// 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/source/source_range.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 RemoveDuplicateCase extends CorrectionProducer {
  @override
  FixKind get fixKind => DartFixKind.REMOVE_DUPLICATE_CASE;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    var node = coveredNode;
    if (node is SwitchCase) {
      var parent = node.parent as SwitchStatement;
      var members = parent.members;
      var index = members.indexOf(node);
      await builder.addDartFileEdit(file, (builder) {
        SourceRange deletionRange;
        if (index > 0 && members[index - 1].statements.isNotEmpty) {
          deletionRange = range.node(node);
        } else {
          deletionRange = range.startEnd(node, node.colon);
        }
        builder.addDeletion(utils.getLinesRange(deletionRange));
      });
    }
  }

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