// 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:io';

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

import '../io.dart';
import '../sdk.dart';

class FuchsiaSdk extends Sdk {
  @override
  String get name => 'Fuchsia';
  @override
  bool get isAvailable => _isAvailable;
  @override
  bool get allowsNonSdkDepsInSdkPackages => true;

  static final bool _isAvailable = _rootDirectory != null;
  static final String? _rootDirectory =
      Platform.environment['FUCHSIA_DART_SDK_ROOT'];

  @override
  String get installMessage =>
      'Please set the FUCHSIA_DART_SDK_ROOT environment variable to point to '
      'the root of the Fuchsia SDK for Dart.';

  @override
  Version? get version {
    if (!_isAvailable) return null;

    _version ??= Version.parse(
      readTextFile(p.join(_rootDirectory!, 'version')).trim(),
    );
    return _version;
  }

  Version? _version;

  @override
  String? packagePath(String name) {
    if (!isAvailable) return null;

    final packagePath = p.join(_rootDirectory!, 'packages', name);
    if (dirExists(packagePath)) return packagePath;

    return null;
  }
}