// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Immutable;
using Microsoft.AspNetCore.Razor.Language.Syntax;
using Microsoft.AspNetCore.Razor.PooledObjects;
 
namespace Microsoft.AspNetCore.Razor.Language.Legacy;
 
internal sealed class TagHelperSpanVisitor : SyntaxWalker
{
    private readonly RazorSourceDocument _source;
    private readonly ImmutableArray<TagHelperSpanInternal>.Builder _spans;
 
    private TagHelperSpanVisitor(RazorSourceDocument source, ImmutableArray<TagHelperSpanInternal>.Builder spans)
    {
        _source = source;
        _spans = spans;
    }
 
    public static ImmutableArray<TagHelperSpanInternal> VisitRoot(RazorSyntaxTree syntaxTree)
    {
        using var _ = ArrayBuilderPool<TagHelperSpanInternal>.GetPooledObject(out var builder);
 
        var visitor = new TagHelperSpanVisitor(syntaxTree.Source, builder);
        visitor.Visit(syntaxTree.Root);
 
        return builder.ToImmutableAndClear();
    }
 
    public override void VisitMarkupTagHelperElement(MarkupTagHelperElementSyntax node)
    {
        var span = new TagHelperSpanInternal(node.GetSourceSpan(_source), node.TagHelperInfo.BindingResult);
        _spans.Add(span);
 
        base.VisitMarkupTagHelperElement(node);
    }
}