webprogrammierung/php/model/LocalArticleManager.php

<?php
require_once 'ArticleManagerDAO.php';
require_once 'Article.php';
/**
 * Klasse: Eine lokale Lösung des ArticleManagerDAO.
 * Schreibt zunächst Daten lokal in das Verzeichnis und kann diese wieder auslesen.
 *
 * @author Niklas Ortmann
 */
class LocalArticleManager implements ArticleManagerDAO {

    private $file;
    private static $instance = null;

    /**
     * Konstruktor
     */
    public function __construct()
    {
        $this->file = __DIR__ . '/../../data/articles.json';
    }

    /**
     * Gibt die LocalArticleManager-Instanz zurück.
     * @return LocalArticleManager
     */
    public static function getInstance()
    {
        if (self::$instance == null) {
            self::$instance = new LocalArticleManager();
        }
        return self::$instance;
    }

    /**
     * Speichert alle Artikel/Beiträge in der Datei.
     * @param $articles
     * @return void
     */
    public function saveArticle($articles)
    {
        file_put_contents(
            $this->file,
            json_encode($articles, JSON_PRETTY_PRINT)
        );
    }

    public function addArticle($title, $content, $author, $category, $tags)
    {
        $articles = $this->getAllArticles();

        $articles[] = [
            "id" => count($articles)+1,
            "title" => $title,
            "content" => $content,
            "author" => $author,
            "category" => $category,
            "tags" => $tags,
            "creationDate" => date("Y-m-d H:i:s")
        ];

        $this->saveArticle($articles);
    }

    public function updateArticle($id, $article, $author)
    {
        if (empty($article)) {
            // TODO: Implement Exception.
            return;
        }

        // Berechtigungsprüfung:
        if ($article->getAuthor() !== $author) {
            // TODO: Implement Exception.
            return;
        }

        // Beitrag aktualisieren:
        $articles = $this->getAllArticles();
        $updated = false;

        foreach ($articles as $index => $storedArticle) {
            if (isset($storedArticle['id']) && $storedArticle['id'] == $id) {
                $articles[$index] = [
                    "id" => $id,
                    "title" => $article->getTitle(),
                    "content" => $article->getContent(),
                    "author" => $author,
                    "category" => $article->getCategory(),
                    "tags" => $article->getTags(),
                    "creationDate" => $article->getCreationDate()
                ];
                $updated = true;
                break;
            }else{
                // TODO: Implement Exception.
                return;
            }
        }

        // Nur speichern, wenn Beitrag geändert wurde:
        if ($updated) {
            $this->saveArticle($articles);
        }
    }

    public function deleteArticle($id)
    {
        $articles = $this->getAllArticles();
        $articleFound = false;

        foreach ($articles as $index => $article) {
            if (isset($article['id']) && $article['id'] == $id) {
                unset($articles[$index]);
                $articleFound = true;
                break; // Schleife abbrechen, da die ID eindeutig ist
            }
        }

        if ($articleFound) {
            // array_values stellt sicher, dass die Array-Keys wieder fortlaufend bei 0 beginnen
            $this->saveArticle(array_values($articles));
        }
    }

    public function getArticle($id)
    {
        $articles = $this->getAllArticles();

        foreach ($articles as $article) {
            if (isset($article['id']) && $article['id'] == $id) {
                return new Article(intval($article['id']), $article['title'], $article['content'], $article['author'], $article['category'], $article['tags'], $article['creationDate']);
            }
        }

        return null;
    }

    public function getAllArticles(): array
    {
        if (!file_exists($this->file)) {
            return [];
        }

        $json = file_get_contents($this->file);
        $articles = json_decode($json, true);

        return is_array($articles) ? $articles : [];
    }

    public function getArticlesByAuthor($author)
    {
        $articles = $this->getAllArticles();
        $filteredArticles = [];

        foreach ($articles as $article) {
            if (isset($article['author']) && $article['author'] == $author) {
                $filteredArticles[] = new Article(
                    intval($article['id']),
                    $article['title'],
                    $article['content'],
                    $article['author'],
                    $article['category'],
                    $article['tags'],
                    $article['creationDate']
                );
            }
        }
        return $filteredArticles;
    }
}
?>