<?php
// Mastodonapi extension, https://codeberg.org/simonpipe/yellow-mastodonapi

class YellowMastodonapi {
    const VERSION = "0.9.2";
    public $yellow;         // access to API

    // Initialize extension
    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("mastodonapiUpdateInterval", "30");
        $this->yellow->system->setDefault("mastodonapiLimit", "20");
        $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("mastodonapiMaxAge", "0");
        $this->yellow->system->setDefault("mastodonapiStatus", "public");
    }

    // Handle update
    public function onUpdate($action) {
        if ( $action=="mastodon" || $action=="daily" || $action=="install" ) {
            $this->updateMastodonPosts();
        }
    }

    // Handle command
    public function onCommand($command, $text) {
        if ( $command=="mastodonapi" ) {
            echo "Mastodon Import gestartet...\n";
            $count = $this->updateMastodonPosts();
            if ( $count===false ) {
                echo "Fehler: API nicht erreichbar oder falsche ID.\n";
                return 500;
            }
            echo "Erfolg: " . $count . " neue Posts verarbeitet.\n";
            return true;
        }
        return 0;
    }

    // Handle periodic update
    public function onTick() {
        $interval = intval($this->yellow->system->get("mastodonapiUpdateInterval")) * 60;
        $statusFile = $this->getStatusFile();
        $lastUpdate = file_exists($statusFile) ? intval(file_get_contents($statusFile)) : 0;
        if ( time() - $lastUpdate >= $interval ) {
            $this->updateMastodonPosts();
        }
    }

    // Update Mastodon posts
    public function updateMastodonPosts() {
        $postsCreated = $this->processMastodonFeed();
        if ( $postsCreated!==false ) {
            file_put_contents($this->getStatusFile(), time());
        }
        return $postsCreated;
    }

    // Process Mastodon feed and create pages
    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");
        $statusSetting = $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;
        $headers = array("User-Agent: YellowMastodonapi/" . self::VERSION);
        if ( !empty($accessToken) ) $headers[] = "Authorization: Bearer " . $accessToken;
        $ch = curl_init($apiUrl);
        curl_setopt_array($ch, array(
            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;
        $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 ( $maxAgeHours > 0 ) {
                if ( strtotime($createdAt) < ( time() - ( $maxAgeHours * 3600 ) ) ) continue;
            }
            $tags = array_column($post["tags"] ?? array(), "name");
            if ( !empty($hashtag) && !in_array(strtolower($hashtag), array_map("strtolower", $tags)) ) continue;
            $title = $this->generateTitle($contentHtml);
            $titleSlug = $this->generateTitleSlug($title);
            $fileName = date("Y-m-d", strtotime($createdAt)) . "-" . $titleSlug . ".md";
            $fullPath = $this->yellow->system->get("coreServerDocument") . $targetFolder . $fileName;
            if ( file_exists($fullPath) ) continue;
            
            if ( !is_dir(dirname($fullPath)) ) {
                mkdir(dirname($fullPath), 0777, true);
                chmod(dirname($fullPath), 0777);
            }

            $imageFilenames = array();
            $imageAltTexts = array();
            foreach ( $post["media_attachments"] ?? array() as $media ) {
                if ( ( $media["type"] ?? "" )==="image" ) {
                    $filename = $this->downloadAndSaveImage($media, $this->yellow->system->get("coreServerDocument") . "media/images/");
                    if ( $filename ) {
                        $imageFilenames[] = $filename;
                        $imageAltTexts[] = $media["description"] ?? "";
                    }
                }
            }
            $markdownContent = $this->generateMarkdown(
                $title, $titleSlug, $createdAt, $contentHtml, 
                $post["account"]["display_name"] ?: $defaultAuthor, 
                $post["account"]["url"] ?: "#", 
                $defaultAuthor, $defaultTag, $imageFilenames, $imageAltTexts, $statusSetting
            );
            file_put_contents($fullPath, $markdownContent);
            chmod($fullPath, 0666);
            $postsCreated++;
        }
        return $postsCreated;
    }

    // Download and save image
    private function downloadAndSaveImage($media, $dirPath) {
        $imageUrl = $media["remote_url"] ?? $media["url"] ?? $media["preview_url"] ?? null;
        if ( empty($imageUrl) ) return false;
        
        if ( !is_dir($dirPath) ) {
            mkdir($dirPath, 0777, true);
            chmod($dirPath, 0777);
        }

        $fileName = basename(parse_url($imageUrl, PHP_URL_PATH));
        $fullPath = $dirPath . $fileName;
        
        if ( file_exists($fullPath) ) return $fileName;
        
        $ch = curl_init($imageUrl);
        curl_setopt_array($ch, array(
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_USERAGENT => "YellowMastodonapi/" . self::VERSION,
            CURLOPT_SSL_VERIFYPEER => true,
        ));
        $imgData = curl_exec($ch);
        curl_close($ch);
        
        if ( !$imgData ) return false;
        file_put_contents($fullPath, $imgData);
        chmod($fullPath, 0666);
        return $fileName;
    }

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

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

    // Generate markdown content
    private function generateMarkdown($title, $slug, $dateTime, $html, $origAuthor, $origUrl, $yellowAuthor, $yellowTag, $images, $alts, $status) {
        $date = new DateTime($dateTime);
        $pub = $date->format("Y-m-d H:i:s");
        $content = trim(html_entity_decode(strip_tags(str_replace(array("<br>", "</p>"), array("\n", "</p>\n"), $html)), ENT_QUOTES | ENT_HTML5, "UTF-8"));
        $content = str_replace(array("\n", "#"), array("\n> ", "&#35;"), $content);
        $imageMarkdown = "";
        $featuredImage = $featuredImageAlt = "";
        foreach ( $images as $i => $filename ) {
            $alt = isset($alts[$i]) ? htmlspecialchars($alts[$i], ENT_QUOTES) : "";
            $imageMarkdown .= "\n<img src=\"/media/images/$filename\" alt=\"$alt\"/>\n";
            if ( $i===0 ) {
                $featuredImage = "Image: $filename\n";
                $featuredImageAlt = "ImageAlt: $alt\n";
            }
        }
        $authorSafe = str_replace("@", "&#64;", $origAuthor);
        return "---\n" .
            "Title: $title\n" .
            "TitleSlug: $slug\n" .
            "Published: $pub\n" .
            "Author: $yellowAuthor\n" .
            "Layout: blog\n" .
            "Tag: $yellowTag\n" .
            "Status: $status\n" .
            $featuredImage . $featuredImageAlt .
            "---\n\n" .
            $imageMarkdown . "\n" .
            "> " . $content . "\n>\n" .
            "> — <a target=\"_blank\" href=\"$origUrl\">$authorSafe</a>";
    }

    // Return status file path
    private function getStatusFile() {
        return $this->yellow->system->get("coreWorkerDirectory") . "mastodonapi.status";
    }
}