<?php
// Public Domain
// MastodonAPI extension, https://codeberg.org/simonpipe/yellow-mastodonapi

class YellowMastodonAPI {
    const VERSION = "0.1";
    public $yellow;

    public function onLoad($yellow) {
        $this->yellow = $yellow;
        $this->yellow->system->setDefault("mastodonapiInstanceUrl", "https://example.social");
        $this->yellow->system->setDefault("mastodonapiAccountId", "");
        $this->yellow->system->setDefault("mastodonapiAccessToken", ""); 
        $this->yellow->system->setDefault("mastodonapiHashtag", "");
        $this->yellow->system->setDefault("mastodonapiAuthor", "YellowUser");
        $this->yellow->system->setDefault("mastodonapiTag", "Fediverse");
        $this->yellow->system->setDefault("mastodonapiFolder", "content/2-blog/");
        $this->yellow->system->setDefault("mastodonapiTriggerPath", "/mastodonapi-webhook-CHANGE_THIS_SECRET_KEY");
        $this->yellow->system->setDefault("mastodonapiLimit", "20");
        $this->yellow->system->setDefault("mastodonapiStatus", "public"); // public; draft = page is not visible, user needs to log in, requires draft extension; unlisted = page is not visible, but can be accessed with the correct link
        $this->yellow->system->setDefault("mastodonapiMaxAge", "0"); // In Stunden. 0 = alle Toots.
    }

    public function onRequest($scheme, $address, $base, $location, $fileName) {
        $triggerPath = $this->yellow->system->get("mastodonapiTriggerPath");
        if ($location == $triggerPath) {
            $postsCreated = $this->processMastodonFeed();
            $this->sendResponse(
                $postsCreated !== false 
                    ? "Mastodon/GoToSocial API feed processed. Created $postsCreated posts."
                    : "Error processing Mastodon/GoToSocial API feed.",
                $postsCreated !== false ? 200 : 500
            );
            return 1;
        }
        return 0;
    }

    public function onCommand($command, $text) {
        if (!$this->yellow) return 500;
        switch ($command) {
            case "mastodonapi":
                if (!empty($text)) return 400;
                $postsCreated = $this->processMastodonFeed();
                return ($postsCreated !== false) ? 0 : 500;
            default:
                return 0;
        }
    }

    private function processMastodonFeed() {
        $instanceUrl   = $this->yellow->system->get("mastodonapiInstanceUrl");
        $accountId     = $this->yellow->system->get("mastodonapiAccountId");
        $accessToken   = $this->yellow->system->get("mastodonapiAccessToken");
        $hashtag       = ltrim($this->yellow->system->get("mastodonapiHashtag"), '#');
        $defaultAuthor = $this->yellow->system->get("mastodonapiAuthor");
        $defaultTag    = $this->yellow->system->get("mastodonapiTag");
        $targetFolder  = $this->yellow->system->get("mastodonapiFolder");
        $status        = $this->yellow->system->get("mastodonapiStatus");
        $maxAgeHours   = intval($this->yellow->system->get("mastodonapiMaxAge"));
        $limit         = intval($this->yellow->system->get("mastodonapiLimit"));

        if (empty($instanceUrl) || empty($accountId)) {
            return false;
        }

        $apiUrl = rtrim($instanceUrl, "/") . "/api/v1/accounts/" . $accountId . "/statuses?limit=" . $limit;

        $headers = ["User-Agent: YellowMastodonAPI"];
        if (!empty($accessToken)) {
            $headers[] = "Authorization: Bearer " . $accessToken;
        }

        $ch = curl_init($apiUrl);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTPHEADER => $headers,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2
        ]);
        $json = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($json === false || $httpCode < 200 || $httpCode >= 300) {
            return false;
        }

        $posts = json_decode($json, true);
        if (!is_array($posts)) {
            return false;
        }

        $config = $this->getYellowConfig();
        $postsCreated = 0;

        foreach ($posts as $post) {
            if (!empty($post['reblog']) || (!empty($post['reblogged']) && $post['reblogged'] === true)) continue;
            if (!is_null($post['in_reply_to_id'])) continue;

            $contentHtml = $post['content'] ?? '';
            $createdAt   = $post['created_at'] ?? '';
            if ($maxAgeHours > 0) {
                $postTimestamp = strtotime($createdAt);
                $threshold = time() - ($maxAgeHours * 3600);
                if ($postTimestamp < $threshold) continue;
            }
            $tags        = array_column($post['tags'] ?? [], 'name');

            if (!empty($hashtag) && !in_array(strtolower($hashtag), array_map('strtolower', $tags))) {
                continue;
            }

            $title = $this->generateTitle($contentHtml);
            $titleSlug = $this->generateTitleSlug($title);
            $datePrefix = date('Y-m-d', strtotime($createdAt));
            $fileName = $datePrefix . '-' . $titleSlug . '.md';
            $fullPath = $config->get("coreServerDocument") . $targetFolder . $fileName;

            if (file_exists($fullPath)) continue;
            if (!is_dir(dirname($fullPath))) mkdir(dirname($fullPath), 0755, true);

            $authorName = $post['account']['display_name'] ?: $defaultAuthor;
            $authorUrl  = $post['account']['url'] ?: "#";

            $imageFilenames = [];
            $imageAltTexts  = [];

            foreach ($post['media_attachments'] ?? [] as $media) {
                if (($media['type'] ?? '') === 'image') {
                    $filename = $this->downloadAndSaveImage($media, $config->get("coreServerDocument") . 'media/images/');
                    if ($filename) {
                        $imageFilenames[] = $filename;
                        $imageAltTexts[]  = $media['description'] ?? '';
                    }
                }
            }

            $markdownContent = $this->generateMarkdown(
                $title,
                $titleSlug,
                $createdAt,
                $contentHtml,
                $authorName,
                $authorUrl,
                $defaultAuthor,
                $defaultTag,
                $imageFilenames,
                $imageAltTexts,
                $status
            );

            file_put_contents($fullPath, $markdownContent);
            $postsCreated++;
        }

        return $postsCreated;
    }

    private function downloadAndSaveImage($media, $dirPath) {
        $imageUrl = $media['remote_url']
                 ?? $media['url']
                 ?? $media['preview_url']
                 ?? ($media['meta']['original']['url'] ?? null)
                 ?? ($media['meta']['small']['url'] ?? null);

        if (empty($imageUrl)) {
            return false;
        }

        if (!is_dir($dirPath)) mkdir($dirPath, 0755, true);

        $fileName = basename(parse_url($imageUrl, PHP_URL_PATH));
        $fullPath = $dirPath . $fileName;
        if (file_exists($fullPath)) return $fileName;

        $ch = curl_init($imageUrl);
        $headers = ["User-Agent: YellowMastodonAPI"];
        $accessToken = $this->yellow->system->get("mastodonapiAccessToken");
        if (!empty($accessToken)) {
            $headers[] = "Authorization: Bearer " . $accessToken;
        }
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTPHEADER => $headers,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
        ]);
        $imgData = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($imgData === false || $httpCode < 200 || $httpCode >= 300) {
            return false;
        }

        file_put_contents($fullPath, $imgData);
        return $fileName;
    }

    private function generateTitle($content) {
        $text = strip_tags($content);
        $text = preg_replace('/https?:\/\/[^\s]+|#\w+/u', '', $text);
        $text = preg_replace('/[^\p{L}\p{N}\s-]/u', '', $text);
        $text = trim(preg_replace('/\s+/', ' ', $text));
        $words = explode(' ', $text);
        return trim(mb_substr(implode(' ', array_slice($words, 0, 7)), 0, 100, 'UTF-8')) ?: "Mastodon Post";
    }

    private function generateTitleSlug($title) {
        $slug = mb_strtolower($title, 'UTF-8');
        $slug = str_replace(['ä','ö','ü','Ä','Ö','Ü','ß',' '], ['ae','oe','ue','ae','oe','ue','ss','-'], $slug);
        return trim(preg_replace('/[^a-z0-9-]+/', '', $slug), '-');
    }

    private function generateMarkdown($title, $slug, $dateTime, $html, $origAuthor, $origUrl, $yellowAuthor, $yellowTag, $images = [], $alts = [], $status = "public") {
        $date = new DateTime($dateTime);
        $formattedDate = $date->format('Y-m-d');
        $formattedTime = $date->format('H:i:s');

        $content = strip_tags($html);
        $content = html_entity_decode($content, ENT_QUOTES | ENT_HTML5, 'UTF-8');

        $hashtagString = ''; 
        if (preg_match('/(\s*(#\w+))+$/u', $content, $matches)) {
            $content = substr($content, 0, -strlen($matches[0]));
            if (preg_match_all('/#(\w+)/u', $matches[0], $tags)) {
                $safeHashtags = array_map(function($tag) {
                    return str_replace('#', '&num;', $tag);
                }, $tags[0]);
                $hashtagString = implode(' ', $safeHashtags);
            }
        }
    
        $content = trim(preg_replace('/\s+/', ' ', $content));

        $imageMarkdown = '';
        foreach ($images as $i => $filename) {
            $alt = isset($alts[$i]) ? htmlspecialchars($alts[$i], ENT_QUOTES) : '';
            $imageMarkdown .= "\n<img src=\"/media/images/" . $filename . "\" alt=\"" . $alt . "\"/>\n";
        }

        $featuredImage = '';
        $featuredImageAlt = '';
        if (!empty($images)) {
            $featuredImage = "Image: " . $images[0] . "\n";
            if (isset($alts[0]) && !empty($alts[0])) {
                $featuredImageAlt = "ImageAlt: " . htmlspecialchars($alts[0], ENT_QUOTES) . "\n";
            }
        }

        $htmlSafeAuthorName = str_replace('@', '&#64;', $origAuthor);

        $blockquote = "> $content";
        if (!empty($hashtagString)) {
            $blockquote .= "\n>\n> " . $hashtagString;
        }
        $blockquote .= "\n>\n> — <a target=\"_blank\" href=\"$origUrl\">$htmlSafeAuthorName</a>";

        return <<<MD
---
Title: $title
TitleSlug: $slug
Published: $formattedDate $formattedTime
Author: $yellowAuthor
Layout: blog
Tag: $yellowTag
Status: $status
$featuredImage$featuredImageAlt---
$imageMarkdown
$blockquote
MD;
    }

    private function getYellowConfig() {
        return $this->yellow ? $this->yellow->system : null;
    }

    private function sendResponse($message, $statusCode = 200) {
        if (!headers_sent()) {
            header("HTTP/1.1 $statusCode");
            header("Content-Type: text/html; charset=UTF-8");
        }
        
        // Basis-URL aus der aktuellen Anfrage bestimmen
            $fullUrl = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http")
                     . "://{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";

            // Trigger-Pfad aus der Yellow-Konfiguration holen
            $triggerPath = $this->yellow->system->get("mastodonapiTriggerPath");

            // Ziel-URL: Alles vor dem Trigger-Pfad abschneiden
            $redirectUrl = str_replace($triggerPath, "/", $fullUrl);
            
        echo "<!DOCTYPE html><html><head>";
        echo "<meta http-equiv='refresh' content='5;url={$redirectUrl}'>";
        echo "<title>Mastodon/GoToSocial API</title></head><body>";
        echo "<p>" . htmlspecialchars($message) . "</p>";
        echo "<p>You will be redirected in 5 seconds...</p>";
        echo "</body></html>";
        exit;
    }
}