// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';

final _defaultDependenciesZoneKey = const Symbol(
  'buildConfigDefaultDependencies',
);
final _packageZoneKey = const Symbol('buildConfigPackage');

T runInBuildConfigZone<T>(
  T Function() fn,
  String package,
  List<String> defaultDependencies,
) => runZoned(
  fn,
  zoneValues: {
    _packageZoneKey: package,
    _defaultDependenciesZoneKey: defaultDependencies,
  },
);

String get currentPackage {
  final package = Zone.current[_packageZoneKey] as String?;
  if (package == null) {
    throw StateError(
      'Must be running inside a build config zone, which can be done using '
      'the `runInBuildConfigZone` function.',
    );
  }
  return package;
}

List<String> get currentPackageDefaultDependencies {
  final defaultDependencies =
      Zone.current[_defaultDependenciesZoneKey] as List<String>?;
  if (defaultDependencies == null) {
    throw StateError(
      'Must be running inside a build config zone, which can be done using '
      'the `runInBuildConfigZone` function.',
    );
  }
  return defaultDependencies;
}