<?php

require_once __DIR__ . "/vendor/autoload.php";

$oDotEnv = new Dotenv\Dotenv(__DIR__);
$oDotEnv->load();

$sDynIP = gethostbyname(getenv("SUBDOMAIN") . "." . getenv("DOMAIN"));
$sExternalIP = file_get_contents("http://ipv4.icanhazip.com");
$sExternalIP = filter_var($sExternalIP, FILTER_SANITIZE_STRING);
$sExternalIP = trim(preg_replace('/\s+/', '', $sExternalIP));

if ($sDynIP != $sExternalIP) {
	echo "IP has changed... changing ip from {$sDynIP} to {$sExternalIP}...\n";
	updateRecord(getenv("DOMAIN"), getenv("SUBDOMAIN"), "A", 60, $sExternalIP, $sDynIP);
}

function updateRecord($sDomain, $sSubDomain, $sType = "A", $iTTL = 20, $sContent, $sOldIp)
{
	try {
		$oCurl = curl_init();
		$aData = [
			"type" => $sType,
			"name" => $sSubDomain,
			"content" => $sContent,
			"ttl" => $iTTL,
		];

		$oPayload = json_encode($aData);

		curl_setopt_array($oCurl, [
			CURLOPT_RETURNTRANSFER => true,
			CURLOPT_URL => getenv("API_BASE_URL") . $sDomain,
			CURLOPT_HTTPHEADER => [
				'X-Auth-Username: ' . getenv("API_USER"),
				'X-Auth-Password: ' . getenv("API_PASS"),
				'Content-Type: application/json'
			],
			CURLOPT_POST => true,
			CURLOPT_POSTFIELDS => $oPayload,
			CURLINFO_HEADER_OUT => true,
		]);

		$oResponse = curl_exec($oCurl);
		$aResponse = json_decode($oResponse);

		curl_close($oCurl);

		if ($aResponse->message == "ok") {
			logToFile("Changed IP from {$sOldIp} to {$sContent}!");
		} else {
			logToFile("Error: " . serialize($aResponse));
		}
	} catch (Exception $e) {
		logToFile("Exception: " . $e->getMessage());
	}
}

function logToFile($sMessage)
{
	$file = fopen("log.txt", "a+");
	fwrite($file, "[" . date("Y-m-d H:i:s") . "] " . $sMessage);
	fclose($file);
}