From 44578ace80a974631b4becddba997affac625765 Mon Sep 17 00:00:00 2001
From: Florian Pritz <bluewind@xinu.at>
Date: Sat, 13 Aug 2016 00:14:29 +0200
Subject: borg-restore.pl: WIP

Signed-off-by: Florian Pritz <bluewind@xinu.at>
---
 borg-restore.pl | 135 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 116 insertions(+), 19 deletions(-)

(limited to 'borg-restore.pl')

diff --git a/borg-restore.pl b/borg-restore.pl
index 0a50578..95bb75d 100755
--- a/borg-restore.pl
+++ b/borg-restore.pl
@@ -10,20 +10,33 @@ borg-restore.pl - Restore paths from borg backups
 
 Script that helps to restore files from borg backups.
 
-Takes one or more paths, looks for their backups, shows a list of distinct
+Takes one path, looks for its backups, shows a list of distinct
 versions and allows to select one to be restored.
 
+Also allows to specify a time for automatic selection of the backup that has to
+be restored.  If a time is specified, the script will automatically select the
+newest backup that is at least as old as the time value that is passed.
+
+Backups are restored to their original destination if that destination does not
+exist.  If restoration should be attempted to an existing destination, the
+destination has to be passed as an argument.
+
 =cut
 
 =head1 SYNOPSIS
 
-borg-restore.pl [options] <path>
+borg-restore.pl [options] <path> [[<time spec>] <destination>]
 
  Options:
   --help, -h           short help message
   --debug              show debug messages
   --update-cache, -u   update cache files
 
+ Time spec:
+  Select the newest backup that is at least <time spec> old.
+  Format: <number><unit>
+  Units: s (seconds), min (minutes), h (hours), d (days), m (months = 31 days)
+
 =cut
 
 use v5.10;
@@ -95,10 +108,9 @@ sub find_archives {
 	my %seen_modtime;
 	my @ret;
 
-	#debug(sprintf("Found %d archive(s) with the following times for %s", @$modtimes+0, $path));
 	debug("All modification times from the database:\n", Dumper($modtimes));
 
-	debug("Building archive list");
+	debug("Building unique archive list");
 
 	for my $archive (@$archives) {
 		my $modtime = $$modtimes[get_archive_index($archive, $archives)];
@@ -120,7 +132,7 @@ sub find_archives {
 	return \@ret;
 }
 
-sub select_archive {
+sub user_select_archive {
 	my $archives = shift;
 
 	my $selected_archive;
@@ -145,6 +157,71 @@ sub select_archive {
 	return ${$archives}[$selection];
 }
 
+sub select_archive_timespec {
+	my $archives = shift;
+	my $timespec = shift;
+
+	my $seconds = timespec_to_seconds($timespec);
+	if (!defined($seconds)) {
+		say STDERR "Error: Invalid time specification";
+		return undef;
+	}
+
+	my $target_timestamp = time - $seconds;
+
+	debug("Searching for newest archive that contains a copy before ", format_timestamp($target_timestamp));
+
+	for my $archive (reverse @$archives) {
+		if ($archive->{modification_time} < $target_timestamp) {
+			return $archive;
+		}
+	}
+
+	return undef;
+}
+
+sub format_timestamp {
+	my $timestamp = shift;
+
+	my $dt = DateTime->from_epoch(epoch => $timestamp);
+	return $dt->strftime("%a. %F %H:%M:%S");
+}
+
+sub timespec_to_seconds {
+	my $timespec = shift;
+
+	if ($timespec =~ m/^(?<value>[0-9.]+)(?<unit>.+)$/) {
+		my $value = $+{value};
+		my $unit = $+{unit};
+
+		my %factors = (
+			s       => 1,
+			second  => 1,
+			seconds => 1,
+			minute  => 60,
+			minutes => 60,
+			h       => 60*60,
+			hour    => 60*60,
+			hours   => 60*60,
+			d       => 60*60*24,
+			day     => 60*60*24,
+			days    => 60*60*24,
+			m       => 60*60*24*31,
+			month   => 60*60*24*31,
+			months  => 60*60*24*31,
+			y       => 60*60*24*365,
+			year    => 60*60*24*365,
+			years   => 60*60*24*365,
+		);
+
+		if (exists($factors{$unit})) {
+			return $value * $factors{$unit};
+		}
+	}
+
+	return undef;
+}
+
 sub restore {
 	my $path = shift;
 	my $archive = shift;
@@ -490,6 +567,21 @@ sub main {
 
 	my @paths = @ARGV;
 
+	my $path;
+	my $timespec;
+	my $destination;
+
+	if (@ARGV == 1) {
+		$path = $ARGV[0];
+	} elsif (@ARGV == 2) {
+		$path = $ARGV[0];
+		$destination = $ARGV[1];
+	} elsif (@ARGV == 3) {
+		$path = $ARGV[0];
+		$timespec = $ARGV[1];
+		$destination = $ARGV[2];
+	}
+
 	# TODO only accept one source path
 	# <source path> [time spec] <destination path>
 	# handle destination path similar to rsync
@@ -498,27 +590,32 @@ sub main {
 	#
 	# time spec: take most recent backup that is at least $timespec old
 
-	#if (@paths > 1) {
-		#say STDERR "ERROR: more than one path is currently not supported";
-		#exit 1;
-	#}
+	my $abs_path = abs_path($path);
+	if (!defined($destination)) {
+		$destination = $abs_path;
+	}
+	my $backup_path = $abs_path;
+	$backup_path =~ s/^\Q$backup_prefix\E//;
 
-	for my $path (@paths) {
-		my $abs_path = abs_path($path);
-		my $destination = $abs_path;
-		my $backup_path = $abs_path;
-		$backup_path =~ s/^\Q$backup_prefix\E//;
+	debug("Asked to restore $backup_path to $destination");
 
-		debug( "Asked to restore $backup_path to $destination");
+	my $archives = find_archives($backup_path);
 
-		my $archives = find_archives($backup_path);
+	my $selected_archive;
 
-		my $selected_archive = select_archive($archives);
-		next if not defined($selected_archive);
+	if (defined($timespec)) {
+		$selected_archive = select_archive_timespec($archives, $timespec);
+	} else {
+		$selected_archive = user_select_archive($archives);
+	}
 
-		restore($backup_path, $selected_archive, $destination);
+	if (!defined($selected_archive)) {
+		say STDERR "Error: No archive selected or selection invalid";
+		return 1;
 	}
 
+	restore($backup_path, $selected_archive, $destination);
+
 	return 0;
 }
 
-- 
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