<?php
/**
 * WooCommerce Twig Extension.
 *
 * Registers all WooCommerce and WordPress functions/filters needed
 * by the child theme's Twig templates.
 *
 * @package WcBootstrap
 * @since 0.1.0
 */

namespace WcBootstrap\Twig;

use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;
use Twig\TwigFilter;

class WooCommerceExtension extends AbstractExtension {

    /**
     * {@inheritdoc}
     */
    public function getFunctions(): array {
        return array_merge(
            $this->getWordPressFunctions(),
            $this->getWooCommerceFunctions()
        );
    }

    /**
     * {@inheritdoc}
     */
    public function getFilters(): array {
        return [
            // Escaping filters (parent registers as functions only, templates use as |filter).
            new TwigFilter( 'esc_html', 'esc_html', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFilter( 'esc_attr', 'esc_attr', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFilter( 'esc_url', 'esc_url', [ 'is_safe' => [ 'html' ] ] ),

            // Slug/sanitize filters.
            new TwigFilter( 'sanitize_title', 'sanitize_title' ),

            // Text processing filters.
            new TwigFilter( 'wpautop', 'wpautop', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFilter( 'wp_kses_post', 'wp_kses_post', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFilter( 'wptexturize', 'wptexturize' ),
            new TwigFilter( 'do_shortcode', 'do_shortcode', [ 'is_safe' => [ 'html' ] ] ),
        ];
    }

    /**
     * WordPress core functions not registered by the parent theme's TwigService.
     *
     * @return TwigFunction[]
     */
    private function getWordPressFunctions(): array {
        return [
            // Hook system.
            new TwigFunction( 'do_action', [ $this, 'doAction' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'apply_filters', [ $this, 'applyFilters' ] ),

            // Security.
            new TwigFunction( 'wp_nonce_field', function ( string $action = '-1', string $name = '_wpnonce', bool $referer = true ): string {
                return wp_nonce_field( $action, $name, $referer, false );
            }, [ 'is_safe' => [ 'html' ] ] ),

            // Options and settings.
            new TwigFunction( 'get_option', 'get_option' ),

            // User functions.
            new TwigFunction( 'get_current_user_id', 'get_current_user_id' ),
            new TwigFunction( 'is_user_logged_in', 'is_user_logged_in' ),

            // URL helpers.
            new TwigFunction( 'wp_lostpassword_url', 'wp_lostpassword_url' ),
            new TwigFunction( 'get_permalink', 'get_permalink' ),
            new TwigFunction( 'get_term_link', 'get_term_link' ),
            new TwigFunction( 'wp_get_attachment_url', 'wp_get_attachment_url' ),

            // Content rendering (echo-based, wrapped in ob_start).
            new TwigFunction( 'get_avatar', 'get_avatar', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'the_title', function (): string {
                ob_start();
                the_title();
                return ob_get_clean();
            }, [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'the_content', function (): string {
                ob_start();
                the_content();
                return ob_get_clean();
            }, [ 'is_safe' => [ 'html' ] ] ),

            // Taxonomy.
            new TwigFunction( 'term_description', 'term_description', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'single_term_title', function ( string $prefix = '' ): string {
                return single_term_title( $prefix, false );
            } ),

            // Date/time.
            new TwigFunction( 'date_i18n', 'date_i18n' ),

            // Text processing (as functions).
            new TwigFunction( 'wpautop', 'wpautop', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wptexturize', 'wptexturize' ),
            new TwigFunction( 'wp_parse_url', 'wp_parse_url' ),

            // Formatting.
            new TwigFunction( 'sprintf', 'sprintf' ),

            // Dynamic function calls.
            new TwigFunction( 'call_user_func', [ $this, 'callUserFunc' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'fn', [ $this, 'callFunction' ] ),

            // Product loop helpers (set global $product for WC hooks in Twig loops).
            new TwigFunction( 'wc_setup_product_data', [ $this, 'setupProductData' ] ),
            new TwigFunction( 'wp_reset_postdata', 'wp_reset_postdata' ),
        ];
    }

    /**
     * WooCommerce-specific functions.
     *
     * @return TwigFunction[]
     */
    private function getWooCommerceFunctions(): array {
        return [
            // URL functions.
            new TwigFunction( 'wc_get_cart_url', 'wc_get_cart_url' ),
            new TwigFunction( 'wc_get_checkout_url', 'wc_get_checkout_url' ),
            new TwigFunction( 'wc_get_page_permalink', 'wc_get_page_permalink' ),
            new TwigFunction( 'wc_get_endpoint_url', 'wc_get_endpoint_url' ),
            new TwigFunction( 'wc_get_account_endpoint_url', 'wc_get_account_endpoint_url' ),
            new TwigFunction( 'wc_logout_url', 'wc_logout_url' ),

            // Boolean helpers.
            new TwigFunction( 'wc_coupons_enabled', 'wc_coupons_enabled' ),
            new TwigFunction( 'wc_shipping_enabled', 'wc_shipping_enabled' ),
            new TwigFunction( 'wc_ship_to_billing_address_only', 'wc_ship_to_billing_address_only' ),
            new TwigFunction( 'wc_terms_and_conditions_checkbox_enabled', 'wc_terms_and_conditions_checkbox_enabled' ),

            // Order functions.
            new TwigFunction( 'wc_get_order', 'wc_get_order' ),
            new TwigFunction( 'wc_get_order_status_name', 'wc_get_order_status_name' ),
            new TwigFunction( 'wc_format_datetime', 'wc_format_datetime' ),
            new TwigFunction( 'wc_date_format', 'wc_date_format' ),

            // Product functions.
            new TwigFunction( 'wc_attribute_label', 'wc_attribute_label' ),
            new TwigFunction( 'wc_placeholder_img_src', 'wc_placeholder_img_src' ),
            new TwigFunction( 'wc_get_image_size', 'wc_get_image_size' ),

            // Account functions.
            new TwigFunction( 'wc_get_account_menu_items', 'wc_get_account_menu_items' ),
            new TwigFunction( 'wc_get_account_menu_item_classes', 'wc_get_account_menu_item_classes' ),
            new TwigFunction( 'wc_get_account_orders_columns', 'wc_get_account_orders_columns' ),
            new TwigFunction( 'wc_get_account_orders_actions', 'wc_get_account_orders_actions' ),
            new TwigFunction( 'wc_get_account_payment_methods_columns', 'wc_get_account_payment_methods_columns' ),
            new TwigFunction( 'wc_get_account_formatted_address', 'wc_get_account_formatted_address', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wc_get_customer_saved_methods_list', 'wc_get_customer_saved_methods_list' ),
            new TwigFunction( 'wc_get_credit_card_type_label', 'wc_get_credit_card_type_label' ),

            // Content/form functions (echo-based, need output capture).
            new TwigFunction( 'wc_print_notices', [ $this, 'wcPrintNotices' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wc_display_item_meta', [ $this, 'wcDisplayItemMeta' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wc_query_string_form_fields', [ $this, 'wcQueryStringFormFields' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'woocommerce_form_field', [ $this, 'woocommerceFormField' ], [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'woocommerce_breadcrumb', function ( array $args = [] ): string {
                ob_start();
                woocommerce_breadcrumb( $args );
                return ob_get_clean();
            }, [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'woocommerce_quantity_input', function ( array $args = [], $product = null ): string {
                ob_start();
                woocommerce_quantity_input( $args, $product, true );
                return ob_get_clean();
            }, [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'woocommerce_product_loop_start', function (): string {
                return woocommerce_product_loop_start( false );
            }, [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'woocommerce_product_loop_end', function (): string {
                return woocommerce_product_loop_end( false );
            }, [ 'is_safe' => [ 'html' ] ] ),

            // Text/policy functions.
            new TwigFunction( 'wc_terms_and_conditions_checkbox_text', 'wc_terms_and_conditions_checkbox_text', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wc_replace_policy_page_link_placeholders', 'wc_replace_policy_page_link_placeholders', [ 'is_safe' => [ 'html' ] ] ),
            new TwigFunction( 'wc_get_privacy_policy_text', 'wc_get_privacy_policy_text', [ 'is_safe' => [ 'html' ] ] ),

            // Data helpers.
            new TwigFunction( 'wc_get_post_data_by_key', 'wc_get_post_data_by_key' ),
            new TwigFunction( 'wc_get_page_id', 'wc_get_page_id' ),

            // Template recursion (renders a WC template and returns HTML).
            new TwigFunction( 'wc_get_template', [ $this, 'wcGetTemplate' ], [ 'is_safe' => [ 'html' ] ] ),
        ];
    }

    // -------------------------------------------------------------------------
    // Method implementations for functions that need special handling.
    // -------------------------------------------------------------------------

    /**
     * Execute a WordPress action hook and capture its output.
     *
     * Actions may echo HTML (e.g., rendering sub-templates). Output buffering
     * captures this so it can be returned as a Twig-safe string.
     *
     * @param string $tag  Action hook name.
     * @param mixed  ...$args Arguments to pass to the hook.
     * @return string Captured HTML output.
     */
    public function doAction( string $tag, ...$args ): string {
        ob_start();
        do_action( $tag, ...$args );
        return ob_get_clean();
    }

    /**
     * Apply WordPress filters.
     *
     * @param string $tag   Filter hook name.
     * @param mixed  ...$args Arguments (first is the value to filter).
     * @return mixed Filtered value.
     */
    public function applyFilters( string $tag, ...$args ): mixed {
        return apply_filters( $tag, ...$args );
    }

    /**
     * Call a user function and capture its output.
     *
     * Used for tab callbacks that echo content.
     *
     * @param callable $callback Function to call.
     * @param mixed    ...$args  Arguments.
     * @return string Captured output.
     */
    public function callUserFunc( callable $callback, ...$args ): string {
        ob_start();
        call_user_func( $callback, ...$args );
        return ob_get_clean();
    }

    /**
     * Allowlist of PHP functions that can be called via fn() in Twig templates.
     *
     * Prevents arbitrary function execution (e.g., exec, system) if template
     * context were ever compromised. Only functions actually used in templates
     * are permitted.
     */
    private const ALLOWED_FUNCTIONS = [
        'WC',
        '_n',
        'get_pagenum_link',
        'wc_review_ratings_enabled',
        'wc_get_product_category_list',
        'wc_get_product_tag_list',
        'woocommerce_page_title',
        'wc_get_customer_available_downloads',
    ];

    /**
     * Call a whitelisted PHP function by name and return its result.
     *
     * Enables `fn('WC')` in templates to access the WooCommerce singleton
     * and chain method calls via Twig's property accessor.
     *
     * Only functions in the ALLOWED_FUNCTIONS list can be called. This prevents
     * arbitrary code execution if template context were ever compromised.
     *
     * @param string $name Function name.
     * @param mixed  ...$args Arguments.
     * @return mixed Function return value.
     *
     * @throws \RuntimeException If function is not allowed or does not exist.
     */
    public function callFunction( string $name, ...$args ): mixed {
        if ( ! in_array( $name, self::ALLOWED_FUNCTIONS, true ) ) {
            throw new \RuntimeException( "Function {$name} is not allowed. Add it to ALLOWED_FUNCTIONS." );
        }
        if ( ! function_exists( $name ) ) {
            throw new \RuntimeException( "Function {$name} does not exist." );
        }
        return $name( ...$args );
    }

    /**
     * Set up global product data for WC hook-based rendering in Twig loops.
     *
     * WooCommerce hooks (woocommerce_before_shop_loop_item, etc.) read from
     * the global $product. When iterating products in Twig (related, upsells),
     * the global must be updated before rendering each product card.
     *
     * @param \WC_Product $product Product object.
     * @return string Empty string (Twig requires a return value).
     */
    public function setupProductData( \WC_Product $product ): string {
        $GLOBALS['product'] = $product;
        $post = get_post( $product->get_id() );
        if ( $post ) {
            setup_postdata( $GLOBALS['post'] = $post );
        }
        return '';
    }

    /**
     * Capture wc_print_notices() output.
     *
     * @return string Rendered notices HTML.
     */
    public function wcPrintNotices(): string {
        ob_start();
        wc_print_notices();
        return ob_get_clean();
    }

    /**
     * Render item meta without echoing.
     *
     * @param mixed $item WC_Order_Item object.
     * @param array $args Display arguments.
     * @return string Rendered meta HTML.
     */
    public function wcDisplayItemMeta( $item, array $args = [] ): string {
        $args['echo'] = false;
        return wc_display_item_meta( $item, $args );
    }

    /**
     * Render query string form fields and return HTML.
     *
     * @param mixed  $values    Values array or null.
     * @param array  $exclude   Keys to exclude.
     * @param string $currentKey Current key prefix.
     * @return string Hidden input fields HTML.
     */
    public function wcQueryStringFormFields( $values = null, array $exclude = [], string $currentKey = '' ): string {
        return wc_query_string_form_fields( $values, $exclude, $currentKey, true );
    }

    /**
     * Render a WooCommerce form field and return HTML.
     *
     * @param string $key   Field key.
     * @param array  $args  Field arguments.
     * @param mixed  $value Field value.
     * @return string Rendered field HTML.
     */
    public function woocommerceFormField( string $key, array $args, $value = null ): string {
        $args['return'] = true;
        return woocommerce_form_field( $key, $args, $value );
    }

    /**
     * Render a WooCommerce template and return its HTML.
     *
     * Enables recursive template calls from within Twig templates.
     * The rendered template goes through the same interception pipeline,
     * so it will use the Twig version if one exists.
     *
     * @param string $templateName Template name (e.g., 'order/order-downloads.php').
     * @param array  $args         Template context variables.
     * @return string Rendered HTML.
     */
    public function wcGetTemplate( string $templateName, array $args = [] ): string {
        ob_start();
        wc_get_template( $templateName, $args );
        return ob_get_clean();
    }
}