// Copyright (c) 2021, 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/dart/ast/ast.dart';
import 'package:analyzer/src/dart/resolver/lexical_lookup.dart';
import 'package:analyzer/src/generated/resolver.dart';

/// Class containing static methods for resolving identifiers as implicit
/// property gets/sets on the type of `this`.
class ThisLookup {
  /// Do not construct
  ThisLookup._() {
    assert(false, 'Do not construct instances of LexicalLookup');
  }

  /// Attempts to resolve an identifier with name [id] via implicit `this.`,
  /// assuming we are trying to look up a getter.  If a matching element is
  /// found, a [LexicalLookupResult] is returned.  Otherwise `null` is returned.
  static LexicalLookupResult? lookupGetter(
      ResolverVisitor resolver, SimpleIdentifier node) {
    var id = node.name;
    var thisType = resolver.thisType;
    if (thisType == null) {
      return null;
    }

    var propertyResult = resolver.typePropertyResolver.resolve(
      receiver: null,
      receiverType: thisType,
      name: id,
      propertyErrorEntity: node,
      nameErrorEntity: node,
    );

    final callFunctionType = propertyResult.callFunctionType;
    if (callFunctionType != null) {
      return LexicalLookupResult(
        callFunctionType: callFunctionType,
      );
    }

    final recordField = propertyResult.recordField;
    if (recordField != null) {
      return LexicalLookupResult(
        recordField: recordField,
      );
    }

    var getterElement = propertyResult.getter;
    if (getterElement != null) {
      return LexicalLookupResult(requested: getterElement);
    } else {
      return LexicalLookupResult(recovery: propertyResult.setter);
    }
  }

  /// Attempts to resolve an identifier with name [id] via implicit `this.`,
  /// assuming we are trying to look up a setter.  If a matching element is
  /// found, a [LexicalLookupResult] is returned.  Otherwise `null` is returned.
  static LexicalLookupResult? lookupSetter(
      ResolverVisitor resolver, SimpleIdentifier node) {
    var id = node.name;
    var thisType = resolver.thisType;
    if (thisType == null) {
      return null;
    }

    var propertyResult = resolver.typePropertyResolver.resolve(
      receiver: null,
      receiverType: thisType,
      name: id,
      propertyErrorEntity: node,
      nameErrorEntity: node,
    );

    var setterElement = propertyResult.setter;
    if (setterElement != null) {
      return LexicalLookupResult(requested: setterElement);
    } else {
      return LexicalLookupResult(recovery: propertyResult.getter);
    }
  }
}