using Microsoft.CodeAnalysis.CSharp.Syntax.InternalSyntax;

namespace Microsoft.CodeAnalysis.CSharp.Syntax;

public sealed class ConstantPatternSyntax : PatternSyntax
{
	private ExpressionSyntax? expression;

	public ExpressionSyntax Expression => ((SyntaxNode)this).GetRedAtZero<ExpressionSyntax>(ref expression);

	internal ConstantPatternSyntax(Microsoft.CodeAnalysis.CSharp.Syntax.InternalSyntax.CSharpSyntaxNode green, SyntaxNode? parent, int position)
		: base(green, parent, position)
	{
	}

	internal override SyntaxNode? GetNodeSlot(int index)
	{
		if (index != 0)
		{
			return null;
		}
		return (SyntaxNode?)(object)((SyntaxNode)this).GetRedAtZero<ExpressionSyntax>(ref expression);
	}

	internal override SyntaxNode? GetCachedSlot(int index)
	{
		if (index != 0)
		{
			return null;
		}
		return (SyntaxNode?)(object)expression;
	}

	public override void Accept(CSharpSyntaxVisitor visitor)
	{
		visitor.VisitConstantPattern(this);
	}

	public override TResult? Accept<TResult>(CSharpSyntaxVisitor<TResult> visitor)
	{
		return visitor.VisitConstantPattern(this);
	}

	public ConstantPatternSyntax Update(ExpressionSyntax expression)
	{
		if (expression != Expression)
		{
			ConstantPatternSyntax constantPatternSyntax = SyntaxFactory.ConstantPattern(expression);
			SyntaxAnnotation[] annotations = ((SyntaxNode)this).GetAnnotations();
			if (annotations == null || annotations.Length == 0)
			{
				return constantPatternSyntax;
			}
			return constantPatternSyntax.WithAnnotations(annotations);
		}
		return this;
	}

	public ConstantPatternSyntax WithExpression(ExpressionSyntax expression)
	{
		return Update(expression);
	}
}