import 'dart:io';

/// Holds filesystem paths that are resolved once during app startup so they can
/// be read synchronously from widget `build()` methods (which cannot await the
/// async `path_provider` lookups). [documentsDir] is populated in `main()`
/// before `runApp`.
class AppPaths {
  /// Absolute path to the app's documents directory. Set exactly once during
  /// startup; reading it before that completes throws (intentional — surfaces
  /// an init-order bug instead of silently using an empty path).
  static late final String documentsDir;

  /// Persistent location of the user-chosen chat background image. Constant
  /// filename, so replacing the image overwrites in place — callers must
  /// `evict()` it from the image cache after writing.
  static String get chatBackgroundImage =>
      '$documentsDir${Platform.pathSeparator}chat_background.img';
}