<?php

class VkBridge extends BridgeAbstract
{
    const MAINTAINER = 'em92';
    // const MAINTAINER = 'pmaziere';
    // const MAINTAINER = 'ahiles3005';
    const NAME = 'VK.com';
    const URI = 'https://vk.com/';
    const CACHE_TIMEOUT = 300; // 5min
    const DESCRIPTION = 'Working with open pages';
    const PARAMETERS = [
        [
            'u' => [
                'name' => 'Group or user name',
                'exampleValue' => 'elonmusk_tech',
                'required' => true
            ],
            'hide_reposts' => [
                'name' => 'Hide reposts',
                'type' => 'checkbox',
            ]
        ]
    ];
    const TEST_DETECT_PARAMETERS = [
        'https://vk.com/id1' => ['u' => 'id1'],
        'https://vk.com/groupname' => ['u' => 'groupname'],
        'https://m.vk.com/groupname' => ['u' => 'groupname'],
        'https://vk.com/groupname/anythingelse' => ['u' => 'groupname'],
        'https://vk.com/groupname?w=somethingelse' => ['u' => 'groupname'],
        'https://vk.com/with_underscore' => ['u' => 'with_underscore'],
    ];

    protected $pageName;
    protected $tz = 0;
    private $urlRegex = '/vk\.com\/([\w]+)/';

    public function getURI()
    {
        if (!is_null($this->getInput('u'))) {
            return static::URI . urlencode($this->getInput('u'));
        }

        return parent::getURI();
    }

    public function getName()
    {
        if ($this->pageName) {
            return $this->pageName;
        }

        return parent::getName();
    }

    public function detectParameters($url)
    {
        if (preg_match($this->urlRegex, $url, $matches)) {
            return ['u' => $matches[1]];
        }

        return null;
    }

    public function collectData()
    {
        $text_html = $this->getContents();

        $text_html = iconv('windows-1251', 'utf-8//ignore', $text_html);

        $html = str_get_html($text_html);
        foreach ($html->find('script') as $script) {
            preg_match('/tz: ([0-9]+)/', $script->outertext, $matches);
            if (count($matches) > 0) {
                $this->tz = intval($matches[1]);
                break;
            }
        }
        $pageName = $html->find('meta[property="og:title"]', 0);
        if (is_object($pageName)) {
            $pageName = $pageName->getAttribute('content');
            $this->pageName = $pageName;
        }
        foreach ($html->find('div.replies') as $comment_block) {
            $comment_block->outertext = '';
        }

        // expensive operation
        $save = $html->save();
        $html->load($save);

        $pinned_post_item = null;
        $last_post_id = 0;

        foreach ($html->find('.post') as $post) {
            if ($post->find('.wall_post_text_deleted')) {
                // repost of deleted post
                continue;
            }

            defaultLinkTo($post, self::URI);

            $is_pinned_post = false;
            if (strpos($post->getAttribute('class'), 'post_fixed') !== false) {
                $is_pinned_post = true;
            }

            // Remove 'Show more' button
            foreach ($post->find('button.PostTextMore') as $junk) {
                $junk->outertext = '';
            }

            $content_suffix = '';

            // looking for external links
            $external_link_selectors = [
                'a.page_media_link_title',
                'div.page_media_link_title > a',
                'div.media_desc > a.lnk',
            ];

            foreach ($external_link_selectors as $sel) {
                if (is_object($post->find($sel, 0))) {
                    $a = $post->find($sel, 0);
                    $innertext = $a->innertext;
                    $parsed_url = parse_url($a->getAttribute('href'));
                    if (strpos($parsed_url['path'], '/away.php') !== 0) {
                        continue;
                    }
                    parse_str($parsed_url['query'], $parsed_query);
                    $content_suffix .= "<br>External link: <a href='" . $parsed_query['to'] . "'>$innertext</a>";
                }
            }

            // remove external link from content
            $external_link_selectors_to_remove = [
                'div.page_media_thumbed_link',
                'div.page_media_link_desc_wrap',
                'div.media_desc > a.lnk',
            ];

            foreach ($external_link_selectors_to_remove as $sel) {
                if (is_object($post->find($sel, 0))) {
                    $post->find($sel, 0)->outertext = '';
                }
            }

            // looking for article
            $article = $post->find('a.article_snippet', 0);
            if (is_object($article)) {
                if (strpos($article->getAttribute('class'), 'article_snippet_mini') !== false) {
                    $article_title_selector = 'div.article_snippet_mini_title';
                    $article_author_selector = 'div.article_snippet_mini_info > .mem_link,
						div.article_snippet_mini_info > .group_link';
                    $article_thumb_selector = 'div.article_snippet_mini_thumb';
                } else {
                    $article_title_selector = 'div.article_snippet__title';
                    $article_author_selector = 'div.article_snippet__author';
                    $article_thumb_selector = 'div.article_snippet__image';
                }
                $article_title = $article->find($article_title_selector, 0)->innertext;
                $article_author = $article->find($article_author_selector, 0)->innertext;
                $article_link = $article->getAttribute('href');
                $article_img_element_style = $article->find($article_thumb_selector, 0)->getAttribute('style');
                preg_match('/background-image: url\((.*)\)/', $article_img_element_style, $matches);
                if (count($matches) > 0) {
                    $content_suffix .= "<br><img src='" . $matches[1] . "'>";
                }
                $content_suffix .= "<br>Article: <a href='$article_link'>$article_title ($article_author)</a>";
                $article->outertext = '';
            }

            // get all videos
            foreach ($post->find('a.page_post_thumb_video') as $a) {
                $video_title = htmlspecialchars_decode($a->getAttribute('aria-label'));
                $video_title_split_pos = strrpos($video_title, ' is ');
                if ($video_title_split_pos !== false) {
                    $video_title = substr($video_title, 0, $video_title_split_pos);
                }
                $video_link = $a->getAttribute('href');
                $this->appendVideo($video_title, $video_link, backgroundToImg($a), $content_suffix);
                $a->outertext = '';
            }

            // get all photos
            foreach ($post->find('div.wall_text a.page_post_thumb_wrap') as $a) {
                $result = $this->getPhoto($a);
                if ($result == null) {
                    continue;
                }
                $a->outertext = '';
                $content_suffix .= "<br>$result";
            }

            // get albums
            foreach ($post->find('.page_album_wrap') as $el) {
                $a = $el->find('.page_album_link', 0);
                $album_title = $a->find('.page_album_title_text', 0)->getAttribute('title');
                $album_link = $a->getAttribute('href');
                $el->outertext = '';
                $content_suffix .= "<br>Album: <a href='$album_link'>$album_title</a>";
            }

            // get photo documents
            foreach ($post->find('a.page_doc_photo_href') as $a) {
                $doc_link = $a->getAttribute('href');
                $doc_gif_label_element = $a->find('.page_gif_label', 0);
                $doc_title_element = $a->find('.doc_label', 0);

                if (is_object($doc_gif_label_element)) {
                    $gif_preview_img = backgroundToImg($a->find('.page_doc_photo', 0));
                    $content_suffix .= "<br>Gif: <a href='$doc_link'>$gif_preview_img</a>";
                } elseif (is_object($doc_title_element)) {
                    $doc_title = $doc_title_element->innertext;
                    $content_suffix .= "<br>Doc: <a href='$doc_link'>$doc_title</a>";
                } else {
                    continue;
                }

                $a->outertext = '';
            }

            // get other documents
            foreach ($post->find('div.page_doc_row') as $div) {
                $doc_title_element = $div->find('a.page_doc_title', 0);

                if (is_object($doc_title_element)) {
                    $doc_title = $doc_title_element->innertext;
                    $doc_link = $doc_title_element->getAttribute('href');
                    $content_suffix .= "<br>Doc: <a href='$doc_link'>$doc_title</a>";
                } else {
                    continue;
                }

                $div->outertext = '';
            }

            // get polls
            foreach ($post->find('div.page_media_poll_wrap') as $div) {
                $poll_title = $div->find('.page_media_poll_title', 0)->innertext;
                $content_suffix .= "<br>Poll: $poll_title";
                foreach ($div->find('div.page_poll_text') as $poll_stat_title) {
                    $content_suffix .= '<br>- ' . $poll_stat_title->innertext;
                }
                $div->outertext = '';
            }

            // get sign / post author
            $post_author = $pageName;
            $author_selectors = ['a.wall_signed_by', 'a.author'];
            foreach ($author_selectors as $author_selector) {
                $a = $post->find($author_selector, 0);
                if (is_object($a)) {
                    $post_author = $a->innertext;
                    $a->outertext = '';
                    break;
                }
            }

            // fix links and get post hashtags
            $hashtags = [];
            foreach ($post->find('a') as $a) {
                $href = $a->getAttribute('href');
                $innertext = $a->innertext;

                $hashtag_prefix = '/feed?section=search&q=%23';
                $hashtag = null;

                if ($href && substr($href, 0, strlen($hashtag_prefix)) === $hashtag_prefix) {
                    $hashtag = urldecode(substr($href, strlen($hashtag_prefix)));
                } elseif (substr($innertext, 0, 1) == '#') {
                    $hashtag = $innertext;
                }

                if ($hashtag) {
                    $a->outertext = $innertext;
                    $hashtags[] = $hashtag;
                    continue;
                }

                $parsed_url = parse_url($href);

                if (array_key_exists('path', $parsed_url) === false) {
                    continue;
                }

                if (strpos($parsed_url['path'], '/away.php') === 0) {
                    parse_str($parsed_url['query'], $parsed_query);
                    $a->setAttribute('href', iconv(
                        'windows-1251',
                        'utf-8//ignore',
                        $parsed_query['to']
                    ));
                }
            }

            $copy_quote = $post->find('div.copy_quote', 0);
            if (is_object($copy_quote)) {
                if ($this->getInput('hide_reposts') === true) {
                    continue;
                }
                if ($copy_post_header = $copy_quote->find('div.copy_post_header', 0)) {
                    $copy_post_header->outertext = '';
                }

                $second_copy_quote = $copy_quote->find('div.published_sec_quote', 0);
                if (is_object($second_copy_quote)) {
                    $second_copy_quote_author = $second_copy_quote->find('a.copy_author', 0)->outertext;
                    $second_copy_quote_content = $second_copy_quote->find('div.copy_post_date', 0)->outertext;
                    $second_copy_quote->outertext = "<br>Reposted ($second_copy_quote_author): $second_copy_quote_content";
                }
                $copy_quote_author = $copy_quote->find('a.copy_author', 0)->outertext;
                $copy_quote_content = $copy_quote->innertext;
                $copy_quote->outertext = "<br>Reposted ($copy_quote_author): <br>$copy_quote_content";
            }

            foreach ($post->find('.SecondaryAttachment') as $sa) {
                $sa_href = $sa->getAttribute('href');
                if (!$sa_href) {
                    $sa_href = '';
                }
                $sa_task_click = $sa->getAttribute('data-task-click');

                if (str_starts_with($sa_href, 'https://vk.com/doc')) {
                    // document
                    $doc_title = $sa->find('.SecondaryAttachment__childrenText', 0)->innertext;
                    $doc_size = $sa->find('.SecondaryAttachmentSubhead', 0)->innertext;
                    $doc_link = $sa_href;
                    $content_suffix .= "<br>Doc: <a href='$doc_link'>$doc_title</a> ($doc_size)";
                    $sa->outertext = '';
                } else if (str_starts_with($sa_href, 'https://vk.com/@')) {
                    // article
                    $article_title = $sa->find('.SecondaryAttachment__childrenText', 0)->innertext;
                    $article_author = explode('Article · from ', $sa->find('.SecondaryAttachmentSubhead', 0)->innertext)[1];
                    $article_link = $sa_href;
                    $content_suffix .= "<br>Article: <a href='$article_link'>$article_title ($article_author)</a>";
                    $sa->outertext = '';
                } else if ($sa_task_click == 'SecondaryAttachment/playAudio') {
                    // audio
                    $audio_json = json_decode(html_entity_decode($sa->getAttribute('data-audio')));
                    $audio_link = $audio_json->url;
                    $audio_title = $sa->find('.SecondaryAttachment__childrenText', 0)->innertext;
                    $audio_author = $sa->find('.SecondaryAttachmentSubhead', 0)->innertext;
                    $content_suffix .= "<br>Audio: <a href='$audio_link'>$audio_title ($audio_author)</a>";
                    $sa->outertext = '';
                } else if ($sa_task_click == 'SecondaryAttachment/playPlaylist') {
                    // playlist link
                    $playlist_title = $sa->find('.SecondaryAttachment__childrenText', 0)->innertext;
                    $playlist_link = $sa->find('.SecondaryAttachment__link', 0)->getAttribute('href');
                    $content_suffix .= "<br>Playlist: <a href='$playlist_link'>$playlist_title</a>";
                    $sa->outertext = '';
                }
            }

            $item = [];
            $content = strip_tags(backgroundToImg($post->find('div.wall_text', 0)->innertext), '<a><br><img>');
            $content .= $content_suffix;
            if (!$content) {
                $content = '(empty post)';
            }
            $content = str_get_html($content);
            foreach ($content->find('img') as $img) {
                $parsed_src = parse_url($img->getAttribute('src'));

                // unblur images (case of impf)
                // get original images instead of thumbnails (case of impg)
                $imgPrefix = array_reduce(['/impf/', '/impg/'], function ($a, $c) use ($parsed_src) {
                    if ($a) {
                        return $a;
                    }
                    if (str_starts_with($parsed_src['path'], $c)) {
                        return $c;
                    }
                    return $a;
                }, '');
                if ($imgPrefix) {
                    $new_src = $parsed_src['scheme'] . '://' . $parsed_src['host'];
                    $new_src .= substr($parsed_src['path'], strlen($imgPrefix) - 1);
                    $img->setAttribute('src', $new_src);
                }
            }
            $item['content'] = $content->outertext;
            $item['categories'] = $hashtags;

            // get post link
            $post_link = $post->find('a.PostHeaderSubtitle__link', 0)->getAttribute('href');
            preg_match('/wall-?\d+_(\d+)/', $post_link, $preg_match_result);
            $item['post_id'] = intval($preg_match_result[1]);
            $item['uri'] = $post_link;
            $item['timestamp'] = $this->getTime($post);
            $item['title'] = $this->getTitle($item['content']);
            $item['author'] = $post_author;
            if ($is_pinned_post) {
                // do not append it now
                $pinned_post_item = $item;
            } else {
                $last_post_id = $item['post_id'];
                $this->items[] = $item;
            }
        }

        if (!is_null($pinned_post_item)) {
            if (count($this->items) == 0) {
                $this->items[] = $pinned_post_item;
            } elseif ($last_post_id < $pinned_post_item['post_id']) {
                $this->items[] = $pinned_post_item;
                usort($this->items, function ($item1, $item2) {
                    return $item2['post_id'] - $item1['post_id'];
                });
            }
        }
    }

    private function getPhoto($a)
    {
        $onclick = $a->getAttribute('onclick');
        preg_match('/return showPhoto\(.+?({.*})/', $onclick, $preg_match_result);
        if (count($preg_match_result) == 0) {
            return;
        }

        $arg = htmlspecialchars_decode(str_replace('queue:1', '"queue":1', $preg_match_result[1]));
        $data = json_decode($arg, true);
        if ($data == null) {
            return;
        }

        $thumb = $data['temp']['base'] . $data['temp']['x_'][0];
        $original = '';
        foreach (['y_', 'z_', 'w_'] as $key) {
            if (!isset($data['temp'][$key])) {
                continue;
            }
            if (!isset($data['temp'][$key][0])) {
                continue;
            }
            if (substr($data['temp'][$key][0], 0, 4) == 'http') {
                $base = '';
            } else {
                $base = $data['temp']['base'];
            }
            $original = $base . $data['temp'][$key][0];
        }

        if ($original) {
            return "<a href='$original'><img src='$thumb'></a>";
        } else {
            return backgroundToImg($a);
        }
    }

    private function getTitle($content)
    {
        $content = explode('<br>', $content)[0];
        $content = strip_tags($content);
        preg_match('/^[:\,"\w\ \p{L}\(\)\?#«»\-\–\—||&\.%\\₽\/+\;\!]+/mu', htmlspecialchars_decode($content), $result);
        if (count($result) == 0) {
            return 'untitled';
        }
        return $result[0];
    }

    private function getTime($post)
    {
        $accurateDateElement = $post->find('span.rel_date', 0);
        if ($accurateDateElement) {
            return $accurateDateElement->getAttribute('time');
        } else {
            $strdate = $post->find('time.PostHeaderSubtitle__item', 0)->plaintext;
            $strdate = preg_replace('/[\x00-\x1F\x7F-\xFF]/', ' ', $strdate);

            $date = date_parse($strdate);
            if (!$date['year']) {
                if (strstr($strdate, 'today') !== false) {
                    $strdate = date('d-m-Y') . ' ' . $strdate;
                } elseif (strstr($strdate, 'yesterday ') !== false) {
                    $time = time() - 60 * 60 * 24;
                    $strdate = date('d-m-Y', $time) . ' ' . $strdate;
                } elseif ($date['month'] && intval(date('m')) < $date['month']) {
                    $strdate = $strdate . ' ' . (date('Y') - 1);
                } else {
                    $strdate = $strdate . ' ' . date('Y');
                }

                $date = date_parse($strdate);
            } elseif ($date['hour'] === false) {
                $date['hour'] = $date['minute'] = '00';
            }
            return strtotime($date['day'] . '-' . $date['month'] . '-' . $date['year'] . ' ' .
                $date['hour'] . ':' . $date['minute']) - $this->tz;
        }
    }

    private function getContents()
    {
        $httpHeaders = [
            'Accept-language: en',
            'Cookie: remixlang=3',
        ];
        $redirects = 0;
        $uri = $this->getURI();

        while ($redirects < 2) {
            $response = getContents($uri, $httpHeaders, [CURLOPT_FOLLOWLOCATION => false], true);

            if (in_array($response['code'], [200, 304])) {
                return $response['content'];
            }

            $headers = $response['headers'];
            $uri = urljoin(self::URI, $headers['location'][0]);

            if (str_contains($uri, '/429.html')) {
                returnServerError('VK responded "Too many requests"');
            }

            if (!preg_match('#^https?://vk.com/#', $uri)) {
                returnServerError('Unexpected redirect location');
            }

            $redirects++;
        }

        returnServerError('Too many redirects, while retreving content from VK');
    }

    protected function appendVideo($video_title, $video_link, $previewImg, &$content_suffix)
    {
        if (!$video_title) {
            $video_title = '(empty)';
        }

        $content_suffix .= '<br><a href="' . htmlspecialchars($video_link) . '">' . $previewImg;
        $content_suffix .= 'Video: ' . $video_title . '</a>';
    }
}