<?php
/**
 * Shielda Verifier Class
 * Handles server-to-server token verification with Shielda API.
 */

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

class Shielda_Verifier {

    /**
     * Cache for request-level verification result to prevent multiple verifications of the same token.
     *
     * @var array|null
     */
    private $cached_result = null;

    /**
     * Get plugin settings.
     *
     * @return array
     */
    public function get_settings() {
        return get_option('shielda_settings', array());
    }

    /**
     * Get API URL.
     *
     * @return string
     */
    public function get_api_url() {
        return SHIELDA_VERIFY_API_URL;
    }

    /**
     * Get Site Key.
     *
     * @return string
     */
    public function get_site_key() {
        $settings = $this->get_settings();
        return !empty($settings['site_key']) ? trim($settings['site_key']) : '';
    }

    /**
     * Get Secret Key.
     *
     * @return string
     */
    public function get_secret_key() {
        $settings = $this->get_settings();
        return !empty($settings['secret_key']) ? trim($settings['secret_key']) : '';
    }

    /**
     * Check if a specific form protection is enabled.
     *
     * @param string $key
     * @return bool
     */
    public function is_enabled($key) {
        $settings = $this->get_settings();
        return !empty($settings[$key]) && $settings[$key] === '1';
    }

    /**
     * Verify captcha response token.
     *
     * @param string|null $token
     * @return array
     */
    public function verify($token = null) {
        if (!is_null($this->cached_result)) {
            return $this->cached_result;
        }

        if (is_null($token)) {
            if (isset($_POST['darban-captcha-response'])) {
                $token = sanitize_text_field(wp_unslash($_POST['darban-captcha-response']));
            } elseif (isset($_POST['shielda-captcha-response'])) {
                $token = sanitize_text_field(wp_unslash($_POST['shielda-captcha-response']));
            }
        }

        $secret_key = $this->get_secret_key();

        if (empty($token)) {
            $result = array(
                'success' => false,
                'message' => __('لطفاً چالش امنیتی شیلدا (کپچا) را حل کنید.', 'shielda-captcha'),
                'code'    => 'missing_token'
            );
            $this->cached_result = $result;
            return $result;
        }

        if (empty($secret_key)) {
            $result = array(
                'success' => false,
                'message' => __('کلید امنیتی (Secret Key) شیلدا در تنظیمات وارد نشده است.', 'shielda-captcha'),
                'code'    => 'missing_secret'
            );
            $this->cached_result = $result;
            return $result;
        }

        $verify_endpoint = SHIELDA_VERIFY_API_URL;

        $payload = array(
            'secret'   => $secret_key,
            'response' => $token,
        );

        $response = wp_remote_post($verify_endpoint, array(
            'method'      => 'POST',
            'timeout'     => 10,
            'redirection' => 5,
            'httpversion' => '1.1',
            'blocking'    => true,
            'headers'     => array(
                'Content-Type' => 'application/json',
                'Accept'       => 'application/json',
            ),
            'body'        => wp_json_encode($payload),
        ));

        if (is_wp_error($response)) {
            $result = array(
                'success' => false,
                'message' => sprintf(__('خطا در ارتباط با سرور اعتبارسنجی شیلدا: %s', 'shielda-captcha'), $response->get_error_message()),
                'code'    => 'connection_error'
            );
            $this->cached_result = $result;
            return $result;
        }

        $response_code = wp_remote_retrieve_response_code($response);
        $body          = wp_remote_retrieve_body($response);
        $data          = json_decode($body, true);

        if ($response_code !== 200 || !is_array($data) || empty($data['success'])) {
            $error_info = '';
            if (!empty($data['error_codes']) && is_array($data['error_codes'])) {
                $error_info = ' (' . implode(', ', $data['error_codes']) . ')';
            }
            $result = array(
                'success' => false,
                'message' => __('پاسخ اعتبارسنجی کپچا نامعتبر است یا زمان آن منقضی شده است.', 'shielda-captcha') . $error_info,
                'code'    => 'invalid_captcha',
                'raw'     => $data
            );
            $this->cached_result = $result;
            return $result;
        }

        $result = array(
            'success'      => true,
            'message'      => __('اعتبارسنجی با موفقیت انجام شد.', 'shielda-captcha'),
            'challenge_ts' => isset($data['challenge_ts']) ? $data['challenge_ts'] : '',
            'hostname'     => isset($data['hostname']) ? $data['hostname'] : '',
        );

        $this->cached_result = $result;
        return $result;
    }
}