<?php
/**
 * Shared coupon burn helpers for cash content / topic orders.
 *
 * Idempotent via coupon_usage.order_number. Prefer note.coupon snapshot ids
 * so burn still works after use_coupon increments used_count past limit.
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

if (!function_exists('aksrt_coupon_usage_exists')) {
    /**
     * Whether a coupon_usage row already exists for this order.
     */
    function aksrt_coupon_usage_exists(string $order_number): bool {
        if ($order_number === '' || !class_exists('\AKSRT\Core\DBMigrator')) {
            return false;
        }
        global $wpdb;
        $table = \AKSRT\Core\DBMigrator::table('coupon_usage');
        if ($table === '') {
            return false;
        }
        $found = $wpdb->get_var($wpdb->prepare(
            "SELECT id FROM {$table} WHERE order_number = %s LIMIT 1",
            $order_number
        ));
        return !empty($found);
    }
}

if (!function_exists('aksrt_burn_order_coupon')) {
    /**
     * Burn coupon for a paid cash order (use_coupon + log_usage).
     *
     * @param array<string,mixed> $meta Order note JSON (coupon_code / coupon / coupon_discount).
     * @return bool True when a burn was attempted (or already burned).
     */
    function aksrt_burn_order_coupon(string $order_number, array $meta, int $buyer_id = 0): bool {
        if ($order_number === '' || !class_exists('\AKSRT\Payment\Coupon')) {
            return false;
        }
        if (aksrt_coupon_usage_exists($order_number)) {
            return true;
        }

        $coupon = is_array($meta['coupon'] ?? null) ? $meta['coupon'] : [];
        $coupon_code = sanitize_text_field((string) ($coupon['code'] ?? $meta['coupon_code'] ?? ''));
        $coupon_discount = (float) ($meta['coupon_discount'] ?? $meta['discount'] ?? ($coupon['discount'] ?? 0));
        if ($coupon_code === '') {
            return false;
        }

        $coupon_api = \AKSRT\Payment\Coupon::get_instance();
        $coupon_api->use_coupon($coupon_code);

        // Prefer snapshot id: post-increment validate may fail on usage_limit edge.
        $coupon_id = (int) ($coupon['id'] ?? 0);
        if ($coupon_id <= 0) {
            $validated = $coupon_api->validate($coupon_code, max(0.01, $coupon_discount), [
                'user_id' => max(0, $buyer_id),
            ]);
            $coupon_id = (int) ($validated['coupon']['id'] ?? 0);
        }

        if ($coupon_id > 0) {
            $coupon_api->log_usage($coupon_id, max(0, $buyer_id), $order_number, max(0.0, $coupon_discount));
        }

        return true;
    }
}