<?php

class Configuration {
    private $items = array();
    
    public function add($id) {
        $result = new DomainConfiguration();
        $result->id = $id;
        array_push($this->items, $result);
        return $result;
    }
    
    public function getDomainConfig($domain) {
        foreach ($this->items as $domainConfig) {
            if (in_array($domain, $domainConfig->domains)) {
                return $domainConfig;
            }
        }
   	$excstr = 'No configuration found for requested domain. ';
	$excstr .= implode($domain);  
        throw new Exception($excstr);
    }
}

class DomainConfiguration {
    public $domains;
    public $servers = array();
    public $username;
    
    public function addServer($type, $hostname) {
        $server = $this->createServer($type, $hostname);
        $server->username = $this->username;
        array_push($this->servers, $server);
        return $server;
    }
    
    private function createServer($type, $hostname) {
        switch ($type) {
            case 'imap':
                return new Server($type, $hostname, 143, 993);
            case 'pop3':
                return new Server($type, $hostname, 110, 995);
            case 'smtp':
                return new Server($type, $hostname, 25, 465);
            default:
                throw new Exception("Unrecognized server type \"$type\"");
        }
    }
}

class Server {
    public $type;
    public $hostname;
    public $username;
    public $endpoints;
    public $samePassword;
    
    public function __construct($type, $hostname, $defaultPort, $defaultSslPort) {
        $this->type = $type;
        $this->hostname = $hostname;
        $this->defaultPort = $defaultPort;
        $this->defaultSslPort = $defaultSslPort;
        $this->endpoints = array();
        $this->samePassword = true;
    }
    
    public function withUsername($username) {
        $this->username = $username;
        return $this;
    }
    
    public function withDifferentPassword() {
        $this->samePassword = false;
        return $this;
    }
    
    public function withEndpoint($socketType, $port = null, $authentication = 'password-cleartext') {
        if ($port === null) {
            $port = $socketType === 'SSL' ? $this->defaultSslPort : $this->defaultPort;
        }
        
        array_push($this->endpoints, (object)array(
            'socketType' => $socketType,
            'port' => $port,
            'authentication' => $authentication));
            
        return $this;
    }
    
    
}

interface UsernameResolver {
    public function findUsername($request);
}

class AliasesFileUsernameResolver implements UsernameResolver {
    private $fileName;
    
    function __construct($fileName = "/etc/mail/aliases") {
        $this->fileName = $fileName;
    }
    
    public function findUsername($request) {
        static $cachedEmail = null;
        static $cachedUsername = null;
        
        if ($request->email === $cachedEmail) {
            return $cachedUsername;
        }
        
        $fp = fopen($this->fileName, 'rb');
        
        if ($fp === false) {
            throw new Exception("Unable to open aliases file \"$fileName\"");
        }
        
        $username =  $this->findLocalPart($fp, $request->localpart);
        if (strpos($username, "@") !== false || strpos($username, ",") !== false) {
            $username = null;
        }
         
        $cachedEmail = $request->email;
        $cachedUsername = $username;
        return $username;        
    }
    
    protected function findLocalPart($fp, $localPart) {
        while (($line = fgets($fp)) !== false) {
            $matches = array();
            if (!preg_match("/^\s*" . preg_quote($localPart) . "\s*:\s*(\S+)\s*$/", $line, $matches)) continue;
            return $matches[1];
        }        
    }
}

abstract class RequestHandler {
    public function handleRequest() {
        $request = $this->parseRequest();
        $this->expandRequest($request);
	//file_put_contents('request.log', $request, FILE_APPEND);
        $config = $this->getDomainConfig($request);
        $this->writeResponse($config, $request);
    }
    
    protected abstract function parseRequest();
    protected abstract function writeResponse($config, $request);
    
    protected function expandRequest(&$request) {
	$localpart = null;
	$domain = null;

	$headerarr = getallheaders();	
	if (is_object($request) && is_object($request->email)) {
		list($localpart, $domain) = explode('@', $request->email);
	} 
	
	if (array_key_exists('email', $_GET)) {
		list($localpart, $domain) = explode('@', $_GET['email']);
	}
	else
	if (array_key_exists('Email', $_GET)) {
		list($localpart, $domain) = explode('@', $_GET['Email']);
	} 
	else
	if (array_key_exists('emailaddress', $_GET)) {
		list($localpart, $domain) = explode('@', $_GET['emailaddress']);
	}
	else	
	if (array_key_exists('HTTP_X_ANCHORMAILBOX', $_SERVER))
	{
		list($localpart, $domain) = explode('@', $_SERVER['HTTP_X_ANCHORMAILBOX']);
	}
	else 	
	if (array_key_exists('X-AnchorMailbox', $headerarr))
	{
		list($localpart, $domain) = explode('@', $headerarr['X-AnchorMailbox']);
	}
	else 
	if (array_key_exists('X-User-Identity', $headerarr))
	{
		list($localpart, $domain) = explode('@', $headerarr['X-User-Identity']);
	}
		
	if ((empty($localpart) || empty($domain) || is_null($localpart) || is_null($domain)) && 0)
	{
		//$excstr = "No email header found. ";
		//$excstr .= get_data($headerarr);
		$arrstr = "No email header found, here are header, headerarr ";
		$arrstr .= implode(",", array_map( function($v, $k) { return $k. ':' .$v; }, $headerarr, array_keys($headerarr) ));
		$arrstr .= " Meira .... GET ";
		$arrstr .= implode(",", array_map( function($v, $k) { return $k. ':' .$v; }, $_GET, array_keys($_GET) ));
		$arrstr .= "Meira .... POST ";
		$arrstr .= implode(",", array_map( function($v, $k) { return $k. ':' .$v; }, $_POST, array_keys($_POST) ));
		$arrstr .= "Meira .... SERVER ";
		$arrstr .= implode(",", array_map( function($v, $k) { return $k. ':' .$v; }, $_SERVER, array_keys($_SERVER) ));

		Throw new Exception($arrstr);
	}				
	
        
        if (!isset($request->localpart)) {
	    if (empty($localpart)) {
		    $request->localpart = "name";
	    } else {
	            $request->localpart = $localpart;
	    }
        }

        if (!isset($request->domain)) {
	    if(empty($domain)) {
		$request->domain = str_replace("autodiscover.", "", $_SERVER['HTTP_HOST']);
	    } else {
	        $request->domain = strtolower($domain);
	    }
        }
	
	//if (!isset($request->email)) {
	    $request->email = "$request->localpart@$request->domain";
	//}
    }
    
    protected function getDomainConfig($request) {
        static $cachedEmail = null;
        static $cachedConfig = null;
        
        if ($cachedEmail === $request->email) {
            return $cachedConfig;
        }

        $cachedConfig = $this->readConfig($request);
        $cachedEmail = $request->email;
        
        return $cachedConfig->getDomainConfig($request->domain);
    }
    
    protected function readConfig($vars) {
        foreach ($vars as $var => $value) {
            $$var = $value;
        }
        
        $config = new Configuration();
        include './autoconfig.settings.php';
        return $config;
    }
    
    protected function getUsername($server, $request) {
        if (is_string($server->username)) {
            return $server->username;
        }
        
        if ($server->username instanceof UsernameResolver) {
            $resolver = $server->username;
            return $resolver->findUsername($request);
        }
    }
}

class MozillaHandler extends RequestHandler {
    public function writeResponse($config, $request) {
        header("Content-Type: text/xml");
        $writer = new XMLWriter();
        $writer->openURI("php://output");
    
        $this->writeXml($writer, $config, $request);
        $writer->flush();
    }
    
    protected function parseRequest() {
	return (object)array('email' => "");
        //return (object)array('email' => $_GET['emailaddress']);
    }
    
    protected function writeXml($writer, $config, $request) {
        $writer->startDocument("1.0");
        $writer->setIndent(4);
        $writer->startElement("clientConfig");
        $writer->writeAttribute("version", "1.1");
        
        $this->writeEmailProvider($writer, $config, $request);
        
        $writer->endElement();
        $writer->endDocument();
    }   
    
    protected function writeEmailProvider($writer, $config, $request) {
        $writer->startElement("emailProvider");
        $writer->writeAttribute("id", $config->id);
        
        foreach ($config->domains as $domain) {
            $writer->writeElement("domain", $domain);
        }
        
        $writer->writeElement("displayName", $config->name);
        $writer->writeElement("displayShortName", $config->nameShort);
        
        foreach ($config->servers as $server) {
            foreach ($server->endpoints as $endpoint) {
                $this->writeServer($writer, $server, $endpoint, $request);
            }
        }
        
        $writer->endElement();
    }
    
    protected function writeServer($writer, $server, $endpoint, $request) {
        switch ($server->type) {
            case 'imap':
            case 'pop3':
                $this->writeIncomingServer($writer, $server, $endpoint, $request);
                break;
            case 'smtp':
                $this->writeSmtpServer($writer, $server, $endpoint, $request);
                break;
        }
    }
    
    protected function writeIncomingServer($writer, $server, $endpoint, $request) {
        $authentication = $this->mapAuthenticationType($endpoint->authentication);
        if (empty($authentication)) return;
        
        $writer->startElement("incomingServer");
        $writer->writeAttribute("type", $server->type);
        $writer->writeElement("hostname", $server->hostname);
        $writer->writeElement("port", $endpoint->port);
        $writer->writeElement("socketType", $endpoint->socketType);
        $writer->writeElement("username", $this->getUsername($server, $request));
        $writer->writeElement("authentication", $authentication);
        $writer->endElement();
    }
    
    protected function writeSmtpServer($writer, $server, $endpoint, $request) {
        $authentication = $this->mapAuthenticationType($endpoint->authentication);
        if ($authentication === null) return;
                
        $writer->startElement("outgoingServer");
        $writer->writeAttribute("type", "smtp");
        $writer->writeElement("hostname", $server->hostname);
        $writer->writeElement("port", $endpoint->port);
        $writer->writeElement("socketType", $endpoint->socketType);
        
        if ($authentication !== false) {
            $writer->writeElement("username", $this->getUsername($server, $request));
            $writer->writeElement("authentication", $authentication);
        }
        
        $writer->writeElement("addThisServer", "true");
        $writer->writeElement("useGlobalPreferredServer", "true");
        $writer->endElement();
    }
    
    protected function mapAuthenticationType($authentication) {
        switch ($authentication) {
            case 'password-cleartext':
                return 'password-cleartext';
            case 'CRAM-MD5':
                return 'password-encrypted';
            case 'none':
                return false;
            default:
                return null;
        }        
    }
}

class OutlookHandler extends RequestHandler {
    public function writeResponse($config, $request) {
        header("Content-Type: application/xml");
    
        $writer = new XMLWriter();
        $writer->openMemory();
                
        $this->writeXml($writer, $config, $request);
        
        $response = $writer->outputMemory(true);
        echo $response;
    }
    
    protected function parseRequest() {
	/*
        $postdata = file_get_contents("php://input");
        
        if (strlen($postdata) > 0) {
            $xml = simplexml_load_string($postdata);
            return (object)array('email' => $xml->Request->EMailAddress);
        }*/
        
        return (object)array('email' => "");
    }
    
    public function writeXml($writer, $config, $request) {
        $writer->startDocument("1.0", "utf-8");
        $writer->setIndent(4);
        $writer->startElement("Autodiscover");
        $writer->writeAttribute("xmlns", "http://schemas.microsoft.com/exchange/autodiscover/responseschema/2006");
        $writer->startElement("Response");
        $writer->writeAttribute("xmlns", "http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a");
        $writer->startElement("User");
	$writer->writeElement("DisplayName", $request->email);
	$writer->writeElement("AutoDiscoverSMTPAddress", $request->email);
	$writer->endElement(); 
        $writer->startElement("Account");
        $writer->writeElement("AccountType", "email");
        $writer->writeElement("Action", "settings");
        
        foreach ($config->servers as $server) {
            foreach ($server->endpoints as $endpoint) {
                if ($this->writeProtocol($writer, $server, $endpoint, $request))
                    break;
            }
        }        
        
        $writer->endElement();
        
        $writer->endElement();
        $writer->endElement();
        $writer->endDocument();
    }
    
    protected function writeProtocol($writer, $server, $endpoint, $request) {
        switch ($endpoint->authentication) {
            case 'password-cleartext':
            case 'SPA':
                break;
            case 'none':
                if ($server->type !== 'smtp') return false;
                break;
            default:
                return false;
        }
        
        $writer->startElement('Protocol');
        $writer->writeElement('Type', strtoupper($server->type));
        $writer->writeElement('Server', $server->hostname);
        $writer->writeElement('Port', $endpoint->port);
        $writer->writeElement('LoginName', $this->getUsername($server, $request));
        $writer->writeElement('DomainRequired', 'off');
        $writer->writeElement('SPA', $endpoint->authentication === 'SPA' ? 'on' : 'off');
        
        switch ($endpoint->socketType) {
            case 'plain':
                $writer->writeElement("SSL", "off");
                break;
            case 'SSL':
                $writer->writeElement("SSL", "on");
                $writer->writeElement("Encryption", "SSL");
                break;
            case 'STARTTLS':
                $writer->writeElement("SSL", "on");
                $writer->writeElement("Encryption", "TLS");
                break;
        }
        
        $writer->writeElement("AuthRequired", $endpoint->authentication !== 'none' ? 'on' : 'off');
        
        if ($server->type == 'smtp') {
            $writer->writeElement('UsePOPAuth', $server->samePassword ? 'on' : 'off');
            $writer->writeElement('SMTPLast', 'off');
        }
        
        $writer->endElement();
        
        return true;
    }
    
    protected function mapAuthenticationType($authentication) {
        switch ($authentication) {
            case 'password-cleartext':
                return 'password-cleartext';
            case 'CRAM-MD5':
                return 'password-encrypted';
            case 'none':
                return false;
            default:
                return null;
        }        
    }    
    
}

if (strpos($_SERVER['SERVER_NAME'], "autoconfig.") === 0) {
    // Configuration for Mozilla Thunderbird, Evolution, KMail, Kontact
    $handler = new MozillaHandler();
} else if (strpos($_SERVER['SERVER_NAME'], "autodiscover.") === 0) {
    // Configuration for Outlook
    $handler = new OutlookHandler();
} else 
{
    $handler = new OutlookHandler();
}

//file_put_contents('request.log', $_SERVER, FILE_APPEND);
$handler->handleRequest();