Storage & File Management

/**
 * File system entry base interface
 */
interface Entry {
  /** Whether this entry is a file */
  isFile: boolean;
  /** Whether this entry is a directory */
  isDirectory: boolean;
  /** Name of this entry, excluding the path leading to it */
  name: string;
  /** Full absolute path from the root to this entry */
  fullPath: string;
}

/**
 * File entry interface extending base Entry
 */
interface FileEntry extends Entry {
  /**
   * Get File object for reading file properties
   * @param successCallback Success callback with File object
   * @param errorCallback Error callback with FileError
   */
  file(successCallback: (file: File) => void, errorCallback?: (error: FileError) => void): void;
  
  /**
   * Create FileWriter for writing to the file
   * @param successCallback Success callback with FileWriter
   * @param errorCallback Error callback with FileError
   */
  createWriter(successCallback: (writer: FileWriter) => void, errorCallback?: (error: FileError) => void): void;
}

/**
 * Directory entry interface extending base Entry
 */
interface DirectoryEntry extends Entry {
  /**
   * Create directory reader for listing contents
   * @returns DirectoryReader instance
   */
  createReader(): DirectoryReader;
  
  /**
   * Get or create a file within this directory
   * @param path Relative path to the file
   * @param options Flags for file operations
   * @param successCallback Success callback with FileEntry
   * @param errorCallback Error callback with FileError
   */
  getFile(path: string, options?: Flags, successCallback?: (entry: FileEntry) => void, errorCallback?: (error: FileError) => void): void;
  
  /**
   * Get or create a directory within this directory
   * @param path Relative path to the directory
   * @param options Flags for directory operations
   * @param successCallback Success callback with DirectoryEntry
   * @param errorCallback Error callback with FileError
   */
  getDirectory(path: string, options?: Flags, successCallback?: (entry: DirectoryEntry) => void, errorCallback?: (error: FileError) => void): void;
}

/**
 * File operation flags
 */
interface Flags {
  /** Create file/directory if it doesn't exist */
  create?: boolean;
  /** Fail if file/directory already exists (only with create: true) */
  exclusive?: boolean;
}

/**
 * File writing options
 */
interface IWriteOptions {
  /** Replace existing file content (default: true) */
  replace?: boolean;
  /** Append to existing file content */
  append?: boolean;
  /** Truncate file before writing */
  truncate?: number;
}

/**
 * File removal result
 */
interface RemoveResult {
  /** Whether removal was successful */
  success: boolean;
  /** Entry that was removed */
  fileRemoved: Entry;
}

/**
 * File class providing comprehensive file system operations
 */
class File {
  /** Read-only directory where the application is installed */
  static applicationDirectory: string;
  
  /** Directory where to store app-specific data files */
  static dataDirectory: string;
  
  /** Directory where to store cached data files */
  static cacheDirectory: string;
  
  /** Directory where to store external app-specific data files */
  static externalApplicationStorageDirectory: string;
  
  /** Directory where to store external data files */
  static externalDataDirectory: string;
  
  /** Directory where to store external cached data files */
  static externalCacheDirectory: string;
  
  /** External storage (SD card) root directory */
  static externalRootDirectory: string;
  
  /** Temporary file directory */
  static tempDirectory: string;
  
  /** Synced data directory (iOS) */
  static syncedDataDirectory: string;
  
  /** Documents directory */
  static documentsDirectory: string;
  
  /** Shared directory */
  static sharedDirectory: string;

  /**
   * Get available free disk space
   * @returns Promise resolving to free space in bytes
   */
  static getFreeDiskSpace(): Promise<number>;

  /**
   * Check if directory exists
   * @param path Directory path
   * @param dir Directory name
   * @returns Promise resolving to boolean indicating existence
   */
  static checkDir(path: string, dir: string): Promise<boolean>;

  /**
   * Create directory
   * @param path Parent directory path
   * @param dirName Directory name to create
   * @param replace Whether to replace existing directory
   * @returns Promise resolving to DirectoryEntry
   */
  static createDir(path: string, dirName: string, replace: boolean): Promise<DirectoryEntry>;

  /**
   * Remove directory
   * @param path Directory path
   * @param dirName Directory name to remove
   * @returns Promise resolving to RemoveResult
   */
  static removeDir(path: string, dirName: string): Promise<RemoveResult>;

  /**
   * Move directory to new location
   * @param path Source directory path
   * @param dirName Source directory name
   * @param newPath Destination directory path
   * @param newDirName New directory name
   * @returns Promise resolving to DirectoryEntry or Entry
   */
  static moveDir(path: string, dirName: string, newPath: string, newDirName: string): Promise<DirectoryEntry | Entry>;

  /**
   * Copy directory to new location
   * @param path Source directory path
   * @param dirName Source directory name
   * @param newPath Destination directory path
   * @param newDirName New directory name
   * @returns Promise resolving to Entry
   */
  static copyDir(path: string, dirName: string, newPath: string, newDirName: string): Promise<Entry>;

  /**
   * List directory contents
   * @param path Directory path
   * @param dirName Directory name
   * @returns Promise resolving to array of Entry objects
   */
  static listDir(path: string, dirName: string): Promise<Entry[]>;

  /**
   * Remove directory recursively
   * @param path Directory path
   * @param dirName Directory name
   * @returns Promise resolving to RemoveResult
   */
  static removeRecursively(path: string, dirName: string): Promise<RemoveResult>;

  /**
   * Check if file exists
   * @param path File path
   * @param file File name
   * @returns Promise resolving to boolean indicating existence
   */
  static checkFile(path: string, file: string): Promise<boolean>;

  /**
   * Create file
   * @param path File path
   * @param fileName File name to create
   * @param replace Whether to replace existing file
   * @returns Promise resolving to FileEntry
   */
  static createFile(path: string, fileName: string, replace: boolean): Promise<FileEntry>;

  /**
   * Remove file
   * @param path File path
   * @param fileName File name to remove
   * @returns Promise resolving to RemoveResult
   */
  static removeFile(path: string, fileName: string): Promise<RemoveResult>;

  /**
   * Write file with content
   * @param path File path
   * @param fileName File name
   * @param text Content to write (string, Blob, or ArrayBuffer)
   * @param options Write options
   * @returns Promise indicating write completion
   */
  static writeFile(path: string, fileName: string, text: string | Blob | ArrayBuffer, options: IWriteOptions): Promise<any>;

  /**
   * Write to existing file
   * @param path File path
   * @param fileName File name
   * @param text Content to write
   * @returns Promise indicating write completion
   */
  static writeExistingFile(path: string, fileName: string, text: string | Blob | ArrayBuffer): Promise<void>;

  /**
   * Read file as text
   * @param path File path
   * @param file File name
   * @returns Promise resolving to file content as string
   */
  static readAsText(path: string, file: string): Promise<string>;

  /**
   * Read file as data URL (base64)
   * @param path File path
   * @param file File name
   * @returns Promise resolving to data URL string
   */
  static readAsDataURL(path: string, file: string): Promise<string>;

  /**
   * Read file as binary string
   * @param path File path
   * @param file File name
   * @returns Promise resolving to binary string
   */
  static readAsBinaryString(path: string, file: string): Promise<string>;

  /**
   * Read file as array buffer
   * @param path File path
   * @param file File name
   * @returns Promise resolving to ArrayBuffer
   */
  static readAsArrayBuffer(path: string, file: string): Promise<ArrayBuffer>;

  /**
   * Move file to new location
   * @param path Source file path
   * @param fileName Source file name
   * @param newPath Destination file path
   * @param newFileName New file name
   * @returns Promise resolving to Entry
   */
  static moveFile(path: string, fileName: string, newPath: string, newFileName: string): Promise<Entry>;

  /**
   * Copy file to new location
   * @param path Source file path
   * @param fileName Source file name
   * @param newPath Destination file path
   * @param newFileName New file name
   * @returns Promise resolving to Entry
   */
  static copyFile(path: string, fileName: string, newPath: string, newFileName: string): Promise<Entry>;

  /**
   * Resolve local filesystem URL to Entry
   * @param fileUrl File URL to resolve
   * @returns Promise resolving to Entry
   */
  static resolveLocalFilesystemUrl(fileUrl: string): Promise<Entry>;

  /**
   * Resolve directory URL to DirectoryEntry
   * @param directoryUrl Directory URL to resolve
   * @returns Promise resolving to DirectoryEntry
   */
  static resolveDirectoryUrl(directoryUrl: string): Promise<DirectoryEntry>;

  /**
   * Get directory from DirectoryEntry
   * @param directoryEntry Parent directory entry
   * @param directoryName Directory name to get
   * @param flags Operation flags
   * @returns Promise resolving to DirectoryEntry
   */
  static getDirectory(directoryEntry: DirectoryEntry, directoryName: string, flags: Flags): Promise<DirectoryEntry>;

  /**
   * Get file from DirectoryEntry
   * @param directoryEntry Parent directory entry
   * @param fileName File name to get
   * @param flags Operation flags
   * @returns Promise resolving to FileEntry
   */
  static getFile(directoryEntry: DirectoryEntry, fileName: string, flags: Flags): Promise<FileEntry>;
}

import { File } from 'ionic-native';

// Create and write to a file
async function saveUserData(userData: any) {
  try {
    const fileName = 'userdata.json';
    const data = JSON.stringify(userData);
    
    await File.writeFile(File.dataDirectory, fileName, data, { replace: true });
    console.log('User data saved successfully');
  } catch (error) {
    console.error('Error saving user data:', error);
  }
}

// Read file content
async function loadUserData() {
  try {
    const fileName = 'userdata.json';
    const exists = await File.checkFile(File.dataDirectory, fileName);
    
    if (exists) {
      const content = await File.readAsText(File.dataDirectory, fileName);
      return JSON.parse(content);
    } else {
      console.log('User data file does not exist');
      return null;
    }
  } catch (error) {
    console.error('Error loading user data:', error);
    return null;
  }
}

// List directory contents
async function listCacheFiles() {
  try {
    const entries = await File.listDir(File.cacheDirectory, '');
    console.log('Cache files:');
    entries.forEach(entry => {
      console.log(`- ${entry.name} (${entry.isFile ? 'file' : 'directory'})`);
    });
  } catch (error) {
    console.error('Error listing cache files:', error);
  }
}

// Create directory structure
async function setupAppDirectories() {
  try {
    await File.createDir(File.dataDirectory, 'images', false);
    await File.createDir(File.dataDirectory, 'documents', false);
    await File.createDir(File.dataDirectory, 'cache', false);
    console.log('App directories created');
  } catch (error) {
    console.error('Error creating directories:', error);
  }
}

/**
 * File upload configuration options
 */
interface FileUploadOptions {
  /** Name of form element. Defaults to 'file' */
  fileKey?: string;
  /** File name to use when saving on server. Defaults to 'image.jpg' */
  fileName?: string;
  /** HTTP method to use - PUT or POST. Defaults to POST */
  httpMethod?: string;
  /** Mime type of data to upload. Defaults to 'image/jpeg' */
  mimeType?: string;
  /** Set of optional key/value pairs to pass in the HTTP request */
  params?: { [key: string]: string };
  /** Whether to upload despite invalid SSL certificate */
  trustAllHosts?: boolean;
  /** Chunked transfer encoding. Defaults to true */
  chunkedMode?: boolean;
  /** Headers to add to the request */
  headers?: { [key: string]: string };
  /** Unique id for the request */
  id?: string;
}

/**
 * File upload result
 */
interface FileUploadResult {
  /** Number of bytes sent to server as part of upload */
  bytesSent: number;
  /** HTTP response code returned by server */
  responseCode: number;
  /** HTTP response returned by server */
  response: string;
  /** HTTP response headers returned by server */
  headers: { [key: string]: string };
}

/**
 * File transfer error
 */
interface FileTransferError {
  /** Error code */
  code: number;
  /** Error source URI */
  source: string;
  /** Error target URI */
  target: string;
  /** HTTP status code (when available) */
  http_status?: number;
  /** Response body (when available) */
  body?: string;
  /** Exception message (when available) */
  exception?: string;
}

/**
 * Transfer class for uploading and downloading files
 */
class Transfer {
  /**
   * Create new Transfer instance
   * @returns Transfer instance
   */
  constructor();

  /**
   * Upload file to remote server
   * @param fileUrl Local file URL to upload
   * @param url Server URL to upload to
   * @param options Upload configuration options
   * @param trustAllHosts Whether to trust all SSL certificates
   * @returns Promise resolving to FileUploadResult
   */
  upload(fileUrl: string, url: string, options?: FileUploadOptions, trustAllHosts?: boolean): Promise<FileUploadResult>;

  /**
   * Download file from remote server
   * @param source Remote file URL to download
   * @param target Local file path to save to
   * @param trustAllHosts Whether to trust all SSL certificates
   * @param options Download options
   * @returns Promise resolving to FileEntry
   */
  download(source: string, target: string, trustAllHosts?: boolean, options?: { [key: string]: any }): Promise<any>;

  /**
   * Set progress listener for transfer operations
   * @param listener Progress callback function
   */
  onProgress(listener: (event: ProgressEvent) => any): void;

  /**
   * Abort the file transfer
   */
  abort(): void;
}

import { Transfer, FileUploadOptions } from 'ionic-native';

// Upload file with progress monitoring
async function uploadPhoto(localFileUri: string) {
  const transfer = new Transfer();
  
  // Set up progress monitoring
  transfer.onProgress((progress) => {
    const percentage = (progress.loaded / progress.total) * 100;
    console.log(`Upload progress: ${percentage.toFixed(2)}%`);
  });

  const options: FileUploadOptions = {
    fileKey: 'photo',
    fileName: 'photo.jpg',
    mimeType: 'image/jpeg',
    params: {
      userId: '12345',
      albumId: 'vacation2023'
    },
    headers: {
      'Authorization': 'Bearer your-token-here'
    }
  };

  try {
    const result = await transfer.upload(localFileUri, 'https://api.example.com/upload', options);
    console.log('Upload successful:', result);
    console.log('Server response:', result.response);
  } catch (error) {
    console.error('Upload failed:', error);
  }
}

// Download file with error handling
async function downloadDocument(remoteUrl: string, localPath: string) {
  const transfer = new Transfer();
  
  try {
    const fileEntry = await transfer.download(remoteUrl, localPath, false, {
      headers: {
        'Authorization': 'Bearer your-token-here'
      }
    });
    
    console.log('Download successful:', fileEntry.toURL());
    return fileEntry;
  } catch (error) {
    console.error('Download failed:', error);
    throw error;
  }
}

/**
 * SQLite database configuration
 */
interface SQLiteConfig {
  /** Database name */
  name: string;
  /** Database location (default, Documents, Library) */
  location?: string;
  /** iOS database location (Library, Documents, Shared) */
  iosDatabaseLocation?: string;
  /** Android database location */
  androidDatabaseLocation?: string;
  /** Android lock workaround */
  androidLockWorkaround?: number;
  /** Create from location */
  createFromLocation?: number;
}

/**
 * SQL result set for query results
 */
interface SQLiteResultSet {
  /** Number of rows returned by query */
  rows: SQLiteResultSetRowList;
  /** Number of rows affected by INSERT, UPDATE, or DELETE */
  rowsAffected: number;
  /** Row ID of last inserted row (INSERT only) */
  insertId: string;
}

/**
 * SQL result row list
 */
interface SQLiteResultSetRowList {
  /** Number of rows */
  length: number;
  /** Get item at specific index */
  item(index: number): any;
}

/**
 * SQL transaction interface
 */
interface SQLiteTransaction {
  /**
   * Execute SQL statement
   * @param sql SQL statement to execute
   * @param values Parameter values for SQL statement
   * @param success Success callback with results
   * @param error Error callback
   */
  executeSql(
    sql: string,
    values?: any[],
    success?: (tx: SQLiteTransaction, result: SQLiteResultSet) => void,
    error?: (tx: SQLiteTransaction, error: any) => boolean
  ): void;
}

/**
 * SQLite database object
 */
interface SQLiteObject {
  /**
   * Open database connection
   * @returns Promise indicating database is ready
   */
  open(): Promise<any>;

  /**
   * Close database connection
   * @returns Promise indicating database is closed
   */
  close(): Promise<any>;

  /**
   * Execute SQL statement
   * @param statement SQL statement
   * @param params Statement parameters
   * @returns Promise resolving to result set
   */
  executeSql(statement: string, params?: any[]): Promise<any>;

  /**
   * Add SQL statement to transaction queue
   * @param statement SQL statement
   * @param values Statement values
   * @returns Promise resolving to result set
   */
  addTransaction(statement: string, values?: any[]): Promise<any>;

  /**
   * Execute transaction
   * @param fn Transaction function
   * @returns Promise indicating transaction completion
   */
  transaction(fn: (tx: SQLiteTransaction) => void): Promise<any>;

  /**
   * Execute read-only transaction
   * @param fn Transaction function
   * @returns Promise indicating transaction completion
   */
  readTransaction(fn: (tx: SQLiteTransaction) => void): Promise<any>;

  /**
   * Start next transaction from queue
   * @returns Promise indicating transaction completion
   */
  startNextTransaction(): Promise<any>;

  /**
   * Delete database
   * @returns Promise indicating deletion completion
   */
  deleteDatabase(): Promise<any>;
}

/**
 * SQLite class for database operations
 */
class SQLite {
  /**
   * Create SQLite database instance
   * @param config Database configuration
   * @returns SQLiteObject instance
   */
  static create(config: SQLiteConfig): SQLiteObject;
}

import { SQLite, SQLiteObject } from 'ionic-native';

// Create and initialize database
async function initDatabase(): Promise<SQLiteObject> {
  const db = SQLite.create({
    name: 'app.db',
    location: 'default'
  });

  try {
    await db.open();
    
    // Create tables
    await db.executeSql(`
      CREATE TABLE IF NOT EXISTS users (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        name TEXT NOT NULL,
        email TEXT UNIQUE NOT NULL,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
      )
    `, []);

    await db.executeSql(`
      CREATE TABLE IF NOT EXISTS settings (
        key TEXT PRIMARY KEY,
        value TEXT NOT NULL
      )
    `, []);

    console.log('Database initialized successfully');
    return db;
  } catch (error) {
    console.error('Error initializing database:', error);
    throw error;
  }
}

// Insert user data
async function createUser(db: SQLiteObject, name: string, email: string) {
  try {
    const result = await db.executeSql(`
      INSERT INTO users (name, email) VALUES (?, ?)
    `, [name, email]);
    
    console.log('User created with ID:', result.insertId);
    return result.insertId;
  } catch (error) {
    console.error('Error creating user:', error);
    throw error;
  }
}

// Query users
async function getUsers(db: SQLiteObject) {
  try {
    const result = await db.executeSql('SELECT * FROM users ORDER BY created_at DESC', []);
    
    const users = [];
    for (let i = 0; i < result.rows.length; i++) {
      users.push(result.rows.item(i));
    }
    
    return users;
  } catch (error) {
    console.error('Error getting users:', error);
    throw error;
  }
}

// Use transactions for multiple operations
async function transferData(db: SQLiteObject, fromUserId: number, toUserId: number, amount: number) {
  try {
    await db.transaction((tx) => {
      tx.executeSql(`
        UPDATE accounts SET balance = balance - ? WHERE user_id = ?
      `, [amount, fromUserId]);
      
      tx.executeSql(`
        UPDATE accounts SET balance = balance + ? WHERE user_id = ?
      `, [amount, toUserId]);
      
      tx.executeSql(`
        INSERT INTO transactions (from_user_id, to_user_id, amount, created_at) 
        VALUES (?, ?, ?, datetime('now'))
      `, [fromUserId, toUserId, amount]);
    });
    
    console.log('Transfer completed successfully');
  } catch (error) {
    console.error('Transfer failed:', error);
    throw error;
  }
}

/**
 * SecureStorage instance for encrypted key-value storage
 */
interface SecureStorageObject {
  /**
   * Get value for key from secure storage
   * @param key Storage key
   * @returns Promise resolving to stored value
   */
  get(key: string): Promise<string>;

  /**
   * Set key-value pair in secure storage
   * @param key Storage key
   * @param value Value to store
   * @returns Promise indicating storage completion
   */
  set(key: string, value: string): Promise<any>;

  /**
   * Remove key from secure storage
   * @param key Storage key to remove
   * @returns Promise resolving to removed key
   */
  remove(key: string): Promise<string>;

  /**
   * Get all keys from secure storage
   * @returns Promise resolving to array of keys
   */
  keys(): Promise<string[]>;

  /**
   * Clear all data from secure storage
   * @returns Promise indicating clear completion
   */
  clear(): Promise<any>;
}

/**
 * SecureStorage class for creating encrypted storage instances
 */
class SecureStorage {
  /**
   * Create SecureStorage instance
   * @returns SecureStorageObject instance
   */
  constructor();

  /**
   * Create secure storage with identifier
   * @param store Storage identifier
   * @returns Promise resolving to SecureStorageObject
   */
  create(store: string): Promise<SecureStorageObject>;
}

import { SecureStorage } from 'ionic-native';

// Create secure storage instance
let secureStorage: any;

async function initSecureStorage() {
  try {
    const storage = new SecureStorage();
    secureStorage = await storage.create('app_secure_store');
    console.log('Secure storage initialized');
  } catch (error) {
    console.error('Error initializing secure storage:', error);
  }
}

// Store sensitive data
async function storeCredentials(username: string, token: string) {
  try {
    await secureStorage.set('username', username);
    await secureStorage.set('auth_token', token);
    console.log('Credentials stored securely');
  } catch (error) {
    console.error('Error storing credentials:', error);
  }
}

// Retrieve sensitive data
async function getCredentials() {
  try {
    const username = await secureStorage.get('username');
    const token = await secureStorage.get('auth_token');
    
    return { username, token };
  } catch (error) {
    console.error('Error retrieving credentials:', error);
    return null;
  }
}

// List all stored keys
async function listStoredKeys() {
  try {
    const keys = await secureStorage.keys();
    console.log('Stored keys:', keys);
    return keys;
  } catch (error) {
    console.error('Error listing keys:', error);
    return [];
  }
}

// Clear all secure storage
async function clearAllSecureData() {
  try {
    await secureStorage.clear();
    console.log('All secure data cleared');
  } catch (error) {
    console.error('Error clearing secure data:', error);
  }
}

/**
 * NativeStorage class for simple key-value storage
 */
class NativeStorage {
  /**
   * Store item with key
   * @param reference Storage key
   * @param value Value to store (will be JSON serialized)
   * @returns Promise indicating storage completion
   */
  static setItem(reference: string, value: any): Promise<any>;

  /**
   * Get item by key
   * @param reference Storage key
   * @returns Promise resolving to stored value (JSON parsed)
   */
  static getItem(reference: string): Promise<any>;

  /**
   * Remove item by key
   * @param reference Storage key to remove
   * @returns Promise indicating removal completion
   */
  static remove(reference: string): Promise<any>;

  /**
   * Clear all stored data
   * @returns Promise indicating clear completion
   */
  static clear(): Promise<any>;

  /**
   * Get all storage keys
   * @returns Promise resolving to array of keys
   */
  static keys(): Promise<string[]>;
}

import { NativeStorage } from 'ionic-native';

// Store user preferences
async function saveUserPreferences(preferences: any) {
  try {
    await NativeStorage.setItem('user_preferences', preferences);
    console.log('User preferences saved');
  } catch (error) {
    console.error('Error saving preferences:', error);
  }
}

// Load user preferences
async function loadUserPreferences() {
  try {
    const preferences = await NativeStorage.getItem('user_preferences');
    return preferences;
  } catch (error) {
    console.log('No preferences found, using defaults');
    return getDefaultPreferences();
  }
}

// Store app settings
async function saveAppSettings(settings: any) {
  try {
    await NativeStorage.setItem('app_settings', settings);
    await NativeStorage.setItem('last_updated', new Date().toISOString());
    console.log('App settings saved');
  } catch (error) {
    console.error('Error saving app settings:', error);
  }
}

// Cache API responses
async function cacheApiResponse(key: string, data: any, ttl: number = 3600000) {
  try {
    const cacheItem = {
      data,
      timestamp: Date.now(),
      ttl
    };
    
    await NativeStorage.setItem(`cache_${key}`, cacheItem);
    console.log(`Cached data for key: ${key}`);
  } catch (error) {
    console.error('Error caching data:', error);
  }
}

// Get cached data with expiration check
async function getCachedData(key: string) {
  try {
    const cacheItem = await NativeStorage.getItem(`cache_${key}`);
    const now = Date.now();
    
    if (now - cacheItem.timestamp < cacheItem.ttl) {
      return cacheItem.data;
    } else {
      await NativeStorage.remove(`cache_${key}`);
      return null;
    }
  } catch (error) {
    return null;
  }
}

// List all storage keys
async function listAllStorageKeys() {
  try {
    const keys = await NativeStorage.keys();
    console.log('Storage keys:', keys);
    return keys;
  } catch (error) {
    console.error('Error listing keys:', error);
    return [];
  }
}

/**
 * Zip utilities class for archive extraction
 */
class Zip {
  /**
   * Extract files from a ZIP archive to a destination folder
   * @param sourceZip Path to the source ZIP file
   * @param destUrl Destination folder path for extraction
   * @param onProgress Optional callback for progress updates
   * @returns Promise that resolves with 0 for success, -1 for error
   */
  static unzip(
    sourceZip: string, 
    destUrl: string, 
    onProgress?: (progress: { loaded: number; total: number }) => void
  ): Promise<number>;
}

import { Zip } from 'ionic-native';

// Basic ZIP extraction
try {
  const result = await Zip.unzip('/path/to/archive.zip', '/path/to/destination/');
  if (result === 0) {
    console.log('ZIP extraction successful');
  } else {
    console.log('ZIP extraction failed');
  }
} catch (error) {
  console.error('Extraction error:', error);
}

// ZIP extraction with progress tracking
Zip.unzip(
  '/path/to/large-archive.zip', 
  '/path/to/destination/',
  (progress) => {
    const percent = Math.round((progress.loaded / progress.total) * 100);
    console.log(`Extraction progress: ${percent}%`);
    // Update UI progress bar
    updateProgressBar(percent);
  }
).then((result) => {
  if (result === 0) {
    console.log('Large archive extracted successfully');
    showSuccessMessage();
  } else {
    console.log('Large archive extraction failed');
    showErrorMessage();
  }
}).catch((error) => {
  console.error('Extraction failed:', error);
  showErrorMessage();
});

// Extract app update ZIP file
async function extractAppUpdate(updateZipPath: string) {
  const extractPath = '/path/to/app/updates/';
  
  try {
    const result = await Zip.unzip(
      updateZipPath,
      extractPath,
      (progress) => {
        const percent = (progress.loaded / progress.total) * 100;
        console.log(`Update extraction: ${percent.toFixed(1)}%`);
      }
    );
    
    if (result === 0) {
      console.log('App update extracted successfully');
      return true;
    } else {
      console.error('App update extraction failed');
      return false;
    }
  } catch (error) {
    console.error('Update extraction error:', error);
    return false;
  }
}