// Copyright (c) 2020, 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:io';
import 'dart:isolate';

import 'package:package_config/package_config.dart';
import 'package:path/path.dart' as p;

/// The [PackageConfig] parsed from the current isolates package config file.
final Future<PackageConfig> currentPackageConfig = () async {
  return loadPackageConfigUri(await packageConfigUri);
}();

final Future<Uri> packageConfigUri = () async {
  var uri = await Isolate.packageConfig;
  if (uri == null) {
    throw StateError('Unable to find a package config');
  }
  return uri;
}();

final _originalWorkingDirectory = Directory.current.uri;

/// Returns an `package:` URI for [path] if it is in a package, otherwise
/// returns an absolute file URI.
Future<Uri> absoluteUri(String path) async {
  final uri = p.toUri(path);
  final absoluteUri =
      uri.isAbsolute ? uri : _originalWorkingDirectory.resolveUri(uri);
  try {
    final packageConfig = await currentPackageConfig;
    return packageConfig.toPackageUri(absoluteUri) ?? absoluteUri;
  } on StateError {
    // Workaround for a missing package config.
    return absoluteUri;
  }
}