// Copyright (c) 2022, 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 RemoveUnnecessaryLate extends CorrectionProducer {
  @override
  bool get canBeAppliedInBulk => true;

  @override
  bool get canBeAppliedToFile => true;

  @override
  FixKind get fixKind => DartFixKind.REMOVE_UNNECESSARY_LATE;

  @override
  FixKind get multiFixKind => DartFixKind.REMOVE_UNNECESSARY_LATE_MULTI;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    final declaration = node;
    if (declaration is! VariableDeclaration) {
      return;
    }
    final declarationList = declaration.parent;
    if (declarationList is! VariableDeclarationList) {
      return;
    }

    if (declarationList.variables.any((v) => v.initializer == null)) {
      // At least one variable declared in the same list does _not_ have an
      // initializer; removing `late` may make such a variable declaration
      // invalid.
      return;
    }

    final lateToken = declarationList.lateKeyword;
    if (lateToken == null) {
      return;
    }

    await builder.addDartFileEdit(file, (builder) {
      builder.addDeletion(range.startStart(lateToken, lateToken.next!));
    });
  }

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