<?php
/**
 * PSR-4 Autoloader
 * Automatically loads classes based on PSR-4 standards
 */

spl_autoload_register(function ($className) {
    // PSR-4 mapping for the application
    $prefixes = [
        'App\\' => __DIR__ . '/../app/',
        'Models\\' => __DIR__ . '/../models/',
        'Controllers\\' => __DIR__ . '/../controllers/',
        'Utils\\' => __DIR__ . '/../utils/',
        'Services\\' => __DIR__ . '/../services/',
        'Middleware\\' => __DIR__ . '/../middleware/'
    ];

    // Check for exact class match first (for legacy classes)
    $legacyMappings = [
        'Config' => __DIR__ . '/Config.php',
        'Security' => __DIR__ . '/../utils/Security.php',
        'Validation' => __DIR__ . '/../utils/Validation.php',
        'Database' => __DIR__ . '/Database.php',
        'UserModel' => __DIR__ . '/../models/UserModel.php',
        'ChatMessageModel' => __DIR__ . '/../models/ChatMessageModel.php',
        'ActiveViewerModel' => __DIR__ . '/../models/ActiveViewerModel.php'
    ];

    // First check legacy mappings
    if (isset($legacyMappings[$className])) {
        $file = $legacyMappings[$className];
        if (file_exists($file)) {
            require_once $file;
            return;
        }
    }

    // Check PSR-4 mappings
    foreach ($prefixes as $prefix => $baseDir) {
        $len = strlen($prefix);
        if (strncmp($prefix, $className, $len) !== 0) {
            continue;
        }

        $relativeClass = substr($className, $len);
        $file = $baseDir . str_replace('\\', '/', $relativeClass) . '.php';

        if (file_exists($file)) {
            require_once $file;
            if (Config::isDebug()) {
                error_log("Autoloaded: {$className} from {$file}");
            }
            return;
        }
    }

    // Class not found - this will throw an exception from spl_autoload_register
    if (Config::isDebug()) {
        error_log("Autoloader: Class {$className} not found in any mapping");
    }
});

/**
 * Optional: Load additional helper functions
 */
if (file_exists(__DIR__ . '/helpers.php')) {
    require_once __DIR__ . '/helpers.php';
}

/**
 * Optional: Load composer autoloader if it exists (for future dependencies)
 */
$composerAutoloader = __DIR__ . '/../vendor/autoload.php';
if (file_exists($composerAutoloader)) {
    require_once $composerAutoloader;
}

// Verify critical classes are loaded
$criticalClasses = [
    'Config',
    'Security',
    'Validation',
    'Database'
];

foreach ($criticalClasses as $class) {
    if (!class_exists($class, false)) {
        // Try to load manually
        $legacyPaths = [
            'Config' => 'includes/Config.php',
            'Security' => 'utils/Security.php',
            'Validation' => 'utils/Validation.php',
            'Database' => 'includes/Database.php'
        ];

        if (isset($legacyPaths[$class])) {
            $path = __DIR__ . '/../' . $legacyPaths[$class];
            if (file_exists($path)) {
                require_once $path;
            }
        }
    }
}