<?php
/**
 * LLMs Text Generator for WordPress
 *
 * @package     AIContentGuide
 * @author      Fulgid
 * @copyright   2025 Fulgid Software Solutions Pvt Ltd
 * @license     GPL-2.0+
 *
 * @wordpress-plugin
 * Plugin Name: LLMs Text Generator for WordPress
 * Plugin URI:  https://fulgid.in/ai-content-guide
 * Description: The ultimate AI SEO plugin for WordPress! Generate professional llms.txt files to get featured in ChatGPT, Claude & AI search results. Boost your content's AI discoverability with beautiful formatting and rich metadata.
 * Version:     1.0.8
 * Author:      Fulgid
 * Author URI:  https://fulgid.in
 * Text Domain: ai-content-guide-llms-text-generator
 * License:     GPL-2.0+
 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt
 */

// If this file is called directly, abort.
if (!defined('ABSPATH')) {
    exit;
}

/**
 * Currently plugin version.
 */
define('FULGID_AICOGU_VERSION', '1.0.8');

/**
 * The core plugin class.
 */
class FULGID_AICOGU_Content_Guide {

    /**
     * The unique instance of the plugin.
     *
     * @var FULGID_AICOGU_Content_Guide
     */
    private static $instance;

    /**
     * Gets an instance of the plugin.
     *
     * @return FULGID_AICOGU_Content_Guide
     */
    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Constructor.
     */
    private function __construct() {
        $this->define_constants();
        $this->includes();
        $this->init_hooks();
    }

    /**
     * Define plugin constants.
     */
    private function define_constants() {
        define('FULGID_AICOGU_PATH', plugin_dir_path(__FILE__));
        define('FULGID_AICOGU_URL', plugin_dir_url(__FILE__));
        define('FULGID_AICOGU_BASE', plugin_basename(__FILE__));
    }

    /**
     * Include required files.
     */
    private function includes() {
        // Admin interface
        require_once FULGID_AICOGU_PATH . 'admin/class-admin.php';
        
        // Core functionality
        require_once FULGID_AICOGU_PATH . 'includes/class-activator.php';
        require_once FULGID_AICOGU_PATH . 'includes/class-deactivator.php';
        require_once FULGID_AICOGU_PATH . 'includes/class-content-analyzer.php';
        require_once FULGID_AICOGU_PATH . 'includes/class-file-manager.php';
        require_once FULGID_AICOGU_PATH . 'includes/class-seo-integrator.php';
    }

    /**
     * Initialize hooks.
     */
    private function init_hooks() {
        register_activation_hook(__FILE__, array('FULGID_AICOGU_Activator', 'activate'));
        register_deactivation_hook(__FILE__, array('FULGID_AICOGU_Deactivator', 'deactivate'));

        // Admin hooks
        add_action('admin_menu', array($this, 'add_menu_page'));
        add_action('admin_enqueue_scripts', array($this, 'enqueue_admin_scripts'));
        
        // Plugin functionality hooks
        add_action('save_post', array($this, 'schedule_file_regeneration'), 10, 3);
        add_action('fulgid_aicogu_regenerate_file', array($this, 'regenerate_file'));
        
        // Add rewrite rules for serving llms.txt
        add_action('init', array($this, 'add_rewrite_rules'));
        add_filter('query_vars', array($this, 'add_query_vars'));
        add_filter('redirect_canonical', array($this, 'prevent_llms_txt_redirect'), 10, 2);
        add_action('template_redirect', array($this, 'handle_llms_txt_request'));
        
        // Plugin action links
        add_filter('plugin_action_links_' . FULGID_AICOGU_BASE, array($this, 'add_plugin_action_links'));
    }

    /**
     * Add admin menu page.
     */
    public function add_menu_page() {
        add_menu_page(
            esc_html__('llms.txt generator', 'ai-content-guide-llms-text-generator'),
            esc_html__('llms.txt generator', 'ai-content-guide-llms-text-generator'),
            'manage_options',
            'ai-content-guide-llms-text-generator',
            array($this, 'display_admin_page'),
            'dashicons-format-aside',
            30
        );
    }

    /**
     * Display admin page.
     */
    public function display_admin_page() {
        if (!current_user_can('manage_options')) {
            wp_die(__('You do not have sufficient permissions to access this page.'));
        }
        require_once FULGID_AICOGU_PATH . 'admin/partials/admin-display.php';
    }

    /**
     * Enqueue admin scripts and styles.
     *
     * @param string $hook The current admin page.
     */
    public function enqueue_admin_scripts($hook) {
         if ('toplevel_page_ai-content-guide-llms-text-generator' !== $hook) {
        return;
    }

        wp_enqueue_style(
            'fulgid-aicogu-admin',
            FULGID_AICOGU_URL . 'admin/css/admin.css',
            array(),
            FULGID_AICOGU_VERSION
        );

        wp_enqueue_script(
            'fulgid-aicogu-admin',
            FULGID_AICOGU_URL . 'admin/js/admin.js',
            array('jquery'),
            FULGID_AICOGU_VERSION,
            true
        );

        wp_localize_script(
            'fulgid-aicogu-admin',
            'fulgidAicoguParams',
            array(
                'ajaxUrl' => admin_url('admin-ajax.php'),
                'nonce' => wp_create_nonce('fulgid-aicogu-nonce'),
                'i18n' => array(
                    'regenerating' => esc_html__('Regenerating file...', 'ai-content-guide-llms-text-generator'),
                    'error' => esc_html__('An error occurred.', 'ai-content-guide-llms-text-generator'),
                    'success' => esc_html__('File regenerated successfully!', 'ai-content-guide-llms-text-generator')
                )
            )
        );
    }

    /**
     * Schedule file regeneration when a post is saved.
     *
     * @param int     $post_id Post ID.
     * @param WP_Post $post    Post object.
     * @param bool    $update  Whether this is an existing post being updated.
     */
    public function schedule_file_regeneration($post_id, $post, $update) {
        // Skip auto-saves and revisions
        if (wp_is_post_revision($post_id) || wp_is_post_autosave($post_id)) {
            return;
        }

        // Check if post type should be included in llms.txt
        $settings = get_option('fulgid_aicogu_settings', array());
        $included_post_types = isset($settings['post_types']) ? $settings['post_types'] : array('post', 'page');
        
        if (!in_array($post->post_type, $included_post_types)) {
            return;
        }

        // Schedule regeneration if not already scheduled
        if (!wp_next_scheduled('fulgid_aicogu_regenerate_file')) {
            wp_schedule_single_event(time() + 300, 'fulgid_aicogu_regenerate_file');
        }
    }

    /**
     * Regenerate the llms.txt file.
     */
    public function regenerate_file() {
        $content_analyzer = new FULGID_AICOGU_Content_Analyzer();
        $file_manager = new FULGID_AICOGU_File_Manager();
        
        // Get content
        $content = $content_analyzer->analyze_site_content();
        
        // Generate and save file
        $file_manager->generate_file($content);
    }

    /**
     * Add rewrite rules for serving llms.txt file.
     */
    public function add_rewrite_rules() {
        add_rewrite_rule(
            '^llms\.txt$',
            'index.php?fulgid_aicogu_llms_txt=1',
            'top'
        );
        
        // Add rule for llms-full.txt
        add_rewrite_rule(
            '^llms-full\.txt$',
            'index.php?fulgid_aicogu_llms_full_txt=1',
            'top'
        );
    }

    /**
     * Add custom query variables.
     *
     * @param array $vars Query variables.
     * @return array
     */
    public function add_query_vars($vars) {
        $vars[] = 'fulgid_aicogu_llms_txt';
        $vars[] = 'fulgid_aicogu_llms_full_txt';
        return $vars;
    }

    /**
     * Prevent WordPress from redirecting llms.txt URLs.
     *
     * @param string $redirect_url The redirect URL.
     * @param string $requested_url The requested URL.
     * @return string|false
     */
    public function prevent_llms_txt_redirect($redirect_url, $requested_url) {
        // Debug logging (remove in production)
        if (defined('WP_DEBUG') && WP_DEBUG) {
            error_log("LLMS.txt Redirect Debug - Requested: {$requested_url}, Redirect: {$redirect_url}");
        }
        
        // Check if WordPress is trying to redirect TO a trailing slash version of llms.txt
        // Only prevent redirects when the destination has a trailing slash
        if (preg_match('/\/llms(-full)?\.txt\/$/', $redirect_url)) {
            if (defined('WP_DEBUG') && WP_DEBUG) {
                error_log("LLMS.txt Redirect - Prevented redirect for: {$requested_url}");
            }
            return false; // Prevent redirect
        }
        return $redirect_url;
    }

    /**
     * Handle requests for llms.txt and llms-full.txt.
     */
    public function handle_llms_txt_request() {
        $file_manager = new FULGID_AICOGU_File_Manager();
        
        if (get_query_var('fulgid_aicogu_llms_txt')) {
            $file_manager = new FULGID_AICOGU_File_Manager();
            $content = $file_manager->get_file_content();
            
            header('Content-Type: text/markdown');
            
            // For markdown content, we need to be careful with escaping to preserve formatting
            // while still ensuring security
            echo wp_kses($content, array(
                // Allow only specific markdown-related HTML
                'h1' => array(),
                'h2' => array(),
                'h3' => array(),
                'p' => array(),
                'a' => array('href' => array(), 'title' => array()),
                'ul' => array(),
                'ol' => array(),
                'li' => array(),
                'blockquote' => array(),
                'code' => array(),
                'pre' => array(),
                'em' => array(),
                'strong' => array(),
                'br' => array(),
            ));
            
            exit;
        }
        
        // Handle llms-full.txt requests
        if (get_query_var('fulgid_aicogu_llms_full_txt')) {
            $content = $file_manager->get_full_file_content();
            
            header('Content-Type: text/markdown');
                    
            // For markdown content, we need to be careful with escaping to preserve formatting
            // while still ensuring security
            echo wp_kses($content, array(
                // Allow only specific markdown-related HTML
                'h1' => array(),
                'h2' => array(),
                'h3' => array(),
                'p' => array(),
                'a' => array('href' => array(), 'title' => array()),
                'ul' => array(),
                'ol' => array(),
                'li' => array(),
                'blockquote' => array(),
                'code' => array(),
                'pre' => array(),
                'em' => array(),
                'strong' => array(),
                'br' => array(),
            ));
            
            exit;
        }
    }

    /**
     * Add plugin action links.
     *
     * @param array $links Plugin action links.
     * @return array
     */
    public function add_plugin_action_links($links) {
        $plugin_links = array(
            '<a href="' . admin_url('admin.php?page=ai-content-guide-llms-text-generator') . '">' . esc_html__('Settings', 'ai-content-guide-llms-text-generator') . '</a>',
        );
        return array_merge($plugin_links, $links);
    }
}

// Initialize the plugin
function fulgid_aicogu_init() {
    FULGID_AICOGU_Content_Guide::get_instance();
}
add_action('plugins_loaded', 'fulgid_aicogu_init');