realfan/src/base.methods.php

<?php

function get_request_json() {
	return @json_decode(file_get_contents('php://input'));
}

function unquote($text) {
	$text = str_replace("'", "", $text);
	$text = str_replace('"', '', $text);
	return $text;
}

# HTTP result => JSON
function hres_json($code, $status, $message) {
	header('Content-Type: application/json');
	return hres(json_encode([
		'status' => $status,
		'message' => $message
	]), $code);
}

# HTTP result
function hres($message, $code=200) {
	http_response_code($code);
	die($message);
}

# Support instance aliases!
function resolve_instance($txt) {
	$txt = preg_replace('/^https?:\/\//', '', strtolower(trim($txt)));
	if (!preg_match('/^[a-zA-Z0-9\-\.]+$/', $txt))
		return false;

	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, 'https://'.$txt.'/.well-known/host-meta');
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_HEADER, 1);
	curl_setopt($ch, CURLOPT_NOBODY, 1);
	$output = curl_exec($ch);
	$headers = explode("\n", $output);
	if (count($headers) === 0)
		return false;

	$name = false;
	$httpret = trim($headers[0]);
	$httpret = explode(' ', $httpret);
	if (count($httpret) !== 2)
		return false;
	$httpret = intval($httpret[1]);

	# search for location header
	if (in_array($httpret, [301, 302])) {
		foreach ($headers as $header) {
			$header = strtolower(trim($header));
			if (str_starts_with($header, 'location:')) {
				$url = trim(preg_replace('/^location:/','',$header));
				$url = parse_url($url);
				if (isset($url['host'])) {
					$name = $url['host'];
					break;
				}
			}
		}
	} else if ($httpret === 200) {
		$name = $txt;
	}
	if ($name === false)
		return $name;
	
	return 'https://'.$name;
}