import 'package:package_info_plus/package_info_plus.dart';
import 'version/app_identity.dart';

/// Single source of truth for the app's identity shown inside the running app.
class AppInfo {
  AppInfo._();

  /// Hard-coded fallback mirroring pubspec.yaml and AppIdentity
  static const String fallbackVersion = '1.0.2+102';

  static PackageInfo? _cached;

  static Future<PackageInfo> _load() async {
    return _cached ??= await PackageInfo.fromPlatform();
  }

  /// Resolves the build version in the form `MAJOR.MINOR.PATCH+BUILD`
  static Future<String> versionString() async {
    try {
      final info = await _load();
      final name = info.version.isEmpty ? AppIdentity.current().semanticVersion : info.version;
      final build = info.buildNumber.isEmpty ? '${AppIdentity.current().buildNumber}' : info.buildNumber;
      return '$name+$build';
    } catch (_) {
      return AppIdentity.current().displayString;
    }
  }

  /// The user-facing `MAJOR.MINOR.PATCH` portion (e.g. `1.0.0`).
  static Future<String> versionName() async {
    try {
      final info = await _load();
      return info.version.isEmpty ? AppIdentity.current().semanticVersion : info.version;
    } catch (_) {
      return AppIdentity.current().semanticVersion;
    }
  }

  /// The monotonically increasing `+BUILD` portion (e.g. `100`).
  static Future<String> buildNumber() async {
    try {
      final info = await _load();
      return info.buildNumber.isEmpty ? '${AppIdentity.current().buildNumber}' : info.buildNumber;
    } catch (_) {
      return '${AppIdentity.current().buildNumber}';
    }
  }

  /// The immutable application identity
  static AppIdentity get identity => AppIdentity.current();
}