// 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:dartdoc/src/element_type.dart';
import 'package:dartdoc/src/model/model.dart';

/// A [ModelElement] for a [FunctionElement] that isn't part of a type definition.
class ModelFunction extends ModelFunctionTyped with Categorization {
  ModelFunction(
      FunctionElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph);

  @override
  bool get isStatic {
    return _func.isStatic;
  }

  @override
  String get name => element.name ?? '';

  @override
  FunctionElement get _func => (element as FunctionElement);
}

/// A [ModelElement] for a [FunctionTypedElement] that is an
/// explicit typedef.
///
/// Distinct from ModelFunctionTypedef in that it doesn't
/// have a name, but we document it as "Function" to match how these are
/// written in declarations.
class ModelFunctionAnonymous extends ModelFunctionTyped {
  ModelFunctionAnonymous(
      FunctionTypedElement element, PackageGraph packageGraph)
      : super(element, null, packageGraph);

  @override
  ModelElement get enclosingElement {
    // These are not considered to be a part of libraries, so we can simply
    // blindly instantiate a ModelElement for their enclosing element.
    return ModelElement.fromElement(element.enclosingElement, packageGraph);
  }

  @override
  String get name => 'Function';

  @override
  String get linkedName => 'Function';

  @override
  bool get isPublic => false;
}

/// A [ModelElement] for a [FunctionTypedElement] that is part of an
/// explicit typedef.
class ModelFunctionTypedef extends ModelFunctionTyped {
  ModelFunctionTypedef(
      FunctionTypedElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph);

  @override
  String get name {
    Element e = element;
    while (e != null) {
      if (e is FunctionTypeAliasElement || e is GenericTypeAliasElement) {
        return e.name;
      }
      e = e.enclosingElement;
    }
    assert(false);
    return super.name;
  }
}

class ModelFunctionTyped extends ModelElement
    with TypeParameters
    implements EnclosedElement {
  @override
  List<TypeParameter> typeParameters = [];

  ModelFunctionTyped(
      FunctionTypedElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph, null) {
    _calcTypeParameters();
  }

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

  @override
  ModelElement get enclosingElement => library;

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

  @override
  String get kind => 'function';

  String get linkedReturnType => modelType.createLinkedReturnTypeName();

  // Food for mustache. TODO(jcollins-g): what about enclosing elements?
  bool get isInherited => false;

  @override
  DefinedElementType get modelType => super.modelType;

  FunctionTypedElement get _func => (element as FunctionTypedElement);
}