// 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:analysis_server/src/services/correction/dart/abstract_producer.dart';
import 'package:analysis_server/src/services/correction/fix.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
import 'package:analyzer_plugin/utilities/range_factory.dart';

class ReplaceWithNullAware extends CorrectionProducer {
  @override
  FixKind get fixKind => DartFixKind.REPLACE_WITH_NULL_AWARE;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    var node = coveredNode;
    if (node is Expression) {
      await builder.addDartFileEdit(file, (builder) {
        var parent = node.parent;
        while (parent != null) {
          if (parent is MethodInvocation && parent.target == node) {
            builder.addSimpleReplacement(range.token(parent.operator), '?.');
          } else if (parent is PropertyAccess && parent.target == node) {
            builder.addSimpleReplacement(range.token(parent.operator), '?.');
          } else {
            break;
          }
          node = parent;
          parent = node.parent;
        }
      });
    }
  }

  /// Return an instance of this class. Used as a tear-off in `FixProcessor`.
  static ReplaceWithNullAware newInstance() => ReplaceWithNullAware();
}