// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Razor.Test.Common;
using Microsoft.CodeAnalysis.Remote.Razor;
using Microsoft.CodeAnalysis.Test.Utilities;
using Xunit;
using Xunit.Abstractions;
 
namespace Microsoft.CodeAnalysis.Razor.Remote;
 
public class RemoteMefCompositionTest(ITestOutputHelper testOutputHelper) : ToolingTestBase(testOutputHelper)
{
    [Fact]
    public async Task CompositionIsCached()
    {
        using var tempRoot = new TempRoot();
        var cacheDirectory = tempRoot.CreateDirectory().Path;
        var exportProvider = await RemoteMefComposition.CreateExportProviderAsync(cacheDirectory, DisposalToken);
 
        Assert.NotNull(RemoteMefComposition.TestAccessor.SaveCacheFileTask);
        await RemoteMefComposition.TestAccessor.SaveCacheFileTask;
 
        Assert.Single(Directory.GetFiles(cacheDirectory));
    }
 
    [Fact]
    public async Task CacheFileIsUsed()
    {
        using var tempRoot = new TempRoot();
        var cacheDirectory = tempRoot.CreateDirectory().Path;
        var exportProvider = await RemoteMefComposition.CreateExportProviderAsync(cacheDirectory, DisposalToken);
 
        Assert.NotNull(RemoteMefComposition.TestAccessor.SaveCacheFileTask);
        await RemoteMefComposition.TestAccessor.SaveCacheFileTask;
 
        Assert.Single(Directory.GetFiles(cacheDirectory));
 
        RemoteMefComposition.TestAccessor.ClearSaveCacheFileTask();
 
        exportProvider = await RemoteMefComposition.CreateExportProviderAsync(cacheDirectory, DisposalToken);
 
        Assert.Null(RemoteMefComposition.TestAccessor.SaveCacheFileTask);
    }
 
    [Fact]
    public async Task CorruptCacheFileIsOverwritten()
    {
        using var tempRoot = new TempRoot();
        var cacheDirectory = tempRoot.CreateDirectory().Path;
        var cacheFile = RemoteMefComposition.TestAccessor.GetCacheCompositionFile(cacheDirectory);
 
        File.WriteAllText(cacheFile, "This is not a valid cache file.");
 
        var exportProvider = await RemoteMefComposition.CreateExportProviderAsync(cacheDirectory, DisposalToken);
 
        Assert.NotNull(RemoteMefComposition.TestAccessor.SaveCacheFileTask);
        await RemoteMefComposition.TestAccessor.SaveCacheFileTask;
 
        Assert.Single(Directory.GetFiles(cacheDirectory));
        Assert.True(new FileInfo(cacheFile).Length > 35);
    }
 
    [Fact]
    public async Task CleansOldCacheFiles()
    {
        using var tempRoot = new TempRoot();
        var cacheDirectory = tempRoot.CreateDirectory().Path;
        Directory.CreateDirectory(cacheDirectory);
 
        File.WriteAllText(Path.Combine(cacheDirectory, Path.GetRandomFileName()), "");
        File.WriteAllText(Path.Combine(cacheDirectory, Path.GetRandomFileName()), "");
        File.WriteAllText(Path.Combine(cacheDirectory, Path.GetRandomFileName()), "");
        File.WriteAllText(Path.Combine(cacheDirectory, Path.GetRandomFileName()), "");
 
        Assert.Equal(4, Directory.GetFiles(cacheDirectory).Length);
 
        var cacheFile = RemoteMefComposition.TestAccessor.GetCacheCompositionFile(cacheDirectory);
 
        var exportProvider = await RemoteMefComposition.CreateExportProviderAsync(cacheDirectory, DisposalToken);
 
        Assert.NotNull(RemoteMefComposition.TestAccessor.SaveCacheFileTask);
        await RemoteMefComposition.TestAccessor.SaveCacheFileTask;
 
        Assert.Single(Directory.GetFiles(cacheDirectory));
        Assert.True(new FileInfo(cacheFile).Length > 35);
    }
}