<?php
// imap2rss.php .
// A simple PHP script to convert the data in an IMAP mailbox available
// over the internet to an RSS file readable by news aggregators. Parts borrowed
// from the snippets available at:
// http://www.icemelon.com/tutorials.php?id=3&/PHP/Generate%20RSS%20Feeds/
//
// Released under the terms of the GNU Public License
// (http://www.gnu.org/licenses/gpl.txt)
//
// Project page: http://www.noaxs.net/imap2rss/
// @author Dave Currie (dave@noaxs.net) - http://www.noaxs.net
// @date 20/02/2005
//-------------------------------------------------------------------

// GLOBAL CONFIGURATION
// Version of imap2rss.php
$vers = "1.0beta3";
// Permalink for this feed - just points to the current page.
$feedLink = "http://".$_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
// Configuration file directory - used if you want to place your configuration file somewhere outside your web server path.  Make sure the user
// running the web server has read permission to this file
$configurationDirectory = "/etc";

// Part types taken from php.net documentation
$parttypes = array ("text", "multipart", "message", "application", "audio", "image", "video", "other");

// Check if an external configuration has been chosen and load it if possible
if(isset($_GET['conf'])) {
	// First, strip out dangerous characters
	$slashpos = strrpos($_GET['conf'], '/');
	if($slashpos === false)
		$slashpos = strrpos($_GET['conf'], '\\');
	if($slashpos !== false)
		$conf = substr($_GET['conf'], $slashpos+1);
	else
		// Open the file inside the configuration directory
		$conf = $configurationDirectory."/".$_GET['conf'].".conf.php";
	// If the file exists, load the parameters.
	if(file_exists($conf)) {
		require($conf);
		$feedLink .= "?conf=".$_GET['conf'];
	} else {
		// Configuration file does not exist - error and exit
		die("Selected configuration not available");
	}
}

// Load variables only if an external configuration was not selected.
if(!isset($srvStr)) {
	// Server string for IMAP connection.
	// See http://www.php.net/manual/en/function.imap-open.php
	// for more details on what this string should look like.
	// Hint: Changing "localhost" for your hostname should do it.
	$srvStr = "{localhost:143/notls}INBOX";
	// IMAP account username
	$accountUser = "username";
	// IMAP account password
	$accountPass = "password";
	// Maximum number of messages to include in the feed
	// (from newest, 0 for no limit)
	$maxMsgNum = 0;
	// Title for this feed
	$feedTitle = "imap2rss.php Feed";
	// Feed description
	$feedDesc = "Sample description";
	// Feed language 
	$feedLang = "en-gb";
	// Feed editor's name
	$feedEditor = "Feed Editor";
	// Feed editor's email
	$feedEditorMail = "editor@example.com";
	// General Options
	// Munge sender emails - 1 for yes, 0 for no
	$mungeSenderEmail = 0;
	// Make http addresses links in plain-text emails
	$makeHttpLinks = 1;
	// Make email addresses mailto: links in plain-text emails
	$makeMailtoLinks = 1;
}

//-------------------------------------------------------------------
// reEncodeString()
// Goes through a string an reencodes all the html entities that it
// finds into a format that won't make XML parsers choke.
function reEncodeString($string) {
	$temp = $string;
	$ents = get_html_translation_table(HTML_ENTITIES);
	$special = get_html_translation_table();
	$table = array_diff($ents, $special);
	foreach($table as $item) {
        	$temp = str_replace($item, "&amp;".substr($item, 1), $temp);
	}
	return $temp;
}

//-------------------------------------------------------------------
// mungeEmailAddress()
// Munges an email address to prevent being harvested by spambots.
// This is really simple, you can replace this with whatever technique you prefer.
// Remember that for the feed to validate as RSS, this needs to be a valid address,
// @ sign and all, so the munging is limited.
// dave@noaxs.net becomes dave.NOSP@MMER.noaxs.net - it's unusual enough to get past
// most bots, I think, at least for the time being.
function mungeEmailAddress($address) {
	return str_replace("@", ".NOSP@MMER.", $address);
}

//-------------------------------------------------------------------
// renderPlainText()
// Processes plain text so that it looks decent when rendered as HTML.
// All it does is substitute newline characters for <br> tags.
// It also substitutes URLs for links and email addresses for mailto:
// links.
function renderPlainText($text) {
	global $makeHttpLinks, $makeMailtoLinks;
	// Throw in <br> tags
	$retval = str_replace("\n", "<br/>\n", $text);
	if($makeHttpLinks) {
		// Replace urls with links
		$retval = preg_replace('/\s(\w+:\/\/)(\S+)/',
					' <a href="\\1\\2" target="_blank">\\1\\2</a>', $retval);
	}
	if($makeMailtoLinks) {
		// Replace email addresses with mailto: links
		$retval = preg_replace('/\s(\w+@)(\S+)/',
					' <a href="mailto:\\1\\2">\\1\\2</a>', $retval);
	}
	return $retval;
}

//-------------------------------------------------------------------
// returnAttachment()
// This function returns a given attachment from an item.
function returnAttachment($itemId, $attachId) {
	global $vers, $parttypes, $srvStr, $accountUser, $accountPass;
	$inbox = imap_open($srvStr, $accountUser, $accountPass);
	$msgStructure = imap_fetchstructure($inbox, $itemId);
	$part = $msgStructure->parts[$attachId-1];
	$ctype = $parttypes[$part->type]."/".$part->subtype;
	$filename = "filename";
	foreach($part->parameters as $param) {
		if($param->attribute=="NAME")
			$filename = $param->value;
	}
	header("content-type: ".$ctype);
	header("content-disposition: attachment; filename=".$filename);
	// Returned data depends on whether the attachment is binary or text
	if($part->type>0) {
		// Binary attachment - convert from base64 to binary
		echo base64_decode(imap_fetchbody($inbox, $itemId, $attachId));
	} else {
		// Text attachment - just display it as-is
		echo imap_fetchbody($inbox, $itemId, $attachId);
	}
	imap_close($inbox);
	return;
}

//-------------------------------------------------------------------
// showArticle()
// This function displays a post in an html page. This
// functionality exists to complement permalink/guid behaviour
// in RSS and also to enable compatibility with readers like
// Thunderbird, that always load the permalink instead of
// displaying the summary.
function showArticle($articleId) {
	global $vers, $srvStr, $accountUser, $accountPass, $mungeSenderEmail;
	$inbox = imap_open($srvStr, $accountUser, $accountPass);
	header('Content-type: text/html');
	// Retrieve post information from the message header
	$headers = imap_headerinfo($inbox, $articleId);
	$subject = htmlentities($headers->subject);
	$author = htmlentities($headers->fromaddress);
	// If author email munging is enabled...
        if($mungeSenderEmail) {
                $author = mungeEmailAddress($author);
        }
	// Format the date according to the standard
	$entryDate = date("D, d M Y H:i:s O", $headers->udate);
	// Get the message body.
	// Negotiate the presence of attachments.
	$msgStructure = imap_fetchstructure($inbox, $articleId);
	if(count($msgStructure->parts)>1) {
		$body = imap_fetchbody($inbox, $articleId, "1");
		if($msgStructure->parts[0]->subtype=="PLAIN")
			$body = renderPlainText($body);
		$body .= "<h3>Attachments:</h3>\n";
		$partCount = 0;
		foreach($msgStructure->parts as $part) {
			$partCount++;
			if (isset($part->disposition)) {
				foreach($part->parameters as $param) {
					if($param->attribute=="NAME")
						// Generate the link for retrieving attachments
						$body .="<a href=\"".$feedLink;
						if(isset($_GET['conf'])) {
							$body .= "?conf=".$_GET['conf']."&amp;";
						} else {
							$body .= "?";
						}
						$body .="itemId=".$articleId."&attachId=".$partCount."\">";
						$body .=$param->value."</a><br/>\n";
						break;
				}
			}
		}
	} else {
		$body = imap_body($inbox, $articleId);
	}
	// If the body is plain-text, run the HTML rendering function
	if($msgStructure->subtype=="PLAIN")
		$body = renderPlainText($body);
	imap_close($inbox);
// The HTML used for displaying post content.
?>
<html>
<head>
	<title><?php echo $subject;?></title>
</head>
<body>
<div style="background:#eeeeee; border:solid 1px"
<strong><?php echo $subject; ?></strong><br />
<i><?php echo "by: ".$author.", @ ".$entryDate;?></i>
</div>
<br />
<?php echo $body; ?>
</body>
</html>
<?php
}
//-------------------------------------------------------------------
// generateFeed()
// Opens an IMAP connection to the specified server and converts the
// contents of the inbox to an RSS feed.
function generateFeed() {
	global 	$vers, $srvStr, $accountUser, $accountPass, $feedTitle, $maxMsgNum,
		$feedLink, $feedDesc, $feedLang, $feedEditor, $feedEditorMail, $mungeSenderEmail;
	
	$inbox = imap_open($srvStr, $accountUser, $accountPass);
	
	$pubDate = date("D, d M Y H:i:s O", time());
	
	header('Content-type: text/xml');
	
	// RSS header
	echo "<?xml version=\"1.0\"?>\n";
	echo "<rss version=\"2.0\" xmlns:dc=\"http://purl.org/dc/elements/1.1/\">\n";
	echo "   <channel>\n";
	echo "       <title>$feedTitle</title>\n";
	echo "       <link>$feedLink</link>\n";
	echo "       <description>$feedDesc</description>\n";
	echo "       <language>$feedLang</language>\n";
	echo "       <generator>IMAP2RSS v.$vers</generator>\n";
	echo "       <managingEditor>$feedEditor ($feedEditorMail)</managingEditor>\n";
	echo "       <webMaster>$feedEditor ($feedEditorMail)</webMaster>\n";
	echo "       <pubDate>$pubDate</pubDate>\n";
	
	// Calculate the number of items to include in the feed.
	$msgCount = imap_num_msg($inbox);
	if($maxMsgNum && $msgCount>$maxMsgNum)
		$lowerLimit = $msgCount - $maxMsgNum;
	else
		$lowerLimit = 0;
	// Generate item entries
	for($i=$msgCount; $i>$lowerLimit; $i--) {
		$headers = imap_headerinfo($inbox, $i);
		$subject = reEncodeString(htmlentities($headers->subject));
		// Use htmlentities() because sometimes the address appears
		// inside angle brackets.
		$author = reEncodeString(htmlentities($headers->fromaddress));
		// If author email munging is enabled...
		if($mungeSenderEmail) {
			$author = mungeEmailAddress($author);
		}
		// Format the date according to the standard
		$entryDate = date("D, d M Y H:i:s O", $headers->udate);
		// Set the item link depending on whether there is a custom
		// configuration in use or not.
		$itemUrl = $feedLink.((isset($_GET['conf']))?"&amp;":"?")."itemId=$i";
		
		// Negotiate the presence of attachments.
		$msgStructure = imap_fetchstructure($inbox, $i);
		if(count($msgStructure->parts)>1) {
			$body = imap_fetchbody($inbox, $i, "1");
			// If the body is plain-text, run the HTML rendering function
			if($msgStructure->parts[0]->subtype=="PLAIN")
				$body = renderPlainText($body);
			$body .= "<h3>Attachments:</h3>\n";
			$partCount = 0;
			foreach($msgStructure->parts as $part) {
				$partCount++;
				if (isset($part->disposition)) {
					foreach($part->parameters as $param) {
						if($param->attribute=="NAME")
							// Generate the link for retrieving attachments
							$body .="<a href=\"".$feedLink;
							if(isset($_GET['conf'])) {
								$body .= "&amp;";
							} else {
								$body .= "?";
							}
							$body .="itemId=".$i."&attachId=".$partCount."\">";
							$body .=$param->value."</a><br/>\n";
							break;
					}
				}
			}
		} else {
			$body = imap_body($inbox, $i);
			// If the body is plain-text, run the HTML rendering function
			if($msgStructure->subtype=="PLAIN")
				$body = renderPlainText($body);
		}
		// Clean up output to avoid problems with the XML produced
		$body = reEncodeString(htmlentities($body));
		echo "       <item>\n";
		echo "        <title>$subject</title>\n";
		echo "               <link>$itemUrl</link>\n";
		echo "               <pubDate>$entryDate</pubDate>\n";
		echo "               <description>$body</description>\n";
		echo "               <dc:creator>$author</dc:creator>\n";
		echo "               <guid>$itemUrl</guid>\n";
		echo "       </item>\n";
	}
	echo "     </channel>\n";
	echo "</rss> ";
	
	imap_close($inbox);
}

// display page body
// If an itemId has been set, display that item in an HTML page.
// If an itemId and an attachId have been set, return that attachment
// If not, show the entire feed.
if(isset($_GET['itemId'])) {
	if(isset($_GET['attachId'])) {
		returnAttachment($_GET['itemId'], $_GET['attachId']);
	} else {
		showArticle($_GET['itemId']);
	}
} else {
	generateFeed();
}
?>