FacebookBridge.php

<?php
class FacebookBridge extends BridgeAbstract{

	public function loadMetadatas() {

		$this->maintainer = "teromene";
		$this->name = "Facebook";
		$this->uri = "http://www.facebook.com/";
		$this->description = "Input a page title or a profile log. For a profile log, please insert the parameter as follow : myExamplePage/132621766841117";
		$this->update = "31/03/2016";

		$this->parameters[] =
		'[
			{
				"name" : "Username",
				"identifier" : "u",
				"required" : "required"
			}
		]';
	}

	public function collectData(array $param) {

		//Extract a string using start and end delimiters
		function ExtractFromDelimiters($string, $start, $end) {
			if (strpos($string, $start) !== false) {
				$section_retrieved = substr($string, strpos($string, $start) + strlen($start));
				$section_retrieved = substr($section_retrieved, 0, strpos($section_retrieved, $end));
				return $section_retrieved;
			} return false;
		}

		//Utility function for cleaning a Facebook link
		$unescape_fb_link = function ($matches) {
			if (is_array($matches) && count($matches) > 1) {
				$link = $matches[1];
				if (strpos($link, '/') === 0)
					$link = 'https://www.facebook.com'.$link.'"';
				if (strpos($link, 'facebook.com/l.php?u=') !== false)
					$link = urldecode(ExtractFromDelimiters($link, 'facebook.com/l.php?u=', '&'));
				return ' href="'.$link.'"';
			}
		};

		//Utility function for converting facebook emoticons
		$unescape_fb_emote = function ($matches) {
			static $facebook_emoticons = array(
				'smile' => ':)',
				'frown' => ':(',
				'tongue' => ':P',
				'grin' => ':D',
				'gasp' => ':O',
				'wink' => ';)',
				'pacman' => ':<',
				'grumpy' => '>_<',
				'unsure' => ':/',
				'cry' => ':\'(',
				'kiki' => '^_^',
				'glasses' => '8-)',
				'sunglasses' => 'B-)',
				'heart' => '<3',
				'devil' => ']:D',
				'angel' => '0:)',
				'squint' => '-_-',
				'confused' => 'o_O',
				'upset' => 'xD',
				'colonthree' => ':3',
				'like' => '&#x1F44D;');
			$len = count($matches);
			if ($len > 1)
				for ($i = 1; $i < $len; $i++)
					foreach ($facebook_emoticons as $name => $emote)
						if ($matches[$i] === $name)
							return $emote;
			return $matches[0];
		};

		$html = null;

		//Handle captcha response sent by the viewer
		if (isset($_POST['captcha_response']))
		{
			if (session_status() == PHP_SESSION_NONE)
				session_start();
			if (isset($_SESSION['captcha_fields'], $_SESSION['captcha_action']))
			{
				$captcha_action = $_SESSION['captcha_action'];
				$captcha_fields = $_SESSION['captcha_fields'];
				$captcha_fields['captcha_response'] = preg_replace("/[^a-zA-Z0-9]+/", "", $_POST['captcha_response']);
				$http_options = array(
					'http' => array(
						'method'  => 'POST',
						'user_agent'=> ini_get('user_agent'),
						'header'=>array("Content-type: application/x-www-form-urlencoded\r\nReferer: $captcha_action\r\nCookie: noscript=1\r\n"),
						'content' => http_build_query($captcha_fields),
					),
				);
				$context  = stream_context_create($http_options);
				$html = file_get_contents($captcha_action, false, $context);
				if ($html === FALSE) { $this->returnError('Failed to submit captcha response back to Facebook', 500); }
				unset($_SESSION['captcha_fields']);
				$html = str_get_html($html);
			}
			unset($_SESSION['captcha_fields']);
			unset($_SESSION['captcha_action']);
		}

		//Retrieve page contents
		if (is_null($html)) {
			if (isset($param['u'])) {
				if (!strpos($param['u'], "/")) {
					$html = file_get_html('https://www.facebook.com/'.urlencode($param['u']).'?_fb_noscript=1') or $this->returnError('No results for this query.', 404);
				} else {
					$html = file_get_html('https://www.facebook.com/pages/'.$param['u'].'?_fb_noscript=1') or $this->returnError('No results for this query.', 404);
				}
			} else {
				$this->returnError('You must specify a Facebook username.', 400);
			}
		}

		//Handle captcha form?
		$captcha = $html->find('div.captcha_interstitial', 0);
		if (!is_null($captcha))
		{
			//Save form for submitting after getting captcha response
			if (session_status() == PHP_SESSION_NONE)
				session_start();
			$captcha_fields = array();
			foreach ($captcha->find('input, button') as $input)
				$captcha_fields[$input->name] = $input->value;
			$_SESSION['captcha_fields'] = $captcha_fields;
			$_SESSION['captcha_action'] = 'https://www.facebook.com'.$captcha->find('form', 0)->action;

			//Show captcha filling form to the viewer, proxying the captcha image
			$img = base64_encode(file_get_contents($captcha->find('img', 0)->src));
			header('HTTP/1.1 500 '.Http::getMessageForCode(500));
			header('Content-Type: text/html');
			die('<form method="post" action="?'.$_SERVER['QUERY_STRING'].'">'
				.'<h2>Facebook captcha challenge</h2>'
				.'<p>Unfortunately, rss-bridge cannot fetch the requested page.<br />'
				.'Facebook wants rss-bridge to resolve the following captcha:</p>'
				.'<p><img src="data:image/png;base64,'.$img.'" /></p>'
				.'<p><b>Response:</b> <input name="captcha_response" placeholder="please fill in" />'
				.'<input type="submit" value="Submit!" /></p>'
				.'</form>');
		}

		//No captcha? We can carry on retrieving page contents :)
		$element = $html->find('[id^=PagePostsSectionPagelet-]')[0]->children(0)->children(0)->children(0);

		if(isset($element)) {

			$author = str_replace(' | Facebook', '', $html->find('title#pageTitle', 0)->innertext);
			$profilePic = 'https://graph.facebook.com/'.$param['u'].'/picture?width=200&amp;height=200';
			$this->name = $author;

			foreach($element->children() as $post) {
			
				$item = new \Item();

				if($post->hasAttribute("data-time")) {

					//Retrieve post contents
					$content = preg_replace('/(?i)><div class=\"clearfix([^>]+)>(.+?)div\ class=\"userContent\"/i', '', $post);
					$content = preg_replace('/(?i)><div class=\"_59tj([^>]+)>(.+?)<\/div><\/div><a/i', '', $content);
					$content = preg_replace('/(?i)><div class=\"_3dp([^>]+)>(.+?)div\ class=\"[^u]+userContent\"/i', '', $content);
					$content = preg_replace('/(?i)><div class=\"_4l5([^>]+)>(.+?)<\/div>/i', '', $content);

					//Remove html nodes, keep only img, links, basic formatting
					$content = strip_tags($content,'<a><img><i><u>');

					//Adapt link hrefs: convert relative links into absolute links and bypass external link redirection
					$content = preg_replace_callback('/ href=\"([^"]+)\"/i', $unescape_fb_link, $content);

					//Clean useless html tag properties and fix link closing tags
					foreach (array('onmouseover', 'onclick', 'target', 'ajaxify', 'tabindex',
						'class', 'style', 'data-[^=]*', 'aria-[^=]*', 'role', 'rel', 'id') as $property_name)
							$content = preg_replace('/ '.$property_name.'=\"[^"]*\"/i', '', $content);
					$content = preg_replace('/<\/a [^>]+>/i', '</a>', $content);

					//Convert textual representation of emoticons eg "<i><u>smile emoticon</u></i>" back to ASCII emoticons eg ":)"
					$content = preg_replace_callback('/<i><u>([^ <>]+) ([^<>]+)<\/u><\/i>/i', $unescape_fb_emote, $content);

					//Retrieve date of the post
					$date = $post->find("abbr")[0];
					if(isset($date) && $date->hasAttribute('data-utime')) {
						$date = $date->getAttribute('data-utime');
					} else {
						$date = 0;
					}

					//Build title from username and content
					$title = $author;
					if (strlen($title) > 24)
						$title = substr($title, 0, strpos(wordwrap($title, 24), "\n")).'...';
					$title = $title.' | '.strip_tags($content);
					if (strlen($title) > 64)
						$title = substr($title, 0, strpos(wordwrap($title, 64), "\n")).'...';

					//Use first image as thumbnail if available, or profile pic fallback
					$thumbnail = $post->find('img', 1)->src;
					if (strlen($thumbnail) == 0)
						$thumbnail = $profilePic;

					//Build and add final item
					$item->uri = 'https://facebook.com'.$post->find('abbr')[0]->parent()->getAttribute('href');
					$item->thumbnailUri = $thumbnail;
					$item->content = $content;
					$item->title = $title;
					$item->author = $author;
					$item->timestamp = $date;
					$this->items[] = $item;
				}
			}
		}
	}

	public function setDatas(array $param){
		if (isset($param['captcha_response']))
			unset($param['captcha_response']);
		parent::setDatas($param);
	}

	public function getName() {
		return (isset($this->name) ? $this->name.' - ' : '').'Facebook Bridge';
	}

	public function getURI() {
		return 'http://facebook.com';
	}

	public function getCacheDuration() {
		return 300; // 5 minutes
	}
}