<?php
/**
 * LLMs.txt Module for TigerStyle Heat
 */

// Prevent direct access
if (!defined('ABSPATH')) {
    exit;
}

class TigerStyleSEO_Llms_txt {
    private static $instance = null;
    
    public static function instance() {
        if (is_null(self::$instance)) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    private function __construct() {
        $this->init_hooks();
    }
    
    /**
     * Initialize hooks
     */
    private function init_hooks() {
        add_action('template_redirect', array($this, 'handle_llmstxt_request'), 1);
        add_action('admin_post_update_llmstxt', array($this, 'handle_llmstxt_update'));
    }
    
    /**
     * Handle llms.txt requests
     */
    public function handle_llmstxt_request() {
        if (!$this->is_llmstxt_request()) {
            return;
        }
        
        // Check if llms.txt is enabled
        if (!TigerStyleSEO_Utils::get_option('llmstxt_enabled', false)) {
            status_header(404);
            return;
        }
        
        $content = $this->get_llmstxt_content();
        
        // Set headers for markdown content
        header('Content-Type: text/plain; charset=UTF-8');
        header('X-Robots-Tag: noindex, nofollow, nosnippet, noarchive');
        
        echo $content;
        exit;
    }
    
    /**
     * Check if current request is for llms.txt
     */
    private function is_llmstxt_request() {
        $request_uri = $_SERVER['REQUEST_URI'] ?? '';
        return (strpos($request_uri, '/llms.txt') !== false) || 
               (isset($_GET['llms']) && $_GET['llms'] === 'txt');
    }
    
    /**
     * Get llms.txt content
     */
    private function get_llmstxt_content() {
        $custom_content = TigerStyleSEO_Utils::get_option('llmstxt_content', '');
        if (!empty($custom_content)) {
            return $custom_content;
        }
        
        // Generate default content
        return $this->get_default_llmstxt();
    }
    
    /**
     * Generate default llms.txt content based on WordPress site
     */
    private function get_default_llmstxt() {
        $site_name = get_bloginfo('name');
        $site_description = get_bloginfo('description');
        
        $content = "# {$site_name}\n\n";
        
        if (!empty($site_description)) {
            $content .= "> {$site_description}\n\n";
        }
        
        $content .= "This is a WordPress website";
        if (!empty($site_description)) {
            $content .= " focused on " . strtolower($site_description);
        }
        $content .= ". Below are the key resources for understanding this site:\n\n";
        
        // Add main navigation links
        $content .= "## Main Pages\n";
        
        // Get key pages
        $pages = get_pages(array(
            'sort_order' => 'ASC',
            'sort_column' => 'menu_order',
            'number' => 10
        ));
        
        foreach ($pages as $page) {
            $content .= "- [{$page->post_title}](" . get_permalink($page) . ")";
            if (!empty($page->post_excerpt)) {
                $content .= ": " . wp_strip_all_tags($page->post_excerpt);
            }
            $content .= "\n";
        }
        
        // Add recent posts
        $posts = get_posts(array(
            'numberposts' => 5,
            'post_status' => 'publish'
        ));
        
        if (!empty($posts)) {
            $content .= "\n## Recent Content\n";
            foreach ($posts as $post) {
                $content .= "- [{$post->post_title}](" . get_permalink($post) . ")";
                if (!empty($post->post_excerpt)) {
                    $content .= ": " . wp_strip_all_tags($post->post_excerpt);
                }
                $content .= "\n";
            }
        }
        
        // Add contact and additional info
        $content .= "\n## Technical Information\n";
        $content .= "- WordPress Version: " . get_bloginfo('version') . "\n";
        $content .= "- Site URL: " . get_bloginfo('url') . "\n";
        $content .= "- Admin Email: " . get_bloginfo('admin_email') . "\n";
        $content .= "- Language: " . get_bloginfo('language') . "\n";
        $content .= "- Content generated: " . current_time('Y-m-d H:i:s T') . "\n\n";
        $content .= "---\n";
        $content .= "*This llms.txt file is automatically generated by TigerStyle Heat Manager*";
        
        return $content;
    }
    
    /**
     * Handle llms.txt settings update
     */
    public function handle_llmstxt_update() {
        // Verify nonce and permissions
        if (!TigerStyleSEO_Utils::verify_nonce('llmstxt_nonce', 'update_llmstxt') || 
            !TigerStyleSEO_Utils::current_user_can_manage()) {
            wp_die(__('Security check failed.', 'tigerstyle-heat'));
        }
        
        // Update settings
        $enabled = isset($_POST['llmstxt_enabled']) ? 1 : 0;
        $content = isset($_POST['llmstxt_content']) ? TigerStyleSEO_Utils::sanitize_textarea($_POST['llmstxt_content']) : '';
        
        TigerStyleSEO_Utils::update_option('llmstxt_enabled', $enabled);
        TigerStyleSEO_Utils::update_option('llmstxt_content', $content);
        
        TigerStyleSEO_Utils::redirect_with_message('llmstxt_updated');
    }
    
    /**
     * Render admin page
     */
    public function render_admin_page() {
        include TIGERSTYLE_HEAT_PLUGIN_DIR . 'admin/pages/llms-txt.php';
    }
}