#!/usr/bin/perl
use strict;
use warnings;

use lib $ENV{GL_LIBDIR};
use Gitolite::Common;
use Gitolite::Conf::Load;

=for usage
Usage:  gitolite list-dangling-repos

List all existing repos that no one can access remotely any more.  They could
be normal repos that were taken out of "repo" statements in the conf file, or
wildcard repos whose matching "wild" pattern was taken out or changed so it no
longer matches.

I would advise caution if you use this as a basis for deleting repos from the
file system.  A bug in this program could cause you to lose important data!
=cut

usage() if @ARGV and $ARGV[0] eq '-h';

# get the two lists we need.  %repos is the list of repos in "repo" statements
# in the conf file.  %phy_repos is the list of actual repos on disk.  Our job
# is to cull %phy_repos of all keys that have a matching key in %repos, where
# "matching" means "string equal" or "regex match".
my %repos = map { chomp; $_ => 1 } `gitolite list-repos`;
for my $r ( grep /^@/, keys %repos ) {
    map { chomp; $repos{$_} = 1; } `gitolite list-members $r`;
}
my %phy_repos = map { chomp; $_ => 1 } `gitolite list-phy-repos`;

# Remove exact matches.  But for repo names like "gtk+", you could have
# collapsed this into the next step (the regex match).
for my $pr (keys %phy_repos) {
    next unless exists $repos{$pr};
    delete $repos{$pr};
    delete $phy_repos{$pr};
}

# Remove regex matches.
for my $pr (keys %phy_repos) {
    my $matched = 0;
    my $pr2 = Gitolite::Conf::Load::generic_name($pr);
    for my $r (keys %repos) {
        if ($pr =~ /^$r$/ or $pr2 =~ /^$r$/) {
            $matched = 1;
            next;
        }
    }
    delete $phy_repos{$pr} if $matched;
}

# what's left in %phy_repos are dangling repos.
print join("\n", sort keys %phy_repos), "\n";
