// 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:analysis_server/src/utilities/extensions/ast.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 UseEffectiveIntegerDivision extends CorrectionProducer {
  @override
  FixKind get fixKind => DartFixKind.USE_EFFECTIVE_INTEGER_DIVISION;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    for (var n in node.withParents) {
      if (n is MethodInvocation) {
        if (n.offset == errorOffset && n.length == errorLength) {
          var target = n.target;
          if (target != null) {
            target = target.unParenthesized;
            await builder.addDartFileEdit(file, (builder) {
              // replace "/" with "~/"
              var binary = target as BinaryExpression;
              builder.addSimpleReplacement(range.token(binary.operator), '~/');
              // remove everything before and after
              builder.addDeletion(range.startStart(n, binary.leftOperand));
              builder.addDeletion(range.endEnd(binary.rightOperand, n));
            });
          }
          // done
          break;
        }
      }
    }
  }

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