#!/usr/bin/env perl

# Copyright (C) 2007-2008  Chris Waters
#

use strict;
use warnings FATAL => qw( all );

use vars qw( $VERSION );
$VERSION = '0.01';

use Nebulous::Client;

use Getopt::Long qw( GetOptions :config auto_help auto_version );
use Pod::Usage qw( pod2usage );

use Digest::MD5;
use URI;

my ($validate,$server,$nouris);

$server = $ENV{'NEB_SERVER'} unless $server;

$validate = 1;
$nouris   = 1;

GetOptions(
    'server|s=s'     => \$server,
) || pod2usage( 2 );

my $key = shift;

pod2usage( -msg => "Unknown option: @ARGV", -exitval => 2 ) if @ARGV;
pod2usage( -msg => "Required options: --server", -exitval => 2 )
    unless $server;
pod2usage( -msg => "missing key", exitval => 2 )
    unless defined $key;

my $neb = Nebulous::Client->new(
    proxy => "$server",
);

die "can't connected to Nebulous Server: $server"
    unless defined $neb;

my $stat = $neb->stat($key);
die "nebulous key: $key not found" unless $stat;   
my $instances = $neb->find_instances($key, 'any');
die "no instances found" unless $instances;   

my $user_copies;
eval {
    $user_copies = $neb->getxattr($key, "user.copies");
};
unless(defined($user_copies)) {
    $user_copies = 2;
}

my @validation;
my %md5sum_uniq;
my %md5sum_valid;
my $last_f = '';
my $existing_copies = 0;
my @existance;
my @md5sums;
my @files = map {URI->new($_)->file if $_} @$instances;

for (my $i = 0; $i <= $#files; $i++) {
    if (-e $files[$i]) {
	$existance[$i] = 1;
	$existing_copies++;
	my $fh;
	open($fh,$files[$i]);
	$md5sums[$i] = Digest::MD5->new->addfile($fh)->hexdigest;
	close($fh);

	$md5sum_uniq{$md5sums[$i]} = 1;

	if ($md5sums[$i] eq 'd41d8cd98f00b204e9800998ecf8427e') {
	    $existance[$i] = 0;
	    next;
	}

	push @{ $md5sum_valid{$md5sums[$i]} }, $files[$i];
	$last_f = $files[$i];
    }
    else {
	$existance[$i] = 0;
	$md5sums[$i] = 'NON-EXISTANT';
	$md5sum_uniq{$md5sums[$i]} = 1;
	push @{ $md5sum_valid{$md5sums[$i]} }, $files[$i];
    }
}

my $N_mds = scalar(keys(%md5sum_uniq));
my $N_files = scalar(@files);
if ($N_files < $user_copies) {
    print "Insufficient copies ($N_files) of $key, replicating!\n";
    system("neb-replicate $key");
}
if ($N_mds == 1) {
    print "Nebulous key $key is consistent.\n";
}
else {
    my $valid_sum = '';
    my $valid_file = '';
    my $m;
    foreach $m (keys %md5sum_valid) {
	if (($m ne 'd41d8cd98f00b204e9800998ecf8427e')&&($m ne 'NON-EXISTANT')) {
	    if ($valid_sum ne '') {
		die "Too many acceptable files for key $key\n";
	    }
	    $valid_sum = $m;
	    $valid_file = ${ $md5sum_valid{$m} }[0];
	}
    }
    if ($valid_sum eq '') {
	die "No acceptable file for key $key\n";
    }
    else {
	print "Repairing instances\n";
	foreach $m (keys %md5sum_valid) {
	    if ($m ne $valid_sum) {
		foreach my $f (@{ $md5sum_valid{$m} }) {
		    print "\tcp $valid_file $f\n";
		    system("cp $valid_file $f");
		    if ($? >> 8 != 0) {
			if ($existance[0] == 1) {
			    # We can fix this with culls and replications.
			    print "Attempting to fix this.\n";
			    print("neb-replicate $key\n");
			    system("neb-replicate $key");
			    if ($? >> 8 == 0) {
				my $bad_volume = (split /\//, $f)[2];
				print("neb-cull --volume $bad_volume $key\n");
				system("neb-cull --volume $bad_volume $key");
			    }
			    else {
				die "Failed to copy file $valid_file to $f, and subsequent replication also failed!\n";
			    }
			}
			else {
			    die "Failed to copy file $valid_file to $f!\n";
			}
		    }
		}
	    }
	}
    }
}

# if ($N_files > $user_copies) {
#     my @split = split /\//, $last_f;
#     my $volume = $split[2];
#     print "Culling extra copy: neb-cull --volume $volume $key\n";
#     system("neb-cull --volume $volume $key");
# }



__END__

=pod

=head1 NAME

neb-repair - tool to check and repair instances

=head1 SYNOPSIS

    neb-repair [--server <URL>] <key> 

=head1 DESCRIPTION

This program repairs instances and corrects instance counts for a nebulous key.  

=head1 OPTIONS

=over 4

=item * --server|-s <URL>

URL of the Nebulous server to connect to.

Optional if the appropriate environment variable is set.

=back

=head1 ENVIRONMENT

These environment variables may be used in place of the specified command line
options.  All command line option will override the corresponding environment
value.

=over 4

=item * C<NEB_SERVER>

Equivalent to --server|-s

=back

=head1 CREDITS



=head1 SUPPORT

Please contact the author directly via e-mail.

=head1 AUTHOR

Chris Waters

=head1 COPYRIGHT

Copyright (C) 2007-2008  Chris Waters

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.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA  02111-1307, USA.

The full text of the license can be found in the L<perlgpl> Pod as supplied
with Perl 5.8.1 and later.

=head1 SEE ALSO

L<Nebulous::Server>, L<neb-initdb>, L<neb-addvol>, L<nebdiskd>, L<neb-df>,
L<neb-touch>, C<regex(7)>

=cut
