#!/usr/pkg/bin/perl -w
# (c) 2005/05/31 yoya@awm.jp

use strict;
use FileHandle;

my $rm_com = 'rm';
my $rm_opt = '-rf';

sub usage {
    my $msg = shift;
    print STDERR $msg . "\n";
    print STDERR "Usage: $0 remain path depth [path depth [...]]\n";
    print STDERR "ex) $0 6 cap0 3 cap1 3\n";
    exit 1;
}

MAIN: {
    my $argc = @ARGV;
    usage("too few arguments") if ($argc < 3);
    usage("mismatch path and depth") if (($argc % 2) == 0);
    my $remain = shift @ARGV;
    my %path_table = @ARGV;
    my @folder_list = ();
# get target folder list
    foreach my $path (keys %path_table) {
	my $depth = $path_table{$path};
	foreach my $p (get_folder_list($depth, $path)) {
	    push @folder_list, $p;
	}
    }
# create time ascend order sorting
    @folder_list = sort { get_ctime($a) <=> get_ctime($b) } @folder_list;
# remain new folder
    for (1 .. $remain) {
	my $tail = pop @folder_list;
	last unless (defined($tail));
    }
# remove old folder
    foreach my $dir (@folder_list) {
	die "dir is empty!!" if ($dir eq '');
	exec $rm_com, $rm_opt, $dir;
    }
    exit 0;
}

# get folder list (recursive)
sub get_folder_list {
    my ($depth, $path) = @_;
    my @folder_list = ();
    if ($depth < 1) {
	return $path;
    }
    foreach my $p (get_child_folder_list($path)) {
	foreach my $p2 (get_folder_list($depth - 1, $path . '/' . $p)) {
	    push @folder_list, $p2;
	}
    }
    return @folder_list;
}

# get folder list (one level only)
sub get_child_folder_list {
    my $path = shift;
    my $fh = new FileHandle;
    my @folder_list = ();
    opendir($fh, $path);
    while(defined(my $d = readdir($fh))) {
	next if ($d =~ /^\.$/);
	next if ($d =~ /^\.\.$/);
	push @folder_list, $d;
    }
    closedir($fh);
    return @folder_list;
}

# get create time
sub get_ctime {
    my $file = shift;
    my $fh = new FileHandle $file, "r";
    my @fs = stat($fh);
    my $ctime =  $fs[9];
    close($fh);
    return $ctime;
}