lib_tlb.php

<?php

function tlb_address_hash_salt() : string
{
		# FIXME: generate a hash or nonce based on TlbConfig?
		# or perhaps on something related to tor?
	return -1;
}

function tlb_address(?string $address = null) : string
{
	if ($address !== null)
		return $address;
	$protocol = $_SERVER['SERVER_PROTOCOL']??null;
	if ($protocol === null)
		throw new Exception('unknown protocol');
	if ($protocol === 'HTTP/1.0')
		$schema = 'http';
	else if ($protocol === 'HTTP/1.1')
		$schema = 'http';
	else if ($protocol === 'HTTP/2.0')
		$schema = 'http';
	else
		throw new Exception('unsupported protocol');

	if ($schema === 'http')
		if (($_SERVER['HTTPS']??null) === 'on')
			$schema = 'https';

	$host = $_SERVER['SERVER_NAME'] ?? null;
	if ($host === null)
		throw new Exception('unknown hostname');

		# in this case we don't mind the port number
	if (preg_match('/[.]onion$/', $host))
		return $schema .'://' .$host;
	$port = $_SERVER['SERVER_PORT']??null;
	if ($port === null)
		throw new Exception('unknown port');


	$a = parse_url($_SERVER['REQUEST_URI']);
	if (empty($a['path']))
		throw new \Exception('empty request uri path');
	$b = explode('/', $a['path']);
	array_pop($b);
	$b[] = '';
	$base = implode('/', $b);

	return $schema .'://' .$host .':' .$port .$base;
}

function tlb_address_id(?string $address = null)
{
	return sha1(tlb_address($address) ."\x00" .tlb_address_hash_salt($address));
}

function tlb_config(string $key, ?string $default = null) : string
{
	$CDB = config_db_pdo();
	$rcd = $CDB->queryFetch('SELECT value FROM config WHERE key = ?', [ $key ]);
	if ($rcd === null)
		$v = $default;
	else
		$v = array_shift($rcd);

	if ($v === null)
		throw new Exception(sprintf('unsupported config: "%s"', $key));
	return $v;
}

function wiki_config_save(string $key, string $value)
{
	$CDB = config_db_pdo();
	$rcd = $CDB->execParams('UPDATE config SET value = ? WHERE key = ?', [ $value, $key ]);
}

function tlb_connection_records() : array /* of arrays */
{
	return
		array_map(function($str) { return explode(' ', $str); },
			array_filter(
				explode("\n", tlb_config('federation.connections')),
				function($str) { return ($str !== '') && ($str[0] !== '#'); } ) );
}

function tlb_connections() : array
{
	return
		array_values(
			array_filter(
				array_map('current',
					tlb_connection_records() ),
				function($v) { return ($v !== null); } ) );
}

function tlb_connection_url(string $key) : string
{
	if ($key === tlb_address())
		return $key;
	return
			array_one(
				array_map(function($rcd) { return isset($rcd[1]) ? $rcd[1] : $rcd[0]; },
					array_filter(
						tlb_connection_records(),
						function($rcd) use($key) { return (($rcd[0]??null) === $key) || (isset($rcd[1]) && ($rcd[1] === $key)); } ) ) );
}

function tlb_download_connection($url) : string
{
	$a = parse_url($url);
	$h = curl_init($url);
	if ($use_tor_proxy = preg_match('/[.]onion$/', $a['host']??null)) {
		curl_setopt($h, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
		curl_setopt($h, CURLOPT_PROXY, 'localhost:9050'); }
	else {
		curl_setopt($h, CURLOPT_PROXYTYPE, null);
		curl_setopt($h, CURLOPT_PROXY, null); }
	curl_setopt($h, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($h, CURLOPT_TIMEOUT, 3);
	$v = curl_exec($h);
#tp(compact('url', 'v', 'use_tor_proxy'));
	return $v;
}

function tlb_site_name() : ?string
{
	$a = parse_url(tlb_address());
	if (empty($a['path']))
		throw new \Exception('empty url path');
	$b = explode('/', $a['path']);
	array_pop($b);
	if ($b) {
		$v = array_pop($b);
		if ($v)
			return str_replace('tlb-', '', $v); }
	return null;
}