#!/usr/bin/perl
#
# Accepts a HTTP PUT request to set the cluster membership of a host.
#

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_active_member
{
	my $parameters = shift;
	my $host_uuid  = $parameters->{host_uuid};

	my $query = "
SELECT
	scan_cluster_node_in_ccm,
	scan_cluster_node_crmd_member,
	scan_cluster_node_cluster_member
FROM
	scan_cluster_nodes
WHERE
	scan_cluster_node_host_uuid = ".$anvil->Database->quote($host_uuid)."
";
	$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
	} });

	if ($count == 1)
	{
		my $row                    = $results->[0];
		my $is_in_ccm         = $row->[0];
		my $is_crmd_member    = $row->[1];
		my $is_cluster_member = $row->[2];
		$anvil->Log->variables({ source => $THIS_FILE, line => __LINE__, level => 2, list => {
			is_in_ccm         => $is_in_ccm,
			is_crmd_member    => $is_crmd_member,
			is_cluster_member => $is_cluster_member
		} });

		return $is_in_ccm && $is_crmd_member && $is_cluster_member;
	}

	return 0;
}

sub alter_host_membership
{
	# Expects the first of positional parameters to be a hash.
	my $parameters      = shift;
	my $host_uuid       = $parameters->{host_uuid};
	my $is_join_cluster = $parameters->{is_join_cluster};

	if ($is_join_cluster)
	{
		join_cluster({ host_uuid => $host_uuid });
	}
	else
	{
		leave_cluster({ host_uuid => $host_uuid });
	}
}

# Re-adds a host to its anvil cluster.
#
# Note: not to be confused wtih adding a new host the an anvil.
sub join_cluster
{
	my $parameters = shift;
	my $host_uuid  = $parameters->{host_uuid};

	# Determine whether host is already a cluster member.
	my $is_active_member = get_active_member({ host_uuid => $host_uuid });
	# Find out whether the host is online before trying to make it join the cluster.
	my $is_online = $anvil->data->{hosts}{host_uuid}{$host_uuid}{host_status} eq "online" ? 1 : 0;

	$anvil->Log->variables({ source => $THIS_FILE, line => __LINE__, level => 2, list => {
		is_active_member => $is_active_member,
		is_online        => $is_online
	} });

	if (not $is_active_member && $is_online)
	{
		$anvil->Database->insert_or_update_jobs({
			job_command     => $anvil->data->{path}{exe}{'anvil-safe-start'},
			job_host_uuid   => $host_uuid,
			job_description => "job_0337",
			job_name        => "cgi-bin::set_membership::join",
			job_progress    => 0,
			job_title       => "job_0336"
		});
	}
}

# Removes a host from its anvil cluster.
#
# Note: does not permanently remove the host; can be re-added.
sub leave_cluster
{
	my $parameters = shift;
	my $host_uuid  = $parameters->{host_uuid};

	# Determine whether host is already a cluster member.
	my $is_active_member = get_active_member({ host_uuid => $host_uuid });

	$anvil->Log->variables({ source => $THIS_FILE, line => __LINE__, level => 2, list => {
		is_active_member => $is_active_member
	} });

	if ($is_active_member)
	{
		$anvil->Database->insert_or_update_jobs({
			job_command     => $anvil->data->{path}{exe}{'anvil-safe-stop'},
			job_host_uuid   => $host_uuid,
			job_description => "job_0339",
			job_name        => "cgi-bin::set_membership::leave",
			job_progress    => 0,
			job_title       => "job_0338"
		});
	}
}

$anvil->Get->switches;

$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 $response_body = {};

my $request_body;

my $is_decode_json_success = eval {
	$request_body = decode_json($anvil->data->{cgi}{PUTDATA}{value});
};

if (not $is_decode_json_success)
{
	$anvil->Log->entry({
		source    => $THIS_FILE,
		line      => __LINE__,
		level     => 0,
		'print'   => 1,
		priority  => "err",
		key       => "error_0304",
		variables => { request_body_string => $anvil->data->{cgi}{PUTDATA}{value}, json_decode_error => $_ }
	});
}

my $host_uuid                = exists $request_body->{host_uuid} ? $request_body->{host_uuid} : $anvil->data->{switches}{'host-uuid'};
# Defaults to join; will check whether host is already part of its anvil cluster.
my $is_member                = exists $request_body->{is_member} ? $request_body->{is_member} : $anvil->data->{switches}{'is-member'};
my $host_uuid_variable_name  = "host UUID";

if ($host_uuid)
{
	if (exists $anvil->data->{hosts}{host_uuid}{$host_uuid})
	{
		alter_host_membership({ host_uuid => $host_uuid, is_join_cluster => $is_member });
	}
	else
	{
		handle_invalid_uuid({ name => $host_uuid_variable_name, uuid => $host_uuid });
	}
}

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