<?php

/**
 * Main AnswerRails plugin class + the answerrails() accessor.
 *
 * This class lives in its own file, not in answerrails.php (#95): the
 * Freemius step-18 main-file guard means the free↔paid auto-deactivation
 * swap can momentarily load BOTH builds' main files in one request. A
 * top-level `class AnswerRails` in the main file fatals on redeclaration;
 * behind require_once in its own file, the double-load is idempotent.
 */
if ( !defined( 'ABSPATH' ) ) {
    exit;
}
/**
 * Main AnswerRails Plugin Class
 */
class AnswerRails {
    /**
     * Single instance of the plugin
     */
    private static $instance = null;

    /**
     * Tracks whether the database connection is available for this request.
     */
    private $database_ready = true;

    /**
     * Plugin components
     */
    public $core;

    public $response_service;

    public $admin;

    public $knowledge;

    public $knowledge_ajax;

    public $rag_analytics;

    // #259: the consent declaration (WP Consent API + Complianz). Held as an
    // ownership reference in the documented convention (bin/audit/README.md) —
    // the object registers its own hooks in its constructor and is not called
    // again, so this property is write-only and LOAD-BEARING.
    public $consent_declaration;

    // ⚠ AnswerRails_Knowledge_Loader is the single owner of the knowledge
    // admin and the knowledge REST controller — no property here holds
    // either. A second object self-registers its hooks, and WP cannot
    // dedupe two objects: the routes register twice.
    /**
     * Get singleton instance
     */
    public static function instance() {
        if ( null === self::$instance ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Constructor
     */
    private function __construct() {
        // Ensure the singleton reference is populated immediately so any
        // re-entrant calls to answerrails() during construction receive the
        // in-progress instance rather than triggering another instantiation.
        self::$instance = $this;
        AnswerRails_Utils::debug_log( 'constructor:start' );
        $this->init_hooks();
        $this->database_ready = $this->check_database_ready();
        AnswerRails_Utils::debug_log( 'constructor:db-check', array(
            'database_ready' => $this->database_ready,
        ) );
        $this->load_dependencies();
        AnswerRails_Utils::debug_log( 'constructor:dependencies-loaded' );
        if ( !$this->database_ready ) {
            AnswerRails_Utils::debug_log( 'constructor:database-unavailable' );
            return;
        }
        $this->init_components();
        AnswerRails_Utils::debug_log( 'constructor:components-initialized' );
    }

    /**
     * Initialize WordPress hooks
     */
    private function init_hooks() {
        add_action( 'init', array($this, 'init'), 10 );
        add_action( 'rest_api_init', array($this, 'register_rest_routes') );
        // Activation/deactivation hooks
        register_activation_hook( ANSWERRAILS_PLUGIN_FILE, array($this, 'activate') );
        register_deactivation_hook( ANSWERRAILS_PLUGIN_FILE, array($this, 'deactivate') );
    }

    /**
     * Load plugin dependencies
     */
    private function load_dependencies() {
        AnswerRails_Utils::debug_log( 'load_dependencies:start' );
        // Core includes.
        // #176 D1: the save-time sanitisation helpers, loaded FIRST —
        // this plugin's own register_setting() block and the one in
        // AnswerRails Pro both call into them.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-settings-sanitise.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-theme.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-core.php';
        // #259 (D1/D2): the consent declaration — WP Consent API + Complianz.
        // Loaded beside Core because it decorates Core's frontend script tags.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-consent-declaration.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-response-service.php';
        // #174: the advanced-privacy frontend enqueue lives in
        // AnswerRails_Core (decision 25 D4), which never enqueues an asset
        // this plugin does not ship.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-knowledge-loader.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-knowledge-ajax.php';
        // REST API classes - UNIFIED SYSTEM
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-logger.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-response-service.php';
        // #130: ledger STORAGE, loaded first — privacy-tools depends on it,
        // never the other way round.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-privacy-ledgers.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-privacy-tools.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-link-matcher.php';
        // #144 Layer A: the site content index (standing closed-world
        // grounding context) — needed by the REST prompt-assembly path and
        // by admin-side cache invalidation, so loaded centrally.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-site-index.php';
        // #142 Layer B: lookup-table focus resolution — the canonical
        // entry-line format authority (writer used by the knowledge sync
        // path, parser by the REST retrieval path), so loaded centrally.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-focus-resolver.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-api-health-monitor.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-moderation-service.php';
        // #119 visitor-input moderation (depends on the health monitor)
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-provider-interface.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-provider-factory.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-model-capabilities.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-openai-provider.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-mistral-provider.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/providers/class-answerrails-anthropic-provider.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-api-router.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-rag-analytics.php';
        // Local chunk store + chunker: needed by the REST chat path (lexical
        // fallback) as well as the knowledge loader, so loaded centrally.
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/knowledge/class-answerrails-knowledge-chunker.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/knowledge/class-answerrails-chunk-store.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-rest-auth.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-rest-openai.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-rest-chat.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-rest-router.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-knowledge-rest.php';
        require_once ANSWERRAILS_PLUGIN_DIR . 'includes/class-answerrails-migrations.php';
        // Update delivery is not this plugin's job: Freemius delivers the
        // premium build, .org/WP core the free one (#95).
        // Admin includes
        if ( is_admin() ) {
            require_once ANSWERRAILS_PLUGIN_DIR . 'admin/class-answerrails-admin.php';
            require_once ANSWERRAILS_PLUGIN_DIR . 'admin/class-answerrails-chatlog-list-table.php';
        }
        AnswerRails_Utils::debug_log( 'load_dependencies:complete' );
    }

    /**
     * Initialize plugin components
     */
    private function init_components() {
        AnswerRails_Utils::debug_log( 'init_components:start' );
        // Initialize core components (frontend only - NO REST API functions)
        $this->core = new AnswerRails_Core();
        // #259 (D1/D2): declare AnswerRails to the WP Consent API and to
        // Complianz. Constructed here, on every request, for the same
        // reason the privacy tooling is: a consent declaration that only
        // happens on some requests is a declaration a CMP can miss.
        // ⚠ A DECLARATION, NOT A FIX — see the class docblock.
        $this->consent_declaration = new AnswerRails_Consent_Declaration();
        // Shared response utilities available to REST and Pro handlers
        $this->response_service = new AnswerRails_Response_Service();
        // FIXED: Initialize Knowledge Loader (not the old Knowledge class)
        $this->knowledge = new AnswerRails_Knowledge_Loader();
        // ⚠ The Knowledge REST controller is constructed by the loader and
        // nowhere else: a second object runs register_rest_route() twice per
        // route ($override defaults to false, so WP APPENDS), publishing
        // duplicated endpoint entries.
        // Initialize AJAX handler
        $this->knowledge_ajax = new AnswerRails_Knowledge_Ajax($this->knowledge);
        // Initialize logger and bootstrap
        AnswerRails_Logger::bootstrap();
        // DSAR tooling (#110): WP core privacy exporter/eraser, registered
        // unconditionally on every request.
        AnswerRails_Privacy_Tools::register();
        // #144: site-index cache invalidation. Registered HERE (every
        // request), not in a REST-request-scoped constructor — the events
        // that stale the index (publish/edit/delete) fire on ADMIN
        // requests. The mechanism is unconditional; how far the index
        // REACHES is decided at render time.
        AnswerRails_Site_Index::register();
        // ⚠ #163: link-cache invalidation registers HERE, not in
        // AnswerRails_REST_Chat's constructor — that constructor runs only
        // in REST chat requests, and knowledge items are saved and deleted
        // in ADMIN requests too. Registered here it covers both, and the
        // 1-hour transient TTL stays a backstop rather than the only
        // invalidation in operation.
        add_action( 'save_post_answerrails_kb', array('AnswerRails_Link_Matcher', 'clear_cache') );
        add_action( 'delete_post', array('AnswerRails_Link_Matcher', 'clear_cache') );
        // #377 D8: the recovery re-check's cron callback, the key-save
        // re-checks and admin_init reconciliation. Every request: the event
        // fires on whatever request WP-Cron runs on, and keys are saved on
        // admin requests.
        AnswerRails_API_Health_Monitor::register_recovery_hooks();
        // Initialize RAG Analytics
        if ( class_exists( 'AnswerRails_RAG_Analytics' ) ) {
            $this->rag_analytics = new AnswerRails_RAG_Analytics();
        }
        // Initialize admin interface
        if ( is_admin() ) {
            $this->admin = new AnswerRails_Admin($this->knowledge);
            // ⚠ The Knowledge Admin is NOT constructed here: its
            // constructor hooks admin_init, admin_notices and
            // admin_enqueue_scripts, and a second object registers all
            // three a second time. The loader owns the one hook-registering
            // instance; admin/views/knowledge.php builds a separate
            // render-only instance whose hooks are dead on arrival (it is
            // constructed after all three have already fired).
        }
        AnswerRails_Utils::debug_log( 'init_components:complete' );
    }

    /**
     * Plugin initialization
     */
    public function init() {
        AnswerRails_Utils::debug_log( 'init:start', array(
            'database_ready' => $this->database_ready,
            'core_loaded'    => (bool) $this->core,
        ) );
        if ( !$this->database_ready || !$this->core ) {
            AnswerRails_Utils::debug_log( 'init:skipped' );
            return;
        }
        // Custom post types and taxonomies
        $this->register_post_types();
        // Shortcode
        add_shortcode( 'answerrails_chat', array($this->core, 'chat_shortcode') );
        // Legacy AJAX hooks for knowledge management only
        // ADD THIS: Initialize migrations
        AnswerRails_Migrations::init();
        if ( is_admin() ) {
            add_action( 'admin_notices', array('AnswerRails_Migrations', 'display_migration_notices') );
        }
        do_action( 'answerrails_init', $this );
        AnswerRails_Utils::debug_log( 'init:complete' );
    }

    /**
     * Register custom post types
     */
    public function register_post_types() {
        // Knowledge items post type (shortened name)
        register_post_type( 'answerrails_kb', array(
            'labels'          => array(
                'name'               => __( 'Knowledge Items', 'answerrails' ),
                'singular_name'      => __( 'Knowledge Item', 'answerrails' ),
                'menu_name'          => __( 'Knowledge', 'answerrails' ),
                'add_new'            => __( 'Add Knowledge', 'answerrails' ),
                'add_new_item'       => __( 'Add New Knowledge Item', 'answerrails' ),
                'edit_item'          => __( 'Edit Knowledge Item', 'answerrails' ),
                'new_item'           => __( 'New Knowledge Item', 'answerrails' ),
                'view_item'          => __( 'View Knowledge Item', 'answerrails' ),
                'search_items'       => __( 'Search Knowledge Items', 'answerrails' ),
                'not_found'          => __( 'No knowledge items found', 'answerrails' ),
                'not_found_in_trash' => __( 'No knowledge items found in trash', 'answerrails' ),
            ),
            'public'          => false,
            'show_ui'         => false,
            'show_in_menu'    => false,
            'capability_type' => 'post',
            'capabilities'    => array(
                'edit_post'          => 'manage_options',
                'read_post'          => 'manage_options',
                'delete_post'        => 'manage_options',
                'edit_posts'         => 'manage_options',
                'edit_others_posts'  => 'manage_options',
                'delete_posts'       => 'manage_options',
                'publish_posts'      => 'manage_options',
                'read_private_posts' => 'manage_options',
            ),
            'supports'        => array('title', 'editor'),
            'has_archive'     => false,
            'rewrite'         => false,
        ) );
        // Chat logs post type - AUDIT ACCESS
        register_post_type( 'answerrails_chatlog', array(
            'labels'          => array(
                'name'          => __( 'Chat Logs', 'answerrails' ),
                'singular_name' => __( 'Chat Log', 'answerrails' ),
                'menu_name'     => __( 'Chat Logs', 'answerrails' ),
                'all_items'     => __( 'All Chat Logs', 'answerrails' ),
                'view_item'     => __( 'View Chat Log', 'answerrails' ),
                'search_items'  => __( 'Search Chat Logs', 'answerrails' ),
                'not_found'     => __( 'No chat logs found', 'answerrails' ),
            ),
            'public'          => false,
            'show_ui'         => false,
            'show_in_menu'    => false,
            'capability_type' => 'post',
            'capabilities'    => array(
                'create_posts'       => 'do_not_allow',
                'edit_post'          => 'manage_options',
                'read_post'          => 'manage_options',
                'delete_post'        => 'manage_options',
                'edit_posts'         => 'manage_options',
                'edit_others_posts'  => 'manage_options',
                'delete_posts'       => 'manage_options',
                'read_private_posts' => 'manage_options',
            ),
            'supports'        => array('title', 'editor', 'custom-fields'),
            'rewrite'         => false,
        ) );
        // Ideas post type - AUDIT ACCESS
        register_post_type( 'answerrails_idea', array(
            'labels'          => array(
                'name'          => __( 'Ideas', 'answerrails' ),
                'singular_name' => __( 'Idea', 'answerrails' ),
                'menu_name'     => __( 'Captured Ideas', 'answerrails' ),
                'all_items'     => __( 'All Ideas', 'answerrails' ),
                'view_item'     => __( 'View Idea', 'answerrails' ),
                'search_items'  => __( 'Search Ideas', 'answerrails' ),
            ),
            'public'          => false,
            'show_ui'         => true,
            'show_in_menu'    => false,
            'capability_type' => 'post',
            'capabilities'    => array(
                'create_posts'      => 'do_not_allow',
                'edit_post'         => 'manage_options',
                'read_post'         => 'manage_options',
                'delete_post'       => 'manage_options',
                'edit_posts'        => 'manage_options',
                'edit_others_posts' => 'manage_options',
                'delete_posts'      => 'manage_options',
            ),
            'supports'        => array('title', 'editor'),
            'rewrite'         => false,
        ) );
        // Consent records post type - AUDIT ACCESS
        register_post_type( 'answerrails_consent', array(
            'labels'          => array(
                'name'          => __( 'Consent Records', 'answerrails' ),
                'singular_name' => __( 'Consent Record', 'answerrails' ),
                'menu_name'     => __( 'Consent Records', 'answerrails' ),
                'all_items'     => __( 'All Consent Records', 'answerrails' ),
                'view_item'     => __( 'View Consent Record', 'answerrails' ),
                'search_items'  => __( 'Search Consent Records', 'answerrails' ),
            ),
            'public'          => false,
            'show_ui'         => true,
            'show_in_menu'    => false,
            'capability_type' => 'post',
            'capabilities'    => array(
                'create_posts'      => 'do_not_allow',
                'edit_post'         => 'manage_options',
                'read_post'         => 'manage_options',
                'delete_post'       => 'manage_options',
                'edit_posts'        => 'manage_options',
                'edit_others_posts' => 'manage_options',
                'delete_posts'      => 'manage_options',
            ),
            'supports'        => array('title', 'custom-fields'),
            'rewrite'         => false,
        ) );
    }

    /**
     * Register REST API routes - UNIFIED SYSTEM ONLY
     */
    public function register_rest_routes() {
        if ( !$this->database_ready ) {
            return;
        }
        // Only use the unified REST Router system
        AnswerRails_REST_Router::register_routes_now();
        // Knowledge REST routes are auto-registered by the single
        // AnswerRails_Knowledge_REST controller, which AnswerRails_Knowledge_Loader
        // constructs and owns — a second construction here registers every
        // knowledge route twice (#139).
    }

    // ⚠ #179: this plugin registers NO text domain. The free build is
    // .org-hosted: core auto-loads its language packs from
    // WP_LANG_DIR/plugins (since 4.6), and the .org review asks for exactly
    // that. ⚠ CONDITION: the
    // Domain Path header is tooling metadata, NOT a runtime registration —
    // core does NOT load .mo files bundled inside languages/ unless
    // load_plugin_textdomain() / WP_Textdomain_Registry::set_custom_path()
    // registers the path. languages/ ships EMPTY, so nothing is lost today;
    // if a build ever bundles .mo files (the premium build cannot use .org
    // packs), a registration must return WITH them — parked with the
    // Freemius-split pipeline, see TEXTDOMAIN_REMOVAL_DESIGN.md
    /**
     * Plugin activation
     */
    public function activate() {
        AnswerRails_Utils::debug_log( 'activate:start' );
        if ( !$this->database_ready ) {
            AnswerRails_Utils::debug_log( 'activate:database-unavailable' );
            return;
        }
        // Create database tables if needed
        $this->create_tables();
        AnswerRails_Utils::debug_log( 'activate:after-create-tables' );
        // Set default options
        $this->set_default_options();
        AnswerRails_Utils::debug_log( 'activate:after-set-defaults' );
        // Run migrations on activation
        if ( class_exists( 'AnswerRails_Migrations' ) ) {
            AnswerRails_Utils::debug_log( 'activate:before-migrations' );
            AnswerRails_Migrations::schedule_async_run();
            AnswerRails_Utils::debug_log( 'activate:after-migrations' );
        }
        // #377 D8 step 7: a Down chat streak outlives deactivation (which
        // clears its re-check), so activation re-arms it.
        if ( class_exists( 'AnswerRails_API_Health_Monitor' ) ) {
            ( new AnswerRails_API_Health_Monitor() )->reconcile_recovery();
        }
        // Flush rewrite rules
        flush_rewrite_rules();
        AnswerRails_Utils::debug_log( 'activate:after-flush-rewrite' );
        do_action( 'answerrails_activated' );
        AnswerRails_Utils::debug_log( 'activate:complete' );
    }

    /**
     * Plugin deactivation
     */
    public function deactivate() {
        if ( !$this->database_ready ) {
            return;
        }
        // Clean up if needed
        flush_rewrite_rules();
        // #132 W7: clear the plugin's scheduled events. Deactivation is NOT
        // uninstall — options and data are untouched (#127 owns uninstall);
        // the schedules are re-created on next activation/init.
        wp_clear_scheduled_hook( 'answerrails_purge_old_logs' );
        // Migration 1.9.0 clears the legacy daily-check event a pre-#95
        // install may still have scheduled; nothing here registers it.
        wp_clear_scheduled_hook( 'answerrails_hourly_sync' );
        // #377 D8 step 6: every recovery re-check carries args [$api], and
        // wp_clear_scheduled_hook() without args clears only the [] events —
        // so this hook is cleared BY HOOK, whatever its args.
        wp_unschedule_hook( 'answerrails_recovery_probe' );
        do_action( 'answerrails_deactivated' );
    }

    /**
     * Create database tables
     */
    private function create_tables() {
        if ( !$this->database_ready ) {
            return;
        }
        global $wpdb;
        $charset_collate = $wpdb->get_charset_collate();
        // Using custom post types - no additional tables needed
    }

    /**
     * Set default options (Core + REST system unified)
     */
    private function set_default_options() {
        if ( !$this->database_ready ) {
            return;
        }
        $defaults = array(
            'answerrails_chat_enabled'                      => true,
            'answerrails_business_name'                     => 'Your Business',
            'answerrails_chat_title'                        => 'How can we help you today?',
            'answerrails_welcome_message'                   => 'Hi! I\'m here to help with any questions about our products and services.',
            'answerrails_chat_system_prompt'                => 'You are a helpful customer service assistant for a small business. Provide accurate, friendly responses about products and services.',
            'answerrails_provider_openai_model'             => AnswerRails_Utils::default_model( 'openai' ),
            'answerrails_chat_temperature'                  => 0.4,
            'answerrails_chat_max_tokens'                   => 1600,
            'answerrails_privacy_mode'                      => 'session',
            'answerrails_version'                           => ANSWERRAILS_VERSION,
            'answerrails_active_provider'                   => 'mistral',
            'answerrails_provider_openai_api_key'           => '',
            'answerrails_provider_mistral_api_key'          => '',
            'answerrails_provider_mistral_model'            => AnswerRails_Utils::default_model( 'mistral' ),
            'answerrails_provider_anthropic_api_key'        => '',
            'answerrails_provider_anthropic_model'          => AnswerRails_Utils::default_model( 'anthropic' ),
            'answerrails_provider_openai_org'               => '',
            'answerrails_provider_openai_project'           => '',
            'answerrails_provider_openai_base'              => 'https://api.openai.com/v1',
            'answerrails_api_debug'                         => 0,
            'answerrails_services_json'                     => '[]',
            'answerrails_hide_idea_in_reply'                => 0,
            'answerrails_use_knowledge'                     => 1,
            'answerrails_knowledge_max_attachments'         => 12,
            'answerrails_knowledge_vector_store_id'         => '',
            'answerrails_capture_ideas'                     => 1,
            'answerrails_privacy_log_conversations'         => 0,
            'answerrails_privacy_logging_mode'              => 'anonymized',
            'answerrails_privacy_retention_days'            => 180,
            'answerrails_require_consent'                   => 0,
            'answerrails_recaptcha_enabled'                 => 0,
            'answerrails_recaptcha_site_key'                => '',
            'answerrails_recaptcha_secret'                  => '',
            'answerrails_recaptcha_min_score'               => '0.5',
            'answerrails_strip_emojis'                      => 1,
            'answerrails_widget_title'                      => 'AnswerRails Assistant',
            'answerrails_widget_subtitle'                   => 'Shop help & product suggestions',
            'answerrails_assistant_label'                   => 'Assistant',
            'answerrails_avatar_image_id'                   => 0,
            'answerrails_avatar_url'                        => '',
            'answerrails_display_mode'                      => 'home_only',
            'answerrails_custom_pages'                      => array(),
            'answerrails_links_new_tab'                     => 1,
            'answerrails_links_decorate'                    => 1,
            'answerrails_primary_domains'                   => wp_parse_url( home_url(), PHP_URL_HOST ),
            'answerrails_remote_validation_allowed_domains' => '',
            'answerrails_rag_enabled'                       => 1,
            'answerrails_rag_confidence_threshold_high'     => 0.8,
            'answerrails_rag_confidence_threshold_medium'   => 0.6,
            'answerrails_rag_confidence_threshold_low'      => 0.4,
            'answerrails_rag_track_performance'             => 1,
            'answerrails_rag_detect_deflection'             => 1,
            'answerrails_rag_identify_gaps'                 => 1,
        );
        foreach ( $defaults as $option => $value ) {
            if ( false === get_option( $option ) ) {
                add_option( $option, $value );
            }
        }
    }

    /**
     * Determine if the global database connection is ready for use.
     */
    private function check_database_ready() : bool {
        global $wpdb;
        if ( !isset( $wpdb ) || !$wpdb instanceof wpdb ) {
            return false;
        }
        if ( property_exists( $wpdb, 'ready' ) && !$wpdb->ready ) {
            return false;
        }
        if ( empty( $wpdb->dbh ) ) {
            return false;
        }
        return true;
    }

}

/**
 * Initialize the plugin
 */
function answerrails() {
    return AnswerRails::instance();
}