// 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/element/element2.dart';
import 'package:analyzer/dart/element/scope.dart';
import 'package:dartdoc/src/model/comment_referable.dart';
import 'package:dartdoc/src/model/kind.dart';
import 'package:dartdoc/src/model/model.dart';

/// Represents a [PrefixElement2] for dartdoc.
///
/// Like [Parameter], it doesn't have doc pages, but participates in lookups.
/// Forwards to its referenced library if referred to directly.
class Prefix extends ModelElement with HasNoPage {

  @override
  final PrefixElement2 element2;

  /// [library] is the library the prefix is defined in, not the [Library]
  /// referred to by the [PrefixElement2].
  Prefix(this.element2, super.library, super.packageGraph);

  @override
  bool get isCanonical => false;

  // TODO(jcollins-g): consider connecting PrefixElement to the imported library
  // in analyzer?
  late final Library associatedLibrary =
      getModelForElement2(_getImportedLibraryElement()!) as Library;

  LibraryElement2? _getImportedLibraryElement() {
    final importLists =
        library.element2.fragments.map((fragment) => fragment.libraryImports2);
    return importLists
        .expand((import) => import)
        .firstWhere((i) => i.prefix2?.element == element2)
        .importedLibrary2;
  }

  @override
  Library? get canonicalModelElement => associatedLibrary.canonicalLibrary;

  @override
  Scope get scope => element2.scope;

  @override
  ModelElement get enclosingElement => library;

  @override
  String? get href => canonicalModelElement?.href;

  @override
  Kind get kind => Kind.prefix;

  @override
  Map<String, CommentReferable> get referenceChildren => {};

  @override
  Iterable<CommentReferable> get referenceParents => [library];
}