<?php
defined('ABSPATH') || exit;

final class RefRef_Storefront {
    /** The browser's handle: RefRef's opaque, unsigned ID of its referral clicks. */
    public static function handle_id(): string {
        $handle = WC()->session ? WC()->session->get('refref_handle') : '';
        return is_string($handle) ? $handle : '';
    }
    public static function consent(): bool {
        if (!WC()->session || !WC()->session->get('refref_consent')) { return false; }
        return !function_exists('wp_has_consent') || wp_has_consent('marketing');
    }
    public static function register(): void {
        add_action('wc_ajax_refref_bootstrap', [self::class, 'bootstrap']);
        add_action('wc_ajax_refref', [self::class, 'request']);
        add_action('wp_enqueue_scripts', static function () {
            if (!RefRef_Config::connection()) { return; }
            wp_enqueue_script('refref', plugins_url('storefront.js', REFREF_PLUGIN_FILE), ['wp-i18n'], '0.1.0', true);
            wp_set_script_translations('refref', 'refref');
            wp_add_inline_script('refref', 'window.refrefStore=' . wp_json_encode(['endpoint' => WC_AJAX::get_endpoint('refref'), 'bootstrap' => WC_AJAX::get_endpoint('refref_bootstrap')]) . ';', 'before');
        });
        add_shortcode('refref', [self::class, 'surface']);
        add_action('woocommerce_account_dashboard', static function () { echo wp_kses_post(self::surface()); });
        add_action('woocommerce_thankyou', static function () { echo wp_kses_post(self::surface()); });
        add_filter('wp_privacy_personal_data_exporters', static function ($exporters) {
            $exporters['refref'] = ['exporter_friendly_name' => 'RefRef', 'callback' => [self::class, 'export']];
            return $exporters;
        });
        add_filter('wp_privacy_personal_data_erasers', static function ($erasers) {
            $erasers['refref'] = ['eraser_friendly_name' => 'RefRef', 'callback' => [self::class, 'erase']];
            return $erasers;
        });
    }
    public static function bootstrap(): void {
        nocache_headers();
        WC()->session->set_customer_session_cookie(true);
        $csrf = WC()->session->get('refref_csrf');
        if (!$csrf) { $csrf = bin2hex(random_bytes(32)); WC()->session->set('refref_csrf', $csrf); }
        wp_send_json(['csrf' => $csrf, 'consent' => self::consent(), 'signedIn' => is_user_logged_in(), 'nonces' => ['woocommerce-login-nonce' => wp_create_nonce('woocommerce-login'), 'woocommerce-register-nonce' => wp_create_nonce('woocommerce-register'), 'woocommerce-process-checkout-nonce' => wp_create_nonce('woocommerce-process_checkout')]]);
    }
    public static function request(): void {
        nocache_headers();
        $input = json_decode(file_get_contents('php://input'), true);
        $csrf = WC()->session ? WC()->session->get('refref_csrf') : null;
        // Compare the unslashed Origin exactly; sanitizing it could turn an invalid origin into an allowed one.
        // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Strict origin equality below validates the complete value.
        $origin = isset($_SERVER['HTTP_ORIGIN']) ? wp_unslash($_SERVER['HTTP_ORIGIN']) : '';
        $expected = wp_parse_url(home_url(), PHP_URL_SCHEME) . '://' . wp_parse_url(home_url(), PHP_URL_HOST);
        $port = wp_parse_url(home_url(), PHP_URL_PORT);
        if ($port) { $expected .= ':' . $port; }
        // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Exact method comparison validates the complete value.
        $method = isset($_SERVER['REQUEST_METHOD']) ? wp_unslash($_SERVER['REQUEST_METHOD']) : '';
        if ($method !== 'POST' || $origin !== $expected || !$csrf || !is_array($input) || !is_string($input['csrf'] ?? null) || !hash_equals($csrf, $input['csrf'])) {
            wp_send_json(['error' => __('Refresh this page and try again.', 'refref')], 403);
        }
        try {
            $action = $input['action'] ?? '';
            if ($action === 'withdraw') {
                if (WC()->cart) { foreach (WC()->cart->get_applied_coupons() as $code) { $coupon = new WC_Coupon($code); if ($coupon->get_meta('_refref_handle')) { WC()->cart->remove_coupon($code); } } }
                foreach (['refref_handle', 'refref_guest', 'refref_consent'] as $key) { WC()->session->__unset($key); }
                wp_send_json(['status' => 'cleared']);
            }
            if ($action === 'capture') {
                if (($input['consent'] ?? false) === true) { WC()->session->set('refref_consent', true); }
                if (!self::consent()) { wp_send_json(['error' => __('Allow referral tracking before applying this offer.', 'refref')], 403); }
                $payload = ['handoffToken' => (string) ($input['handoffToken'] ?? '')];
                $handle = self::handle_id();
                if ($handle !== '') { $payload['handle'] = $handle; }
                $result = RefRef_Transport::shopper('capture', $payload);
                WC()->session->set('refref_handle', $result['handle']);
                wp_send_json(['status' => 'captured']);
            }
            if ($action === 'offer') {
                if (!self::consent() || self::handle_id() === '') { wp_send_json(['status' => 'unavailable']); }
                $result = RefRef_Transport::shopper('offer', ['handle' => self::handle_id()]);
                $result['cartChanged'] = false;
                if (($result['status'] ?? '') === 'ready' && WC()->cart && !WC()->cart->has_discount($result['code'])) {
                    if (!WC()->cart->apply_coupon($result['code'])) { throw new RuntimeException(esc_html__('The offer does not apply to this cart.', 'refref')); }
                    $result['cartChanged'] = true;
                }
                wp_send_json($result);
            }
            if (!in_array($action, ['share', 'account'], true)) { throw new RuntimeException(esc_html__('Unknown referral action.', 'refref')); }
            if (!is_user_logged_in()) { wp_send_json(['status' => 'sign_in_required']); }
            $pagination = [];
            foreach (['referralsCursor', 'rewardsCursor'] as $key) {
                if (is_string($input[$key] ?? null) && strlen($input[$key]) <= 2048) { $pagination[$key] = $input[$key]; }
            }
            wp_send_json(RefRef_Transport::shopper($action, ['customerId' => (string) get_current_user_id()], $pagination));
        } catch (Throwable $error) {
            wp_send_json(['error' => $error->getMessage()], 503);
        }
    }
    public static function surface(): string {
        if (!RefRef_Config::connection()) { return ''; }
        if (!is_user_logged_in()) { return '<p><a href="' . esc_url(wc_get_page_permalink('myaccount')) . '">' . esc_html__('Sign in to get your referral link', 'refref') . '</a></p>'; }
        return '<section class="refref-account"><h2>' . esc_html__('Your referrals', 'refref') . '</h2><button type="button" class="button wp-element-button refref-share">' . esc_html__('Get referral link', 'refref') . '</button><p class="refref-message" role="status"></p><div class="refref-history"></div></section>';
    }
    /**
     * The store's own customer and guest IDs of a verified WordPress privacy request.
     * WordPress uses the email to find its own account and orders; RefRef never receives the email
     * and never uses it to identify or merge Participants.
     */
    private static function privacy_subjects(string $email): array {
        $user = get_user_by('email', $email);
        $guests = [];
        $orders = [];
        // Every order of the email, a page at a time, so no guest ID is left out.
        for ($page = 1; ; $page++) {
            $batch = wc_get_orders(['billing_email' => $email, 'limit' => 100, 'paged' => $page, 'orderby' => 'ID', 'order' => 'ASC']);
            foreach ($batch as $order) {
                $orders[] = $order;
                foreach (['_refref_guest', '_refref_paid_guest'] as $key) {
                    $guest = $order->get_meta($key);
                    if (is_string($guest) && wp_is_uuid($guest)) { $guests[] = $guest; }
                }
            }
            if (count($batch) < 100) { break; }
        }
        $payload = ['customerId' => $user ? (string) $user->ID : null, 'guests' => array_values(array_unique($guests))];
        return [$payload['customerId'] || $payload['guests'] ? $payload : null, $orders];
    }
    /** The WordPress request ID, so a repeated callback converges on the same hosted request. */
    private static function privacy_request_id(string $email, string $action): string {
        // WordPress checks the privacy screen capability and nonce before invoking this callback.
        // The ID only correlates the request; the trusted callback email/action must also match.
        // phpcs:ignore WordPress.Security.NonceVerification.Missing
        $id = isset($_POST['id']) ? absint(wp_unslash($_POST['id'])) : 0;
        $request = $id ? wp_get_user_request($id) : false;
        if ($request && $request->email === $email && $request->action_name === $action) { return (string) $id; }
        $ids = get_posts(['post_type' => 'user_request', 'post_name__in' => [$action], 'title' => $email, 'post_status' => ['request-confirmed', 'request-completed'], 'numberposts' => 1, 'orderby' => 'ID', 'order' => 'DESC', 'fields' => 'ids']);
        return $ids ? (string) $ids[0] : 'manual-' . time();
    }
    private static function privacy_call(string $action, string $email, array $payload, string $request_action) {
        $payload['requestId'] = self::privacy_request_id($email, $request_action);
        try {
            return RefRef_Transport::request('/integrations/v1/woocommerce/privacy', RefRef_Transport::proof($action, $payload));
        } catch (RuntimeException $error) {
            return new WP_Error('refref_privacy', sprintf(/* translators: %s: the connection error. */ __('RefRef could not complete this request: %s Try again, or contact RefRef support.', 'refref'), $error->getMessage()));
        }
    }
    public static function export($email, $page = 1) {
        // A store that was never connected, or was disconnected, has no hosted records to read.
        if (!RefRef_Config::connection()) { return ['data' => [], 'done' => true]; }
        [$payload] = self::privacy_subjects($email);
        if (!$payload) { return ['data' => [], 'done' => true]; }
        $result = self::privacy_call('privacy-export', $email, $payload, 'export_personal_data');
        if (is_wp_error($result)) { return $result; }
        $items = [];
        foreach (($result['exports'] ?? []) as $index => $export) {
            $data = [];
            foreach ((array) $export as $name => $value) {
                $data[] = ['name' => (string) $name, 'value' => is_scalar($value) ? (string) $value : wp_json_encode($value)];
            }
            $items[] = ['group_id' => 'refref', 'group_label' => __('RefRef referrals', 'refref'), 'item_id' => 'refref-' . $index, 'data' => $data];
        }
        return ['data' => $items, 'done' => true];
    }
    /**
     * RefRef soft deletes the hosted records and later anonymises them under its privacy policy.
     */
    public static function erase($email, $page = 1) {
        if (!RefRef_Config::connection()) {
            return ['items_removed' => false, 'items_retained' => true,
                'messages' => [__('RefRef is not connected, so it could not delete hosted referral records. Ask RefRef support to delete them.', 'refref')], 'done' => true];
        }
        [$payload, $orders] = self::privacy_subjects($email);
        if (!$payload) {
            return ['items_removed' => false, 'items_retained' => false, 'messages' => [], 'done' => true];
        }
        $result = self::privacy_call('privacy-erase', $email, $payload, 'remove_personal_data');
        if (is_wp_error($result)) { return $result; }
        $removed = (int) ($result['removed'] ?? 0) > 0;
        if ($removed) {
            // The browser handle and the session guest ID of these orders go. The paid-order
            // snapshot stays: refunds of these orders still need it for accounting.
            foreach ($orders as $order) {
                $order->delete_meta_data('_refref_handle');
                $order->delete_meta_data('_refref_guest');
                $order->save();
            }
        }
        return ['items_removed' => $removed, 'items_retained' => $removed,
            'messages' => $removed ? [__('RefRef deleted the referral records of this customer. Order and reward accounting records are kept.', 'refref')] : [], 'done' => true];
    }
}