#!/usr/bin/perl
use File::Basename;
use strict;


my $dir = shift;
unless (-d $dir) {
	print "Arg is not a directory";
	exit 1;
}
my $me = basename $dir;
my ($status, $details);

sub do_command {
	my $command = shift;
	$command =~ /^(\w+)(\s+(.*))?$/;
	my ($do, $args) = ($1, $3);
	if ($do eq 'mail') {
		open MAIL, '|-', qq!mail -s "$me $status" $args! or die "Could not mail";
		print MAIL $details,"\n";
		close MAIL;
	} elsif ($do eq 'exec') {
		system($args);
	} elsif ($do eq 'pipe') {
		open PIPE, '|-', $args;
		print PIPE "$status\n";
		print PIPE $details;
		close PIPE;
	}
}


my ($checkcommand, %on);
$on{success} = [];
$on{failure} = [];
$on{change} = [];

open CONFIG, "$dir/check";
while (<CONFIG>) {
	my @words = split(/\s+/);
	my $command = shift @words;
	if ($command eq 'check') {
		$checkcommand = join(' ', @words);
	} elsif ($command eq 'on') {
		my $when = shift @words;
		if ($when eq 'failure') {
			push @{$on{failure}}, join(' ', @words);
		} elsif ($when eq 'success') {
			push @{$on{success}}, join(' ', @words);
		} elsif ($when eq 'change') {
			push @{$on{change}}, join(' ', @words);
		} else {
			print "Unknown event in 'on', $dir/check line $.\n";
		}
	} else {
		print "Unknown command '$command', $dir/check line $.\n";
	}
}
close CONFIG;

unless ($checkcommand) {
	print "Check command not specified in $dir/check\n";
	exit 1;
}
unless (@{$on{failure}} || @{$on{success}} || @{$on{change}}) {
	print "No actions specified in $dir/check. This is probably a mistake.\n";
}

open STATUS, "$dir/checkstatus";
chomp(my $oldstatus = <STATUS>);
close STATUS;

open CHECK, '-|', $checkcommand;
$status = <CHECK>;
$details = join('', <CHECK>);
close CHECK;
my $exitstatus = $? >> 8;

if ($exitstatus == 0) {
	foreach my $command (@{$on{success}}) {
		do_command $command;
	}
} else {
	foreach my $command (@{$on{failure}}) {
		do_command $command;
	}
}
if ($exitstatus != $oldstatus) {
	foreach my $command(@{$on{change}}) {
		do_command $command;
	}
}

open STATUS, ">$dir/checkstatus";
print STATUS "$exitstatus\n";
print STATUS "$status\n";
print STATUS "$details\n";
close STATUS;