#!/usr/bin/perl -w

use strict;
my ($AMADMIN,$CONFIG,$COMMAND,@output,$host,$filesystem,$level,$tape,$status,$lasthost,$lastfilesystem,$neednull,$needone,%tapes);

&Init;
&Collect;
&Report;

sub Init {
	$AMADMIN = "/usr/sbin/amadmin";
	$CONFIG = "thuis";
	$COMMAND = "$AMADMIN $CONFIG find";
	@output = `$COMMAND`;
	die "Unable to run '$COMMAND'\nPlease run as user 'amanda' or 'root'" if ($?);
}

sub Collect {
	while (@output) {
		my $line = pop(@output);
		chomp $line;
		$line =~ s/\s+/ /g;
		next unless ($line =~ '^20');
		($host,$filesystem,$level,$tape,$status) = (split /\s/,$line)[1,2,3,4,6];
		next unless ($status eq "OK");
		&PreHouseKeeping;
		&Select($tape) if Needed();
		&PostHouseKeeping;
	}
}

sub PreHouseKeeping {
	die "Unknown level ($level) found\n" unless (LevelOne() or LevelNull());
	$lasthost = "" unless defined ($lasthost);
	ResetLevels() if (NewHost() or NewFilesystem());
}

sub LevelNull {
	if ($level eq "0") {
		$needone = 0;
		return 1;
	}
	return 0;
}

sub LevelOne {
	return 1 if ($level eq "1");
	return 0;
}

sub ResetLevels {
	$neednull = $needone = 1;
}

sub NewHost {
	return 1 if ($lasthost ne $host);
	return 0;
}

sub NewFilesystem {
	return 1 if ($lastfilesystem ne $filesystem);
	return 0;
}

sub Select {
	my $tape = "@_";
	$tapes{$tape} = 1;
}

sub Needed {
	return 1 if (LevelNull() and $neednull);
	return 1 if (LevelOne() and $needone);
	return 0;
}

sub PostHouseKeeping {
	$neednull = 0 if LevelNull();
	$needone = 0 if LevelOne();
	$lasthost = $host;
	$lastfilesystem = $filesystem;
}

sub Report {
	print "Need the following tapes:\n";
	foreach (sort keys %tapes) {
		print "$_\n";
	}
}