<?php

if (!defined('ABSPATH')) {
    exit;
}

final class ThreeDL_CC_Free_Cart {
    private const REMOTE_KEY = '3dl_cc_free_remote';
    private const PLACEHOLDER_META = '_3dl_cc_free_placeholder';

    private $plugin;
    private $transfer;
    private $placeholder_id = 0;

    public function __construct(ThreeDL_CC_Free_Plugin $plugin, ThreeDL_CC_Free_Transfer $transfer) {
        $this->plugin = $plugin;
        $this->transfer = $transfer;
    }

    public function hooks(): void {
        if (!$this->plugin->is_main()) {
            return;
        }

        add_filter('woocommerce_add_cart_item', [$this, 'decorate_remote_cart_item'], 20, 2);
        add_filter('woocommerce_get_cart_item_from_session', [$this, 'decorate_remote_cart_item_from_session'], 20, 3);
        add_action('woocommerce_before_calculate_totals', [$this, 'apply_remote_prices'], 20, 1);
        add_action('woocommerce_check_cart_items', [$this, 'validate_remote_items_before_checkout'], 20);
        add_filter('woocommerce_cart_item_name', [$this, 'cart_item_name'], 20, 3);
        add_filter('woocommerce_cart_item_permalink', [$this, 'cart_item_permalink'], 20, 3);
        add_filter('woocommerce_cart_item_thumbnail', [$this, 'cart_item_thumbnail'], 20, 3);
        add_filter('woocommerce_store_api_cart_item_images', [$this, 'store_api_cart_item_images'], 20, 3);
        add_filter('woocommerce_get_item_data', [$this, 'cart_item_data'], 20, 2);
        add_action('woocommerce_checkout_create_order_line_item', [$this, 'copy_remote_data_to_order_item'], 20, 4);
        add_filter('woocommerce_hidden_order_itemmeta', [$this, 'hidden_order_item_meta']);
        add_action('pre_get_posts', [$this, 'hide_placeholder_from_product_admin']);

        // The carrier is a technical implementation detail only. Keep this protection
        // isolated from the proven cart/transfer flow: no order-item detaching, no
        // transfer changes, no runtime synchronization changes.
        add_action('admin_init', [$this, 'protect_placeholder_product_editor'], 1);
        add_action('template_redirect', [$this, 'block_placeholder_product_page'], 0);
        add_filter('woocommerce_product_is_visible', [$this, 'hide_placeholder_product_visibility'], 20, 2);
        add_filter('wp_sitemaps_posts_query_args', [$this, 'exclude_placeholder_from_sitemap'], 10, 2);
    }


    public function hidden_order_item_meta(array $hidden): array {
        $internal = [
            '_3dl_cc_free_remote',
            '_3dl_cc_free_source_url',
            '_3dl_cc_free_source_product_id',
            '_3dl_cc_free_source_variation_id',
            '_3dl_cc_free_source_sku',
        ];

        return array_values(array_unique(array_merge($hidden, $internal)));
    }

    public function import_remote_item(array $payload): bool {
        $this->ensure_cart();
        if (!WC()->cart) {
            return false;
        }

        $placeholder_id = $this->placeholder_product_id();
        if (!$placeholder_id) {
            return false;
        }

        $remote = [
            'source_url' => esc_url_raw((string) ($payload['source_url'] ?? '')),
            'source_name' => sanitize_text_field((string) ($payload['source_name'] ?? '')),
            'product_id' => absint($payload['product_id'] ?? 0),
            'variation_id' => absint($payload['variation_id'] ?? 0),
            'name' => sanitize_text_field((string) ($payload['name'] ?? '')),
            'sku' => sanitize_text_field((string) ($payload['sku'] ?? '')),
            'product_url' => esc_url_raw((string) ($payload['product_url'] ?? '')),
            'image_url' => esc_url_raw((string) ($payload['image_url'] ?? '')),
            'price' => (float) wc_format_decimal($payload['price'] ?? 0, wc_get_price_decimals()),
            'currency' => sanitize_text_field((string) ($payload['currency'] ?? '')),
            'tax_status' => in_array((string) ($payload['tax_status'] ?? ''), ['taxable', 'shipping', 'none'], true) ? (string) $payload['tax_status'] : 'taxable',
            'tax_class' => sanitize_title((string) ($payload['tax_class'] ?? '')),
            'virtual' => !empty($payload['virtual']) && (string) $payload['virtual'] === 'yes' ? 'yes' : 'no',
            'weight' => (string) wc_format_decimal($payload['weight'] ?? ''),
            'length' => (string) wc_format_decimal($payload['length'] ?? ''),
            'width' => (string) wc_format_decimal($payload['width'] ?? ''),
            'height' => (string) wc_format_decimal($payload['height'] ?? ''),
            'shipping_class' => sanitize_title((string) ($payload['shipping_class'] ?? '')),
            'attributes' => $this->sanitize_attributes($payload['attributes'] ?? []),
        ];
        $qty = max(1, absint($payload['qty'] ?? 1));

        if ($remote['name'] === '' || $remote['source_url'] === '' || !$remote['product_id'] || $remote['price'] < 0) {
            return false;
        }

        $cart_item_data = [
            self::REMOTE_KEY => $remote,
            '3dl_cc_free_identity' => hash('sha256', strtolower($remote['source_url']) . '|' . $remote['product_id'] . '|' . $remote['variation_id']),
        ];

        $key = WC()->cart->add_to_cart($placeholder_id, $qty, 0, [], $cart_item_data);
        if (!$key) {
            return false;
        }
        WC()->cart->set_session();
        return true;
    }

    public function decorate_remote_cart_item($cart_item, $cart_item_key = '') {
        if (!is_array($cart_item)) {
            return $cart_item;
        }
        return $this->apply_remote_product_properties($cart_item);
    }

    public function decorate_remote_cart_item_from_session($cart_item, $values, $cart_item_key) {
        if (!is_array($cart_item)) {
            return $cart_item;
        }
        return $this->apply_remote_product_properties($cart_item);
    }

    public function apply_remote_prices($cart): void {
        if (!is_a($cart, 'WC_Cart')) {
            return;
        }
        foreach ($cart->cart_contents as $key => $item) {
            if (!is_array($item)) {
                continue;
            }
            $cart->cart_contents[$key] = $this->apply_remote_product_properties($item);
        }
    }

    private function apply_remote_product_properties(array $item): array {
        $remote = $this->remote_from_item($item);
        if (!$remote || empty($item['data']) || !is_a($item['data'], 'WC_Product')) {
            return $item;
        }
        $item['data']->set_name((string) ($remote['name'] ?? __('Remote product', '3dl-central-checkout-for-woocommerce')));
        $item['data']->set_price((float) $remote['price']);
        $item['data']->set_tax_status((string) ($remote['tax_status'] ?? 'taxable'));
        $item['data']->set_tax_class((string) ($remote['tax_class'] ?? ''));
        $item['data']->set_virtual(($remote['virtual'] ?? 'no') === 'yes');
        $item['data']->set_weight((string) ($remote['weight'] ?? ''));
        $item['data']->set_length((string) ($remote['length'] ?? ''));
        $item['data']->set_width((string) ($remote['width'] ?? ''));
        $item['data']->set_height((string) ($remote['height'] ?? ''));
        $shipping_slug = (string) ($remote['shipping_class'] ?? '');
        if ($shipping_slug !== '') {
            $term = get_term_by('slug', $shipping_slug, 'product_shipping_class');
            if ($term && !is_wp_error($term)) {
                $item['data']->set_shipping_class_id((int) $term->term_id);
            }
        }
        return $item;
    }

    public function validate_remote_items_before_checkout(): void {
        if (!WC()->cart || WC()->cart->is_empty()) {
            return;
        }
        $checkout_context = (function_exists('is_checkout') && is_checkout()) || (defined('WOOCOMMERCE_CHECKOUT') && WOOCOMMERCE_CHECKOUT) || wp_doing_ajax();
        if (!$checkout_context) {
            return;
        }

        foreach (WC()->cart->get_cart() as $item) {
            $remote = $this->remote_from_item($item);
            if (!$remote) {
                continue;
            }
            $result = $this->transfer->validate_remote_item($remote, max(1, absint($item['quantity'] ?? 1)));
            if (is_wp_error($result)) {
                $notice = sprintf(
                    /* translators: 1: remote product name, 2: source-store validation error message. */
                    __('%1$s — source check failed: %2$s', '3dl-central-checkout-for-woocommerce'),
                    esc_html((string) ($remote['name'] ?? __('Remote product', '3dl-central-checkout-for-woocommerce'))),
                    esc_html($result->get_error_message())
                );
                wc_add_notice($notice, 'error');
            }
        }
    }

    public function cart_item_name($name, $cart_item, $cart_item_key) {
        $remote = $this->remote_from_item($cart_item);
        if (!$remote) {
            return $name;
        }
        $label = esc_html((string) $remote['name']);
        if (!empty($remote['product_url'])) {
            $label = '<a href="' . esc_url($remote['product_url']) . '">' . $label . '</a>';
        }
        return $label;
    }

    public function cart_item_permalink($url, $cart_item, $cart_item_key) {
        $remote = $this->remote_from_item($cart_item);
        return $remote && !empty($remote['product_url']) ? esc_url_raw($remote['product_url']) : $url;
    }

    public function cart_item_thumbnail($thumbnail, $cart_item, $cart_item_key) {
        $remote = $this->remote_from_item($cart_item);
        if (!$remote || empty($remote['image_url'])) {
            return $thumbnail;
        }
        return '<img src="' . esc_url($remote['image_url']) . '" alt="' . esc_attr((string) ($remote['name'] ?? '')) . '" class="attachment-woocommerce_thumbnail size-woocommerce_thumbnail" loading="lazy">';
    }

    public function store_api_cart_item_images($images, $cart_item, $cart_item_key) {
        $remote = is_array($cart_item) ? $this->remote_from_item($cart_item) : [];
        if (!$remote || empty($remote['image_url'])) {
            return $images;
        }
        $url = esc_url_raw((string) $remote['image_url']);
        if ($url === '') {
            return $images;
        }
        $name = wp_strip_all_tags((string) ($remote['name'] ?? __('Remote product', '3dl-central-checkout-for-woocommerce')));
        return [(object) [
            'id' => 0,
            'src' => $url,
            'thumbnail' => $url,
            'srcset' => '',
            'sizes' => '',
            'name' => $name,
            'alt' => $name,
        ]];
    }

    public function cart_item_data($item_data, $cart_item): array {
        $remote = $this->remote_from_item($cart_item);
        if (!$remote) {
            return $item_data;
        }
        $item_data[] = [
            'key' => __('From store', '3dl-central-checkout-for-woocommerce'),
            'value' => sanitize_text_field((string) ($remote['source_name'] ?: $remote['source_url'])),
        ];
        if (!empty($remote['attributes']) && is_array($remote['attributes'])) {
            foreach ($remote['attributes'] as $label => $value) {
                $item_data[] = ['key' => (string) $label, 'value' => (string) $value];
            }
        }
        return $item_data;
    }

    public function copy_remote_data_to_order_item($item, $cart_item_key, $values, $order): void {
        $remote = $this->remote_from_item($values);
        if (!$remote || !is_a($item, 'WC_Order_Item_Product')) {
            return;
        }
        $item->set_name((string) $remote['name']);
        $item->add_meta_data(__('From store', '3dl-central-checkout-for-woocommerce'), (string) ($remote['source_name'] ?: $remote['source_url']), true);
        $item->add_meta_data('_3dl_cc_free_remote', 'yes', true);
        $item->add_meta_data('_3dl_cc_free_source_url', (string) $remote['source_url'], true);
        $item->add_meta_data('_3dl_cc_free_source_product_id', absint($remote['product_id']), true);
        $item->add_meta_data('_3dl_cc_free_source_variation_id', absint($remote['variation_id']), true);
        $item->add_meta_data('_3dl_cc_free_source_sku', (string) $remote['sku'], true);
        if (!empty($remote['attributes']) && is_array($remote['attributes'])) {
            foreach ($remote['attributes'] as $label => $value) {
                $item->add_meta_data((string) $label, (string) $value, true);
            }
        }
    }

    public function hide_placeholder_from_product_admin($query): void {
        if (!is_admin() || !$query->is_main_query() || $query->get('post_type') !== 'product') {
            return;
        }
        $placeholder_id = $this->find_placeholder_product_id();
        if (!$placeholder_id) {
            return;
        }
        $not_in = (array) $query->get('post__not_in');
        $not_in[] = $placeholder_id;
        $query->set('post__not_in', array_values(array_unique(array_map('absint', $not_in))));
    }


    /**
     * The helper/carrier product must never behave like a normal catalogue product.
     * Check the queried product itself instead of searching for a stored carrier ID;
     * this makes the direct-URL guard independent of caches and lookup order.
     */
    public function block_placeholder_product_page(): void {
        if (is_admin() || !is_singular('product')) {
            return;
        }

        $product_id = absint(get_queried_object_id());
        if (!$product_id || get_post_meta($product_id, self::PLACEHOLDER_META, true) !== 'yes') {
            return;
        }

        global $wp_query;
        if ($wp_query) {
            $wp_query->set_404();
        }
        status_header(404);
        nocache_headers();

        $template = get_404_template();
        if ($template) {
            include $template;
            exit;
        }

        wp_die('Not found', '', ['response' => 404]);
    }

    /**
     * Extra WooCommerce-level visibility guard for loops/related products/widgets.
     */
    public function hide_placeholder_product_visibility($visible, $product_id) {
        $product_id = absint($product_id);
        if ($product_id && get_post_meta($product_id, self::PLACEHOLDER_META, true) === 'yes') {
            return false;
        }
        return $visible;
    }

    /**
     * If someone reaches the carrier editor by a stale bookmark/direct URL, do not
     * let it be mistaken for a real source product.
     */
    public function protect_placeholder_product_editor(): void {
        if (!is_admin()) {
            return;
        }

        // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only admin routing parameter; this method does not change state.
        $post_id = isset($_GET['post']) ? absint($_GET['post']) : 0;
        // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only admin routing parameter; this method does not change state.
        $action = isset($_GET['action']) ? sanitize_key((string) $_GET['action']) : '';
        if (!$post_id || $action !== 'edit') {
            return;
        }
        if (get_post_meta($post_id, self::PLACEHOLDER_META, true) !== 'yes') {
            return;
        }

        wp_safe_redirect(admin_url('admin.php?page=3dl-central-checkout'));
        exit;
    }

    /**
     * Do not publish the technical carrier in WordPress core product sitemaps.
     */
    public function exclude_placeholder_from_sitemap(array $args, string $post_type): array {
        if ($post_type !== 'product') {
            return $args;
        }

        $placeholder_id = $this->find_placeholder_product_id();
        if (!$placeholder_id) {
            return $args;
        }

        $not_in = isset($args['post__not_in']) ? (array) $args['post__not_in'] : [];
        $not_in[] = $placeholder_id;
        // phpcs:ignore WordPressVIPMinimum.Performance.WPQueryParams.PostNotIn_post__not_in -- Excludes one internal carrier product from the sitemap query.
        $args['post__not_in'] = array_values(array_unique(array_map('absint', $not_in)));
        return $args;
    }

    public static function delete_placeholder_product(): void {
        $ids = get_posts([
            'post_type' => 'product',
            'post_status' => 'any',
            'fields' => 'ids',
            'numberposts' => -1,
            // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Exact lookup of the plugin's single internal carrier product.
            'meta_key' => self::PLACEHOLDER_META,
            // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_value -- Exact lookup of the plugin's single internal carrier product.
            'meta_value' => 'yes',
        ]);
        foreach ($ids as $id) {
            wp_delete_post((int) $id, true);
        }
    }

    private function placeholder_product_id(): int {
        if ($this->placeholder_id > 0 && get_post($this->placeholder_id)) {
            $usable = $this->ensure_simple_placeholder($this->placeholder_id);
            if ($usable) {
                return $usable;
            }
            $this->placeholder_id = 0;
        }
        $found = $this->find_placeholder_product_id();
        if ($found) {
            $usable = $this->ensure_simple_placeholder($found);
            if ($usable) {
                $this->placeholder_id = $usable;
                return $usable;
            }
        }
        if (!class_exists('WC_Product_Simple')) {
            return 0;
        }

        $product = new WC_Product_Simple();
        $product->set_name(__('Central Checkout remote item', '3dl-central-checkout-for-woocommerce'));
        $product->set_status('publish');
        $product->set_catalog_visibility('hidden');
        $product->set_virtual(true);
        $product->set_regular_price('0');
        $product->set_price('0');
        $product->set_tax_status('taxable');
        $id = $product->save();
        if (!$id) {
            return 0;
        }
        update_post_meta($id, self::PLACEHOLDER_META, 'yes');
        $this->placeholder_id = (int) $id;
        return $this->placeholder_id;
    }


    /**
     * The central cart uses one hidden SIMPLE product only as a local carrier for
     * remote cart items. If its product_type taxonomy was changed accidentally,
     * WooCommerce treats an import as a variable product and asks the customer to
     * choose options on the hidden carrier. Self-heal that state before add_to_cart.
     */
    private function ensure_simple_placeholder(int $id): int {
        if ($id <= 0 || !get_post($id)) {
            return 0;
        }

        $product = wc_get_product($id);
        if ($product && $product->is_type('simple')) {
            return $id;
        }

        $result = wp_set_object_terms($id, 'simple', 'product_type', false);
        if (is_wp_error($result)) {
            return 0;
        }

        if (function_exists('wc_delete_product_transients')) {
            wc_delete_product_transients($id);
        }
        clean_post_cache($id);

        $product = wc_get_product($id);
        return ($product && $product->is_type('simple')) ? $id : 0;
    }

    private function find_placeholder_product_id(): int {
        $ids = get_posts([
            'post_type' => 'product',
            'post_status' => 'any',
            'fields' => 'ids',
            'numberposts' => 1,
            // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Exact lookup of the plugin's single internal carrier product.
            'meta_key' => self::PLACEHOLDER_META,
            // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_value -- Exact lookup of the plugin's single internal carrier product.
            'meta_value' => 'yes',
        ]);
        return !empty($ids[0]) ? absint($ids[0]) : 0;
    }

    private function sanitize_attributes($attributes): array {
        if (!is_array($attributes)) {
            return [];
        }
        $out = [];
        foreach ($attributes as $label => $value) {
            if (!is_scalar($label) || !is_scalar($value)) {
                continue;
            }
            $label = sanitize_text_field((string) $label);
            $value = sanitize_text_field((string) $value);
            if ($label !== '' && $value !== '') {
                $out[$label] = $value;
            }
        }
        return $out;
    }

    private function remote_from_item(array $item): array {
        return !empty($item[self::REMOTE_KEY]) && is_array($item[self::REMOTE_KEY]) ? $item[self::REMOTE_KEY] : [];
    }

    private function ensure_cart(): void {
        if (function_exists('wc_load_cart') && (!WC()->session || !WC()->cart)) {
            wc_load_cart();
        }
    }
}