#!/usr/bin/perl

use Pg;
use IO::Select;
use Socket qw(inet_aton);

my $dbname = "xxxx";
my $dbhost = "::1";
my $dbuser = "xxxx";
my $dbpass = "xxxx";
my $max_ttl = 1800;
my $ping_ttl = 60;
my %notify = ("acl_user_insert" => "process_user_insert", "acl_user_update" => "check_user_update", "acl_user_delete" => "process_user_delete");
my $log = "/var/log/acl_change.log";

my $till = time() + $max_ttl - 3;
my $last_ping = time();

#daemonize();

my $conn;

for(;;)
{
	if (time() > $till) { exit; }
	$conn = Pg::setdbLogin($dbhost, 5432, $pgoptions, "", $dbname, $dbuser, $dbpass);

	if (($conn->status != PGRES_CONNECTION_OK))
	{
		_log("Err: $conn->errorMessage");
		undef $conn;
		next;
	}

	foreach $event (keys(%notify))
	{
		my $res = $conn->exec("LISTEN $event");
		if ($res->resultStatus != PGRES_COMMAND_OK)
		{
			_log("LISTEN error: " . $conn->errorMessage . "");
			next;
		}
	}

	my $s = IO::Select->new();
	$s->add($conn->socket);
	for(;;)
	{
		if (time() > $till)
		{
		
			exit;
		}
		my @x = $s->can_read(2);
		if (@x > 0)
		{
			_log("a-ha! socket event");
			$conn->consumeInput;
			while (my ($table, $pid) = $conn->notifies)
			{
				if (exists($notify{$table}))
				{
					_log("Got notify for $table!");
					$notify{$table}();
					sleep 1; # Filtering too many updates/sec
				}
			}
		}
		else
		{
			# _log("empty loop..");
			# some kind of ping
			if (time() > $last_ping + $ping_ttl)
			{
				$last_ping = time();
				my $res = $conn->exec("SELECT 42");
				if ($res->resultStatus != PGRES_TUPLES_OK) {
					_log("DB connection failed (ping check)");
					last;
				}
			}
		}

		if ($conn->status != PGRES_CONNECTION_OK) {
			_log("DB connection failed");
			last;
		}
	}

	undef $s;
}


sub process_user_insert {
	print "process_user_insert\n";
}

sub process_user_update {
	my $user_id = $_[0];
	my $sql = "UPDATE phpbb_users SET ldap_task_status = 2 WHERE user_id = " . $user_id;
	$conn->exec($sql);
}

sub check_user_update {
	my $sql = "SELECT user_id FROM phpbb_users WHERE ldap_task_status = 0";
	my $res = $conn->exec($sql);
	if ($res->resultStatus != PGRES_TUPLES_OK) {
		_log("SELECT error: $conn->errorMessage");
		return -1;
	}
	my @rows;
	while (my @row = $res->fetchrow()) { push @rows, $row[0]; }
	foreach $user_id (@rows)
	{
		print "Processing user " . $user_id . "\n";
		process_user_update($user_id);
	}

	print "process_user_update\n";
}

sub process_user_delete {
	print "process_user_delete\n";
}

sub _log {
	print localtime() . " " . join(" ", @_) . "\n";
}