<?php

class FB2Bridge extends BridgeAbstract
{
    const MAINTAINER = 'teromene';
    const NAME = 'Facebook Bridge | Touch Site';
    const URI = 'https://www.facebook.com/';
    const CACHE_TIMEOUT = 1000;
    const DESCRIPTION = 'Input a page title or a profile log. For a profile log,
 please insert the parameter as follow : myExamplePage/132621766841117';

    const PARAMETERS = [ [
        'u' => [
            'name' => 'Username',
            'required' => true
        ],
        'abbrev_name' => [
            'name' => 'Abbreviate author name in title',
            'type' => 'checkbox',
            'defaultValue' => true,
        ],
    ]];

    public function getIcon()
    {
        return 'https://static.xx.fbcdn.net/rsrc.php/yo/r/iRmz9lCMBD2.ico';
    }

    public function collectData()
    {
        //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) {
                    $link = self::URI . substr($link, 1);
                }
                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 = [
                '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];
        };

        if ($this->getInput('u') !== null) {
            $page = 'https://touch.facebook.com/' . $this->getInput('u');
            $cookies = $this->getCookies($page);
            $pageInfo = $this->getPageInfos($page, $cookies);

            if ($pageInfo['userId'] === null) {
                returnClientError(
                    <<<EOD
Unable to get the page id. You should consider getting the ID by hand, then importing it into FB2Bridge
EOD
                );
            } elseif ($pageInfo['userId'] == -1) {
                returnClientError(
                    <<<EOD
This page is not accessible without being logged in.
EOD
                );
            }
        }

        //Build the string for the first request
        $requestString = 'https://touch.facebook.com/page_content_list_view/more/?page_id='
        . $pageInfo['userId']
        . '&start_cursor=1&num_to_fetch=105&surface_type=timeline';
        $fileContent = getContents($requestString);
        $html = $this->buildContent($fileContent);
        $author = $pageInfo['username'];

        foreach ($html->find('article') as $content) {
            $item = [];

            preg_match('/publish_time\\\":([0-9]+),/', $content->getAttribute('data-store', 0), $match);
            if (isset($match[1])) {
                $timestamp = $match[1];
            } else {
                $timestamp = 0;
            }

            $item['uri'] = html_entity_decode('https://touch.facebook.com'
            . $content->find("div[class='_52jc _5qc4 _78cz _24u0 _36xo']", 0)->find('a', 0)->getAttribute('href'), ENT_QUOTES);

            //Decode images
            $imagecleaned = preg_replace_callback('/<i [^>]* style="[^"]*url\(\'(.*?)\'\).*?><\/i>/m', function ($matches) {
                return "<img src='" . str_replace(['\\3a ', '\\3d ', '\\26 '], [':', '=', '&'], $matches[1]) . "' />";
            }, $content);
            $content = str_get_html($imagecleaned);

            if ($content->find('header', 0) !== null) {
                $content->find('header', 0)->innertext = '';
            }

            if ($content->find('footer', 0) !== null) {
                $content->find('footer', 0)->innertext = '';
            }

            // Replace emoticon images by their textual representation (part of the span)
            foreach ($content->find('span[title*="emoticon"]') as $emoticon) {
                $emoticon->innertext = $emoticon->find('span[aria-hidden="true"]', 0)->innertext;
            }

            //Remove html nodes, keep only img, links, basic formatting
            $content = strip_tags($content, '<a><img><i><u><br><p><h3><h4><section>');

            //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 (
                [
                'onmouseover',
                'onclick',
                'target',
                'ajaxify',
                'tabindex',
                'class',
                '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);

            //Remove the "...Plus" tag
            $content = preg_replace(
                '/… (<span>|)<a href="https:\/\/www\.facebook\.com\/story\.php\?story_fbid=.*?<\/a>/m',
                '',
                $content,
                1
            );

            //Remove tracking images
            $content = preg_replace('/<img src=\'.*?safe_image\.php.*?\' \/>/m', '', $content);

            //Remove the double section tags
            $content = str_replace(
                ['<section><section>', '</section></section>'],
                ['<section>', '</section>'],
                $content
            );

            //Move the section tag link upper, if it is down
            $content = str_get_html($content);
            $sectionContent = $content->find('section', 0);
            if ($sectionContent != null) {
                $sectionLink = $sectionContent->nextSibling();
                if ($sectionLink != null) {
                    $fullLink = '<a href="' . $sectionLink->getAttribute('href') . '">' . $sectionContent->innertext . '</a>';
                    $sectionContent->innertext = $fullLink;
                }
            }

            //Move the href tag upper if it is inside the section
            foreach ($content->find('section > a') as $sectionToFix) {
                $sectionLink = $sectionToFix->getAttribute('href');
                $section = $sectionToFix->parent();
                $section->outertext = '<a href="' . $sectionLink . '">' . $section . '</a>';
            }

            $item['content'] = html_entity_decode($content, ENT_QUOTES);

            $title = $author;
            if ($this->getInput('abbrev_name') === true) {
                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")) . '...';
            }

            $item['title'] = html_entity_decode($title, ENT_QUOTES);
            $item['author'] = html_entity_decode($author, ENT_QUOTES);
            $item['timestamp'] = html_entity_decode($timestamp, ENT_QUOTES);

            if ($item['timestamp'] != 0) {
                array_push($this->items, $item);
            }
        }
    }

    //Builds the HTML from the encoded JS that Facebook provides.
    private function buildContent($pageContent)
    {
        // The html ends with:
        // /div>","replaceifexists
        $regex = '/\\"html\\":(\".+\/div>"),"replace/';
        preg_match($regex, $pageContent, $result);

        $htmlContent = json_decode($result[1]);
        $htmlContent = preg_replace('/(?<!style)="(.*?)"/', '=\'$1\'', $htmlContent);
        $htmlContent = html_entity_decode($htmlContent, ENT_QUOTES, 'UTF-8');

        return str_get_html($htmlContent);
    }

    //Builds the cookie from the page, as Facebook sometimes refuses to give
    //the page if no cookie is provided.
    private function getCookies($pageURL)
    {
        $ctx = stream_context_create([
            'http' => [
                'user_agent' => Configuration::getConfig('http', 'useragent'),
                'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
                ]
            ]);
        $a = file_get_contents($pageURL, 0, $ctx);

        //First request to get the cookie
        $cookies = '';
        foreach ($http_response_header as $hdr) {
            if (strpos($hdr, 'Set-Cookie') !== false) {
                $cLine = explode(':', $hdr)[1];
                $cLine = explode(';', $cLine)[0];
                $cookies .= ';' . $cLine;
            }
        }

        return substr($cookies, 1);
    }

    //Get the page ID and username from the Facebook page.
    private function getPageInfos($page, $cookies)
    {
        $context = stream_context_create([
            'http' => [
                'user_agent' => Configuration::getConfig('http', 'useragent'),
                'header' => 'Cookie: ' . $cookies
                ]
            ]);

        $pageContent = file_get_contents($page, 0, $context);

        if (strpos($pageContent, 'signup-button') != false) {
            return -1;
        }

        //Get the username
        $usernameRegex = '/data-nt=\"FB:TEXT4\">(.*?)<\/div>/m';
        preg_match($usernameRegex, $pageContent, $usernameMatches);
        if (count($usernameMatches) > 0) {
            $username = strip_tags($usernameMatches[1]);
        } else {
            $username = $this->getInput('u');
        }

        //Get the page ID if we don't have a captcha
        $regex = '/page_id=([0-9]*)&/';
        preg_match($regex, $pageContent, $matches);

        if (count($matches) > 0) {
            return ['userId' => $matches[1], 'username' => $username];
        }

        //Get the page ID if we do have a captcha
        $regex = '/"pageID":"([0-9]*)"/';
        preg_match($regex, $pageContent, $matches);

        return ['userId' => $matches[1], 'username' => $username];
    }

    public function getName()
    {
        $username = $this->getInput('u');
        if (isset($username)) {
            return $this->getInput('u') . ' | Facebook';
        } else {
            return self::NAME;
        }
    }

    public function getURI()
    {
        $username = $this->getInput('u');
        if (isset($username)) {
            return 'https://facebook.com/' . $this->getInput('u') . '/posts';
        } else {
            return self::URI;
        }
    }
}
