// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
#nullable disable
 
using System;
using System.Runtime.InteropServices;
using Microsoft.CodeAnalysis;
using Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.Collections;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.InternalElements;
 
[ComVisible(true)]
[ComDefaultInterface(typeof(EnvDTE80.CodeAttribute2))]
public sealed class CodeAttribute : AbstractCodeElement, ICodeElementContainer<CodeAttributeArgument>, EnvDTE.CodeAttribute, EnvDTE80.CodeAttribute2
{
    internal static EnvDTE.CodeAttribute Create(
        CodeModelState state,
        FileCodeModel fileCodeModel,
        AbstractCodeElement parent,
        string name,
        int ordinal)
    {
        var newElement = new CodeAttribute(state, fileCodeModel, parent, name, ordinal);
        return (EnvDTE.CodeAttribute)ComAggregate.CreateAggregatedObject(newElement);
    }
 
    // CodeAttributes are tracked by name+ordinal within their parent node, or FileCodeModel if parent is null.
    private readonly AbstractCodeElement _parent; // NOTE: Ref'd
    private string _name;
    private readonly int _ordinal;
 
    private CodeAttribute(CodeModelState state, FileCodeModel fileCodeModel, AbstractCodeElement parent, string name, int ordinal)
        : base(state, fileCodeModel)
    {
        _parent = parent;
        _name = name;
        _ordinal = ordinal;
    }
 
    EnvDTE.CodeElements ICodeElementContainer<CodeAttributeArgument>.GetCollection()
        => this.Arguments;
 
    protected override EnvDTE.CodeElements GetCollection()
        => GetCollection<CodeAttribute>(Parent);
 
    internal override bool TryLookupNode(out SyntaxNode node)
    {
        node = null;
 
        var parentNode = _parent != null
            ? _parent.LookupNode()
            : FileCodeModel.GetSyntaxRoot();
 
        if (parentNode == null)
        {
            return false;
        }
 
        if (!CodeModelService.TryGetAttributeNode(parentNode, _name, _ordinal, out var attributeNode))
        {
            return false;
        }
 
        node = attributeNode;
        return node != null;
    }
 
    public override EnvDTE.vsCMElement Kind
    {
        get { return EnvDTE.vsCMElement.vsCMElementAttribute; }
    }
 
    public override object Parent => _parent ?? (object)this.FileCodeModel;
 
    public EnvDTE.CodeElements Arguments
    {
        get { return AttributeArgumentCollection.Create(this.State, this); }
    }
 
    public override EnvDTE.CodeElements Children
    {
        get { return Arguments; }
    }
 
    protected override void SetName(string value)
    {
        // Defer to the base type to do the heavy lifting...
        base.SetName(value);
 
        // ...and then update the name we use to track this attribute.
        _name = value;
    }
 
    public string Target
    {
        get
        {
            return CodeModelService.GetAttributeTarget(LookupNode());
        }
 
        set
        {
            UpdateNode(FileCodeModel.UpdateAttributeTarget, value);
        }
    }
 
    public string Value
    {
        get
        {
            return CodeModelService.GetAttributeValue(LookupNode());
        }
 
        set
        {
            UpdateNode(FileCodeModel.UpdateAttributeValue, value);
        }
    }
 
    public EnvDTE80.CodeAttributeArgument AddArgument(string value, object nameObj, object position)
    {
        string name;
 
        if (nameObj == Type.Missing ||
            nameObj == null)
        {
            name = null;
        }
        else if (nameObj is string s)
        {
            name = s;
        }
        else
        {
            throw Exceptions.ThrowEInvalidArg();
        }
 
        return FileCodeModel.EnsureEditor(() =>
        {
            return FileCodeModel.AddAttributeArgument(LookupNode(), name, value, position);
        });
    }
 
    public new void Delete()
        => base.Delete();
}