<?php
/**
 * Plugin Name:       Ordersmith – Orders & Stock Sync for TikTok Shop
 * Description:       TikTok Shop orders, shipping labels, tracking and stock, synced with WooCommerce.
 * Version:           1.0.0
 * Requires at least: 6.5
 * Requires PHP:      7.4
 * Requires Plugins:  woocommerce
 * WC requires at least: 8.0
 * WC tested up to:   11.1
 * Author:            SysRidge
 * Author URI:        https://www.sysridge.com.au
 * Plugin URI:        https://www.sysridge.com.au/ordersmith/
 * License:           GPL-2.0-or-later
 * Text Domain:       ordersmith
 */

defined('ABSPATH') || exit;

const ORDERSMITH_SIGNER = 'https://n8n.sysridge.com.au/orderbridge';
const ORDERSMITH_API = 'https://open-api.tiktokglobalshop.com';
// ponytail: UK only (the one approved market). Make this per-region when more markets are approved.
const ORDERSMITH_AUTHORIZE = 'https://seller-uk.tiktok.com/services/market/custom-authorize/7693406175647598356?shop_region=GB';
const ORDERSMITH_OPTION = 'ordersmith_connection';
const ORDERSMITH_PRO_URL = 'https://www.sysridge.com.au/ordersmith/pro/';

add_action('before_woocommerce_init', function () {
    if (class_exists(\Automattic\WooCommerce\Utilities\FeaturesUtil::class)) {
        \Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility('custom_order_tables', __FILE__, true);
    }
});

/* ---------- token storage (encrypted at rest with a key derived from this site's WP salts) ---------- */

function ordersmith_key(): string
{
    return hash('sha256', wp_salt('secure_auth') . 'ordersmith', true);
}

function ordersmith_encrypt(string $plain): string
{
    $nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
    return base64_encode($nonce . sodium_crypto_secretbox($plain, $nonce, ordersmith_key()));
}

function ordersmith_decrypt(string $stored): ?string
{
    $raw = base64_decode($stored, true);
    if ($raw === false || strlen($raw) <= SODIUM_CRYPTO_SECRETBOX_NONCEBYTES) {
        return null;
    }
    $plain = sodium_crypto_secretbox_open(substr($raw, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES), substr($raw, 0, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES), ordersmith_key());
    return $plain === false ? null : $plain;
}

/** Saved connection, tokens decrypted. Null when not connected, access was revoked, or salts changed (all need a reconnect). */
function ordersmith_connection(string $option = ORDERSMITH_OPTION): ?array
{
    $c = get_option($option);
    if (!is_array($c) || empty($c['tokens']) || !empty($c['revoked'])) {
        return null;
    }
    $tokens = json_decode((string) ordersmith_decrypt($c['tokens']), true);
    return is_array($tokens) ? array_merge($c, ['tokens' => $tokens]) : null;
}

function ordersmith_save_tokens(array $data, array $extra = [], string $option = ORDERSMITH_OPTION): void
{
    $keep = array_intersect_key($data, array_flip(['access_token', 'access_token_expire_in', 'refresh_token', 'refresh_token_expire_in']));
    $c = get_option($option) ?: [];
    unset($c['revoked']); // fresh tokens = reconnected
    update_option($option, array_merge($c, $extra, ['tokens' => ordersmith_encrypt(wp_json_encode($keep))]), false);
}

/**
 * Every connected shop, each tagged with its login ('option') and when that login connected.
 * Ordersmith has one TikTok login; Ordersmith Pro adds shops from more logins through the filter.
 */
function ordersmith_shops(): array
{
    $c = ordersmith_connection();
    $shops = [];
    foreach ($c['shops'] ?? [] as $s) {
        $shops[] = $s + ['option' => ORDERSMITH_OPTION, 'connected_at' => (int) ($c['connected_at'] ?? 0)];
    }
    return apply_filters('ordersmith_shops', $shops);
}

/** A connected shop by 'id' or 'cipher', or null. */
function ordersmith_find_shop(string $key, string $value): ?array
{
    foreach (ordersmith_shops() as $s) {
        if ((string) ($s[$key] ?? '') === $value) {
            return $s;
        }
    }
    return null;
}

/** Seller removed our access on TikTok's side: stop syncing and ask for a reconnect. Old orders stay. */
function ordersmith_revoked(string $why, string $option = ORDERSMITH_OPTION): void
{
    $c = get_option($option);
    if (!is_array($c) || !empty($c['revoked'])) {
        return;
    }
    $c['revoked'] = time();
    update_option($option, $c, false);
    if (!ordersmith_shops()) {
        as_unschedule_all_actions(ORDERSMITH_SYNC_HOOK, [], 'ordersmith'); // nothing left to sync
    }
    ordersmith_log('warning', sprintf('TikTok Shop access was removed for %s (%s). Its orders and stock are no longer syncing until it is reconnected.', $c['seller_name'] ?? 'a shop', $why));
    do_action('ordersmith_revoked', $c['seller_name'] ?? '', $why); // signal for add-ons (e.g. Pro's email alerts)
}

add_action('admin_notices', function () {
    $c = get_option(ORDERSMITH_OPTION);
    // Revoked, or tokens unreadable (site moved and its WP salts changed). TikTok refresh tokens last ~100 years,
    // so plain expiry never needs a reconnect: an offline store just refreshes when it's back.
    if (!$c || !current_user_can('manage_woocommerce') || (empty($c['revoked']) && ordersmith_connection())) {
        return;
    }
    echo '<div class="notice notice-error"><p><strong>Ordersmith:</strong> your TikTok Shop is no longer connected, so orders and stock are not syncing. <a href="' . esc_url(admin_url('admin.php?page=ordersmith')) . '">Reconnect TikTok Shop</a></p></div>';
});

/* ---------- signer + TikTok API ---------- */

function ordersmith_signer(string $route, array $payload)
{
    $res = wp_remote_post(ORDERSMITH_SIGNER . '/' . $route, [
        'timeout' => 20,
        'headers' => ['Content-Type' => 'application/json'],
        'body' => wp_json_encode($payload),
    ]);
    if (is_wp_error($res)) {
        return $res;
    }
    $json = json_decode(wp_remote_retrieve_body($res), true);
    return is_array($json) ? $json : new WP_Error('ordersmith_signer', 'Signer returned an invalid response (HTTP ' . wp_remote_retrieve_response_code($res) . ').');
}

/** Turn a TikTok auth response into an error or its data. */
function ordersmith_tiktok_data($res)
{
    if (is_wp_error($res)) {
        return $res;
    }
    if (($res['code'] ?? -1) !== 0) {
        return new WP_Error('ordersmith_tiktok', sprintf('TikTok error %s: %s', $res['code'] ?? '?', $res['message'] ?? $res['error'] ?? 'unknown'));
    }
    return $res['data'] ?? [];
}

/** Access token for a login, refreshed when it expires within a day. */
function ordersmith_access_token(string $option = ORDERSMITH_OPTION)
{
    $c = ordersmith_connection($option);
    if (!$c) {
        return new WP_Error('ordersmith_not_connected', 'TikTok Shop is not connected.');
    }
    $t = $c['tokens'];
    if (($t['access_token_expire_in'] ?? 0) > time() + DAY_IN_SECONDS) {
        return $t['access_token'];
    }
    $res = ordersmith_signer('refresh', ['refresh_token' => $t['refresh_token']]);
    // Access tokens keep working after a seller cancels; the refresh is where TikTok says so (if the webhook was missed).
    if (!is_wp_error($res) && ($res['code'] ?? 0) === 36004006) {
        ordersmith_revoked('authorisation cancelled in TikTok Seller Center', $option);
    }
    $data = ordersmith_tiktok_data($res);
    if (is_wp_error($data)) {
        return $data;
    }
    ordersmith_save_tokens($data, [], $option);
    return $data['access_token'];
}

/**
 * Signed TikTok Shop API call. $path like '/order/202309/orders/search'.
 * Pass shop-scoped calls with ['shop_cipher' => ...] in $query; the token of that shop's login is used.
 */
function ordersmith_api(string $method, string $path, array $query = [], ?array $body = null, ?string $token = null)
{
    $shop = isset($query['shop_cipher']) ? ordersmith_find_shop('cipher', (string) $query['shop_cipher']) : null;
    $token = $token ?? ordersmith_access_token($shop['option'] ?? ORDERSMITH_OPTION);
    if (is_wp_error($token)) {
        return $token;
    }
    $json = $body === null ? '' : wp_json_encode($body);
    $signed = ordersmith_signer('sign', ['path' => $path, 'query' => (object) $query, 'body' => $json]);
    if (is_wp_error($signed)) {
        return $signed;
    }
    if (empty($signed['query']['sign'])) {
        return new WP_Error('ordersmith_sign', 'Could not sign request: ' . ($signed['error'] ?? 'unknown'));
    }
    // Rate limited: TikTok sends HTTP 429 / 36009002 or HTTP 200 / 12052109. Short bursts clear in a second or two,
    // so retry in place (the signature stays valid for minutes); after that, callers reschedule.
    foreach ([0, 1, 3] as $wait) {
        sleep($wait);
        $res = wp_remote_request(ORDERSMITH_API . $path . '?' . http_build_query($signed['query']), [
            'method' => $method,
            'timeout' => 30,
            'headers' => ['x-tts-access-token' => $token, 'Content-Type' => 'application/json'],
            'body' => $body === null ? null : $json,
        ]);
        if (is_wp_error($res)) {
            return $res;
        }
        $data = json_decode(wp_remote_retrieve_body($res), true);
        if (wp_remote_retrieve_response_code($res) !== 429 && !in_array($data['code'] ?? 0, [36009002, 12052109], true)) {
            return ordersmith_tiktok_data($data);
        }
    }
    return new WP_Error('ordersmith_rate_limited', 'TikTok is busy right now (rate limit). Try again in a minute.');
}

function ordersmith_rate_limited($res): bool
{
    return is_wp_error($res) && $res->get_error_code() === 'ordersmith_rate_limited';
}

/* ---------- orders in ---------- */

// Logs go to WooCommerce → Status → Logs (source "ordersmith"); Woo deletes them after 30 days.
function ordersmith_log(string $level, string $msg): void
{
    wc_get_logger()->log($level, $msg, ['source' => 'ordersmith']);
}

// TikTok status → WooCommerce status. UNPAID is skipped (not a sale yet).
const ORDERSMITH_STATUS = [
    'ON_HOLD' => 'on-hold',
    'AWAITING_SHIPMENT' => 'processing',
    'PARTIALLY_SHIPPING' => 'processing',
    'AWAITING_COLLECTION' => 'processing',
    'IN_TRANSIT' => 'processing', // Abe's call: stay Processing until TikTok confirms delivery
    'DELIVERED' => 'completed',
    'COMPLETED' => 'completed',
    'CANCELLED' => 'cancelled',
];

const ORDERSMITH_SYNC_HOOK = 'ordersmith_sync_orders';

/** Hourly fallback poll when webhooks are live, every 15 min when they're not (e.g. a store TikTok can't reach). */
function ordersmith_sync_every(): int
{
    return get_option('ordersmith_webhook_ok') ? HOUR_IN_SECONDS : 15 * MINUTE_IN_SECONDS;
}

function ordersmith_schedule_sync(bool $reschedule = false): void
{
    if ($reschedule) {
        as_unschedule_all_actions(ORDERSMITH_SYNC_HOOK, [], 'ordersmith');
    }
    if (!as_has_scheduled_action(ORDERSMITH_SYNC_HOOK, [], 'ordersmith')) {
        // Random offset so thousands of stores don't all hit the signer on the same minute.
        as_schedule_recurring_action(time() + wp_rand(60, ordersmith_sync_every()), ordersmith_sync_every(), ORDERSMITH_SYNC_HOOK, [], 'ordersmith');
    }
}
add_action(ORDERSMITH_SYNC_HOOK, 'ordersmith_sync_orders');

/* ---------- webhooks: TikTok → signer → this store → immediate sync ---------- */

// Override for local testing behind a tunnel: define('ORDERSMITH_PUBLIC_URL', 'https://xyz.trycloudflare.com/woo-test') in wp-config.php.
function ordersmith_notify_url(): string
{
    $rest = rest_url('ordersmith/v1/notify');
    return defined('ORDERSMITH_PUBLIC_URL') ? str_replace(untrailingslashit(site_url()), untrailingslashit(ORDERSMITH_PUBLIC_URL), $rest) : $rest;
}

/** Tell the signer where to forward this shop's events. Returns true when registered. */
function ordersmith_register_webhook(string $access_token): bool
{
    $secret = get_option('ordersmith_webhook_secret');
    if (!$secret) {
        $secret = wp_generate_password(48, false);
        update_option('ordersmith_webhook_secret', $secret, false);
    }
    $res = ordersmith_signer('register', ['access_token' => $access_token, 'notify_url' => ordersmith_notify_url(), 'secret' => $secret]);
    $ok = !is_wp_error($res) && !empty($res['ok']);
    if (!$ok) {
        ordersmith_log('warning', 'Instant sync not available (' . (is_wp_error($res) ? $res->get_error_message() : ($res['error'] ?? 'unknown')) . '). Orders will sync every 15 minutes instead.');
    }
    update_option('ordersmith_webhook_ok', $ok ? 1 : 0, false);
    ordersmith_schedule_sync(true);
    return $ok;
}

add_action('rest_api_init', function () {
    register_rest_route('ordersmith/v1', '/notify', [
        'methods' => 'POST',
        'permission_callback' => function (WP_REST_Request $req) {
            $secret = (string) get_option('ordersmith_webhook_secret');
            // Header name is fixed by the signer ("X-OBR-Signature"); never rename it with the plugin.
            $sig = (string) $req->get_header('x_obr_signature');
            return $secret !== '' && hash_equals(hash_hmac('sha256', $req->get_body(), $secret), $sig);
        },
        'callback' => function (WP_REST_Request $req) {
            $event = $req->get_json_params();
            if ((int) ($event['type'] ?? 0) === 6) { // SELLER_DEAUTHORIZATION
                ordersmith_revoked('seller deauthorised the app', ordersmith_find_shop('id', (string) ($event['shop_id'] ?? ''))['option'] ?? ORDERSMITH_OPTION);
                return ['ok' => true];
            }
            // Import right now instead of waiting for WP-Cron (which only wakes on page visits).
            // The signer hangs up after 2 s; ignore_user_abort lets the sync finish anyway.
            ignore_user_abort(true);
            ordersmith_sync_orders();
            return ['ok' => true];
        },
    ]);
});
add_action('ordersmith_sync_orders_now', 'ordersmith_sync_orders');

/** Pull orders changed since the last sync and create/update them in WooCommerce. Returns [created, updated] or WP_Error. */
/**
 * One sync at a time: two notifications arriving together must not import the same order twice.
 * If a sync is already running, queue one more run so changes it may have missed still arrive.
 */
function ordersmith_sync_orders()
{
    if (!add_option('ordersmith_sync_lock', time(), '', false)) { // add_option is atomic: fails if the row exists
        if ((int) get_option('ordersmith_sync_lock') > time() - 5 * MINUTE_IN_SECONDS) {
            if (!as_has_scheduled_action('ordersmith_sync_orders_now', [], 'ordersmith')) {
                as_enqueue_async_action('ordersmith_sync_orders_now', [], 'ordersmith');
            }
            return [0, 0];
        }
        update_option('ordersmith_sync_lock', time(), false); // stale lock from a crashed run: take over
    }
    try {
        return ordersmith_run_sync();
    } finally {
        delete_option('ordersmith_sync_lock');
    }
}

function ordersmith_run_sync()
{
    $shops = ordersmith_shops();
    if (!$shops) {
        return new WP_Error('ordersmith_not_connected', 'Not connected.');
    }
    // Per shop, so one failing shop neither blocks the others nor makes them re-read old orders.
    $last = get_option('ordersmith_shop_sync') ?: [];
    $started = time();
    $counts = [0, 0];
    $failed = null;

    foreach ($shops as $shop) {
        $since = (int) ($last[$shop['id']] ?? get_option('ordersmith_last_sync', time() - 3 * DAY_IN_SECONDS));
        $token = '';
        do {
            $query = ['shop_cipher' => $shop['cipher'], 'page_size' => '50'] + ($token ? ['page_token' => $token] : []);
            // 5 min overlap: an order updated during the last run is fetched again; unchanged ones are skipped.
            $res = ordersmith_api('POST', '/order/202309/orders/search', $query, ['update_time_ge' => $since - 300]);
            if (is_wp_error($res)) {
                ordersmith_log('error', 'Order sync failed for shop ' . $shop['name'] . ': ' . $res->get_error_message());
                do_action('ordersmith_sync_failed', $shop, $res);
                ordersmith_retry_sync_if_limited($res);
                $failed = $res;
                continue 2;
            }
            foreach ($res['orders'] ?? [] as $o) {
                $r = ordersmith_upsert_order($o, $shop);
                if ($r === 'created') {
                    $counts[0]++;
                } elseif ($r === 'updated') {
                    $counts[1]++;
                }
            }
            $token = $res['next_page_token'] ?? '';
        } while ($token !== '');
        $err = ordersmith_sync_returns($shop, $since - 300);
        if (is_wp_error($err)) {
            ordersmith_log('error', 'Refund sync failed for shop ' . $shop['name'] . ': ' . $err->get_error_message());
            do_action('ordersmith_sync_failed', $shop, $err);
            ordersmith_retry_sync_if_limited($err);
            $failed = $err;
            continue;
        }
        $last[$shop['id']] = $started;
        do_action('ordersmith_sync_ok', $shop);
    }
    update_option('ordersmith_shop_sync', $last, false);
    if ($failed) {
        return $failed;
    }
    update_option('ordersmith_last_sync', $started, false); // shown on the settings page: every shop is up to date
    return $counts;
}

/** Completed TikTok refunds/returns → WooCommerce refunds. Returns true or WP_Error. */
function ordersmith_sync_returns(array $shop, int $since)
{
    $token = '';
    do {
        $query = ['shop_cipher' => $shop['cipher'], 'page_size' => '50'] + ($token ? ['page_token' => $token] : []);
        $res = ordersmith_api('POST', '/return_refund/202309/returns/search', $query, ['update_time_ge' => $since]);
        if (is_wp_error($res)) {
            return $res;
        }
        foreach ($res['return_orders'] ?? [] as $r) {
            ordersmith_apply_return($r);
        }
        $token = $res['next_page_token'] ?? '';
    } while ($token !== '');
    return true;
}

function ordersmith_apply_return(array $r): void
{
    // REPLACEMENT returns refund nothing; pending/rejected ones may never pay out.
    if (($r['return_status'] ?? '') !== 'RETURN_OR_REFUND_REQUEST_COMPLETE' || !in_array($r['return_type'] ?? '', ['REFUND', 'RETURN_AND_REFUND'], true)) {
        return;
    }
    $order = ordersmith_find_order((string) $r['order_id']);
    $done = $order ? ($order->get_meta('_ordersmith_returns') ?: []) : [];
    if (!$order || in_array((string) $r['return_id'], $done, true)) {
        return; // order from before we were connected, or already refunded
    }
    // ponytail: refund our own line values (what the seller earned), not TikTok's buyer-paid figures,
    // so Woo totals stay consistent with how the order was imported. One TikTok return line = one unit.
    $lines = [];
    $amount = 0.0;
    // Started from a Woo refund: the items are already refunded in Woo.
    $from_woo = in_array((string) $r['return_id'], $order->get_meta('_ordersmith_woo_returns') ?: [], true);
    foreach ($from_woo ? [] : $r['return_line_items'] ?? [] as $rl) {
        foreach ($order->get_items() as $item_id => $item) {
            if (strcasecmp((string) $item->get_meta('TikTok SKU'), trim((string) ($rl['seller_sku'] ?? ''))) === 0) {
                $unit = (float) $item->get_total() / max(1, $item->get_quantity());
                $lines[$item_id]['qty'] = ($lines[$item_id]['qty'] ?? 0) + 1;
                $lines[$item_id]['refund_total'] = ($lines[$item_id]['refund_total'] ?? 0) + $unit;
                $amount += $unit;
                break;
            }
        }
    }
    if ((float) ($r['refund_amount']['refund_shipping_fee'] ?? 0) > 0) {
        foreach ($order->get_items('shipping') as $item_id => $ship) {
            $left = (float) $ship->get_total() - (float) $order->get_total_refunded_for_item($item_id, 'shipping');
            if ($left > 0) {
                $lines[$item_id] = ['qty' => 0, 'refund_total' => $left];
                $amount += $left;
            }
        }
    }
    $amount = min(round($amount, 2), (float) $order->get_remaining_refund_amount());
    $restock = $r['return_type'] === 'RETURN_AND_REFUND'; // refund-only: the buyer kept the item
    if ($amount > 0) {
        $refund = wc_create_refund([
            'order_id' => $order->get_id(),
            'amount' => $amount,
            'reason' => sprintf('TikTok Shop %s %s: %s', $restock ? 'return' : 'refund', $r['return_id'], $r['return_reason_text'] ?? ''),
            'line_items' => $lines,
            'restock_items' => $restock,
            'refund_payment' => false, // TikTok already paid the buyer
            'ordersmith_from_tiktok' => true, // don't send it back to TikTok
        ]);
        if (is_wp_error($refund)) {
            ordersmith_log('error', 'Could not record refund ' . $r['return_id'] . ' for order ' . $r['order_id'] . ': ' . $refund->get_error_message());
            return; // not marked done: retried next sync
        }
        ordersmith_log('info', sprintf('Recorded TikTok refund %s (%s) on order #%d.', $r['return_id'], wc_format_decimal($amount, 2), $order->get_id()));
    }
    $done[] = (string) $r['return_id'];
    $order = wc_get_order($order->get_id()); // the refund may have changed the status to Refunded
    $order->update_meta_data('_ordersmith_returns', $done);
    $order->save();
}

/**
 * Rate limited, or the network blipped (DNS, timeout: WP_Http's 'http_request_failed'), mid-sync:
 * try again in a few minutes rather than waiting for the hourly poll. Nothing is lost either way.
 */
function ordersmith_retry_sync_if_limited($err): void
{
    $temporary = ordersmith_rate_limited($err) || (is_wp_error($err) && $err->get_error_code() === 'http_request_failed');
    if ($temporary && !as_has_scheduled_action('ordersmith_sync_orders_now', [], 'ordersmith')) {
        as_schedule_single_action(time() + wp_rand(60, 180), 'ordersmith_sync_orders_now', [], 'ordersmith');
    }
}

function ordersmith_find_order(string $tiktok_id): ?WC_Order
{
    // phpcs:ignore WordPress.DB.SlowDBQuery -- single indexed lookup per order; HPOS meta table indexes meta_key.
    $found = wc_get_orders(['limit' => 1, 'meta_key' => '_ordersmith_order_id', 'meta_value' => $tiktok_id, 'status' => 'any']);
    return $found[0] ?? null;
}

/** @return string 'created' | 'updated' | 'skipped' */
function ordersmith_upsert_order(array $o, array $shop): string
{
    $wc_status = ORDERSMITH_STATUS[$o['status'] ?? ''] ?? null;
    if (!$wc_status) {
        return 'skipped'; // UNPAID or unknown
    }
    $order = ordersmith_find_order((string) $o['id']);
    if ($order && (int) $order->get_meta('_ordersmith_update_time') >= (int) $o['update_time']) {
        return 'skipped';
    }
    $is_new = !$order;

    if ($is_new) {
        $order = wc_create_order(['created_via' => 'ordersmith']);
        $order->set_currency($o['payment']['currency'] ?? get_woocommerce_currency());
        $order->set_payment_method_title('TikTok Shop');
        $order->set_customer_ip_address(''); // wc_create_order records the importer's IP, not the buyer's
        $order->set_customer_user_agent('');
        $order->set_date_created((int) $o['create_time']);
        $order->update_meta_data('_ordersmith_order_id', (string) $o['id']);
        $order->update_meta_data('_ordersmith_shop_id', (string) $shop['id']);
        ordersmith_add_items($order, $o);
    }

    ordersmith_set_address($order, $o);
    $order->update_meta_data('_ordersmith_update_time', (int) $o['update_time']);
    $order->update_meta_data('_ordersmith_status', $o['status']);
    $order->update_meta_data('_ordersmith_shipping_type', $o['shipping_type'] ?? ''); // SELLER = seller's own courier, TIKTOK = TikTok label
    $order->update_meta_data('_ordersmith_delivery_option_id', $o['delivery_option_id'] ?? '');
    $order->update_meta_data('_ordersmith_package_id', (string) ($o['packages'][0]['id'] ?? ''));
    // Tracking appears once the package is arranged (TikTok label) or shipped (seller courier). Record it once.
    $li = $o['line_items'][0] ?? [];
    if (!empty($li['tracking_number']) && $li['tracking_number'] !== $order->get_meta('_ordersmith_tracking')) {
        $order->update_meta_data('_ordersmith_tracking', $li['tracking_number']);
        $order->update_meta_data('_ordersmith_carrier_name', $li['shipping_provider_name'] ?? '');
        $order->add_order_note(sprintf('TikTok Shop tracking: %s (%s).', $li['tracking_number'], $li['shipping_provider_name'] ?? ''));
    }
    $order->calculate_totals(false);
    // Orders placed before the shop was connected: the seller already handled their stock by hand (that's why
    // they installed us), so import them for the record only. Mark stock as already reduced so Woo doesn't double-count.
    if ($is_new && (int) $o['create_time'] < (int) ($shop['connected_at'] ?? 0)) {
        $order->save(); // needs an ID first
        $order->get_data_store()->set_stock_reduced($order->get_id(), true);
        $order->add_order_note('Placed before Ordersmith was connected, so WooCommerce stock was not changed for this order.');
    }
    // Never move backwards (e.g. seller completed it, TikTok later says AWAITING_COLLECTION). Cancelled always applies.
    $rank = ['pending' => 0, 'on-hold' => 1, 'processing' => 2, 'completed' => 3, 'refunded' => 4];
    if ($wc_status !== 'cancelled' && ($rank[$order->get_status()] ?? 0) > ($rank[$wc_status] ?? 0)) {
        $wc_status = $order->get_status();
    }
    // Woo reduces stock on on-hold/processing/completed and restores it on cancelled.
    $order->set_status($wc_status, $is_new ? 'Imported from TikTok Shop order ' . $o['id'] . '.' : 'TikTok Shop status: ' . $o['status'] . '.');
    $order->save();
    if ($wc_status === 'cancelled') {
        // Already cancelled in Woo by the seller (restock was held back, see below): restore now. Per-item, so never twice.
        wc_increase_stock_levels($order->get_id()); // by ID: reload, $order's items are stale if Woo's own cancel hook just restored
    }

    if ($is_new) {
        ordersmith_log('info', 'Imported TikTok order ' . $o['id'] . ' as #' . $order->get_id());
    }
    return $is_new ? 'created' : 'updated';
}

// Cancelled in Woo but still live on TikTok: restoring stock now would push the units back to TikTok while
// the buyer still expects them, so hold it until TikTok confirms. (Ordersmith Pro cancels on TikTok first.)
add_filter('woocommerce_can_restore_order_stock', function ($can, $order) {
    if ($can && $order->get_meta('_ordersmith_order_id') && $order->get_meta('_ordersmith_status') !== 'CANCELLED') {
        $order->add_order_note('Ordersmith: stock was NOT restored, because this order is still active on TikTok Shop. Cancel it in TikTok Seller Center; stock is restored once TikTok confirms.');
        return false;
    }
    return $can;
}, 10, 2);

/** TikTok returns one line per unit; group by SKU and match WooCommerce products by SKU (case-insensitive). */
function ordersmith_add_items(WC_Order $order, array $o): void
{
    $groups = [];
    foreach ($o['line_items'] ?? [] as $li) {
        $groups[$li['sku_id']][] = $li;
    }
    foreach ($groups as $lines) {
        $li = $lines[0];
        $qty = count($lines);
        $sku = trim((string) ($li['seller_sku'] ?? ''));
        $product_id = $sku !== '' ? wc_get_product_id_by_sku($sku) : 0; // DB collation makes this case-insensitive
        // Seller's revenue: original price minus the seller's own discount (TikTok funds platform discounts).
        $subtotal = array_sum(array_map(fn($l) => (float) $l['original_price'], $lines));
        $total = $subtotal - array_sum(array_map(fn($l) => (float) $l['seller_discount'], $lines));

        $item = new WC_Order_Item_Product();
        $item->set_props(['product_id' => $product_id, 'quantity' => $qty, 'subtotal' => $subtotal, 'total' => $total]);
        $item->set_name($li['product_name'] . ($li['sku_name'] && $li['sku_name'] !== 'Default' ? ' – ' . $li['sku_name'] : ''));
        $item->add_meta_data('TikTok SKU', $sku ?: '(none)');
        $order->add_item($item);

        if (!$product_id) {
            $msg = sprintf('SKU "%s" (%s) is not in WooCommerce. The order was imported but stock was NOT reduced for this item. Add the SKU to the matching product.', $sku, $li['product_name']);
            $order->add_order_note($msg);
            ordersmith_log('warning', 'Order ' . $o['id'] . ': ' . $msg);
            do_action('ordersmith_unmatched_sku', $sku, (string) $li['product_name'], $order);
        }
    }

    $p = $o['payment'] ?? [];
    $ship = new WC_Order_Item_Shipping();
    $ship->set_method_title($o['delivery_option_name'] ?? 'TikTok Shop shipping');
    $ship->set_total((float) ($p['shipping_fee'] ?? 0));
    $order->add_item($ship);
    // ponytail: no tax lines — UK prices include VAT and TikTok reports tax 0 here. Map item_tax when a market needs it.
}

/** Address is empty while ON_HOLD; filled in on a later sync once TikTok releases it. */
function ordersmith_set_address(WC_Order $order, array $o): void
{
    $a = ($o['recipient_address'] ?? []) + ['first_name' => '', 'last_name' => '', 'name' => '', 'address_line1' => '', 'address_detail' => '', 'region_code' => ''];
    $fields = [
        // Some regions only send "name"; then it all goes in first_name.
        'first_name' => $a['first_name'] ?: $a['name'],
        'last_name' => $a['first_name'] ? $a['last_name'] : '',
        'address_1' => $a['address_line1'] ?: $a['address_detail'],
        'address_2' => trim(implode(' ', array_filter([$a['address_line2'] ?? '', $a['address_line3'] ?? '', $a['address_line4'] ?? '']))),
        'city' => $a['post_town'] ?? '',
        'postcode' => $a['postal_code'] ?? '',
        'country' => $a['region_code'] ?: 'GB',
        'phone' => $a['phone_number'] ?? '',
    ];
    $order->set_address($fields, 'shipping');
    // No buyer email on purpose: TikTok forbids contacting buyers off-platform, and without one Woo sends them nothing.
    $order->set_address($fields, 'billing');
}

/* ---------- tracking out (seller-shipped orders) ---------- */

function ordersmith_shop_cipher(WC_Order $order): ?string
{
    return ordersmith_find_shop('id', (string) $order->get_meta('_ordersmith_shop_id'))['cipher'] ?? null;
}

/** Carriers TikTok accepts for this order's delivery option, as [id => name]. Cached for a day. */
function ordersmith_carriers(WC_Order $order): array
{
    $opt = (string) $order->get_meta('_ordersmith_delivery_option_id');
    $cipher = ordersmith_shop_cipher($order);
    if ($opt === '' || !$cipher) {
        return [];
    }
    $key = 'ordersmith_carriers_' . md5($cipher . $opt);
    $list = get_transient($key);
    if ($list === false) {
        $res = ordersmith_api('GET', "/logistics/202309/delivery_options/$opt/shipping_providers", ['shop_cipher' => $cipher]);
        if (is_wp_error($res)) {
            ordersmith_log('error', 'Could not load carriers: ' . $res->get_error_message());
            return [];
        }
        $list = array_column($res['shipping_providers'] ?? [], 'name', 'id');
        set_transient($key, $list, DAY_IN_SECONDS);
    }
    return $list;
}

function ordersmith_can_ship(WC_Order $order): bool
{
    return $order->get_meta('_ordersmith_shipping_type') === 'SELLER'
        && in_array($order->get_meta('_ordersmith_status'), ['AWAITING_SHIPMENT', 'PARTIALLY_SHIPPING'], true)
        && !$order->get_meta('_ordersmith_shipped_at');
}

add_action('add_meta_boxes', function () {
    $screen = function_exists('wc_get_page_screen_id') ? wc_get_page_screen_id('shop-order') : 'shop_order';
    add_meta_box('ordersmith_tiktok', 'TikTok Shop', 'ordersmith_render_meta_box', $screen, 'side', 'high');
});

function ordersmith_render_meta_box($post_or_order): void
{
    $order = $post_or_order instanceof WC_Order ? $post_or_order : wc_get_order($post_or_order->ID);
    if (!$order || !$order->get_meta('_ordersmith_order_id')) {
        echo '<p>Not a TikTok Shop order.</p>';
        return;
    }
    echo '<p>TikTok order <strong>' . esc_html($order->get_meta('_ordersmith_order_id')) . '</strong><br>Status: ' . esc_html($order->get_meta('_ordersmith_status')) . '</p>';
    if ($order->get_meta('_ordersmith_status') === 'CANCELLED') {
        echo '<p>This order is cancelled on TikTok Shop.</p>';
        return;
    }
    wp_nonce_field('ordersmith_tracking', 'ordersmith_tracking_nonce');
    do_action('ordersmith_order_box', $order); // Ordersmith Pro adds its cancel/refund options here
    // One quiet line, only where Pro would act (before shipping, or after delivery), and only without Pro.
    if (!has_action('ordersmith_order_box') && in_array($order->get_meta('_ordersmith_status'), ['AWAITING_SHIPMENT', 'AWAITING_COLLECTION', 'DELIVERED', 'COMPLETED'], true)) {
        echo '<p class="description">Cancel or refund on TikTok from here with <a href="' . esc_url(ORDERSMITH_PRO_URL) . '" target="_blank" rel="noopener">Ordersmith Pro</a>.</p>';
    }

    if ($at = $order->get_meta('_ordersmith_shipped_at')) {
        echo '<p>✔ Tracking <strong>' . esc_html($order->get_meta('_ordersmith_tracking')) . '</strong> sent to TikTok ' . esc_html(human_time_diff((int) $at)) . ' ago.</p>';
        return;
    }
    if ($order->get_meta('_ordersmith_shipping_type') !== 'SELLER') {
        ordersmith_render_tiktok_shipping($order);
        return;
    }
    if (!ordersmith_can_ship($order)) {
        echo '<p>Tracking can be sent once TikTok marks this order "Awaiting shipment".</p>';
        return;
    }
    $carriers = ordersmith_carriers($order);
    $sel = (string) $order->get_meta('_ordersmith_carrier_id');
    echo '<p><label>Carrier<br><select name="ordersmith_carrier_id" style="width:100%"><option value="">Select…</option>';
    foreach ($carriers as $id => $name) {
        echo '<option value="' . esc_attr($id) . '"' . selected($sel, (string) $id, false) . '>' . esc_html($name) . '</option>';
    }
    echo '</select></label></p>';
    echo '<p><label>Tracking number<br><input type="text" name="ordersmith_tracking" value="' . esc_attr($order->get_meta('_ordersmith_tracking')) . '" style="width:100%"></label></p>';
    echo '<p class="description">Set the order to <strong>Completed</strong> and save. The tracking number is sent to TikTok.</p>';
}

// Save the fields (priority 10 runs before Woo applies the status change at 40, so the completed/cancelled hooks see them).
add_action('woocommerce_process_shop_order_meta', function ($order_id) {
    if (!isset($_POST['ordersmith_tracking_nonce']) || !wp_verify_nonce(sanitize_key($_POST['ordersmith_tracking_nonce']), 'ordersmith_tracking') || !current_user_can('edit_shop_orders')) {
        return;
    }
    $order = wc_get_order($order_id);
    foreach (['ordersmith_carrier_id', 'ordersmith_tracking', 'ordersmith_cancel_reason'] as $field) {
        if (isset($_POST[$field])) {
            $order->update_meta_data('_' . $field, sanitize_text_field(wp_unslash($_POST[$field])));
        }
    }
    $order->save_meta_data();
}, 10);

add_action('woocommerce_order_status_completed', function ($order_id) {
    $order = wc_get_order($order_id);
    if ($order && ordersmith_can_ship($order)) {
        ordersmith_send_tracking($order);
    }
});

/** Mark the whole TikTok order shipped with the seller's carrier + tracking. */
function ordersmith_send_tracking(WC_Order $order): bool
{
    $tracking = trim((string) $order->get_meta('_ordersmith_tracking'));
    $carrier = (string) $order->get_meta('_ordersmith_carrier_id');
    $tt_id = (string) $order->get_meta('_ordersmith_order_id');
    $fail = function (string $why) use ($order, $tt_id) {
        ordersmith_log('error', "Tracking for order $tt_id not sent: $why");
        // Back to Processing so an unshipped TikTok order can't hide behind "Completed".
        $order->update_status('processing', 'TikTok Shop: tracking NOT sent. ' . $why);
        return false;
    };
    if ($tracking === '' || $carrier === '') {
        return $fail('Choose a carrier and enter a tracking number in the TikTok Shop box, then save again.');
    }
    $cipher = ordersmith_shop_cipher($order);
    $detail = ordersmith_api('GET', '/order/202309/orders', ['shop_cipher' => $cipher, 'ids' => $tt_id]);
    if (is_wp_error($detail)) {
        return $fail($detail->get_error_message());
    }
    $line_ids = array_column($detail['orders'][0]['line_items'] ?? [], 'id');
    $res = ordersmith_api('POST', "/fulfillment/202309/orders/$tt_id/packages", ['shop_cipher' => $cipher], [
        'order_line_item_ids' => $line_ids,
        'tracking_number' => $tracking,
        'shipping_provider_id' => $carrier,
    ]);
    if (is_wp_error($res)) {
        return $fail($res->get_error_message());
    }
    $order->update_meta_data('_ordersmith_shipped_at', time());
    $order->add_order_note(sprintf('TikTok Shop: tracking %s sent (%s).', $tracking, ordersmith_carriers($order)[$carrier] ?? $carrier));
    $order->save();
    ordersmith_log('info', "Tracking sent for order $tt_id");
    return true;
}

/* ---------- TikTok-shipped orders: arrange shipment + print label ---------- */

function ordersmith_render_tiktok_shipping(WC_Order $order): void
{
    $id = $order->get_id();
    if ($trk = $order->get_meta('_ordersmith_tracking')) {
        echo '<p>Shipping with TikTok label<br>Carrier: ' . esc_html($order->get_meta('_ordersmith_carrier_name')) . '<br>Tracking: <strong>' . esc_html($trk) . '</strong></p>';
        $url = wp_nonce_url(admin_url('admin-post.php?action=ordersmith_label&order_id=' . $id), 'ordersmith_label_' . $id);
        echo '<p><a class="button button-primary" target="_blank" href="' . esc_url($url) . '">Print shipping label</a></p>';
        return;
    }
    if ($order->get_meta('_ordersmith_status') !== 'AWAITING_SHIPMENT' || !$order->get_meta('_ordersmith_package_id')) {
        echo '<p>Shipping with a TikTok label. You can arrange shipment once TikTok marks this order "Awaiting shipment".</p>';
        return;
    }
    $url = admin_url('admin-post.php');
    // Not a <form>: this box sits inside the order edit form, and nested forms break it.
    echo '<p><label><input type="radio" name="ordersmith_handover" value="DROP_OFF" checked form="ordersmith-arrange"> Drop off at a carrier point</label><br>';
    echo '<label><input type="radio" name="ordersmith_handover" value="PICKUP" form="ordersmith-arrange"> Courier pickup</label></p>';
    echo '<p><button type="submit" class="button button-primary" form="ordersmith-arrange">Arrange shipment</button></p>';
    // The real form is printed outside the order form, in the admin footer.
    add_action('admin_footer', function () use ($url, $id) {
        echo '<form id="ordersmith-arrange" method="post" action="' . esc_url($url) . '"><input type="hidden" name="action" value="ordersmith_arrange"><input type="hidden" name="order_id" value="' . (int) $id . '">';
        wp_nonce_field('ordersmith_arrange_' . $id);
        echo '</form>';
    });
}

/** Re-fetch one order from TikTok and apply it (status, tracking). */
function ordersmith_refresh_order(WC_Order $order): void
{
    $d = ordersmith_api('GET', '/order/202309/orders', ['shop_cipher' => ordersmith_shop_cipher($order), 'ids' => $order->get_meta('_ordersmith_order_id')]);
    if (!is_wp_error($d) && !empty($d['orders'][0])) {
        $shop = ['id' => $order->get_meta('_ordersmith_shop_id')];
        ordersmith_upsert_order($d['orders'][0], $shop);
    }
}

function ordersmith_order_from_request(string $nonce_action): WC_Order
{
    $id = absint($_REQUEST['order_id'] ?? 0);
    if (!current_user_can('edit_shop_orders') || !wp_verify_nonce(sanitize_key($_REQUEST['_wpnonce'] ?? ''), $nonce_action . $id)) {
        wp_die('Not allowed.');
    }
    $order = wc_get_order($id);
    if (!$order || !$order->get_meta('_ordersmith_order_id')) {
        wp_die('Not a TikTok Shop order.');
    }
    return $order;
}

add_action('admin_post_ordersmith_arrange', function () {
    $order = ordersmith_order_from_request('ordersmith_arrange_');
    // phpcs:ignore WordPress.Security.NonceVerification.Missing -- nonce checked in ordersmith_order_from_request() above.
    $handover = sanitize_key(wp_unslash($_POST['ordersmith_handover'] ?? '')) === 'pickup' ? 'PICKUP' : 'DROP_OFF';
    $pkg = $order->get_meta('_ordersmith_package_id');
    $res = ordersmith_api('POST', "/fulfillment/202309/packages/$pkg/ship", ['shop_cipher' => ordersmith_shop_cipher($order)], ['handover_method' => $handover]);
    if (is_wp_error($res)) {
        $order->add_order_note('TikTok Shop: could not arrange shipment. ' . $res->get_error_message());
        ordersmith_log('error', 'Arrange shipment failed for ' . $order->get_meta('_ordersmith_order_id') . ': ' . $res->get_error_message());
    } else {
        $order->add_order_note('TikTok Shop: shipment arranged (' . strtolower(str_replace('_', ' ', $handover)) . ').');
        ordersmith_refresh_order($order); // pulls the tracking number so the label button appears
    }
    wp_safe_redirect($order->get_edit_order_url());
    exit;
});

add_action('admin_post_ordersmith_label', function () {
    $order = ordersmith_order_from_request('ordersmith_label_');
    $pkg = $order->get_meta('_ordersmith_package_id');
    // Label URLs expire, so fetch a fresh one on every click.
    $doc = ordersmith_api('GET', "/fulfillment/202309/packages/$pkg/shipping_documents", ['shop_cipher' => ordersmith_shop_cipher($order), 'document_type' => 'SHIPPING_LABEL']);
    if (is_wp_error($doc) || empty($doc['doc_url'])) {
        wp_die('Could not get the label from TikTok: ' . esc_html(is_wp_error($doc) ? $doc->get_error_message() : 'no document returned') . '. Try again in a minute, or print it in TikTok Seller Center.');
    }
    // Label lives on TikTok's CDN: allow exactly that host for this one redirect.
    $host = (string) wp_parse_url($doc['doc_url'], PHP_URL_HOST);
    add_filter('allowed_redirect_hosts', fn($hosts) => array_merge($hosts, [$host]));
    wp_safe_redirect(esc_url_raw($doc['doc_url']));
    exit;
});

/* ---------- stock out: WooCommerce is the source of truth ---------- */

// Fires for every stock change: orders, refunds, admin edits, REST, imports.
add_action('woocommerce_product_set_stock', 'ordersmith_queue_stock');
add_action('woocommerce_variation_set_stock', 'ordersmith_queue_stock');

function ordersmith_queue_stock(WC_Product $product): void
{
    if (!$product->get_sku() || !$product->managing_stock() || !ordersmith_shops()) {
        return;
    }
    // Async + de-duplicated: an order with 5 units of one product pushes once.
    $args = [$product->get_id()];
    if (!as_has_scheduled_action('ordersmith_push_stock', $args, 'ordersmith')) {
        as_enqueue_async_action('ordersmith_push_stock', $args, 'ordersmith');
    }
}

add_action('ordersmith_push_stock', 'ordersmith_push_stock');

/** Find this SKU on TikTok: [product_id, sku_id, warehouse_id], null if not listed, or WP_Error. Cached on the product. */
function ordersmith_tiktok_sku(WC_Product $product, array $shop, bool $fresh = false)
{
    $map = $product->get_meta('_ordersmith_tt_map') ?: [];
    $hit = $map[$shop['id']] ?? null;
    if (!$fresh && $hit !== null) {
        if (isset($hit['missing'])) {
            if ($hit['missing'] > time() - DAY_IN_SECONDS) {
                return null; // not on TikTok as of today; check again tomorrow in case it gets listed
            }
        } else {
            return $hit;
        }
    }
    $res = ordersmith_api('POST', '/product/202309/products/search', ['shop_cipher' => $shop['cipher'], 'page_size' => '10'], ['seller_skus' => [$product->get_sku()]]);
    if (is_wp_error($res)) {
        return $res; // don't cache failures
    }
    $found = [];
    foreach ($res['products'] ?? [] as $p) {
        foreach ($p['skus'] ?? [] as $s) {
            if (strcasecmp(trim($s['seller_sku'] ?? ''), trim($product->get_sku())) === 0) {
                // ponytail: first warehouse only. Multi-warehouse sellers need a warehouse picker.
                $found = [$p['id'], $s['id'], $s['inventory'][0]['warehouse_id'] ?? ''];
                break 2;
            }
        }
    }
    $map[$shop['id']] = $found ?: ['missing' => time()];
    $product->update_meta_data('_ordersmith_tt_map', $map);
    $product->save_meta_data();
    return $found ?: null;
}

function ordersmith_push_stock(int $product_id): void
{
    $product = wc_get_product($product_id);
    if (!$product || !$product->managing_stock()) {
        return;
    }
    $qty = max(0, (int) $product->get_stock_quantity());
    foreach (ordersmith_shops() as $shop) {
        $res = null;
        foreach ([false, true] as $fresh) { // second pass: product may have been re-listed on TikTok with new IDs
            $tt = ordersmith_tiktok_sku($product, $shop, $fresh);
            if (is_wp_error($tt)) {
                $res = $tt;
                break;
            }
            if (!$tt) {
                break; // not sold on TikTok, nothing to do
            }
            [$tt_product, $tt_sku, $warehouse] = $tt;
            $res = ordersmith_api('POST', "/product/202309/products/$tt_product/inventory/update", ['shop_cipher' => $shop['cipher']], [
                'skus' => [['id' => $tt_sku, 'inventory' => [['warehouse_id' => $warehouse, 'quantity' => $qty]]]],
            ]);
            if (!is_wp_error($res)) {
                ordersmith_log('info', sprintf('Stock for %s set to %d on TikTok.', $product->get_sku(), $qty));
                break;
            }
        }
        if (ordersmith_rate_limited($res)) {
            // Absolute quantity, so a later run is always right: reads the stock as it is then.
            as_schedule_single_action(time() + wp_rand(60, 180), 'ordersmith_push_stock', [$product_id], 'ordersmith');
            ordersmith_log('notice', sprintf('TikTok rate limit: stock for %s will be retried in a few minutes.', $product->get_sku()));
            return;
        }
        if (is_wp_error($res)) {
            ordersmith_log('error', sprintf('Could not update TikTok stock for %s: %s', $product->get_sku(), $res->get_error_message()));
            do_action('ordersmith_stock_push_failed', $product, $res, $shop);
            throw new Exception(esc_html($res->get_error_message())); // Action Scheduler marks it failed (visible in Tools → Scheduled Actions)
        }
    }
}

add_action('admin_post_ordersmith_push_all_stock', function () {
    if (!current_user_can('manage_woocommerce')) {
        wp_die('Not allowed.');
    }
    check_admin_referer('ordersmith_push_all_stock');
    $ids = wc_get_products(['limit' => -1, 'return' => 'ids', 'type' => ['simple', 'variation'], 'manage_stock' => true]);
    $n = 0;
    foreach ($ids as $id) {
        $p = wc_get_product($id);
        if ($p && $p->get_sku()) {
            $p->delete_meta_data('_ordersmith_tt_map'); // re-match everything
            $p->save_meta_data();
            ordersmith_queue_stock($p);
            $n++;
        }
    }
    ordersmith_back(sprintf('Sending stock for %d products to TikTok in the background. Products not listed on TikTok are skipped.', $n));
});

/* ---------- admin page: connect / disconnect ---------- */

add_action('admin_menu', function () {
    add_submenu_page('woocommerce', 'Ordersmith', 'Ordersmith', 'manage_woocommerce', 'ordersmith', 'ordersmith_render_page');
});

function ordersmith_page_url(array $args = []): string
{
    return add_query_arg($args, admin_url('admin.php?page=ordersmith'));
}

function ordersmith_render_page(): void
{
    $c = ordersmith_connection();
    // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- TikTok's redirect can't carry a nonce; the code is only used after the admin confirms via a nonce-protected form.
    $code = isset($_GET['code']) ? sanitize_text_field(wp_unslash($_GET['code'])) : '';
    $notice = get_transient('ordersmith_notice_' . get_current_user_id());
    delete_transient('ordersmith_notice_' . get_current_user_id());
    $state = rtrim(strtr(base64_encode(wp_json_encode(['site' => untrailingslashit(site_url())])), '+/', '-_'), '=');
    ?>
    <div class="wrap">
        <h1>Ordersmith for TikTok Shop</h1>
        <?php if ($notice) : ?>
            <div class="notice notice-<?php echo $notice['error'] ? 'error' : 'success'; ?>"><p><?php echo esc_html($notice['msg']); ?></p></div>
        <?php endif; ?>

        <?php if ($code && !$c) : ?>
            <p>TikTok Shop has authorised this store. Confirm to finish connecting.</p>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>">
                <input type="hidden" name="action" value="ordersmith_connect">
                <input type="hidden" name="code" value="<?php echo esc_attr($code); ?>">
                <?php wp_nonce_field('ordersmith_connect'); ?>
                <?php submit_button('Finish connecting', 'primary', 'submit', false); ?>
            </form>
        <?php elseif ($c) : ?>
            <p><strong>Connected</strong> as <?php echo esc_html($c['seller_name'] ?? ''); ?>.</p>
            <table class="widefat striped" style="max-width:640px">
                <thead><tr><th>Shop</th><th>Region</th></tr></thead>
                <tbody>
                <?php foreach ($c['shops'] ?? [] as $shop) : ?>
                    <tr><td><?php echo esc_html($shop['name']); ?></td><td><?php echo esc_html($shop['region']); ?></td></tr>
                <?php endforeach; ?>
                </tbody>
            </table>
            <?php $last = (int) get_option('ordersmith_last_sync'); ?>
            <p><?php echo get_option('ordersmith_webhook_ok')
                ? 'Instant sync is on: new TikTok orders arrive within seconds (with an hourly safety check).'
                : 'Orders sync every 15 minutes (instant sync is unavailable: TikTok can\'t reach this site).'; ?> Last sync: <?php echo $last ? esc_html(human_time_diff($last) . ' ago') : 'not yet'; ?>.
                Problems are recorded in <a href="<?php echo esc_url(admin_url('admin.php?page=wc-status&tab=logs&source=ordersmith')); ?>">WooCommerce → Status → Logs</a>.</p>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline-block;margin-right:8px">
                <input type="hidden" name="action" value="ordersmith_sync_now">
                <?php wp_nonce_field('ordersmith_sync_now'); ?>
                <?php submit_button('Sync orders now', 'primary', 'submit', false); ?>
            </form>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline-block;margin-right:8px">
                <input type="hidden" name="action" value="ordersmith_push_all_stock">
                <?php wp_nonce_field('ordersmith_push_all_stock'); ?>
                <?php submit_button('Send all stock to TikTok', 'secondary', 'submit', false); ?>
            </form>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline-block">
                <input type="hidden" name="action" value="ordersmith_disconnect">
                <?php wp_nonce_field('ordersmith_disconnect'); ?>
                <?php submit_button('Disconnect', 'secondary', 'submit', false); ?>
            </form>
            <?php do_action('ordersmith_settings_page'); // Ordersmith Pro adds its settings here ?>
            <?php if (!has_action('ordersmith_settings_page')) : ?>
                <div style="max-width:640px;margin-top:24px;padding:12px 16px;border:1px solid #dcdcde;background:#fff">
                    <strong>Ordersmith Pro</strong>: connect more than one TikTok Shop, cancel and refund TikTok orders from WooCommerce, and sync prices, titles and descriptions to TikTok Shop.
                    <a href="<?php echo esc_url(ORDERSMITH_PRO_URL); ?>" target="_blank" rel="noopener">Learn more</a>
                </div>
            <?php endif; ?>
        <?php else : ?>
            <p>Connect your TikTok Shop to import orders, send tracking numbers and keep stock in sync.</p>
            <p><a class="button button-primary" href="<?php echo esc_url(ORDERSMITH_AUTHORIZE . '&state=' . $state); ?>">Connect TikTok Shop</a></p>
        <?php endif; ?>
    </div>
    <?php
}

function ordersmith_back(string $msg, bool $error = false): void
{
    // Notice kept server-side (not in the URL) so a crafted link can't show admins a fake message.
    set_transient('ordersmith_notice_' . get_current_user_id(), ['msg' => $msg, 'error' => $error], MINUTE_IN_SECONDS);
    wp_safe_redirect(ordersmith_page_url());
    exit;
}

add_action('admin_post_ordersmith_connect', function () {
    if (!current_user_can('manage_woocommerce')) {
        wp_die('Not allowed.');
    }
    check_admin_referer('ordersmith_connect');
    $code = sanitize_text_field(wp_unslash($_POST['code'] ?? ''));

    $data = ordersmith_tiktok_data(ordersmith_signer('token', ['auth_code' => $code]));
    if (is_wp_error($data)) {
        ordersmith_back('Could not connect: ' . $data->get_error_message() . ' Try connecting again.', true);
    }
    $shops = ordersmith_api('GET', '/authorization/202309/shops', [], null, $data['access_token']);
    if (is_wp_error($shops)) {
        ordersmith_back('Connected, but could not read your shops: ' . $shops->get_error_message(), true);
    }
    $list = array_map(fn($s) => array_intersect_key($s, array_flip(['id', 'name', 'region', 'cipher', 'code'])), $shops['shops'] ?? []);
    ordersmith_save_tokens($data, ['seller_name' => $data['seller_name'] ?? '', 'shops' => $list, 'connected_at' => time()]);
    ordersmith_register_webhook($data['access_token']); // also (re)schedules the poll
    ordersmith_back('TikTok Shop connected.');
});

// Re-arm the schedule if it went missing (e.g. plugin deactivated and reactivated).
add_action('admin_init', function () {
    $c = get_option(ORDERSMITH_OPTION);
    if ($c && empty($c['revoked'])) {
        // Stores connected before webhooks existed: register once.
        if (get_option('ordersmith_webhook_ok') === false && !is_wp_error($t = ordersmith_access_token())) {
            ordersmith_register_webhook($t);
        }
        ordersmith_schedule_sync();
    }
});

add_action('admin_post_ordersmith_sync_now', function () {
    if (!current_user_can('manage_woocommerce')) {
        wp_die('Not allowed.');
    }
    check_admin_referer('ordersmith_sync_now');
    $r = ordersmith_sync_orders();
    is_wp_error($r)
        ? ordersmith_back('Sync failed: ' . $r->get_error_message(), true)
        : ordersmith_back(sprintf('Sync done: %d new, %d updated.', $r[0], $r[1]));
});

add_action('admin_post_ordersmith_disconnect', function () {
    if (!current_user_can('manage_woocommerce')) {
        wp_die('Not allowed.');
    }
    check_admin_referer('ordersmith_disconnect');
    $token = ordersmith_access_token();
    if (!is_wp_error($token)) {
        ordersmith_signer('unregister', ['access_token' => $token]); // stop forwarding this shop's events
    }
    delete_option(ORDERSMITH_OPTION); // tokens gone immediately, as promised in the privacy policy
    delete_option('ordersmith_webhook_ok');
    as_unschedule_all_actions(ORDERSMITH_SYNC_HOOK, [], 'ordersmith');
    ordersmith_back('Disconnected. You can also revoke access in TikTok Shop Seller Center.');
});