import 'package:fluttery/fluttery.dart';

/// Interface for secure storage operations.
///
/// Provides methods for securely storing and retrieving sensitive data
/// like passwords, tokens, API keys, etc. Data stored through this interface
/// is encrypted and stored in the device's secure storage (Keychain on iOS,
/// Keystore on Android).
abstract class SecureStorage implements Service {
  /// Stores a string value securely with the given [key].
  ///
  /// Returns a Future that completes when the value is successfully stored.
  /// Throws an exception if the storage operation fails.
  Future<void> write(String key, String value);

  /// Retrieves the securely stored string value for the given [key].
  ///
  /// Returns the stored value if found, null otherwise.
  /// Throws an exception if the retrieval operation fails.
  Future<String?> read(String key);

  /// Stores an integer value securely with the given [key].
  ///
  /// The integer is converted to a string for storage.
  Future<void> writeInt(String key, int value);

  /// Retrieves the securely stored integer value for the given [key].
  ///
  /// Returns the stored integer if found and valid, null otherwise.
  Future<int?> readInt(String key);

  /// Stores a boolean value securely with the given [key].
  ///
  /// The boolean is converted to a string for storage.
  Future<void> writeBool(String key, bool value);

  /// Retrieves the securely stored boolean value for the given [key].
  ///
  /// Returns the stored boolean if found and valid, null otherwise.
  Future<bool?> readBool(String key);

  /// Stores a double value securely with the given [key].
  ///
  /// The double is converted to a string for storage.
  Future<void> writeDouble(String key, double value);

  /// Retrieves the securely stored double value for the given [key].
  ///
  /// Returns the stored double if found and valid, null otherwise.
  Future<double?> readDouble(String key);

  /// Removes the securely stored value for the given [key].
  ///
  /// Returns a Future that completes when the value is successfully removed.
  Future<void> delete(String key);

  /// Removes all securely stored values.
  ///
  /// Returns a Future that completes when all values are successfully removed.
  /// Use with caution as this operation cannot be undone.
  Future<void> deleteAll();

  /// Returns all keys incl. values in secure storage
  Future<Set<String>> readAll();

  /// Returns all keys currently stored in secure storage.
  ///
  /// Useful for debugging or migration purposes.
  Future<Set<String>> readAllKeys();

  /// Checks if a value exists for the given [key].
  ///
  /// Returns true if a value exists, false otherwise.
  Future<bool> containsKey(String key);
}