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

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

if (isset($_GET["category"]) && !empty($_GET["category"]) && articleCategoryValidator($_GET["category"])){
    $category = $_GET["category"];

    // Sortierung auslesen (Standard: alphabet)
    $sortStyle = isset($_GET['sort']) ? trim($_GET['sort']) : 'alphabet';

    // Aktuelle Seite auslesen
    $page = isset($_GET['page']) ? (int)$_GET['page'] : 1;
    if ($page < 1) { $page = 1; }

    try {
        $articleManager = ArticleManager::getInstance();
        $userManager = UserManager::getInstance();
        $allArticles = $articleManager->getArticlesByCategory($category);
        foreach ($allArticles as $article) {
            $article->setAuthor($userManager->findUser($article->getAuthor())["vorname"] . " " . $userManager->findUser($article->getAuthor())["nachname"]);
        }
        $totalArticles = count($allArticles);

        // --- SORTIERUNG LOGIK ---
        if ($sortStyle === 'alphabet') {
            usort($allArticles, function($a, $b) {
                return strcasecmp($a->getTitle(), $b->getTitle());
            });
        } elseif ($sortStyle === 'likes') {
            usort($allArticles, function($a, $b) {
                return $b->getLikes() <=> $a->getLikes(); // Absteigend nach Likes
            });
        } elseif ($sortStyle === 'newest') {
            usort($allArticles, function($a, $b) {
                return strtotime($b->getCreationDate()) <=> strtotime($a->getCreationDate()); // Neueste zuerst
            });
        } elseif ($sortStyle === 'oldest') {
            usort($allArticles, function($a, $b) {
                return strtotime($a->getCreationDate()) <=> strtotime($b->getCreationDate()); // Älteste zuerst
            });
        }

        // Paginierung konfigurieren
        $limit = 10;
        $totalPages = ceil($totalArticles / $limit);
        if ($page > $totalPages && $totalPages > 0) { $page = $totalPages; }

        $offset = ($page - 1) * $limit;
        $articles = array_slice($allArticles, $offset, $limit);

    } catch (Exception $e) {
        $_SESSION["message"] = "internal_error";
        include_once "content/404.php";
        exit();
    }
} else {
    $_SESSION["message"] = "invalid_category";
    include_once "content/404.php";
    exit();
}
?>