// 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.
 
using System;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.PooledObjects;
using Microsoft.CodeAnalysis.Text;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Shared.Extensions;
 
internal static partial class ISolutionExtensions
{
    public static async Task<ImmutableArray<INamespaceSymbol>> GetGlobalNamespacesAsync(
        this Solution solution,
        CancellationToken cancellationToken)
    {
        var results = ArrayBuilder<INamespaceSymbol>.GetInstance();
 
        foreach (var projectId in solution.ProjectIds)
        {
            var project = solution.GetProject(projectId)!;
            if (project.SupportsCompilation)
            {
                var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
#nullable disable // Can 'compilation' be null here?
                results.Add(compilation.Assembly.GlobalNamespace);
#nullable enable
            }
        }
 
        return results.ToImmutableAndFree();
    }
 
    public static TextDocumentKind? GetDocumentKind(this Solution solution, DocumentId documentId)
        => solution.GetTextDocument(documentId)?.Kind;
 
    internal static TextDocument? GetTextDocumentForLocation(this Solution solution, Location location)
    {
        switch (location.Kind)
        {
            case LocationKind.SourceFile:
                return solution.GetDocument(location.SourceTree);
            case LocationKind.ExternalFile:
                var documentId = solution.GetDocumentIdsWithFilePath(location.GetLineSpan().Path).FirstOrDefault();
                return solution.GetTextDocument(documentId);
            default:
                return null;
        }
    }
 
    public static Solution WithTextDocumentText(this Solution solution, DocumentId documentId, SourceText text, PreservationMode mode = PreservationMode.PreserveIdentity)
    {
        var documentKind = solution.GetDocumentKind(documentId);
        switch (documentKind)
        {
            case TextDocumentKind.Document:
                return solution.WithDocumentText(documentId, text, mode);
 
            case TextDocumentKind.AnalyzerConfigDocument:
                return solution.WithAnalyzerConfigDocumentText(documentId, text, mode);
 
            case TextDocumentKind.AdditionalDocument:
                return solution.WithAdditionalDocumentText(documentId, text, mode);
 
            case null:
                throw new InvalidOperationException(WorkspaceExtensionsResources.The_solution_does_not_contain_the_specified_document);
 
            default:
                throw ExceptionUtilities.UnexpectedValue(documentKind);
        }
    }
 
    public static Workspace? TryGetWorkspace(this Solution solution)
        => solution.WorkspaceKind == WorkspaceKind.RemoteWorkspace
            ? null
            : solution.Workspace;
}