<?php
/**
 * Cache Manager
 * 
 * Handles the generation and management of the feature cache file
 */

// Exit if accessed directly
if (!defined('ABSPATH')) exit;

class AdvSet_CacheManager {

    private function __construct() {
        // Private constructor to prevent instantiation
    }

    public static function getInstance() {
        static $instance = null;
        if ($instance === null) {
            $instance = new self();
        }
        return $instance;
    }

    /**
     * Get the source code of a function
     * 
     * @param callable $function The function to get the source from
     * @return string The function source code
     */
    private function get_function_source($function) {
        try {
            $reflector = new ReflectionFunction($function);
            $filename = $reflector->getFileName();
            $startLine = $reflector->getStartLine();
            $endLine = $reflector->getEndLine();

            $code = file_get_contents($filename);
            $tokens = token_get_all($code);

            $functionCode = "";
            $insideFunction = false;
            $bracesCount = null;
            $currentLine = 1;

            foreach ($tokens as $token) {
                if (is_array($token)) {
                    $currentLine = $token[2]; // Zeilennummer aus dem Token
                    
                    // Funktion erst ab der Start-Zeile suchen
                    if ($currentLine < $startLine) {
                        continue;
                    }

                    // Start der gesuchten Funktion finden
                    if ($token[0] === T_FUNCTION) {
                        $insideFunction = true;
                    }
                }

                if ($insideFunction) {
                    $functionCode .= is_array($token) ? $token[1] : $token;
                    
                    // Geschweifte Klammern zählen
                    if ($token === '{') $bracesCount = ($bracesCount === null) ? 1 : $bracesCount + 1;
                    if ($token === '}') $bracesCount--;

                    // Ende der Funktion erreicht
                    if ($bracesCount === 0 && $insideFunction) {
                        break;
                    }
                }

                // Falls wir über das Ende der Funktion hinaus sind, abbrechen
                if ($currentLine > $endLine) {
                    break;
                }
            }

            return trim($functionCode);
        } catch (ReflectionException $e) {
            return false;
        }
    }
    
    /**
     * Generate the cache file with active features
     * 
     * @return bool Whether the file was successfully generated
     */
    public function generate_cache_file() {
        $settings = get_option('advanced_settings_settings', []);
        
        // Get all features that should be executed
        $active_features = [];
        foreach ($settings as $feature_id => $feature_settings) {
            $feature = advset_get_feature($feature_id);
            if ($feature && isset($feature['execution_handler'])) {
                if (!empty($feature_settings) && (!isset($feature['execution_condition']) || call_user_func($feature['execution_condition'], $feature_settings) === true)) {
                    $active_features[$feature_id] = [
                        'handler' => $feature['execution_handler'],
                        'settings' => $feature_settings
                    ];
                }
            }
        }
        
        // Start building the cache file content
        $content = "<?php\n";
        $content .= "/**\n";
        $content .= " * Advanced Settings - Active Features Cache\n";
        $content .= " * =======================================\n";
        $content .= " * \n";
        $content .= " * WARNING: THIS FILE IS AUTOMATICALLY GENERATED!\n";
        $content .= " * Manual changes will be overwritten when plugin settings are saved.\n";
        $content .= " * \n";
        $content .= " * Plugin Information:\n";
        $content .= " * ------------------\n";
        $content .= " * Name:      Advanced Settings\n";
        $content .= " * Version:   " . ADVSET_VERSION . "\n";
        $content .= " * \n";
        $content .= " * Cache Status:\n";
        $content .= " * -------------\n";
        $content .= " * Generated: " . wp_date('Y-m-d H:i:s P') . "\n";
        $content .= " * Settings Hash:   " . md5(serialize($settings)) . "\n";
        $content .= " * Cache Location:  " . ADVSET_CACHE_FILE . "\n";
        $content .= " * \n";
        $content .= " * Troubleshooting:\n";
        $content .= " * ---------------\n";
        $content .= " * If plugin features are not working as expected:\n";
        $content .= " * 1. Delete this cache file\n";
        $content .= " * 2. Deactivate and reactivate the plugin\n";
        $content .= " * 3. Save the plugin settings again\n";
        $content .= " * \n";
        $content .= " */\n\n";
        
        // Add security check
        $content .= "// Security check: Prevent direct access\n";
        $content .= "if (!defined('ABSPATH')) exit;\n\n";
        
        // Add each active feature's handler
        foreach ($active_features as $feature_id => $feature) {
            $content .= "\n\n\n";
            $content .= "/**\n";
            $content .= " * FEATURE: " . $feature_id . "\n";
            $content .= " */\n";
            // Get the function source
            $handler = $feature['handler'];
            if (is_string($handler)) {
                $content .= "" . $handler . "();\n";
            } else {
                $source = $this->get_function_source($handler);
                if ($source) {
                    // Add the function with settings
                    $content .= "call_user_func(" . preg_replace('/\n    /', "\n", $source) . ", " . preg_replace('/\n( +)?/', "\n$1$1", var_export($feature['settings'], true)) . ");\n";
                }
            }
        }
        
        $content .= "\n\n\n";
        $content .= "return true;\n";
        
        // Try to write the file
        if (!file_exists(dirname(ADVSET_CACHE_FILE))) {
            mkdir(dirname(ADVSET_CACHE_FILE), 0755, true);
        }
        $result = file_put_contents(ADVSET_CACHE_FILE, $content);
        
        return $result !== false;
    }
    
    /**
     * Execute active features directly (fallback)
     */
    public function execute_active_features_fallback() {
        $settings = get_option('advanced_settings_settings', []);
        
        foreach ($settings as $feature_id => $feature_settings) {
            $feature = advset_get_feature($feature_id);
            if ($feature && isset($feature['execution_handler'])) {
                if (!empty($feature_settings) && (!isset($feature['execution_condition']) || call_user_func($feature['execution_condition'], $feature_settings) === true)) {
                    call_user_func($feature['execution_handler'], $feature_settings);
                }
            }
        }
    }
    
    /**
     * Clean up cache on plugin deactivation
     */
    public function cleanup_cache() {
        if (file_exists(ADVSET_CACHE_FILE)) {
            unlink(ADVSET_CACHE_FILE);
        }
        
        // Try to remove cache directory if empty
        $cache_dir = dirname(ADVSET_CACHE_FILE);
        if (file_exists($cache_dir) && basename($cache_dir) === 'advanced-settings') {
            @rmdir($cache_dir);
        }
    }
}