// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
#if !MICROSOFT_CODEANALYSIS_PUBLIC_API_ANALYZERS
 
using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis;
 
namespace Analyzer.Utilities
{
    internal static class DocumentExtensions
    {
        public static async ValueTask<SemanticModel> GetRequiredSemanticModelAsync(this Document document, CancellationToken cancellationToken)
        {
            if (document.TryGetSemanticModel(out var semanticModel))
                return semanticModel;
 
            semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
            return semanticModel ?? throw new InvalidOperationException("SyntaxTree is required to accomplish the task but is not supported by document");
        }
 
        public static async ValueTask<SyntaxTree> GetRequiredSyntaxTreeAsync(this Document document, CancellationToken cancellationToken)
        {
            if (document.TryGetSyntaxTree(out var syntaxTree))
                return syntaxTree;
 
            syntaxTree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
            return syntaxTree ?? throw new InvalidOperationException("SyntaxTree is required to accomplish the task but is not supported by document");
        }
 
        public static async ValueTask<SyntaxNode> GetRequiredSyntaxRootAsync(this Document document, CancellationToken cancellationToken)
        {
            if (document.TryGetSyntaxRoot(out var root))
                return root;
 
            root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
            return root ?? throw new InvalidOperationException("SyntaxTree is required to accomplish the task but is not supported by document");
        }
    }
}
 
#endif