<?php

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

final class AISEO_Plugin {
    /**
     * @var AISEO_Plugin|null
     */
    private static $instance = null;

    /**
     * @var AISEO_OpenAI_Client
     */
    private $openai_client;

    /**
     * @var AISEO_Scanner
     */
    private $scanner;

    /**
     * @var AISEO_Admin
     */
    private $admin;

    private function __construct() {
        $this->openai_client = new AISEO_OpenAI_Client();
        $this->scanner = new AISEO_Scanner($this->openai_client);
        $this->admin = new AISEO_Admin($this->scanner, $this->openai_client);

        add_action('admin_init', array($this, 'maybe_upgrade'));
        add_filter('plugin_action_links_' . plugin_basename(AISEO_AUDITOR_FILE), array($this, 'plugin_action_links'));
    }

    public static function instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    public static function activate() {
        self::maybe_run_activation_bootstrap();

        if (false === get_option('aiseo_auditor_version', false)) {
            add_option('aiseo_auditor_version', AISEO_AUDITOR_VERSION);
        } else {
            update_option('aiseo_auditor_version', AISEO_AUDITOR_VERSION);
        }
    }

    public function maybe_upgrade() {
        if (get_option('aiseo_auditor_version') === AISEO_AUDITOR_VERSION) {
            return;
        }

        self::maybe_run_activation_bootstrap();
        update_option('aiseo_auditor_version', AISEO_AUDITOR_VERSION);
    }

    private static function maybe_run_activation_bootstrap() {
        $license_key = self::ensure_local_license_key();
        if ('' === $license_key) {
            return;
        }

        $requests_remaining = get_option('aiseo_requests_remaining', false);
        if (false === $requests_remaining || '' === trim((string) $requests_remaining)) {
            update_option('aiseo_requests_remaining', 5, false);
        }

        $result = self::register_first_requests($license_key);
        update_option('aiseo_first_requests_status', $result, false);

        if (!empty($result['success'])) {
            update_option('aiseo_first_requests_registered', '1', false);
            if (isset($result['requests'])) {
                update_option('aiseo_requests_remaining', max(0, absint($result['requests'])), false);
            }
        }
    }

    public static function sync_requests_remaining() {
        $license_key = self::ensure_local_license_key();
        if ('' === $license_key) {
            return array(
                'success' => false,
                'requests' => max(0, absint(get_option('aiseo_requests_remaining', 0))),
                'message' => 'Missing local site ID.',
            );
        }

        $result = self::register_first_requests($license_key);
        update_option('aiseo_first_requests_status', $result, false);

        if (!empty($result['success']) && isset($result['requests'])) {
            update_option('aiseo_first_requests_registered', '1', false);
            update_option('aiseo_requests_remaining', max(0, absint($result['requests'])), false);
        }

        return $result;
    }

    private static function ensure_local_license_key() {
        $existing = trim((string) get_option('aiseo_license_key', ''));
        if ('' !== $existing) {
            return $existing;
        }

        $license_key = self::generate_numeric_license_key();
        update_option('aiseo_license_key', $license_key, false);

        return $license_key;
    }

    private static function generate_numeric_license_key() {
        $digits = '';

        for ($i = 0; $i < 10; $i++) {
            try {
                $digit = random_int(0 === $i ? 1 : 0, 9);
            } catch (Exception $exception) {
                $digit = wp_rand(0 === $i ? 1 : 0, 9);
            }

            $digits .= (string) $digit;
        }

        return $digits;
    }

    private static function register_first_requests($license_key) {
        $endpoint = defined('AISEO_AUDITOR_FIRST_REQUESTS_ENDPOINT') ? AISEO_AUDITOR_FIRST_REQUESTS_ENDPOINT : '';
        $endpoint = esc_url_raw((string) apply_filters('aiseo_first_requests_endpoint', $endpoint));
        $activation_key = defined('AISEO_AUDITOR_FIRST_REQUESTS_SHARED_KEY') ? (string) AISEO_AUDITOR_FIRST_REQUESTS_SHARED_KEY : '';
        $activation_key = (string) apply_filters('aiseo_first_requests_shared_key', $activation_key);
        if ('' === $endpoint) {
            return array(
                'success' => false,
                'message' => 'First requests endpoint is not configured.',
            );
        }

        $payload = array(
            'domain' => self::activation_domain(),
            'site_url' => home_url('/'),
            'license_key' => $license_key,
            'requests' => 5,
            'activation_key' => $activation_key,
            'plugin' => array(
                'name' => defined('AISEO_AUDITOR_NAME') ? AISEO_AUDITOR_NAME : 'AiVisibility',
                'version' => defined('AISEO_AUDITOR_VERSION') ? AISEO_AUDITOR_VERSION : '',
            ),
        );

        $response = wp_remote_post(
            $endpoint,
            array(
                'timeout' => 12,
                'redirection' => 2,
                'headers' => array(
                    'Accept' => 'application/json',
                    'Content-Type' => 'application/json',
                    'X-AiVisibility-Activation-Key' => $activation_key,
                    'X-AiVisibility-Site' => home_url('/'),
                    'User-Agent' => (defined('AISEO_AUDITOR_NAME') ? AISEO_AUDITOR_NAME : 'AiVisibility') . '/' . (defined('AISEO_AUDITOR_VERSION') ? AISEO_AUDITOR_VERSION : '') . '; ' . home_url('/'),
                ),
                'body' => wp_json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
            )
        );

        if (is_wp_error($response)) {
            return array(
                'success' => false,
                'message' => $response->get_error_message(),
            );
        }

        $status_code = (int) wp_remote_retrieve_response_code($response);
        $body = (string) wp_remote_retrieve_body($response);
        $decoded = json_decode($body, true);

        if ($status_code < 200 || $status_code >= 300 || !is_array($decoded) || empty($decoded['success'])) {
            return array(
                'success' => false,
                'status_code' => $status_code,
                'message' => is_array($decoded) && isset($decoded['message']) ? (string) $decoded['message'] : substr($body, 0, 300),
            );
        }

        return array(
            'success' => true,
            'status_code' => $status_code,
            'domain' => isset($decoded['domain']) ? sanitize_text_field((string) $decoded['domain']) : self::activation_domain(),
            'requests' => isset($decoded['requests']) ? absint($decoded['requests']) : 5,
            'license_key' => isset($decoded['license_key']) ? sanitize_text_field((string) $decoded['license_key']) : $license_key,
            'created' => !empty($decoded['created']),
        );
    }

    private static function activation_domain() {
        $host = (string) wp_parse_url(home_url('/'), PHP_URL_HOST);
        $host = strtolower(trim($host));

        return '' !== $host ? $host : strtolower(trim((string) home_url('/')));
    }

    public function plugin_action_links($links) {
        $settings_link = sprintf(
            '<a href="%s">%s</a>',
            esc_url(admin_url('admin.php?page=aiseo-auditor')),
            esc_html__('Settings', 'aivisibility-seo-geo-agent')
        );

        array_unshift($links, $settings_link);

        return $links;
    }

    public function scanner() {
        return $this->scanner;
    }

    public function openai_client() {
        return $this->openai_client;
    }

}