<?php

// TimThumb script created by Tim McDaniels and Darren Hoyt with tweaks by Ben Gillbanks
// http://code.google.com/p/timthumb/

// MIT License: http://www.opensource.org/licenses/mit-license.php

/* Parameters allowed: */

// w: width
// h: height
// zc: zoom crop (0 or 1)
// q: quality (default is 75 and max is 100)

// HTML example: <img src="/scripts/timthumb.php?src=/images/whatever.jpg&w=150&h=200&zc=1" alt="" />
	
if( !isset( $_REQUEST[ "src" ] ) ) { die( "no image specified" ); }

// clean params before use
$src = clean_source( $_REQUEST[ "src" ] );

// set document root
$doc_root = get_document_root($src);
                        
// get path to image on file system
$src = $doc_root . '/' . $src;

$new_width = preg_replace( "/[^0-9]+/", "", $_REQUEST[ 'w' ] );
$new_height = preg_replace( "/[^0-9]+/", "", $_REQUEST[ 'h' ] );
$zoom_crop = preg_replace( "/[^0-9]+/", "", $_REQUEST[ 'zc' ] );

if( !isset( $_REQUEST['q'] ) ) { $quality = 80; } else { $quality = preg_replace("/[^0-9]/", "", $_REQUEST['q'] ); }

// set path to cache directory (default is ./cache)
// this can be changed to a different location
$cache_dir = './cache';

// get mime type of src
$mime_type = mime_type( $src );

// check to see if this image is in the cache already
check_cache( $cache_dir, $mime_type );

// make sure that the src is gif/jpg/png
if( !valid_src_mime_type( $mime_type ) ) {
	$error = "Invalid src mime type: $mime_type";
	die( $error );
}

// check to see if GD function exist
if(!function_exists('imagecreatetruecolor')) {
	$error = "GD Library Error: imagecreatetruecolor does not exist";
	die( $error );
}

if(strlen($src) && file_exists( $src ) ) {

	// open the existing image
	$image = open_image( $mime_type, $src );
	if( $image === false ) { die( 'Unable to open image : ' . $src ); }		

	// Get original width and height
	$width = imagesx( $image );
	$height = imagesy( $image );

	// don't allow new width or height to be greater than the original
	if( $new_width > $width ) { $new_width = $width; }
	if( $new_height > $height ) { $new_height = $height; }

	// generate new w/h if not provided
	if( $new_width && !$new_height ) {
		$new_height = $height * ( $new_width / $width );
	}
	elseif($new_height && !$new_width) {
		$new_width = $width * ( $new_height / $height );
	}
	elseif(!$new_width && !$new_height) {
		$new_width = $width;
		$new_height = $height;
	}

	// create a new true color image
	$canvas = imagecreatetruecolor( $new_width, $new_height );

	if( $zoom_crop ) {

		$src_x = $src_y = 0;
		$src_w = $width;
		$src_h = $height;

		$cmp_x = $width  / $new_width;
		$cmp_y = $height / $new_height;

		// calculate x or y coordinate and width or height of source

		if ( $cmp_x > $cmp_y ) {

			$src_w = round( ( $width / $cmp_x * $cmp_y ) );
			$src_x = round( ( $width - ( $width / $cmp_x * $cmp_y ) ) / 2 );

		}
		elseif ( $cmp_y > $cmp_x ) {

			$src_h = round( ( $height / $cmp_y * $cmp_x ) );
			$src_y = round( ( $height - ( $height / $cmp_y * $cmp_x ) ) / 2 );

		}
        
		imagecopyresampled( $canvas, $image, 0, 0, $src_x, $src_y, $new_width, $new_height, $src_w, $src_h );

	}
	else {

		// copy and resize part of an image with resampling
		imagecopyresampled( $canvas, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

	}

	// output image to browser based on mime type
	show_image( $mime_type, $canvas, $quality, $cache_dir );
	
	// remove image from memory
	imagedestroy( $canvas );
	
} else {

	if( strlen( $src ) ) { echo $src . ' not found.'; } else { echo 'no source specified.'; }
	
}

function show_image ( $mime_type, $image_resized, $quality, $cache_dir ) {

	// check to see if we can write to the cache directory
	$is_writable = 0;
	$cache_file_name = $cache_dir . '/' . get_cache_file();        	

	if( touch( $cache_file_name ) ) {
		// give 666 permissions so that the developer 
		// can overwrite web server user
		chmod( $cache_file_name, 0666 );
		$is_writable = 1;
	}
	else {
		$cache_file_name = NULL;
		header( 'Content-type: ' . $mime_type );
	}
	
	if( stristr( $mime_type, 'gif' ) ) {
		imagegif( $image_resized, $cache_file_name );
	}
	elseif( stristr( $mime_type, 'jpeg' ) ) {
		imagejpeg( $image_resized, $cache_file_name, $quality );
	}
	elseif( stristr( $mime_type, 'png' ) ) {
		imagepng( $image_resized, $cache_file_name, ceil( $quality / 10 ) );
	}
	if( $is_writable ) { show_cache_file( $cache_dir, $mime_type ); }
	exit;

}

function open_image ( $mime_type, $src ) {

	if( stristr( $mime_type, 'gif' ) ) {
		$image = imagecreatefromgif( $src );
	}
	elseif( stristr( $mime_type, 'jpeg' ) ) {
		@ini_set('gd.jpeg_ignore_warning', 1);
		$image = imagecreatefromjpeg( $src );
	}
	elseif( stristr( $mime_type, 'png' ) ) {
		$image = imagecreatefrompng( $src );
	}
	return $image;

}

function mime_type ( $file ) {

        $os = strtolower(php_uname());
	$mime_type = '';

	// use PECL fileinfo to determine mime type
	if( function_exists( 'finfo_open' ) ) {
		$finfo = finfo_open( FILEINFO_MIME );
		$mime_type = finfo_file( $finfo, $file );
		finfo_close( $finfo );
	}

	// try to determine mime type by using unix file command
	// this should not be executed on windows
        if( !valid_src_mime_type( $mime_type ) && !(eregi('windows', php_uname()))) {
		if( preg_match( "/freebsd|linux/", $os ) ) {
                	$mime_type = trim ( @shell_exec( 'file -bi $file' ) );
		}
        }

	// use file's extension to determine mime type
        if( !valid_src_mime_type( $mime_type ) ) {
		$frags = split( "\.", $file );
		$ext = strtolower( $frags[ count( $frags ) - 1 ] );
		$types = array(
 			'jpg'  => 'image/jpeg',
 			'jpeg' => 'image/jpeg',
 			'png'  => 'image/png',
 			'gif'  => 'image/gif'
 		);
		if( strlen( $ext ) && strlen( $types[$ext] ) ) {
			$mime_type = $types[ $ext ];
		}

		// if no extension provided, default to jpg
		if( !strlen( $ext ) && !valid_src_mime_type( $mime_type ) ) {
			$mime_type = 'image/jpeg';
		}
	}
	return $mime_type;

}

function valid_src_mime_type ( $mime_type ) {

	if( preg_match( "/jpg|jpeg|gif|png/i", $mime_type ) ) { return 1; }
	return 0;

}

function check_cache ( $cache_dir, $mime_type ) {

	// make sure cache dir exists
	if( !file_exists( $cache_dir ) ) {
		// give 777 permissions so that developer can overwrite
		// files created by web server user
		mkdir( $cache_dir );
		chmod( $cache_dir, 0777 );
	}
	show_cache_file( $cache_dir, $mime_type );

}

function show_cache_file ( $cache_dir, $mime_type ) {

	$cache_file = get_cache_file();
	if( file_exists( $cache_dir . '/' . $cache_file ) ) {
    
		// check for updates
		$if_modified_since = preg_replace( '/;.*$/', '', $_SERVER[ "HTTP_IF_MODIFIED_SINCE" ] );
		$gmdate_mod = gmdate( 'D, d M Y H:i:s', filemtime( $cache_dir . '/' . $cache_file ) );
		if( strstr( $gmdate_mod, 'GMT' ) ) {
			$gmdate_mod .= " GMT";
		}
		if ( $if_modified_since == $gmdate_mod ) {
			header( "HTTP/1.1 304 Not Modified" );
			exit;
		}
		
		// send headers then display image
		header( "Content-Type: " . $mime_type );
		header( "Last-Modified: " . gmdate( 'D, d M Y H:i:s', filemtime( $cache_dir . '/' . $cache_file ) . " GMT" ) );
		header( "Content-Length: " . filesize( $cache_dir . '/' . $cache_file ) );
		header( "Cache-Control: max-age=9999, must-revalidate" );
		header( "Expires: " . gmdate( "D, d M Y H:i:s", time() + 9999 ) . "GMT" ); 
		readfile( $cache_dir . '/' . $cache_file );
		exit;

	}
    
}

function get_cache_file () {

	global $quality;

	static $cache_file;
	if(!$cache_file) {
		$frags = split( "\.", $_REQUEST['src'] );
		$ext = strtolower( $frags[ count( $frags ) - 1 ] );
		if(!valid_extension($ext)) { $ext = 'jpg'; }
		$cachename = $_REQUEST['src'] . $_REQUEST['w'] . $_REQUEST['h'] . $_REQUEST['zc'] . $quality;
		$cache_file = md5( $cachename ) . '.' . $ext;
	}
	return $cache_file;

}

function valid_extension ($ext) {

	if( preg_match( "/jpg|jpeg|png|gif/i", $ext ) ) return 1;
	return 0;

}

function clean_source ( $src ) {

	// don't allow off site src to be specified via http/https/ftp
	/*
	if( preg_match( "/^((ht|f)tp(s|):\/\/)/i", $src ) ) {
		die( "Improper src specified:" . $src );
	}
	*/
	// remove http/ https/ ftp
	$src = preg_replace("/^((ht|f)tp(s|):\/\/)/i", "", $src);
	// remove domain name from the source url
	$src = str_replace($_SERVER["HTTP_HOST"], "", $src);

	//$src = preg_replace( "/(?:^\/+|\.{2,}\/+?)/", "", $src );
	//$src = preg_replace( '/^\w+:\/\/[^\/]+/', '', $src );

	// don't allow users the ability to use '../' 
	// in order to gain access to files below document root

	// src should be specified relative to document root like:
	// src=images/img.jpg or src=/images/img.jpg
	// not like:
	// src=../images/img.jpg
	$src = preg_replace( "/\.\.+\//", "", $src );

	return $src;

}

function get_document_root ($src) {
	if( @file_exists( $_SERVER['DOCUMENT_ROOT'] . '/' . $src ) ) {
		return $_SERVER['DOCUMENT_ROOT'];
	}
	// the relative paths below are useful if timthumb is moved outside of document root
	// specifically if installed in wordpress themes like mimbo pro:
	// /wp-content/themes/mimbopro/scripts/timthumb.php
	$paths = array( '..', '../..', '../../..', '../../../..' );
	foreach( $paths as $path ) {
		if( @file_exists( $path . '/' . $src ) ) {
			return $path;
		}
	}

}

?>
