<?php
/**
 * WP OAuth Server CE - Autoloader
 * 
 * PSR-4 compatible autoloader for the WP OAuth Server CE plugin.
 * 
 * @package WPOAuth2Server
 * @version 1.0.0
 */

defined('ABSPATH') or die('Direct access not allowed');

/**
 * WP OAuth Server CE Autoloader
 */
class WPOAuth2Server_Autoloader {
    
    private static $instance = null;
    private $namespace_prefix = 'WPOAuth2Server\\';
    private $base_directory;
    
    /**
     * Get singleton instance
     */
    public static function instance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    /**
     * Initialize autoloader
     */
    private function __construct() {
        $this->base_directory = __DIR__ . '/';
        spl_autoload_register([$this, 'autoload']);
    }
    
    /**
     * PSR-4 autoloader implementation
     * 
     * @param string $class The fully-qualified class name
     */
    public function autoload($class) {
        // Check if the class uses our namespace
        $len = strlen($this->namespace_prefix);
        if (strncmp($this->namespace_prefix, $class, $len) !== 0) {
            return; // Not our namespace, let other autoloaders handle it
        }
        
        // Get the relative class name
        $relative_class = substr($class, $len);
        
        // Replace namespace separators with directory separators
        $file = $this->base_directory . str_replace('\\', '/', $relative_class) . '.php';
        
        // If the file exists, require it
        if (file_exists($file)) {
            require_once $file;
        }
    }
    
    /**
     * Register additional namespace mapping
     * 
     * @param string $namespace_prefix The namespace prefix
     * @param string $base_directory The base directory for this namespace
     */
    public function add_namespace($namespace_prefix, $base_directory) {
        // Normalize namespace prefix
        $namespace_prefix = trim($namespace_prefix, '\\') . '\\';
        
        // Normalize base directory
        $base_directory = rtrim($base_directory, '/\\') . '/';
        
        // Store the mapping (for future extension)
        $this->namespace_mappings[$namespace_prefix] = $base_directory;
    }
}

// Initialize the autoloader
WPOAuth2Server_Autoloader::instance();