<?php

/*

	AUTOMATIC IMAGE ROTATOR
	Version 2.2 - December 4, 2003
	Copyright (c) 2002-2003 Dan P. Benjamin, Automatic, Ltd.
	Modified by the OC.de Team
	All Rights Reserved.

	http://www.hiveware.com/imagerotator.php
	
	http://www.automaticlabs.com/
	
	
	DISCLAIMER
	Automatic, Ltd. makes no representations or warranties about
	the suitability of the software, either express or
	implied, including but not limited to the implied
	warranties of merchantability, fitness for a particular
	purpose, or non-infringement. Dan P. Benjamin and Automatic, Ltd.
	shall not be liable for any damages suffered by licensee
	as a result of using, modifying or distributing this
	software or its derivatives.
	
	
	ABOUT
	This PHP script will randomly select an image file from a
	folder of images on your webserver.  You can then link to it
	as you would any standard image file and you'll see a random
	image each time you reload.
	
	When you want to add or remove images from the rotation-pool,
	just add or remove them from the image rotation folder.


	VERSION CHANGES
	Version 1.0
		- Release version
	
	Version 1.5
		- Tweaked a few boring bugs
	
	Version 2.0
		- Complete rewrite from the ground-up
		- Made it clearer where to make modifications
		- Made it easier to specify/change the rotation-folder
		- Made it easier to specify/change supported image types
		- Wrote better instructions and info (you're them reading now)
		- Significant speed improvements
		- More error checking
		- Cleaner code (albeit more PHP-specific)
		- Better/faster random number generation and file-type parsing
		- Added a feature where the image to display can be specified
		- Added a cool feature where, if an error occurs (such as no
		  images being found in the specified folder) *and* you're
		  lucky enough to have the GD libraries compiled into PHP on
		  your webserver, we generate a replacement "error image" on
		  the fly.
		
    Version 2.1
        - Updated a potential security flaw when value-matching
          filenames

    Version 2.2
        - Updated a few more potential security issues
        - Optimized the code a bit.
        - Expanded the doc for adding new mime/image types.

        Thanks to faithful ALA reader Justin Greer for
        lots of good tips and solid code contribution!


	INSTRUCTIONS
	1. Modify the $folder setting in the configuration section below.
	2. Add image types if needed (most users can ignore that part).
	3. Upload this file (rotate.php) to your webserver.  I recommend
	   uploading it to the same folder as your images.
	4. Link to the file as you would any normal image file, like this:

			<img src="http://example.com/rotate.php">

	5. You can also specify the image to display like this:

			<img src="http://example.com/rotate.php?img=gorilla.jpg">
		
		This would specify that an image named "gorilla.jpg" located
		in the image-rotation folder should be displayed.
	
	That's it, you're done.

*/




/* ------------------------- CONFIGURATION -----------------------


	Set $folder to the full path to the location of your images.
	For example: $folder = '/user/me/example.com/images/';
	If the rotate.php file will be in the same folder as your
	images then you should leave it set to $folder = '.';

*/


	$folder = '.';


/*	

	Most users can safely ignore this part.  If you're a programmer,
	keep reading, if not, you're done.  Go get some coffee.

    If you'd like to enable additional image types other than
	gif, jpg, and png, add a duplicate line to the section below
	for the new image type.
	
	Add the new file-type, single-quoted, inside brackets.
	
	Add the mime-type to be sent to the browser, also single-quoted,
	after the equal sign.
	
	For example:
	
	PDF Files:

		$extList['pdf'] = 'application/pdf';
	
    CSS Files:

        $extList['css'] = 'text/css';

    You can even serve up random HTML files:

	    $extList['html'] = 'text/html';
	    $extList['htm'] = 'text/html';

    Just be sure your mime-type definition is correct!

*/

	$extList = array();
	$extList['gif'] = 'image/gif';
	$extList['jpg'] = 'image/jpeg';
	$extList['jpeg'] = 'image/jpeg';
	$extList['png'] = 'image/png';

	// interval in seconds when to switch to the next image
	$interval = 300;

// You don't need to edit anything after this point.


// --------------------- END CONFIGURATION -----------------------

$img = null;

if (substr($folder,-1) != '/')
{
	$folder = $folder . '/';
}

$fileList = array();
$handle = opendir($folder);
while (false !== ($file = readdir($handle)))
{
	if (is_file($file))
	{
		$file_info = pathinfo($file);
		if (isset($extList[strtolower($file_info['extension'])]))
		{
			$fileList[] = $file;
		}
	}
}
closedir($handle);

if (count($fileList) > 0)
{
	$imageNumber = floor(time() / $interval) % count($fileList);
	$img = $folder . $fileList[$imageNumber];
}

if ($img != null)
{
	$imageInfo = pathinfo($img);
	header('Content-type: ' . $extList[$imageInfo['extension']]);

	// Cache-Lebensdauer (in Minuten)
	$exp_gmt = gmdate("D, d M Y H:i:s", time() + $interval) ." GMT";
	$mod_gmt = gmdate("D, d M Y H:i:s", time()) ." GMT";

	header("Expires: " . $exp_gmt);
	header("Last-Modified: " . $mod_gmt);
	header("Cache-Control: public, max-age=" . $interval);
	// Speziell für MSIE 5
	header("Cache-Control: pre-check=" . $interval, false);

	readfile($img);
}
else
{
	if (function_exists('imagecreate'))
	{
		header ("Content-type: image/png");
		$im = @imagecreate (100, 100) or die("Cannot initialize new GD image stream");
		$background_color = imagecolorallocate($im, 255, 255, 255);
		$text_color = imagecolorallocate($im, 0, 0, 0);
		imagestring($im, 2, 5, 5, "IMAGE ERROR", $text_color);
		imagepng($im);
		imagedestroy($im);
	}
}
?>