http2pic.class.php

<?php
/**
 * http2pic by Christian Haschek (https://haschek.solutions)
 *
 * For more info and up2date version of this file visit https://github.com/chrisiaut/http2pic
 * -------------
 *
 * @category   Website rendering API
 * @author     Christian Haschek <christian@haschek.at>
 * @copyright  2015 by HASCHEK SOLUTIONS
 * @link       https://http2pic.haschek.at
 */

//
// Only edit from here if you know what you are doing
//
class http2pic
{
	private $config = array(
		'debug' => true,
		'maxtimeout' => 10,
		'onfailimage' => 'img/pagefailed.jpg',
		'ondomainfailimage' => 'img/domainfailed.jpg',
		'phantomjspath' => 'phantomjs',
		'cachedir' => 'cache/'
	);
	private $params = array();
	function __construct($cfg, $params)
	{
		foreach($this->config as $key => $val)
		{
			if(array_key_exists($key, $cfg))
			{
				$this->config[$key] = $cfg[$key];
			}
		}
		//try to create the cache folder if not exists
		if (!is_dir($this->config['cachedir'])) {
			mkdir($this->config['cachedir']);
		}
		
		$this->params = $params;
		return $this->paramsPrepare();
	}
	
	/**
	* Prepare and validate params
	**/
	function paramsPrepare()
	{
		//validate file type of rendered image
		switch($this->params['type'])
		{
			case 'png': $this->params['type'] = 'png'; break;
			case 'jpg': $this->params['type'] = 'jpg'; break;			
			default: $this->params['type'] = 'png';
		}
		
		//validate timeout
		if (!$this->params['timeout'] || !is_numeric($this->params['timeout']) || ($this->params['timeout'] > $this->config['maxtimeout'] || $this->params['timeout'] < 1))
			$this->params['timeout'] = 10;
			
		//validate viewport
		if ($this->params['viewport'])
		{
			$a = explode('x', $this->params['viewport']);
			$w = $a[0];
			$h = $a[1];
			if (is_numeric($w))
				$this->params['vp_w'] = $w;
			if (is_numeric($h))
				$this->params['vp_h'] = $h;
		}
		
		//validate resize width
		if($this->params['resizewidth'])
		{
			if(!is_numeric($this->params['resizewidth']) || $this->params['resizewidth']<1 || $this->params['resizewidth']>8000)
				unset($this->params['resizewidth']);
		}
		
		if(!$this->params['onfail'])
			$this->params['onfail'] = $this->config['onfailimage'];
		else
			$this->params['onfail'] = rawurldecode($this->params['onfail']);
		
		if(!$this->params['ondomainfail'])
			$this->params['ondomainfail'] = $this->config['ondomainfailimage'];
		else
			$this->params['ondomainfail'] = rawurldecode($this->params['ondomainfail']);
			
	
		//validate URL and check if exists
		if ($this->isBase64($this->params['url']))
			$this->params['url'] = base64_decode($this->params['url']);
		else
			$this->params['url'] = rawurldecode($this->params['url']);
		
			//if the url is not valid or not responding, show onfail image and leave
		if(!$this->isURLValid($this->params['url']) || !(($reachableResult = $this->isURLReachable($this->params['url'])) == 0))
		{
			header('Content-Type: image/jpeg');
			header('Content-Disposition: inline; filename="http2png.jpg"');
			switch ($reachableResult) {
				case 1:
					header('HTTP/1.0 404 File Not Found');
					$result = imagecreatefromjpeg($this->params['onfail']);
					break;
				case 2:
					header('HTTP/1.0 404 Server Not Found');
					$result = imagecreatefromjpeg($this->params['ondomainfail']);
					break;
			}
			imagejpeg($result, NULL, 100);
			return false;
		}
		
		
		
		//prepare file name
		$hash = md5($this->params['url']).'-'.preg_replace("/[^A-Za-z0-9 ]/", '', $this->params['url']).'.'.$this->params['type'];
		$this->params['cache'] = $this->trimToAlphaNumeric($this->params['cache']);
		//if (!$this->params['cache'])
			//$hash = md5(time().rand(1,2000)).$hash;
		$this->params['file'] = $this->config['cachedir'].$hash;
		
		$this->render();
		
		return true;
	}
	
	/**
	* Render using PhantomJS
	**/
	function render()
	{
		$cmd = 'timeout '.$this->params['timeout'].' '.$this->config['phantomjspath'];
		$cmd.= ' --ignore-ssl-errors=yes --ssl-protocol=any '.__DIR__.'/phantom.js ';
		
		$cmd.= ($this->params['url']);
		$cmd.= ','.($this->params['file']);
		$cmd.= ','.$this->params['vp_w'];
		$cmd.= ','.$this->params['vp_h'];
		$cmd.= ','.$this->params['js'];
		
		$cmd = escapeshellcmd($cmd);
		if($this->params['cache'] == "set" || !file_exists($this->params['file']))
		{
			shell_exec($cmd);
			if($this->config['debug'])
			{
				$fp = fopen('debug.log', 'a');
				fwrite($fp, $cmd."\n");
				fclose($fp);
			}
		}
		$this->params['cmd'] = $cmd;
		$this->postRender();
		return $cmd;
	}
	
	/**
	* Called after a render took place.
	* This method will print the image to the user, then
	* resizes or deletes it
	*/
	function postRender()
	{
		// resize if necessary
		if($this->params['resizewidth'])
			$this->resizeImage($this->params['file']);
		
		
		//print image to user
		if ($this->params['type'] === 'png') {
			
			header('Content-Type: image/png');
			header('Content-Disposition: inline; filename="'.$this->params['file'] . '"');
			$result = imagecreatefrompng($this->params['file']);
			imagepng($result, NULL, 9);
		}
		else {
			header('Content-Type: image/jpeg');
			header('Content-Disposition: inline; filename="'.$this->params['file'] . '"');
			$result = imagecreatefromjpeg($this->params['file']);
			imagejpeg($result, NULL, 100);
		}
	}
	
	function resizeImage($file)
	{
		list($width_orig, $height_orig) = getimagesize($file);

		if ($width_orig != $this->params['resizewidth'])
		{
			$ratio_orig = $width_orig/$height_orig;
			$height = $this->params['resizewidth']/$ratio_orig;
	
			// resample
			$image_p = imagecreatetruecolor($this->params['resizewidth'], $height);
			if ($this->params['type'] === 'png')
				$image = imagecreatefrompng($file);
			else
				$image = imagecreatefromjpeg($file);
			imagecopyresampled($image_p, $image, 0, 0, 0, 0, $this->params['resizewidth'], $height, $width_orig, $height_orig);
			
			if ($this->params['type'] === 'png')
				imagepng($image_p, $file, 9);
			else
				imagejpeg($image_p, $file, 100);
		}
	}
	
	function isURLValid($url)
	{
		if(!$this->startsWith($url,'http://') && !$this->startsWith($url,'https://') && !$this->startsWith($url,'ftp://'))
			return false;
		return filter_var($url, FILTER_VALIDATE_URL);
	}

	function startsWith($haystack,$needle)
{
    $length = strlen($needle);
    return (substr($haystack,0,$length) === $needle);
}
	
	/**
	* https://stackoverflow.com/questions/7684771/how-check-if-file-exists-from-the-url
	*/
	function isURLReachable($url)
	{
		$ch = curl_init($url);    
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);		
		if(curl_exec($ch) != false){
			//We were able to connect to a webserver, what did it return?
			$code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
		
			if($code < 400) //status code updated so redirects will also work
				$status = 0;
			else
				$status = 1;
			curl_close($ch);
			return $status;
		} else {
			//We were not able to connect to any webserver so we didn't get a status code
			//to compare against. There must be a problem with the domain that was supplied.
			curl_close($ch);
			return 2;
		}
	}
	
	function trimToAlphaNumeric($string)
	{
		return preg_replace("/[^A-Za-z0-9 ]/", '', $string);
	}
	
	function isBase64($data)
	{
		if (base64_encode(base64_decode($data, true)) === $data)
			return true;
		return false;
	}
}