// Copyright (c) 2015, 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 'package:analyzer_plugin/protocol/protocol_common.dart'
    show SourceChange;
import 'package:analyzer_plugin/utilities/assist/assist.dart';

/// A description of a single proposed assist.
///
/// Clients may not extend, implement or mix-in this class.
class Assist {
  /// A description of the assist being proposed.
  final AssistKind kind;

  /// The change to be made in order to apply the assist.
  final SourceChange change;

  /// Initialize a newly created assist to have the given [kind] and [change].
  Assist(this.kind, this.change);

  @override
  String toString() {
    return 'Assist(kind=$kind, change=$change)';
  }

  /// A function that can be used to sort assists by their relevance.
  ///
  /// The most relevant assists will be sorted before assists with a lower
  /// relevance. Assists with the same relevance are sorted alphabetically.
  static int compareAssists(Assist a, Assist b) {
    if (a.kind.priority != b.kind.priority) {
      // A higher priority indicates a higher relevance
      // and should be sorted before a lower priority.
      return b.kind.priority - a.kind.priority;
    }
    return a.change.message.compareTo(b.change.message);
  }
}