#!/usr/bin/env perl
use autodie;
use strict;
use warnings;
use 5.010;

use Getopt::Long qw/:config bundling/;
use Term::ANSIColor;

my $version = '0.0+git';

my ($cache, $config, $data, $extra);
my $config_file = '/var/cache/icinga/objects.cache';
my $status_file = '/var/lib/icinga/status.dat';
my $context;
my $colours = 1;
my $short = 0;
my $list_type = 's';
my (@for_hosts, @for_groups);

sub have_host {
	my ($host) = @_;
	if ($list_type eq 's') {
		return exists $data->{services}->{$host};
	}
	else {
		return exists $data->{hosts}->{$host};
	}
}

sub with_colour {
	my ($text, $colour) = @_;
	if ($colours) {
		return colored($text, $colour);
	}
	else {
		return $text;
	}
}

sub read_objects_line {
	my ($line, $ref) = @_;

	if ($line =~ / ^ (?:define \s )? (?<context> \w+) \s+ { /x) {
		$context = $+{context};
	}
	elsif ($line =~ / ^ \t (?<key> [^=\t]+ ) [=\t] (?<value> .*) $ /x) {
		$cache->{$+{key}} = $+{value};
	}
	elsif ($line =~ / ^ \t } $ /x) {
		given($context) {
			when(['info', 'programstatus']) {
				${$ref}->{$context} = $cache;
			}
			when('hoststatus') {
				${$ref}->{hosts}->{$cache->{host_name}} = $cache;
			}
			when('servicestatus') {
				push(@{${$ref}->{services}->{$cache->{host_name}}}, $cache);
			}
			when('contactstatus') {
				push(@{${$ref}->{contacts}}, $cache);
			}
			when('hostgroup') {
				${$ref}->{hostgroups}->{$cache->{hostgroup_name}} = $cache;
			}
			when([qw[timeperiod command contactgroup contact host service]]) {
				# skipped for now
			}
			default {
				die("Unknown field in $status_file: $context\n");
			}
		}
		$cache = undef;
	}
}

sub read_objects {
	my ($file, $ref) = @_;

	open(my $fh, '<', $file);
	while (my $line = <$fh>) {
		chomp($line);
		read_objects_line($line, $ref);
	}
	close($fh);
}

sub enhance_status {
	HOST: for my $h (keys %{$data->{services}}) {
		for my $s (@{$data->{services}->{$h}}) {
			if ($s->{current_state} != 0) {
				$extra->{$h}->{service_problem} = 1;
				next HOST;
			}
		}
	}
}

sub service_state {
	my ($digit) = @_;
	given ($digit) {
		when(0) { return with_colour('   OK   ', 'black on_green' ) }
		when(1) { return with_colour(' WARNING', 'black on_yellow') }
		when(2) { return with_colour('CRITICAL', 'white on_red'   ) }
		when(3) { return with_colour(' UNKNOWN', 'white on_blue'  ) }
		default { die("Unknown service state: $digit\n") }
	}
}

sub host_state {
	my ($digit) = @_;
	given($digit) {
		when(0) { return with_colour('    OK     ', 'black on_green') }
		when(1) { return with_colour('   DOWN    ', 'white on_red'  ) }
		when(2) { return with_colour('UNREACHABLE', 'white on_blue' ) }
		default { die("Unknown host state: $digit\n") }
	}
}

sub display_service {
	my ($s) = @_;
	printf(
		"%-20.20s %s %s\n",
		$s->{service_description},
		service_state($s->{current_state}),
		$s->{plugin_output},
	);
}

sub display_host_services {
	my ($host, $all) = @_;

	if ($all and (not $short or $extra->{$host}->{service_problem})) {
		say "\n$host";
	}

	foreach my $service (@{$data->{services}->{$host}}) {

		if ($short and not $service->{current_state}) {
			next;
		}

		if ($all) {
			print "\t";
		}

		display_service($service);
	}
}

sub display_host_single {
	my ($host) = @_;
	my $h = $data->{hosts}->{$host};

	if ($short and not $h->{current_state}) {
		return;
	}

	printf(
		"%-32.32s %s %s\n",
		$h->{host_name},
		host_state($h->{current_state}),
		$h->{plugin_output},
	);
}

sub display_host {
	my ($host, $all) = @_;

	if ($list_type eq 'h') {
		display_host_single($host);
	}
	else {
		display_host_services($host, $all);
	}
}

GetOptions(
	'c|config=s'      => \$config_file,
	'C|no-colours'    => sub { $colours = 0 },
	'f|status-file=s' => \$status_file,
	'g|hostgroup=s'   => sub { push(@for_groups, split(/,/, $_[1])) },
	'h|host=s'        => sub { push(@for_hosts, split(/,/, $_[1])) },
	'l|list=s'        => sub { $list_type = substr($_[1], 0, 1) },
	's|short'         => \$short,
	'V|version'       => sub { say "icli version $version"; exit 0 },
);

read_objects($status_file, \$data);
read_objects($config_file, \$config);
enhance_status();

foreach my $group (@for_groups) {
	if (not exists $config->{hostgroups}->{$group}) {
		die("Unknown hostgroup: $group\n");
	}
	foreach my $host (split(/,/, $config->{hostgroups}->{$group}->{members})) {
		if (not grep { $_ eq $host } @for_hosts) {
			push(@for_hosts, $host);
		}
	}
}

if (@for_hosts) {
	foreach my $host (@for_hosts) {
		if (have_host($host)) {
			display_host(
				$host,
				( @for_hosts > 1),
			);
		}
		else {
			die("Unknown host: $host\n");
		}
	}
}
elsif ($list_type eq 's') {
	foreach my $host (sort keys %{$data->{services}}) {
		display_host($host, 1);
	}
}
elsif ($list_type eq 'h') {
	foreach my $host (sort keys %{$data->{hosts}}) {
		display_host($host, 1);
	}
}
else {
	die("See perldoc -F $0\n");
}

__END__

=head1 NAME

B<icli> - Icinga Command Line Interface

=head1 SYNOPSIS

B<icli> [B<-h> I<host>]

=head1 DESCRIPTION

B<icli> is a command line interface to Icinga. By default it lists all
services and their states.

=head1 OPTIONS

=over

=item B<-c>|B<--config> I<config>

Read config from I<file> instead of the default
F</var/cache/icinga/objects.cache>

=item B<-C>|B<--no-colours>

Disable colours in output

=item B<-f>|B<--status-file> I<file>

Read the status from I<file> instead of the default
F</var/lib/icinga/status.dat>

=item B<-g>|B<--hostgroup> I<hostgroup>

Show details for all hosts in I<hostgroup>

=item B<-h>|B<--host> I<host>

Only show I<host>'s services

=item B<-l>|B<--list> B<hosts>|B<services>

List either services (the default) or hosts.
Note that only the first character of the argument is checked, so C<< icli
-lh >> and C<< icli -ls >> are also fine.

=item B<-s>|B<--short>

Only show services which are not OK

=item B<-V>|B<--version>

Show version information

=back

The argument to B<-g> and B<-h> may also be comma-separated list of
hosts/hostgroups, e.g. C<< icli -h aneurysm,kraftwerk >>.

=head1 EXIT STATUS

Zero, unless errors occured.

=head1 CONFIGURATION

None.

=head1 DEPENDENCIES

None, so far.

=head1 BUGS AND LIMITATIONS

This software is in early development stages. So there will probably be quite
a lot.

=head1 AUTHOR

Copyright (C) 2010 by Daniel Friesel E<lt>derf@chaosdorf.deE<gt>

=head1 LICENSE

  0. You just DO WHAT THE FUCK YOU WANT TO.