// 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 'package:analyzer/src/generated/source.dart';
import 'package:analyzer_plugin/protocol/protocol_common.dart'
    hide AnalysisError;
import 'package:meta/meta.dart';
import 'package:nnbd_migration/src/front_end/driver_provider_impl.dart';
import 'package:pub_semver/src/version.dart';

class DartFixListener {
  final DriverProviderImpl server;

  final SourceChange sourceChange = SourceChange('null safety migration');

  final List<DartFixSuggestion> suggestions = [];

  final DartFixListenerClient client;

  DartFixListener(this.server, this.client);

  /// Record an edit to be sent to the client.
  ///
  /// The associated suggestion should be separately added by calling
  /// [addSuggestion].
  void addEditWithoutSuggestion(Source source, SourceEdit edit) {
    sourceChange.addEdit(source.fullName, -1, edit);
  }

  /// Record a source change to be sent to the client.
  void addSourceFileEdit(
      String description, Location location, SourceFileEdit fileEdit) {
    suggestions.add(DartFixSuggestion(description, location: location));
    for (var sourceEdit in fileEdit.edits) {
      sourceChange.addEdit(fileEdit.file, fileEdit.fileStamp, sourceEdit);
    }
  }

  /// Record a suggestion to be sent to the client.
  ///
  /// The associated edits should be separately added by calling
  /// [addEditWithoutRecommendation].
  void addSuggestion(String description, Location location) {
    suggestions.add(DartFixSuggestion(description, location: location));
  }

  /// Reports to then user that they need to run `dart pub get` after the
  /// migration finishes.
  void reportPubGetNeeded(Map<String, Version> neededPackages) {
    client.onMessage(
        'Your pubspec has been updated.  Please run `dart pub get`.');
  }

  /// Reset this listener so that it can accrue a new set of changes.
  void reset() {
    suggestions.clear();
    sourceChange
      ..edits.clear()
      ..linkedEditGroups.clear()
      ..selection = null
      ..id = null;
  }
}

abstract class DartFixListenerClient {
  /// Add the given [detail] to the list of details to be returned to the
  /// client.
  void onException(String detail);

  /// Callback that reports a fatal error to the client.
  void onFatalError(String detail);

  /// Reports the given [detail] message to the client; not an error condition.
  void onMessage(String detail);
}

class DartFixSuggestion {
  final String description;

  final Location location;

  DartFixSuggestion(this.description, {@required this.location});
}