// Copyright (c) 2019, 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/element/element.dart';
import 'package:analyzer/source/line_info.dart';
import 'package:analyzer/src/dart/element/member.dart' show Member;
import 'package:dartdoc/src/model/model.dart';

class Method extends ModelElement
    with ContainerMember, Inheritable, TypeParameters
    implements EnclosedElement {
  bool _isInherited = false;
  Container _enclosingContainer;
  @override
  List<TypeParameter> typeParameters = [];

  Method(MethodElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph, null) {
    _calcTypeParameters();
  }

  Method.inherited(MethodElement element, this._enclosingContainer,
      Library library, PackageGraph packageGraph,
      {Member originalMember})
      : super(element, library, packageGraph, originalMember) {
    _isInherited = true;
    _calcTypeParameters();
  }

  void _calcTypeParameters() {
    typeParameters = _method.typeParameters.map((f) {
      return ModelElement.from(f, library, packageGraph) as TypeParameter;
    }).toList();
  }

  @override
  CharacterLocation get characterLocation {
    if (enclosingElement is Enum && name == 'toString') {
      // The toString() method on Enums is special, treated as not having
      // a definition location by the analyzer yet not being inherited, either.
      // Just directly override our location with the Enum definition --
      // this is OK because Enums can not inherit from each other nor
      // have their definitions split between files.
      return enclosingElement.characterLocation;
    }
    return super.characterLocation;
  }

  @override
  ModelElement get enclosingElement {
    _enclosingContainer ??=
        ModelElement.from(_method.enclosingElement, library, packageGraph);
    return _enclosingContainer;
  }

  @override
  String get filePath =>
      '${enclosingElement.library.dirName}/${enclosingElement.name}/$fileName';

  String get fullkind {
    if (_method.isAbstract) return 'abstract $kind';
    return kind;
  }

  @override
  String get href {
    if (!identical(canonicalModelElement, this)) {
      return canonicalModelElement?.href;
    }
    assert(!(canonicalLibrary == null || canonicalEnclosingContainer == null));
    assert(canonicalLibrary == library);
    assert(canonicalEnclosingContainer == enclosingElement);
    return '${package.baseHref}$filePath';
  }

  @override
  bool get isInherited => _isInherited;

  bool get isOperator => false;

  @override
  Set<String> get features {
    var allFeatures = super.features;
    if (isInherited) allFeatures.add('inherited');
    return allFeatures;
  }

  @override
  bool get isStatic => _method.isStatic;

  @override
  String get kind => 'method';

  String get linkedReturnType => modelType.createLinkedReturnTypeName();

  @override
  Method get overriddenElement {
    if (_enclosingContainer is Extension) {
      return null;
    }
    ClassElement parent = element.enclosingElement;
    for (var t in parent.allSupertypes) {
      Element e = t.getMethod(element.name);
      if (e != null) {
        assert(e.enclosingElement is ClassElement);
        return ModelElement.fromElement(e, packageGraph);
      }
    }
    return null;
  }

  MethodElement get _method => (element as MethodElement);

  /// Methods can not be covariant; always returns false.
  @override
  bool get isCovariant => false;
}