/**
 * Main plugin class
 */
class Donation_BD {
    /**
     * @var Donation_BD Single instance of this class
     */
    private static $instance;

    /**
     * @var Donation_BD_Admin Admin instance
     */
    public $admin;

    /**
     * @var Donation_BD_Ajax Ajax handler instance
     */
    public $ajax;

    /**
     * @var Donation_BD_Form Form handler instance
     */
    public $form;

    /**
     * @var Donation_BD_Checkout Checkout handler instance
     */
    public $checkout;

    /**
     * Main Donation_BD Instance
     */
    public static function instance() {
        if (!isset(self::$instance) && !(self::$instance instanceof Donation_BD)) {
            self::$instance = new self();
            self::$instance->setup();
        }
        return self::$instance;
    }

    /**
     * Setup plugin
     */
    private function setup() {
        // Load plugin text domain
        add_action('init', array($this, 'load_textdomain'));

        // Initialize components
        $this->init_components();

        // Register hooks
        $this->register_hooks();
    }

    /**
     * Initialize plugin components
     */
    private function init_components() {
        // Admin
        if (is_admin()) {
            $this->admin = new Donation_BD_Admin();
        }

        // Ajax handler
        $this->ajax = new Donation_BD_Ajax();

        // Form handler
        $this->form = new Donation_BD_Form();

        // Checkout handler
        $this->checkout = new Donation_BD_Checkout();

        // Register donation product type
        add_action('init', array($this, 'register_donation_product_type'));
    }

    /**
     * Register hooks
     */
    private function register_hooks() {
        // Add plugin action links
        add_filter('plugin_action_links_' . plugin_basename(DONATION_BD_FILE), array($this, 'plugin_action_links'));

        // Add body class
        add_filter('body_class', array($this, 'add_body_class'));
    }

    /**
     * Register donation product type
     */
    public function register_donation_product_type() {
        require_once DONATION_BD_PLUGIN_DIR . 'includes/class-wc-product-donation.php';
    }

    /**
     * Add plugin action links
     */
    public function plugin_action_links($links) {
        $plugin_links = array(
            '<a href="' . admin_url('admin.php?page=donation-bd-settings') . '">' . __('Settings', 'donation-bd') . '</a>'
        );
        return array_merge($plugin_links, $links);
    }

    /**
     * Add body class
     */
    public function add_body_class($classes) {
        if (is_singular('product')) {
            global $post;
            $product = wc_get_product($post->ID);
            if ($product && $product->get_type() === 'donation') {
                $classes[] = 'donation-product';
            }
        }
        return $classes;
    }

    /**
     * Get template path with proper type casting
     */
    public static function get_template_path($template_name = '') {
        $template_name = (string)$template_name;
        return trailingslashit(DONATION_BD_PLUGIN_DIR . 'templates') . $template_name;
    }

    /**
     * Load a template with proper variable type casting
     */
    public static function get_template($template_name, $args = array()) {
        if (empty($template_name)) {
            return '';
        }

        $template_name = (string)$template_name;
        $template_path = self::get_template_path($template_name);
        
        if (!file_exists($template_path)) {
            return '';
        }

        if (!empty($args) && is_array($args)) {
            extract($args);
        }

        ob_start();
        include $template_path;
        return ob_get_clean();
    }

    /**
     * Load plugin text domain
     */
    public function load_textdomain() {
        $domain = 'donation-bd';
        $locale = apply_filters('plugin_locale', get_locale(), $domain);
        
        // Cast paths to string to prevent null warnings
        $mofile = (string)sprintf('%1$s-%2$s.mo', $domain, $locale);
        $mofile_local = (string)trailingslashit(DONATION_BD_PLUGIN_DIR . 'languages') . $mofile;
        $mofile_global = (string)trailingslashit(WP_LANG_DIR . '/' . $domain) . $mofile;

        // Try to load from global location first
        if (file_exists($mofile_global)) {
            load_textdomain($domain, $mofile_global);
        }
        // Then try local location
        elseif (file_exists($mofile_local)) {
            load_textdomain($domain, $mofile_local);
        }
        // Finally, load from plugin languages directory
        else {
            load_plugin_textdomain($domain, false, dirname(plugin_basename(DONATION_BD_FILE)) . '/languages/');
        }
    }
}