<?php
/**
 * Plugin Name: AbyssGuard
 * Plugin URI: https://www.abyssguard.com
 * Description: AbyssGuard is an invisible security layer for WordPress that protects your site from vulnerabilities, zero-day attacks, harvesters, spam, and hacking attempts - without breaking plugins or generating false positives.
 * Version: 1.0.0
 * Author: AbyssGuard
 * License: GPL v2 or later
 */

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

class AbyssGuard {
    
    private $option_name = 'abyssguard_api_key';
    private $continent_option = 'abyssguard_continent';
    
    public function __construct() {
        // Hook into WordPress initialization
        add_action('init', array($this, 'verify_request'), 1);
        
        // Admin menu
        add_action('admin_menu', array($this, 'add_admin_menu'));
        
        // Register settings
        add_action('admin_init', array($this, 'register_settings'));
        
        // Add settings link on plugins page
        add_filter('plugin_action_links_' . plugin_basename(__FILE__), array($this, 'add_settings_link'));
        
        // Add languages
        add_action('plugins_loaded', array($this, 'load_textdomain'));
    }

    function load_textdomain() {
        load_plugin_textdomain('abyssguard', false, dirname(plugin_basename(__FILE__)) . '/languages');
    }
    
    /**
     * Verify each request with HEAD request
     */
    public function verify_request() {
        // Skip verification for admin pages and AJAX requests
        if (is_admin() || wp_doing_ajax() || wp_doing_cron()) {
            return;
        }

        // Skip for wp-admin internal requests
        $request_uri = isset($_SERVER['REQUEST_URI']) ? sanitize_text_field(wp_unslash($_SERVER['REQUEST_URI'])) : '';
        if (!empty($request_uri) && strpos($request_uri, '/wp-json/') !== false && is_user_logged_in()) {
            return;
        }

        // Skip verification for static assets
        if ($this->is_static_asset()) {
            return;
        }
        
        // Get API key from database
        $api_key = get_option($this->option_name, '');

        // Get selected continent
        $continent = get_option($this->continent_option, '');
        
        // If no API key or continent is set, allow access
        if (empty($api_key) || empty($continent)) {
            return;
        }
        
        // Build URL with continent code
        $verification_url = 'https://engine-' . $continent . '-1.abyssguard.com';
        
        // Collect visitor information from $_SERVER
        $visitor_ip = $this->get_visitor_ip();
        $user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_USER_AGENT'])) : '';
        $request_uri = isset($_SERVER['REQUEST_URI']) ? sanitize_text_field(wp_unslash($_SERVER['REQUEST_URI'])) : '';
        $http_host = isset($_SERVER['HTTP_HOST']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_HOST'])) : '';
        $referer = isset($_SERVER['HTTP_REFERER']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_REFERER'])) : '';
        $request_method = isset($_SERVER['REQUEST_METHOD']) ? sanitize_text_field(wp_unslash($_SERVER['REQUEST_METHOD'])) : '';
        $accept = isset($_SERVER['HTTP_ACCEPT']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_ACCEPT'])) : '';
        $accept_language = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_ACCEPT_LANGUAGE'])) : '';
        
        // Prepare HEAD request with visitor data in headers
        $response = wp_remote_head($verification_url, array(
            'timeout' => 1,
            'headers' => array(
                'x-abyssguard' => $api_key,
                'X-AbyssGuard-ip' => $visitor_ip,
                'X-AbyssGuard-uri' => $request_uri,
                'X-AbyssGuard-host' => $http_host,
                'X-AbyssGuard-referer' => $referer,
                'X-AbyssGuard-method' => $request_method,
                'X-AbyssGuard-user-agent' => $user_agent,
                'X-AbyssGuard-accept' => $accept,
                'X-AbyssGuard-accept-language' => $accept_language,
                'X-AbyssGuard-tech' => 'WordPress v1.0.0'
            ),
            'sslverify' => true
        ));
        
        // Handle timeout or connection errors (allow access)
        if (is_wp_error($response)) {
            $error_message = $response->get_error_message();
            // Log timeout/connection errors but allow access
            // error_log('AbyssGuard: Connection error - ' . $error_message);
            return;
        }
        
        // Get response code
        $response_code = wp_remote_retrieve_response_code($response);
        
        // If 403, block access
        if ($response_code === 403) {
            $this->block_access();
        }
        
        // For 200 OK or any other response, continue normally
        // (including timeouts which are handled as wp_error above)
        return;
    }
    
    /**
     * Get visitor's real IP address
     * Checks for proxy headers first
     */
    private function get_visitor_ip() {
        $ip_keys = array(
            'HTTP_CF_CONNECTING_IP', // Cloudflare
            'HTTP_X_FORWARDED_FOR',
            'HTTP_X_REAL_IP',
            'HTTP_CLIENT_IP',
            'REMOTE_ADDR'
        );
        
        foreach ($ip_keys as $key) {
            if (isset($_SERVER[$key]) && !empty($_SERVER[$key])) {
                $ip = sanitize_text_field(wp_unslash($_SERVER[$key]));
                
                // Handle multiple IPs (X-Forwarded-For can contain multiple IPs)
                if (strpos($ip, ',') !== false) {
                    $ip_list = explode(',', $ip);
                    $ip = trim($ip_list[0]);
                }
                
                // Validate IP address
                if (filter_var($ip, FILTER_VALIDATE_IP)) {
                    return $ip;
                }
            }
        }
        
        return '';
    }

    /**
     * Check if current request is for a static asset
     */
    private function is_static_asset() {
        $request_uri = isset($_SERVER['REQUEST_URI']) ? sanitize_text_field(wp_unslash($_SERVER['REQUEST_URI'])) : '';
        
        // Get file extension
        $path = parse_url($request_uri, PHP_URL_PATH);
        $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
        
        // List of static file extensions to skip
        $static_extensions = array(
            // Images
            'jpg', 'jpeg', 'png', 'gif', 'webp', 'svg', 'ico', 'bmp', 'tiff',
            // Stylesheets
            'css',
            // Fonts
            'woff', 'woff2', 'ttf', 'eot', 'otf',
            // Documents (if you want to skip them)
            'pdf', 'doc', 'docx', 'xls', 'xlsx',
            // Media
            'mp4', 'mp3', 'avi', 'mov', 'wmv', 'wav', 'ogg',
            // Archives
            'zip', 'rar', 'tar', 'gz',
        );
        
        // Check if the extension matches any static file type
        if (in_array($extension, $static_extensions)) {
            return true;
        }
        
        // Also check for common static file patterns
        $static_patterns = array(
            '/favicon\.ico$/',
            '/robots\.txt$/',
            '/sitemap.*\.xml$/',
            '/\.well-known\//',
            '/wp-content\/uploads\//',
        );
        
        foreach ($static_patterns as $pattern) {
            if (preg_match($pattern, $request_uri)) {
                return true;
            }
        }
        
        return false;
    }
    
    /**
     * Block access with 403 response
     */
    private function block_access() {
        status_header(403);
        nocache_headers();
        exit;
    }
    
    /**
     * Add admin menu
     */
    public function add_admin_menu() {
        add_options_page(
            esc_html__('AbyssGuard Settings', 'abyssguard'),
            esc_html__('AbyssGuard', 'abyssguard'),
            'manage_options',
            'abyssguard',
            array($this, 'render_admin_page')
        );
    }
    
    /**
     * Register settings
     */
    public function register_settings() {
        register_setting(
            'svg_settings_group',
            $this->option_name,
            array(
                'type' => 'string',
                'sanitize_callback' => array($this, 'sanitize_api_key'),
                'default' => ''
            )
        );

        register_setting(
            'svg_settings_group',
            $this->continent_option,
            array(
                'type' => 'string',
                'sanitize_callback' => array($this, 'sanitize_continent'),
                'default' => ''
            )
        );
        
        add_settings_section(
            'svg_main_section',
            esc_html__('API Configuration', 'abyssguard'),
            array($this, 'render_section_description'),
            'abyssguard'
        );
        
        add_settings_field(
            'abyssguard_api_key_field',
            esc_html__('API Key', 'abyssguard'),
            array($this, 'render_api_key_field'),
            'abyssguard',
            'svg_main_section'
        );

        add_settings_field(
            'svg_continent_field',
            esc_html__('GEO Node', 'abyssguard'),
            array($this, 'render_continent_field'),
            'abyssguard',
            'svg_main_section'
        );
    }
    
    /**
     * Sanitize API key
     */
    public function sanitize_api_key($value) {
        return sanitize_text_field($value);
    }

    /**
     * Sanitize continent code
     */
    public function sanitize_continent($value) {
        $valid_continents = array('as', 'eu', 'na', 'oc', 'sa');
        $value = strtolower(sanitize_text_field($value));
        
        if (in_array($value, $valid_continents)) {
            return $value;
        }
        
        return '';
    }

    /**
     * Get list of continents
     */
    private function get_continents() {
        return array(
            '' => esc_html__('-- Select GEO Node --', 'abyssguard'),
            'as' => esc_html__('Asia', 'abyssguard'),
            'af' => esc_html__('Africa', 'abyssguard'),
            'eu' => esc_html__('Europe', 'abyssguard'),
            'na' => esc_html__('North America', 'abyssguard'),
            'oc' => esc_html__('Oceania', 'abyssguard'),
            'sa' => esc_html__('South America', 'abyssguard')
        );
    }
    
    /**
     * Render section description
     */
    public function render_section_description() {
        echo '<p>' .esc_html__('Get your API key by signing up for free at:', 'abyssguard') . ' <a href="https://www.abyssguard.com?utm_source=wp_plugin" target="_blank" rel="noopener">AbyssGuard</a>.</p>';
    }
    
    /**
     * Render API key field
     */
    public function render_api_key_field() {
        $api_key = get_option($this->option_name, '');
        echo '<input type="text" name="' . esc_attr($this->option_name) . '" 
              value="' . esc_attr($api_key) . '" 
              class="regular-text" 
              placeholder="' . esc_attr__('API key', 'abyssguard') . '" />';
    }

    /**
     * Render continent field
     */
    public function render_continent_field() {
        $selected_continent = get_option($this->continent_option, '');
        $continents = $this->get_continents();
        
        echo '<select name="' . esc_attr($this->continent_option) . '" class="regular-text">';
        foreach ($continents as $code => $name) {
            $selected = ($selected_continent === $code) ? 'selected' : '';
            echo '<option value="' . esc_attr($code) . '" ' . esc_attr($selected) . '>' . esc_html($name) . '</option>';
        }
        echo '</select>';
    }
    
    /**
     * Render admin page
     */
    public function render_admin_page() {
        if (!current_user_can('manage_options')) {
            return;
        }
        
        settings_errors('svg_messages');
        ?>
        <div class="wrap">
            <h1><?php echo esc_html(get_admin_page_title()); ?></h1>
            
            <div class="card" style="max-width: 800px; margin-top: 20px;">
                <h2><?php echo esc_html__('Important', 'abyssguard'); ?></h2>
                <p>
                    <?php echo esc_html__("Without a valid API key and selected GEO node, the plugin won't work.", 'abyssguard'); ?>
                    <?php echo esc_html__('Please also make sure to configure your host here:', 'abyssguard'); ?> 
                    <a href="https://www.abyssguard.com?utm_source=wp_plugin" target="_blank" rel="noopener">
                        <?php echo esc_html__('AbyssGuard website', 'abyssguard'); ?>
                    </a>.
                    <?php echo esc_html__('You can view your logs there as well.', 'abyssguard'); ?>
                </p>
            </div>
            
            <form action="options.php" method="post" style="margin-top: 20px;">
                <?php
                settings_fields('svg_settings_group');
                do_settings_sections('abyssguard');
                submit_button(esc_html__('Save', 'abyssguard'));
                ?>
            </form>
            
            <div class="card" style="max-width: 800px; margin-top: 20px;">
                <h3><?php echo esc_html__('Status', 'abyssguard'); ?></h3>
                <p><?php echo esc_html__('API Key', 'abyssguard'); ?>: 
                    <?php 
                    $api_key = get_option($this->option_name, '');
                    if (empty($api_key)) {
                        echo '<span style="color: #dc3545;">❌ ' . esc_html__('Not configured', 'abyssguard') . '</span>';
                    } else {
                        echo '<span style="color: #28a745;">✓ ' . esc_html__('Configured', 'abyssguard') . '</span>';
                    }
                    ?>
                </p>
                <p><?php echo esc_html__('GEO Node', 'abyssguard'); ?>: 
                    <?php 
                    $continent = get_option($this->continent_option, '');
                    if (empty($continent)) {
                        echo '<span style="color: #dc3545;">❌ ' . esc_html__('Not configured', 'abyssguard') . '</span>';
                    } else {
                        $continents = $this->get_continents();
                        echo '<span style="color: #28a745;">✓ ' . esc_html($continents[$continent]) . '</span>';
                    }
                    ?>
                </p>
            </div>
        </div>
        <?php
    }
    
    /**
     * Add settings link on plugins page
     */
    public function add_settings_link($links) {
        $settings_link = '<a href="options-general.php?page=abyssguard">Settings</a>';
        array_unshift($links, $settings_link);
        return $links;
    }
}

// Initialize the plugin
new AbyssGuard();

/**
 * Activation hook
 */
register_activation_hook(__FILE__, 'abyssguard_activate_plugin');
function abyssguard_activate_plugin() {
    // Set default options if needed
    if (get_option('abyssguard_api_key') === false) {
        add_option('abyssguard_api_key', '');
    }
}

/**
 * Deactivation hook
 */
register_deactivation_hook(__FILE__, 'abyssguard_deactivate_plugin');
function abyssguard_deactivate_plugin() {
    // Cleanup if needed (optional)
}

/**
 * Uninstall hook - removes all data
 */
register_uninstall_hook(__FILE__, 'abyssguard_uninstall_plugin');
function abyssguard_uninstall_plugin() {
    delete_option('abyssguard_api_key');
}