<?php
// created by blackdotsh @ github
// MIT Licnese

///////////global vars

//the key passed as a get variable from uptimerobot to this script
$key="ChangeME";

/*$CF_domains expects an associated array with domain as key

backup IP,
1 to proxy through cloudflare 0 otherwise
as value

for example:
$CF_domains = array( "google.com" => "8.8.8.8,1" );

sets the domain google.com's backup IP address to 8.8.8.8 and enabling cloudflare proxy (orange cloud),
		github.com's backip IP address to 127.0.0.1  and disabling cloudflare proxy (no orange cloud)
*/
$CF_domains = array( "google.com" => "8.8.8.8,1",
		"github.com" => "127.0.0.1,0");

//API key to your cloudflare account
$CF_key = "";

//Cloudflare email address
$CF_email= "";

//end of global vars
//////////////////////////////////////////////////////////
//global functions

//checks if the domain exists in $CF_domains and the backup IP it's up via HTTP
function checkDomain ($domains, $domain){
	foreach ( $domains as $key => $value ){
		if (strcmp($key, $domain) == 0 ){
			$vars=explode(",",$domains["$domain"]);
			$ip=$vars[0];
			if (checkHost($ip)) {
				return true;
			} else {
				echo "backup server unreachable via HTTP\n";
				return false;
			}
		}
	}
	return false;
}


//checks if host returns "HTTP/1.1 200 OK" within a reasonable time frame
function checkHost ($host) {
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, $host);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	//curl_setopt($ch, CURLOPT_VERBOSE, 1);
	curl_setopt($ch, CURLOPT_HEADER, 1);
	curl_setopt($ch,CURLOPT_TIMEOUT,5);
	$result=curl_exec($ch);

	$headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
	$header = substr($result, 0, $headerSize);
	if (strpos($header, "HTTP/1.1 200 OK") !== false){
		return TRUE;
	} else {
		return FALSE;
	}

}


//interacts with CF API to switch to the backup IP
function cfBkup ($domains, $domain, $subdomain, $cfkey, $cfemail){
	$vars=explode(",",$domains["$subdomain"]);
	$headers = [ 
		"X-Auth-Email: $cfemail",
		"X-Auth-Key: $cfkey",
		"Content-Type: application/json"
	];
	//get ZONE ID
	$ch= curl_init("https://api.cloudflare.com/client/v4/zones?name=$domain");
	curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
	curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
	$results= json_decode(curl_exec($ch), TRUE);
	curl_close($ch);
	//var_dump($results);
	$zoneID=$results['result'][0]['id'];
	
	//get DNS Record ID
	if ($zoneID != "" ) {
		$ch= curl_init("https://api.cloudflare.com/client/v4/zones/$zoneID/dns_records?name=$subdomain");
		curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
		$results= json_decode(curl_exec($ch), TRUE);
		curl_close($ch);
		//var_dump($results);
		$DNSID = $results['result'][0]['id'];
		if ($DNSID != "") {
			$updateVars=explode("," , $domains["$subdomain"]);
			if (strcmp($updateVars[1], "1") == 0 ) {	
				$updateVars[1] = true;
			}
			else {
				$updateVars[1] = false;
			}
			$PUTVars=array("id" => "$DNSID", "type" => "A", "name" => "$subdomain", "content" => "$updateVars[0]", "proxied" => $updateVars[1]);
			$ch= curl_init("https://api.cloudflare.com/client/v4/zones/$zoneID/dns_records/$DNSID");
			curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
			curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
			curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($PUTVars));
			$results= json_decode(curl_exec($ch), TRUE);
			curl_close($ch);
			//var_dump($results);
			if ($results['success'] != TRUE ) {
				echo "An error occured updating DNS reocrd for $subdomain";
			}
		} else {
			echo "Failed to get DNSID for $subdomain";
		}
	} else {
		echo "Failed to get zoneID for $domain";
	}
}
//end of global functions
////////////////////////////////////////////////////////
if (strcmp(urldecode($_GET['key']), $key) != 0){
	//header('Location:  http://speedtest.tele2.net/1000GB.zip');
	echo "invalid key\n";
	die;
}

echo "This is a monitoring script"; //helps to ensure the web hook is correct, feel free to remove it

if (!empty($_GET['monitorURL']) && !empty($_GET['alertType'])){
	// strip http(s)://	
	$url = urldecode($_GET['monitorURL']);
	$checkDomain = implode('/', array_slice(explode('/', preg_replace('/https?:\/\/|www./', '', $url)), 0, 1));

	//check to see if $checkURL is in the $CF_domain list and make sure it's a down alert
	if ( checkDomain($CF_domains, $checkDomain) && strcmp($_GET['alertType'], "1") == 0){
		//do more stuff here for subdomains
		$FQDN=explode(".",$checkDomain);
		$FQDN=$FQDN[sizeof($FQDN)-2].".".$FQDN[sizeof($FQDN)-1];
		
		//if your FQDN is seperated by 2 periods (ex: something.co.uk), uncomment the line below
		// $FQDN=$FQDN[sizeof($FQDN)-3].".".$FQDN[sizeof($FQDN)-2].".".$FQDN[sizeof($FQDN)-1];
		
		echo $FQDN;
		cfBkup ($CF_domains, $FQDN, $checkDomain, $CF_key, $CF_email);
	} else { echo "invalid url or alert type";};
}else {echo "missing get variables";}