<?

require_once('../lib/Respimg.php');

/*
PHP specific settings
*/

ignore_user_abort(true);
//session_start();

/*
Class & configuration initialization
*/

$document_root  = $_SERVER['DOCUMENT_ROOT'];
$requested_uri  = parse_url(urldecode($_SERVER['REQUEST_URI']), PHP_URL_PATH);
$requested_file = basename($requested_uri);
$source_file    = $document_root.$requested_uri;
list($rf_dirname, $rf_basename, $rf_extension, $rf_filename) = array_values(pathinfo($requested_uri));

$viewport_width = !isset($_SESSION['viewport_width']) ? 0 : $_SESSION['viewport_width'];
$card_width = !isset($_SESSION['card_width']) ? 0 : $_SESSION['card_width'];
$carousel_width = !isset($_SESSION['carousel_width']) ? 0 : $_SESSION['carousel_width'];
$content_width = !isset($_SESSION['content_width']) ? 0 : $_SESSION['content_width'];
$type = !empty($_GET['t']) ? $_GET['t'] : '';

$browser_cache = 60*60*24*1;
$generate = true;
$cache_file = $source_file;

$image_path = str_replace("/images","",$rf_dirname);

$image = new Respimg($source_file);
$orig_width = $image->getImageWidth();
$new_width = 0;

/*
Take the info given to use by the detection and make some sense of what we need to generate.
A series of checks is performed and if any fail the cached image doesn't get generated.
*/

switch($type) {
	case 'c':
		$new_width = $card_width;
		break;
	case 'h':
		$new_width = $carousel_width;
		break;
	default:
		$type = 'content';
		$new_width = $content_width;
		break;
}

// No width means no-go
if(empty($new_width)) {
	$generate = false;
}

// No reason to cache an image smaller than the requested width
if($orig_width < $new_width)
	$generate = false;

// No caching of images under 500px
if($orig_width < 500) {
	$generate = false;
}

// If all rules pass we generate the image
if($generate) {
	$cache_path = $document_root.'/image-cache'.$image_path.'/'.$new_width.'/';
	$cache_file = $cache_path.$requested_file;

	// Check to see if we need to regenerate
	if (file_exists($cache_file)) {
		if (filemtime($cache_file) < filemtime($source_file)) {
			unlink($cache_file);
		}
	}

	// Only cache when the cached file doesn't exist
	if (!file_exists($cache_file)) {
		if (!is_dir($cache_path)) {
			mkdir($cache_path, 0755, true);
		}

		$image->smartResize($new_width, 0, true);
		$image->writeImage($cache_file);
	}
}

header("Content-Type: image/jpeg");
header("Cache-Control: private, max-age=".$browser_cache);
header('Expires: '.gmdate('D, d M Y H:i:s', time()+$browser_cache).' GMT');
header('Content-Length: '.filesize($cache_file));

readfile($cache_file);

?>