using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CSharp;

internal static class LookupResultKindExtensions
{
	public static CandidateReason ToCandidateReason(this LookupResultKind resultKind)
	{
		return (CandidateReason)(resultKind switch
		{
			LookupResultKind.Empty => 0, 
			LookupResultKind.NotATypeOrNamespace => 1, 
			LookupResultKind.NotAnAttributeType => 4, 
			LookupResultKind.WrongArity => 5, 
			LookupResultKind.Inaccessible => 8, 
			LookupResultKind.NotCreatable => 6, 
			LookupResultKind.NotReferencable => 7, 
			LookupResultKind.NotAValue => 9, 
			LookupResultKind.NotAVariable => 10, 
			LookupResultKind.NotInvocable => 11, 
			LookupResultKind.StaticInstanceMismatch => 12, 
			LookupResultKind.OverloadResolutionFailure => 13, 
			LookupResultKind.Ambiguous => 15, 
			LookupResultKind.MemberGroup => 16, 
			LookupResultKind.Viable => 0, 
			_ => throw ExceptionUtilities.UnexpectedValue((object)resultKind), 
		});
	}

	public static LookupResultKind WorseResultKind(this LookupResultKind resultKind1, LookupResultKind resultKind2)
	{
		if (resultKind1 == LookupResultKind.Empty)
		{
			return resultKind2;
		}
		if (resultKind2 == LookupResultKind.Empty)
		{
			return resultKind1;
		}
		if ((int)resultKind1 < (int)resultKind2)
		{
			return resultKind1;
		}
		return resultKind2;
	}
}