<?php
/**
 * Copyright seit 2024 Webshop System
 *
 * Admin-Kategorien-Controller für das Webshop-System
 *
 * @author    Webshop System
 * @license   GPL v3
 */

namespace App\Admin\Controllers;

use Doctrine\DBAL\DriverManager;
use Doctrine\DBAL\Exception;

class AdminCategoryController
{
    public function index()
    {
        // Session prüfen
        session_start();
        if (!isset($_SESSION['admin_user_id'])) {
            header('Location: /admin/login');
            exit;
        }

        // DB-Verbindung herstellen
        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Kategorien laden mit Hierarchie und Produktanzahl
            $stmt = $conn->prepare('
                SELECT c.*, 
                       p.name as parent_name,
                       COUNT(pr.id) as product_count
                FROM ws_category c 
                LEFT JOIN ws_category p ON c.parent_id = p.id
                LEFT JOIN ws_product pr ON c.id = pr.category_id
                GROUP BY c.id
                ORDER BY c.parent_id ASC, c.sort_order ASC, c.name ASC
            ');
            $stmt->execute();
            
            $categories = [];
            while ($row = $stmt->fetchAssociative()) {
                $categories[] = $row;
            }
            
            // Hierarchische Struktur erstellen
            $hierarchicalCategories = $this->buildHierarchy($categories);
            
            $this->render('admin/categories/index.html.twig', [
                'title' => 'Webshop Admin - Kategorien',
                'user_name' => $_SESSION['admin_user_name'],
                'categories' => $categories,
                'hierarchicalCategories' => $hierarchicalCategories
            ]);
            
        } catch (Exception $e) {
            $this->render('admin/categories/index.html.twig', [
                'title' => 'Webshop Admin - Kategorien',
                'user_name' => $_SESSION['admin_user_name'],
                'categories' => [],
                'hierarchicalCategories' => [],
                'error' => 'Datenbankfehler: ' . $e->getMessage()
            ]);
        }
    }

    public function show($id)
    {
        // Session prüfen
        session_start();
        if (!isset($_SESSION['admin_user_id'])) {
            header('Location: /admin/login');
            exit;
        }

        // DB-Verbindung herstellen
        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Kategorie laden
            $stmt = $conn->prepare('
                SELECT c.*, p.name as parent_name
                FROM ws_category c 
                LEFT JOIN ws_category p ON c.parent_id = p.id
                WHERE c.id = ?
            ');
            $stmt->execute([$id]);
            $category = $stmt->fetchAssociative();
            
            if (!$category) {
                header('Location: /admin/categories?error=Kategorie nicht gefunden');
                exit;
            }
            
            // Produkte der Kategorie laden
            $stmt = $conn->prepare('
                SELECT p.*, COUNT(op.product_id) as order_count
                FROM ws_product p 
                LEFT JOIN ws_order_product op ON p.id = op.product_id
                WHERE p.category_id = ?
                GROUP BY p.id
                ORDER BY p.created_at DESC
            ');
            $stmt->execute([$id]);
            
            $products = [];
            while ($row = $stmt->fetchAssociative()) {
                $products[] = $row;
            }
            
            // Unterkategorien laden
            $stmt = $conn->prepare('
                SELECT c.*, COUNT(p.id) as product_count
                FROM ws_category c 
                LEFT JOIN ws_product p ON c.id = p.category_id
                WHERE c.parent_id = ?
                GROUP BY c.id
                ORDER BY c.sort_order ASC, c.name ASC
            ');
            $stmt->execute([$id]);
            
            $subcategories = [];
            while ($row = $stmt->fetchAssociative()) {
                $subcategories[] = $row;
            }
            
            $this->render('admin/categories/show.html.twig', [
                'title' => 'Webshop Admin - Kategorie Details',
                'user_name' => $_SESSION['admin_user_name'],
                'category' => $category,
                'products' => $products,
                'subcategories' => $subcategories
            ]);
            
        } catch (Exception $e) {
            header('Location: /admin/categories?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    public function create()
    {
        // Session prüfen
        session_start();
        if (!isset($_SESSION['admin_user_id'])) {
            header('Location: /admin/login');
            exit;
        }

        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
            $this->store();
            return;
        }

        // Kategorien für Parent-Auswahl laden
        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            $stmt = $conn->prepare('SELECT id, name, parent_id FROM ws_category ORDER BY name ASC');
            $stmt->execute();
            
            $categories = [];
            while ($row = $stmt->fetchAssociative()) {
                $categories[] = $row;
            }
            
            $this->render('admin/categories/create.html.twig', [
                'title' => 'Webshop Admin - Neue Kategorie',
                'user_name' => $_SESSION['admin_user_name'],
                'categories' => $categories
            ]);
            
        } catch (Exception $e) {
            header('Location: /admin/categories?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    private function store()
    {
        $name = $_POST['name'] ?? '';
        $description = $_POST['description'] ?? '';
        $parent_id = $_POST['parent_id'] ?? null;
        $sort_order = $_POST['sort_order'] ?? 0;
        $active = isset($_POST['active']) ? 1 : 0;

        if (empty($name)) {
            header('Location: /admin/categories/create?error=Name ist erforderlich');
            exit;
        }

        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Prüfen ob Name bereits existiert
            $stmt = $conn->prepare('SELECT id FROM ws_category WHERE name = ?');
            $stmt->execute([$name]);
            if ($stmt->fetchAssociative()) {
                header('Location: /admin/categories/create?error=Name bereits vergeben');
                exit;
            }
            
            $stmt = $conn->prepare('
                INSERT INTO ws_category (name, description, parent_id, sort_order, active) 
                VALUES (?, ?, ?, ?, ?)
            ');
            $stmt->execute([$name, $description, $parent_id, $sort_order, $active]);
            
            header('Location: /admin/categories?success=Kategorie erfolgreich erstellt');
            exit;
            
        } catch (Exception $e) {
            header('Location: /admin/categories/create?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    public function edit($id)
    {
        // Session prüfen
        session_start();
        if (!isset($_SESSION['admin_user_id'])) {
            header('Location: /admin/login');
            exit;
        }

        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
            $this->update($id);
            return;
        }

        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Kategorie laden
            $stmt = $conn->prepare('SELECT * FROM ws_category WHERE id = ?');
            $stmt->execute([$id]);
            $category = $stmt->fetchAssociative();
            
            if (!$category) {
                header('Location: /admin/categories?error=Kategorie nicht gefunden');
                exit;
            }
            
            // Alle Kategorien für Parent-Auswahl laden (außer sich selbst)
            $stmt = $conn->prepare('SELECT id, name, parent_id FROM ws_category WHERE id != ? ORDER BY name ASC');
            $stmt->execute([$id]);
            
            $categories = [];
            while ($row = $stmt->fetchAssociative()) {
                $categories[] = $row;
            }
            
            $this->render('admin/categories/edit.html.twig', [
                'title' => 'Webshop Admin - Kategorie bearbeiten',
                'user_name' => $_SESSION['admin_user_name'],
                'category' => $category,
                'categories' => $categories
            ]);
            
        } catch (Exception $e) {
            header('Location: /admin/categories?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    private function update($id)
    {
        $name = $_POST['name'] ?? '';
        $description = $_POST['description'] ?? '';
        $parent_id = $_POST['parent_id'] ?? null;
        $sort_order = $_POST['sort_order'] ?? 0;
        $active = isset($_POST['active']) ? 1 : 0;

        if (empty($name)) {
            header('Location: /admin/categories/edit/' . $id . '?error=Name ist erforderlich');
            exit;
        }

        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Prüfen ob Name bereits existiert (außer bei dieser Kategorie)
            $stmt = $conn->prepare('SELECT id FROM ws_category WHERE name = ? AND id != ?');
            $stmt->execute([$name, $id]);
            if ($stmt->fetchAssociative()) {
                header('Location: /admin/categories/edit/' . $id . '?error=Name bereits vergeben');
                exit;
            }
            
            // Prüfen ob Parent-ID nicht auf sich selbst zeigt
            if ($parent_id == $id) {
                header('Location: /admin/categories/edit/' . $id . '?error=Kategorie kann nicht ihre eigene Unterkategorie sein');
                exit;
            }
            
            $stmt = $conn->prepare('
                UPDATE ws_category 
                SET name = ?, description = ?, parent_id = ?, sort_order = ?, active = ?, updated_at = NOW()
                WHERE id = ?
            ');
            $stmt->execute([$name, $description, $parent_id, $sort_order, $active, $id]);
            
            header('Location: /admin/categories/show/' . $id . '?success=Kategorie erfolgreich aktualisiert');
            exit;
            
        } catch (Exception $e) {
            header('Location: /admin/categories/edit/' . $id . '?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    public function delete($id)
    {
        // Session prüfen
        session_start();
        if (!isset($_SESSION['admin_user_id'])) {
            header('Location: /admin/login');
            exit;
        }

        $connectionParams = [
            'dbname' => getenv('DB_DATABASE') ?: 'freeshop',
            'user' => getenv('DB_USERNAME') ?: 'freeshop_user',
            'password' => getenv('DB_PASSWORD') ?: 'freeshop_password',
            'host' => getenv('DB_HOST') ?: 'db',
            'driver' => 'pdo_mysql',
            'port' => getenv('DB_PORT') ?: 3306,
            'charset' => 'utf8mb4',
        ];

        try {
            $conn = DriverManager::getConnection($connectionParams);
            
            // Prüfen ob Kategorie Produkte hat
            $stmt = $conn->prepare('SELECT COUNT(*) as count FROM ws_product WHERE category_id = ?');
            $stmt->execute([$id]);
            $productCount = $stmt->fetchAssociative()['count'];
            
            if ($productCount > 0) {
                header('Location: /admin/categories?error=Kategorie kann nicht gelöscht werden, da Produkte vorhanden sind');
                exit;
            }
            
            // Prüfen ob Kategorie Unterkategorien hat
            $stmt = $conn->prepare('SELECT COUNT(*) as count FROM ws_category WHERE parent_id = ?');
            $stmt->execute([$id]);
            $subcategoryCount = $stmt->fetchAssociative()['count'];
            
            if ($subcategoryCount > 0) {
                header('Location: /admin/categories?error=Kategorie kann nicht gelöscht werden, da Unterkategorien vorhanden sind');
                exit;
            }
            
            $stmt = $conn->prepare('DELETE FROM ws_category WHERE id = ?');
            $stmt->execute([$id]);
            
            header('Location: /admin/categories?success=Kategorie erfolgreich gelöscht');
            exit;
            
        } catch (Exception $e) {
            header('Location: /admin/categories?error=Datenbankfehler: ' . $e->getMessage());
            exit;
        }
    }

    private function buildHierarchy($categories, $parent_id = null)
    {
        $hierarchy = [];
        foreach ($categories as $category) {
            if ($category['parent_id'] == $parent_id) {
                $category['children'] = $this->buildHierarchy($categories, $category['id']);
                $hierarchy[] = $category;
            }
        }
        return $hierarchy;
    }

    protected function render($template, $data = [])
    {
        // Einfache Template-Engine (später durch Twig ersetzen)
        extract($data);
        include __DIR__ . '/../../templates/' . $template;
    }
}