#!/usr/bin/perl
#
# Prints JSON formatted data reporting the status of shared storage (a.k.a. storage groups/shared VGs)
#

use strict;
use warnings;
use Anvil::Tools;
use Data::Dumper;
use JSON;

$| = 1;

my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
if (($running_directory =~ /^\./) && ($ENV{PWD}))
{
	$running_directory =~ s/^\./$ENV{PWD}/;
}

my $anvil = Anvil::Tools->new();

sub handle_invalid_uuid
{
	my $parameters = shift;
	my $name       = $parameters->{name};
	my $uuid       = $parameters->{uuid};

	$anvil->Log->entry({
		source    => $THIS_FILE,
		line      => __LINE__,
		level     => 0,
		'print'   => 1,
		priority  => "err",
		key       => "error_0160",
		variables => { name => $name, uuid => $uuid }
	});
	$anvil->nice_exit({ exit_code => 1 });
}

sub get_storage_groups
{
	my $parameters = shift;
	my $anvil_uuid = $parameters->{anvil_uuid};

	my $storage_groups = [];

	# Use DISTINCT ON (...) to limit the occurence of a storage group to 1 and
	# ORDER BY [free] ASC to only select the storage with lowest free space.
	my $query = "
SELECT
	DISTINCT ON (sgr.storage_group_name) storage_group_name,
	slv.scan_lvm_vg_size,
	slv.scan_lvm_vg_free
FROM
	anvils anv,
	storage_groups sgr,
	storage_group_members sgm,
	scan_lvm_vgs slv
WHERE
	anv.anvil_uuid = sgr.storage_group_anvil_uuid
	AND
	sgr.storage_group_uuid = sgm.storage_group_member_storage_group_uuid
	AND
	sgm.storage_group_member_vg_uuid = slv.scan_lvm_vg_internal_uuid
	AND
	anv.anvil_uuid = ".$anvil->Database->quote($anvil_uuid)."
ORDER BY
	sgr.storage_group_name ASC,
	slv.scan_lvm_vg_free ASC
;";

	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => {
		results => $results,
		count   => $count
	}});
	foreach my $row (@{$results})
	{
		my $storage_group_name = $row->[0];
		my $scan_lvm_vg_size   = $row->[1];
		my $scan_lvm_vg_free   = $row->[2];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => {
			storage_group_name => $storage_group_name,
			scan_lvm_vg_size   => $scan_lvm_vg_size,
			scan_lvm_vg_free   => $scan_lvm_vg_free
		}});

		push(@{$storage_groups}, {
			name => $storage_group_name, total => $scan_lvm_vg_size, free => $scan_lvm_vg_free
		});
	}

	return $storage_groups;
}

$anvil->Get->switches;

# Temporary; for debugging
$anvil->Log->level({ set => 2 });

$anvil->Database->connect;
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, secure => 0, key => "log_0132"});
if (not $anvil->data->{sys}{database}{connections})
{
	# No databases, exit.
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, 'print' => 1, priority => "err", key => "error_0003"});
	$anvil->nice_exit({exit_code => 1});
}

# Read in any CGI variables, if needed.
$anvil->Get->cgi();

$anvil->Database->get_hosts();
$anvil->Database->get_anvils();

print $anvil->Template->get({file => "shared.html", name => "json_headers", show_name => 0})."\n";

my $anvil_uuid               = exists $anvil->data->{cgi}{anvil_uuid}{value} ? $anvil->data->{cgi}{anvil_uuid}{value} : $anvil->data->{switches}{'anvil-uuid'};
my $anvil_uuid_variable_name = "anvil UUID";

my $response_body = {};

if ($anvil_uuid)
{
	if (exists $anvil->data->{anvils}{anvil_uuid}{$anvil_uuid})
	{
		$anvil->Log->variables({
			source => $THIS_FILE,
			line   => __LINE__,
			level  => 2,
			list   => {
				message    => "Valid ".$anvil_uuid_variable_name." received.",
				anvil_uuid => $anvil_uuid
			}
		});

		$response_body->{storage_groups} = get_storage_groups({ anvil_uuid => $anvil_uuid });
	}
	else
	{
		handle_invalid_uuid({ name => $anvil_uuid_variable_name, uuid => $anvil_uuid });
	}
}
else
{
	handle_invalid_uuid({ name => $anvil_uuid_variable_name, uuid => $anvil_uuid });
}

print JSON->new->utf8->encode($response_body)."\n";