// Copyright (c) 2018, 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:analyzer/analysis_rule/analysis_rule.dart';
import 'package:analyzer/analysis_rule/rule_context.dart';
import 'package:analyzer/analysis_rule/rule_visitor_registry.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer/dart/ast/token.dart';
import 'package:analyzer/dart/ast/visitor.dart';
import 'package:analyzer/error/error.dart';

import '../analyzer.dart';
import '../diagnostic.dart' as diag;

const _desc = r'Unnecessary new keyword.';

class UnnecessaryNew extends AnalysisRule {
  UnnecessaryNew() : super(name: LintNames.unnecessary_new, description: _desc);

  @override
  bool get canUseParsedResult => true;

  @override
  DiagnosticCode get diagnosticCode => diag.unnecessaryNew;

  @override
  void registerNodeProcessors(
    RuleVisitorRegistry registry,
    RuleContext context,
  ) {
    var visitor = _Visitor(this);
    registry.addInstanceCreationExpression(this, visitor);
  }
}

class _Visitor extends SimpleAstVisitor<void> {
  final AnalysisRule rule;
  _Visitor(this.rule);

  @override
  void visitInstanceCreationExpression(InstanceCreationExpression node) {
    var keyword = node.keyword;
    if (keyword != null && keyword.type == Keyword.NEW) {
      rule.reportAtToken(keyword);
    }
  }
}