bin/bash
# File Sync Tool for Mac 2016-02-26 for v1.10 r16

# user's log and settings
p_logfile="${HOME}/Library/Logs/filesynctool_$(/bin/date +%F).log"
p_plist="${HOME}/Library/Preferences/fi.aalto.filesynctool.plist"
# if You edit plist manually, do check for errors with
# /usr/libexec/PlistBuddy -c print ~/Library/Preferences/fi.aalto.filesynctool.plist

# use Pashua for building user interface
p_bin='/Applications/Utilities/Pashua.app/Contents/MacOS/Pashua'
# run time GUI parameters for Pashua
p_config="/private/tmp/filesynctool-$(/usr/bin/uuidgen)"

# script directrory
p_dir=$(/usr/bin/dirname "${0}")

# system default rsync does not support -s glob security option!
# use MacPorts or aaltocoreports or exit
if [ -x /opt/aaltocoreports/bin/rsync ]; then
	p_rsync='/opt/aaltocoreports/bin/rsync'
elif [ -x /opt/local/bin/rsync ]; then
	p_rsync='/opt/local/bin/rsync'
else
	echo "$(/bin/date +%F_%H.%M) exit with error: no rsync with -s option?" >> "$p_logfile"
	exit 1
fi

# .plist settings file utility and other common utitilities
p_buddy='/usr/libexec/PlistBuddy'
p_perl='/usr/bin/perl'
p_cat='/bin/cat'

# see some of those from perl, too
export p_plist p_logfile p_dir p_rsync p_buddy

# clean temp and do log
#
s_exit() {
	/bin/rm -f $p_config
	echo "${0} $(/bin/date +%F_%H.%M) exit" >> "$p_logfile"
	exit 0
}

# after sync, show status dialog with prompt for quit, try again, view or remove log or quit
# use:	if error	s_status("NOT ", "[reason]")
#	if success	s_status("", "")
#
s_status() {
	args=("$@")
	$p_cat <<EOF > $p_config	# overwrite
*.title	= Aalto File Sync Status
*.x	= 40
*.y	= 50

txt.type	= text
txt.default	= Sync was ${args[0]}successful

EOF
	# # show warning icon and error description if any
	if [ "NOT " == "${args[0]}" ]
	then
		msg=''
		for (( i=1; i<$#; i=i+1 ))
		do
			msg="$msg${args[$i]} "
		done
		$p_cat <<EOF >> $p_config
img.type	= image
img.path	= ${p_dir}/_warning.png
img.maxwidth	= 36

error.type	= text
error.width	= 450
error.default	= $msg
EOF
		# log warning
		echo "$(/bin/date +%F_%H.%M) error: $msg" >> "$p_logfile"
	fi
	# #
	$p_cat <<EOF >> $p_config	# GUI buttons, ask what next

restart.type	= button
restart.label	= Start Again

log.type	= button
log.label	= Show Log

rml.type	= button
rml.label	= Log remove

quit.type	= defaultbutton
quit.label	= Quit
EOF

	# reveal status dialog
	ret=$("$p_bin" "$p_config")
	
	# act according to button pressed
	if [[ $ret =~ .*restart=1.* ]]
	then
		return	# back to main loop & main GUI

	elif [[ $ret =~ .*log=1.* ]]
	then
		/usr/bin/open -a /Applications/TextEdit.app "$p_logfile"

	elif [[ $ret =~ .*rml=1.* ]]
	then
		rm "$(dirname $p_logfile)/filesynctool_"*
	fi
	s_exit
}

# error happened, do warn and log
#
s_err() {
	s_status 'NOT ' 'Error' "$@"
}

# build upper part of settings dialog GUI
#
s_gui_top() {
	$p_cat << EOF > $p_config	# overwrite!
*.title	= Aalto File Sync Tool
*.x	= 40
*.y	= 50

EOF
}

# build lower part of settings dialog GUI with buttons
#
s_gui_bottom() {
	$p_cat <<EOF >> $p_config
help.type	= button
help.label	= Help

cancel.type	= button
cancel.label	= Quit

run.type	= defaultbutton
run.label	= Start Sync

EOF
}

# read sync settings from settings file to hash of
# hashes and build GUI. To cure syntax headache, see
# perldsc(1), perlretut(1) and PlistBuddy(8)
#
s_gui() {
	s_gui_top
	$p_buddy -c print $p_plist | $p_perl -we '
	 use strict;
	 my (@row, %hash, $syncpair);
	 while(<>) {
		chomp;
		@row = split;
		if ( /^ {4}[^ }]/ ) { # syncpair name
			$syncpair = $row[0];
		}
		if ( /^ {8}/ ) { # option key and value
			/^.*= (.*?)$/;	# save value if any
			$hash{$syncpair}{$row[0]} = $1 ? $1 : "";
		}
	 }
	 # get hash references to hashes with source, target & delete values
	 for $syncpair ( sort keys %hash ) {
	 	# avoid uninitialized values
	 	my ($src, $dst);
	 	$src = $hash{$syncpair}{"source"}      ? $hash{$syncpair}{"source"}      : "";
	 	$dst = $hash{$syncpair}{"destination"} ? $hash{$syncpair}{"destination"} : "";
	 	# dump hash to Pashua GUI format
		print <<EOF;
${syncpair}s.type	= openbrowser
${syncpair}s.label	= ${syncpair} source
${syncpair}s.default	= $src
${syncpair}s.filetype	= directory
${syncpair}s.width	= 500

${syncpair}t.type	= openbrowser
${syncpair}t.label	= ${syncpair} target
${syncpair}t.default	= $dst
${syncpair}t.filetype	= directory
${syncpair}t.width	= 500

${syncpair}e.type	= checkbox
${syncpair}e.label	= Enabled
${syncpair}e.default	= $hash{$syncpair}{"enabled"}

${syncpair}d.type	= checkbox
${syncpair}d.label	= Delete in target if not in source
${syncpair}d.tooltip	= Are You sure? Files on target would be removed!
${syncpair}d.default	= $hash{$syncpair}{"delete"}

-

EOF
	 }' >> $p_config
	s_gui_bottom
}

# no settings available, use empty defaults for GUI
#
s_gui_default() {
	s_gui_top
	for i in "1st" "2nd" "3rd"
	do
		$p_cat <<EOF
${i}s.type	= openbrowser
${i}s.label	= ${i} source
${i}s.default	=
${i}s.filetype	= directory
${i}s.width	= 500

${i}t.type	= openbrowser
${i}t.label	= ${i} target
${i}t.default	=
${i}t.filetype	= directory
${i}t.width	= 500

${i}e.type	= checkbox
${i}e.label	= Enabled
${i}e.default	= 1

${i}d.type	= checkbox
${i}d.label	= Delete in target if not in source
${i}d.tooltip	= Are You sure? Files on target would be removed!
${i}d.default	= 0

-

EOF
	done >> $p_config
	s_gui_bottom
}

# main loop
#
while :
do
	if [ -e $p_plist ]	# set up GUI
	then
		s_gui	 # with saved values
	else
		s_gui_default	# or without
	fi

	# reveal GUI, then process user input

	echo -e "\n\n$(/bin/date +%F_%H.%M) starting GUI for settings" >> "$p_logfile"

	$p_bin $p_config | $p_perl -we '

	 use strict;
	 use POSIX qw(strftime);

	 # hashes for transpose table and sync pair settings
	 my (%t, %h);

	 # initialize with emptiness
	 %h = ();

	 # log when needed
	 sub _synclog
	 {
	 	open my $logfile, ">>", "$ENV{p_logfile}";
	 	print $logfile strftime("+ %F_%H.%M ", localtime), @_, "\n";
	 	close $logfile;
	 }

	 # free space in kB
	 sub _dfree
	 {
		my ($fh, @df);
		open $fh, "-|", "/bin/df", "-k", @_;
		@df=split while <$fh>;
		close $fh;
		return $df[3]
	 }

	 # disk usage in kB
	 sub _dusage
	 {
		my ($fh, @du);
		open $fh, "-|", "/usr/bin/du", "-sk", @_;
		@du=split while <$fh>;
		close $fh;
		return $du[0]
	 }

	 # read sync settings from user input to hash of hashes, see perldsc(1)
	 while(<>) {
	 	chomp;
	 	exit 7	if /^cancel=1$/;
	 	exit 8	if /^help=1$/;
	 	next if /^help=0$/ or /^cancel=0$/ or /^run=0$/ or /^run=1$/ or /[st]=$/;
	 	my @row	= split /=/;
	 	$row[0]	=~ /^(.*?)(.)$/;	# save name, action
	 	$h{$1}{$2} = $row[1] ? $row[1] : "";	# and path
	 }

	 # transpose to PlistBuddy commands
	 %t = (
	 	e => "enabled integer",
	 	d => "delete integer",
	 	t => "destination string",
	 	s => "source string" );

	 # forget old...
	 rename "$ENV{p_plist}", "$ENV{p_plist}.bak";
	 # ...and save new settings
	 for my $p ( sort keys %h )
	 {
	 	for my $k ( sort keys %{ $h{$p} } )
	 	{
	 		system( $ENV{p_buddy}, "-c", "add :$p:$t{$k} $h{$p}{$k}", $ENV{p_plist} );
	 	}
	 }
	 # if mishap with saving, try the back up
	 unless ( -e $ENV{p_plist} ) {

		_synclog "warn: sync settings file lost, trying the restore the back up";

		rename "$ENV{p_plist}.bak", $ENV{p_plist} if -s "$ENV{p_plist}.bak";
	 }

	 # variables
	 my ( $source, $target, $enabled, $delete, @args, $retval, $pair, $k, $count );
	 $count=0;

	 # every source - destination sync pair
	 for $pair ( sort keys %h )
	 {
	 	# emptify
	 	$source=$target=$enabled=$delete=""; @args=();

	 	# sync pair
	 	PROPERTIES: for $k ( sort keys %{ $h{$pair} } )
	 	{
	 		# [x] enabled ?
	 		if ( "e" eq $k && ! ( "1" eq $h{$pair}{"e"} ) ) {
				$enabled="FALSE";
				_synclog "skipping sync ${pair}: not enabled by GUI checkbox";
				last PROPERTIES;
	 		}
	 		# [x] delete ?
	 		if ( "d" eq $k ) {
	 			if ( defined($h{$pair}{"d"}) && ("1" eq $h{$pair}{"d"}) ) {
	 				$delete="--del"
	 			} else {
	 				$delete="--"
	 			}
	 			next;
	 		}
	 		# save path, or skip if empty
	 		if ( "" ne $h{$pair}{$k} ) {
	 			$source="$h{$pair}{$k}"	if "s" eq $k;
	 			$target="$h{$pair}{$k}"	if "t" eq $k;
	 		}
	 	}
	 	# sync pair disabled in GUI?
	 	next if "FALSE" eq $enabled;

	 	# to prevent backups recursively inside itself, source
		# and target must not be the same
	 	next if $source eq $target;

		# rsync works differently with "path" or "path/" as source
		# this time we stick with "path" behavior in app and docs
		# as side efect do unsupport / as source!
		$source=~s,/$,,g;

	 	# paths should be useable, too
	 	exit 3 unless -d "$source" and -r "$source" and -d "$target" and -w "$target";

		# does the sync fit into?
		#
		# abort if tight on free disk space on target
		# ( _dfree($target) < _dusage($source) ) && exit 15;
		#
		# just warn -- we do not know if there are just a few changed files to update
		if ( _dfree("$target") < _dusage("$source") ) {
			_synclog join " ", $pair, ":", $source, ">", $target, "warning: source disk usage bigger than target free space";
		}

	 	# sync settings
	 	@args = ( ${ENV{p_rsync}},
	 		"--log-file=${ENV{p_logfile}}",
	 		"-a",
	 		"-s",
	 		"-v",
	 		"$delete",
	 		"$source",
	 		"$target" );

		# log start attempt
	 	_synclog join " ", "sync", $pair, "starting with\n", @args;

		# run
	 	$retval=system @args;

	 	# if error abort syncs
	 	exit $retval >> 8  if 0 != $retval;

	 	# log success
	 	_synclog join " ", "sync", $pair, "run", ++$count, "without error";
	 }
	 exit 9 if 0 == $count;
	'
	case $? in
		0)
			s_status '' ''	# all syncs without error
			;;
		7)
			s_exit		# quit button pressed
			;;
		8)
			/usr/bin/open "${p_dir}/_AaltoFileSyncToolHelp.html" # help button pressed
			s_exit
			;;
		9)
			s_err "#${?} Check sources, targets and enabled checkboxes: Nothing to sync, paths non-existent or not folders, or same path as source and target"
			;;
		15)
			s_err "#${?} Not enough free space for the sync on target volume"
			;;
		1)
			s_err "#${?} Syntax or usage error"
			;;
		2)
			s_err "#${?} Protocol incompatibility"
			;;
		3)
			s_err "#${?} selecting input/output files, dirs"
			;;
		4)
			s_err "#${?}: Requested action not supported: an attempt was made to manipulate 64-bit files on a platform that cannot support them; or an option was specified that is supported by the client and not by the server"
			;;
		5)
			s_err "#${?} starting client-server protocol"
			;;
		6)
			s_err "#${?} Daemon unable to append to log-file"
			;;
		10)
			s_err "#${?} in socket I/O"
			;;
		11)
			s_err "#${?} in file I/O"
			;;
		12)
			s_err "#${?} in rsync protocol data stream"
			;;
		13)
			s_err "#${?} with program diagnostics"
			;;
		14)
			s_err "#${?} in IPC code"
			;;
		20)
			s_err "#${?} Received SIGUSR1 or SIGINT"
			;;
		21)
			s_err "#${?} Some error returned by waitpid()"
			;;
		22)
			s_err "#${?} allocating core memory buffers"
			;;
		23)
			s_err "#${?} Partial transfer due to error"
			;;
		24)
			s_err "#${?} Partial transfer due to vanished source files"
			;;
		25)
			s_err "#${?} The --max-delete limit stopped deletions"
			;;
		30)
			s_err "#${?} Timeout in data send/receive"
			;;
		35)
			s_err "#${?} Timeout waiting for daemon connection"
			;;
		*)
			s_err "#${?} Unknown error"
			;;
	esac
	/bin/sleep 1;
done

## More features? Start a project maybe? See also:
# https://www.cis.upenn.edu/~bcpierce/unison/
# http://www.opbyte.it/grsync/
# https://rsnapshot.org
# http://www.mikerubel.org/computers/rsync_snapshots/
# http://shop.oreilly.com/product/9780596102463.do
# https://fedoramagazine.org/butterfly-backup/
# https://dropbox.tech/infrastructure/rewriting-the-heart-of-our-sync-engine