<?php
if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

require_once '../model/LocalArticleManager.php';
require_once '../model/ArticleManager.php';
require_once '../model/Article.php';
require_once '../validator/article-validator.php';

if ($_SERVER["REQUEST_METHOD"] === "POST") {
    $_SESSION["old_title"]    = $_POST["title"] ?? '';
    $_SESSION["old_content"]  = $_POST["content"] ?? '';
    $_SESSION["old_category"] = $_POST["category"] ?? ''; // TODO: die Kategorie im Dropdown setzen, wenn der Editor erneut geöffnet wird.
    $_SESSION["old_tags"]     = $_POST["tags"] ?? '';

    if (isset($_GET["id"]) && !empty($_GET["id"])) {
        $id = $_GET["id"];
    } else {
        $_SESSION["message"] = "missing_id";
        header("location: ../../index.php?pfad=updateArticle");
        exit();
    }

    if (!isset($_POST["title"]) ||!isset($_POST["content"]) || !isset($_POST["category"])){
        $_SESSION["message"] = "missing_parameters";
        header("location: ../../index.php?pfad=updateArticle&id=$id");
        exit();
    }else{
        $title = $_POST["title"];
        $content = $_POST["content"];
        $author = $_SESSION["user_email"];
        $category = $_POST["category"];
        $tags = $_POST['tags'] ?? '';

        // -------------------------------- Validierung der Daten: -------------------------
        if (!articleTitleValidator($title)) {
            $_SESSION["message"] = "invalid_title";
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        }

        if (!articleContentValidator($content)) {
            $_SESSION["message"] = "invalid_content";
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        }

        if (!articleCategoryValidator($category)) {
            $_SESSION["message"] = "invalid_category";
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        }

        if (!articleTagValidator($tags)) {
            $_SESSION["message"] = "invalid_tags";
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        } else {
            $cleanedTags = [];
            $rawTags = explode(',', $tags);
            foreach ($rawTags as $rawTag) {
                // Leerzeichen am Anfang/Ende des einzelnen Tags entfernen:
                $tag = trim($rawTag);
                $cleanedTags[] = $tag;
            }
            // Duplikate entfernen:
            $cleanedTags = array_unique($cleanedTags);
            $cleanedTags = implode(',', $cleanedTags);
        }

        // ----------------- Base64-Bilder speichern -----------------
        $blocks = json_decode($content, true);
        $uploadDir = __DIR__ . '/../../uploads/';

        if (!file_exists($uploadDir)) {
            mkdir($uploadDir, 0755, true);
        }

        // --- Verwaiste Bilder löschen:
        try {
            // 1. Alten Artikelzustand vor dem Update aus der Datenbank laden
            $articleManager = ArticleManager::getInstance();
            $oldArticle = $articleManager->getArticle($id);
            $oldBlocks = json_decode($oldArticle->getContent(), true);

            if (is_array($oldBlocks) && is_array($blocks)) {
                $oldImages = [];
                $newImages = [];

                // Alle Bildpfade aus dem alten Zustand sammeln
                foreach ($oldBlocks as $oldBlock) {
                    if (isset($oldBlock['type'], $oldBlock['value']) && $oldBlock['type'] === 'image' && !str_starts_with($oldBlock['value'], 'data:image/')) {
                        $oldImages[] = $oldBlock['value'];
                    }
                }

                // Alle Bildpfade aus dem neuen Zustand sammeln
                foreach ($blocks as $newBlock) {
                    if (isset($newBlock['type'], $newBlock['value']) && $newBlock['type'] === 'image' && !str_starts_with($newBlock['value'], 'data:image/')) {
                        $newImages[] = $newBlock['value'];
                    }
                }

                // Differenz ermitteln: Welche Pfade waren alt da, sind neu aber weg?
                $deletedImages = array_diff($oldImages, $newImages);

                // Diese Dateien physisch vom Server löschen
                foreach ($deletedImages as $imagePath) {
                    // Extra-Sicherheit: Nur Dateien im eigenen Uploads-Ordner löschen
                    $filename = basename($imagePath);
                    $fullDeletePath = $uploadDir . $filename;

                    if (file_exists($fullDeletePath) && is_file($fullDeletePath)) {
                        unlink($fullDeletePath);
                    }
                }
            }
        } catch (\Throwable $e) {
            $_SESSION["message"] = $e->getMessage();
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        }

        // --- NEU hinzugefügte Base64-Bilder:
        if (is_array($blocks)) {
            foreach ($blocks as &$block) {
                // Prüfen, ob der Block ein Bild ist und ein NEUES Bild (Base64-Format) enthält
                if (isset($block['type']) && isset($block['value']) && $block['type'] === 'image' && is_string($block['value'])) {

                    if (str_starts_with($block['value'], 'data:image/')) {
                        $parts = explode(',', $block['value']);
                        if (count($parts) >= 2) {
                            $metadata = $parts[0];
                            $base64Data = $parts[1];

                            preg_match('/data:image\/(?<extension>.*?);/', $metadata, $matches);
                            $extension = $matches['extension'] ?? 'jpg';
                            if ($extension === 'jpeg') { $extension = 'jpg'; }

                            $fileName = 'img_' . uniqid() . '.' . $extension;
                            $filePath = $uploadDir . $fileName;

                            if (file_put_contents($filePath, base64_decode($base64Data)) !== false) {
                                $block['value'] = 'uploads/' . $fileName;
                            } else {
                                $_SESSION["message"] = "image_upload_error";
                                header("location: ../../index.php?pfad=updateArticle&id=$id");
                                exit();
                            }
                        }
                    }
                }
            }
            unset($block);
        }

        // Aktualisiertes Array wieder in JSON konvertieren
        $finalContent = json_encode($blocks, JSON_UNESCAPED_UNICODE);

        // ----------------- Übertragung der validierten Daten in ArticleManager: ---------------------------
        try {
            $articleManager = ArticleManager::getInstance();
            $article = $articleManager->getArticle($id);
            $article->setTitle($title);
            $article->setContent($finalContent);
            $article->setCategory($category);
            $article->setTags($cleanedTags);
            $articleManager->updateArticle($id ,$article, $author);

            unset($_SESSION["old_title"], $_SESSION["old_content"], $_SESSION["old_category"], $_SESSION["old_tags"]);

        } catch (\Throwable $e){
            $_SESSION["message"] = $e->getMessage();
            header("location: ../../index.php?pfad=updateArticle&id=$id");
            exit();
        }
        $_SESSION["message"] = "article_updated";
        // Weiterleitung zur Homepage
        header("location: ../../index.php?pfad=showArticle&id=$id");
    }
}

?>