<?php

namespace App\Controllers;

use App\Database;
use App\Models\Category;

class CategoryController
{
    // Renders the full layout for categories page load
    public static function index()
    {
        global $twig;
        echo $twig->render('layout.twig', ['active_page' => 'categories']);
    }

    // Get single category (JSON)
    public static function getCategory($id) {
        header('Content-Type: application/json');
        try {
            $db = Database::getInstance();
            $category = Category::getById($db, $id);
            if ($category) {
                echo json_encode($category);
            } else {
                http_response_code(404);
                echo json_encode(['error' => 'Category not found']);
            }
        } catch (Exception $e) {
            http_response_code(500);
            echo json_encode(['error' => $e->getMessage()]);
        }
    }

    // Returns the HTML content for the categories page (used by AJAX)
    public static function listCategories()
    {
        global $twig;
        try {
            $db = Database::getInstance();
            $categories = Category::getAll($db);

            // Render only the content block
            echo $twig->render('categories.twig', [
                'categories' => $categories,
            ]);
        } catch (\Exception $e) {
            http_response_code(500);
            error_log("Error fetching categories: " . $e->getMessage());
            echo "Error: " . $e->getMessage();
        }
    }

    // CRUD operations (returns JSON)
    public static function create() {
        header('Content-Type: application/json');
        try {
            $db = Database::getInstance();
            $data = $_POST;

            $name = trim($data['new_category_name'] ?? '');
            $parentId = !empty($data['parent_category_id']) ? (int)$data['parent_category_id'] : null;

            if (empty($name)) {
                http_response_code(400);
                echo json_encode(['error' => 'Category name is required']);
                return;
            }

            $category = new Category($db, null, $name, $parentId);
            if ($category->save()) {
                echo json_encode(['success' => true, 'message' => 'Category added successfully', 'id' => $category->getId()]);
            } else {
                throw new Exception('Failed to save category');
            }
        } catch (Exception $e) {
            http_response_code(500);
            echo json_encode(['error' => $e->getMessage()]);
        }
    }

    public static function update($id) {
        header('Content-Type: application/json');
        try {
            $db = Database::getInstance();
            $data = json_decode(file_get_contents('php://input'), true) ?? $_POST;

            $existing = Category::getById($db, $id);
            if (!$existing) {
                http_response_code(404);
                echo json_encode(['error' => 'Category not found']);
                return;
            }

            $name = trim($data['category_name'] ?? $existing['name']);

            if (empty($name)) {
                http_response_code(400);
                echo json_encode(['error' => 'Category name is required']);
                return;
            }

            $category = new Category($db, $id, $name);
            if ($category->save()) {
                echo json_encode(['success' => true, 'message' => 'Category updated successfully']);
            } else {
                throw new Exception('Failed to update category');
            }
        } catch (Exception $e) {
            http_response_code(500);
            echo json_encode(['error' => $e->getMessage()]);
        }
    }

    public static function delete($id) {
        header('Content-Type: application/json');
        try {
            $db = Database::getInstance();
            if (Category::delete($db, $id)) {
                echo json_encode(['success' => true, 'message' => 'Category deleted successfully']);
            } else {
                http_response_code(404);
                echo json_encode(['error' => 'Category not found']);
            }
        } catch (Exception $e) {
            http_response_code(500);
            echo json_encode(['error' => $e->getMessage()]);
        }
    }
}