<?php
/**
 * File Manager class
 *
 * @package     AIContentGuide
 * @subpackage  AIContentGuide/includes
 */

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

/**
 * Class for managing the llms.txt file.
 */
class FULGID_AICOGU_File_Manager {

    /**
     * Settings array.
     *
     * @var array
     */
    private $settings;

    /**
     * Constructor.
     */
    public function __construct() {
        $this->settings = get_option('fulgid_aicogu_settings', array());
    }

    /**
     * Generate the llms.txt file with the provided content.
     *
     * @param string $content The content to write to the file.
     * @return bool True on success, false on failure.
     */
    public function generate_file($content) {
        // Store the content in the database regardless of file method
        update_option('fulgid_aicogu_file_content', $content);
        
        // Get file method from settings
        $file_method = isset($this->settings['file_method']) ? $this->settings['file_method'] : 'rewrite';
        
        if ('direct' === $file_method) {
            return $this->write_file_directly($content);
        }
        
        // For rewrite method, just store content in database
        // The rewrite rules will serve it dynamically
        
        // Flush rewrite rules to ensure our rule is registered
        flush_rewrite_rules();
        
        return true;
    }

    /**
     * Write the llms.txt file directly to the site root.
     *
     * @param string $content The content to write.
     * @return bool True on success, false on failure.
     */
    private function write_file_directly($content) {
        // Check if we can get the ABSPATH directory
        $root_path = ABSPATH;
        $file_path = $root_path . 'llms.txt';
        
        // Try to write the file
        $result = @file_put_contents($file_path, $content);
        
        if (false === $result) {
            // Log error or set admin notice
            add_action('admin_notices', array($this, 'file_write_error_notice'));
            return false;
        }
        
        return true;
    }

    /**
     * Show admin notice for file write errors.
     */
    public function file_write_error_notice() {
        ?>
        <div class="notice notice-error">
            <p><?php esc_html_e('LLMs Text Generator: Unable to write llms.txt file directly to site root. Please check file permissions or use the rewrite method instead.', 'ai-content-guide-llms-text-generator'); ?></p>
        </div>
        <?php
    }

    /**
     * Get the file content from the database.
     *
     * @return string The file content.
     */
    public function get_file_content() {
        $content = get_option('fulgid_aicogu_file_content', '');
        
        if (empty($content)) {
            // If no content is stored, generate it now
            $content_analyzer = new FULGID_AICOGU_Content_Analyzer();
            $content = $content_analyzer->analyze_site_content();
            
            // Store for future use
            update_option('fulgid_aicogu_file_content', $content);
        }
        
        // Do not escape here - escaping should be done at the output point
        return $content;
    }

    /**
     * Check if the llms.txt file exists and is accessible via URL.
     *
     * @return array Status information.
     */
    public function check_file_status() {
        $result = array(
            'exists' => false,
            'accessible' => false,
            'method' => isset($this->settings['file_method']) ? $this->settings['file_method'] : 'rewrite',
            'url' => site_url('/llms.txt'),
        );
        
        // For direct method, check if file exists in the file system
        if ('direct' === $result['method']) {
            $root_path = ABSPATH;
            $file_path = $root_path . 'llms.txt';
            $result['exists'] = file_exists($file_path);
        } else {
            // For rewrite method, check if content exists in the database
            $content = get_option('fulgid_aicogu_file_content', '');
            $result['exists'] = !empty($content);
        }
        
        // Check if file is accessible via URL
        $response = wp_remote_get($result['url']);
        $result['accessible'] = !is_wp_error($response) && 200 === wp_remote_retrieve_response_code($response);
        
        return $result;
    }

    /**
     * Get last modification time of the file.
     *
     * @return int|bool Timestamp or false if file doesn't exist.
     */
    public function get_last_modified() {
        $file_method = isset($this->settings['file_method']) ? $this->settings['file_method'] : 'rewrite';
        
        if ('direct' === $file_method) {
            $root_path = ABSPATH;
            $file_path = $root_path . 'llms.txt';
            
            if (file_exists($file_path)) {
                return filemtime($file_path);
            }
        }
        
        // For rewrite method or if direct file doesn't exist, use option update time
        return get_option('fulgid_aicogu_file_updated', time());
    }

    /**
     * Add a reference to llms.txt in robots.txt.
     *
     * @param string $robots_content Current robots.txt content.
     * @return string Modified robots.txt content.
     */
    public function add_robots_txt_reference($robots_content) {
        if (empty($this->settings['add_to_robots']) || 'yes' !== $this->settings['add_to_robots']) {
            return $robots_content;
        }
        
        $llms_line = "\n# For LLM training, we have implemented an llms.txt file following https://llmstxt.org/ guidelines.";
        $llms_line .= "\n# This file helps AI systems better understand our website content.";
        $llms_line .= "\nSitemap: " . site_url('/llms.txt');
        
        // Check if reference already exists
        if (strpos($robots_content, 'llms.txt') !== false) {
            return $robots_content;
        }
        
        return $robots_content . $llms_line;
    }
    
    /**
     * Generate an enhanced llms-full.txt file with comprehensive content.
     * 
     * @param string $basic_content The basic llms.txt content.
     * @return string The expanded content for llms-full.txt.
     */
    public function generate_full_file($basic_content) {
        // Check if full file generation is enabled
        if (empty($this->settings['generate_full_file']) || 'yes' !== $this->settings['generate_full_file']) {
            return $basic_content;
        }
        
        // Start with enhanced header for full file
        $full_content = "# " . get_bloginfo('name') . " - Complete Content Archive\n\n";
        $full_content .= "> **Full llms.txt file with comprehensive content and metadata**\n\n";
        $full_content .= "🌐 **Website:** [" . home_url() . "](" . home_url() . ")\n";
        $full_content .= "📅 **Generated:** " . date('Y-m-d H:i:s T') . "\n";
        $full_content .= "📄 **File Type:** llms-full.txt (Extended Version)\n\n";
        $full_content .= "---\n\n";
        
        // Add basic content first
        $full_content .= $basic_content . "\n\n";
        
        // Add comprehensive content sections
        $full_content .= "## 📖 Complete Content Archive\n\n";
        $full_content .= "_This section contains full content for better AI understanding._\n\n";
        
        // Add more detailed content for each post type
        $post_types = isset($this->settings['post_types']) ? $this->settings['post_types'] : array('post', 'page');
        
        foreach ($post_types as $post_type) {
            $post_type_obj = get_post_type_object($post_type);
            if (!$post_type_obj) {
                continue;
            }
            
            $full_content .= "### 📑 " . $post_type_obj->labels->name . " - Full Content\n\n";
            
            // Get a limited number of posts
            $args = array(
                'post_type' => $post_type,
                'post_status' => 'publish',
                'posts_per_page' => 15,  // More content for full version
                'orderby' => 'date',
                'order' => 'DESC',
            );
            
            $posts = get_posts($args);
            
            if (empty($posts)) {
                $full_content .= "_No content available for this post type._\n\n";
                continue;
            }
            
            foreach ($posts as $post) {
                $title = $post->post_title;
                $url = get_permalink($post->ID);
                $post_content = wp_strip_all_tags($post->post_content);
                $excerpt = $post->post_excerpt;
                $date = get_the_date('Y-m-d', $post->ID);
                $author = get_the_author_meta('display_name', $post->post_author);
                
                // Get categories and tags
                $categories = get_the_category($post->ID);
                $tags = get_the_tags($post->ID);
                
                // Limit content length but allow more than basic version
                $max_length = 2000;  // Double the basic limit for full version
                if (strlen($post_content) > $max_length) {
                    $post_content = substr($post_content, 0, $max_length) . '...';
                }
                
                $full_content .= "#### 📄 {$title}\n\n";
                $full_content .= "**URL:** [{$url}]({$url})\n";
                $full_content .= "**Published:** {$date} | **Author:** {$author}\n";
                
                if (!empty($categories)) {
                    $cat_names = array_map(function($cat) { return $cat->name; }, $categories);
                    $full_content .= "**Categories:** " . implode(', ', $cat_names) . "\n";
                }
                
                if (!empty($tags)) {
                    $tag_names = array_map(function($tag) { return $tag->name; }, $tags);
                    $full_content .= "**Tags:** " . implode(', ', $tag_names) . "\n";
                }
                
                if (!empty($excerpt)) {
                    $full_content .= "\n**Excerpt:** _{$excerpt}_\n";
                }
                
                $full_content .= "\n**Content:**\n{$post_content}\n\n";
                $full_content .= "---\n\n";
            }
        }
        
        // Add site statistics section
        $full_content .= $this->get_site_statistics();
        
        // Add footer for full file
        $full_content .= "## ℹ️ About This Full File\n\n";
        $full_content .= "This llms-full.txt file provides comprehensive content for AI training and understanding.\n";
        $full_content .= "It includes complete post content, metadata, and site statistics.\n\n";
        $full_content .= "**Generated by:** LLMs Text Generator for WordPress\n";
        $full_content .= "**Enhanced by:** [llmstxt.in](https://llmstxt.in/?utm_source=plugin&utm_medium=full-file)\n";
        $full_content .= "**Made with ❤️ by:** [Fulgid](https://fulgid.in)\n";
        $full_content .= "**Last Updated:** " . date('Y-m-d H:i:s T') . "\n\n";
        $full_content .= "_This file is automatically regenerated when content changes._\n";
        
        // Store the full content
        update_option('fulgid_aicogu_full_file_content', $full_content);
        
        return $full_content;
    }
    
    /**
     * Get detailed site statistics for full file.
     *
     * @return string
     */
    private function get_site_statistics() {
        $content = "## 📊 Detailed Site Statistics\n\n";
        
        // Get all post types and their counts
        $post_types = get_post_types(array('public' => true), 'objects');
        $content .= "### Content Statistics\n\n";
        
        foreach ($post_types as $post_type) {
            $count = wp_count_posts($post_type->name)->publish;
            $content .= "- **{$post_type->labels->name}:** {$count} published\n";
        }
        
        // Get taxonomy statistics
        $taxonomies = get_taxonomies(array('public' => true), 'objects');
        $content .= "\n### Taxonomy Statistics\n\n";
        
        foreach ($taxonomies as $taxonomy) {
            $terms = get_terms(array('taxonomy' => $taxonomy->name, 'hide_empty' => false));
            if (!is_wp_error($terms)) {
                $count = count($terms);
                $content .= "- **{$taxonomy->labels->name}:** {$count} terms\n";
            }
        }
        
        // Get user statistics
        $user_count = count_users();
        $content .= "\n### User Statistics\n\n";
        $content .= "- **Total Users:** {$user_count['total_users']}\n";
        
        foreach ($user_count['avail_roles'] as $role => $count) {
            $role_obj = get_role($role);
            $role_name = ucfirst($role);
            $content .= "- **{$role_name}:** {$count}\n";
        }
        
        $content .= "\n";
        
        return $content;
    }
    
    /**
     * Get the full file content from the database.
     *
     * @return string The full file content.
     */
    public function get_full_file_content() {
        $content = get_option('fulgid_aicogu_full_file_content', '');
        
        if (empty($content)) {
            // If no content is stored, generate it now
            $basic_content = $this->get_file_content();
            $content = $this->generate_full_file($basic_content);
        }
        
        return $content;
    }
}