// 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 UseEqEqNull extends CorrectionProducer {
  @override
  bool get canBeAppliedInBulk => true;

  @override
  bool get canBeAppliedToFile => true;

  @override
  FixKind get fixKind => DartFixKind.USE_EQ_EQ_NULL;

  @override
  FixKind get multiFixKind => DartFixKind.USE_EQ_EQ_NULL_MULTI;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    if (coveredNode is IsExpression) {
      var isExpression = coveredNode as IsExpression;
      await builder.addDartFileEdit(file, (builder) {
        builder.addReplacement(
            range.endEnd(isExpression.expression, isExpression), (builder) {
          builder.write(' == null');
        });
      });
    }
  }

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