Support for use as ConfigurationProvider

[stevefan1999-personal]

Is your feature request related to a problem? Please describe.
I use .NET Generic Host for my CLI application but I have multiple layers of configuration. More specifically, I want to integrate CommandLineUtils as one of the ConfigurationProvider layers.

Describe the solution you'd like
Add a way or best practice towards the use of Custom ConfigurationProvider

Describe alternatives you've considered
Having two sets of options class and copy the CLI options into Host options.

Additional context
Add any other context or screenshots about the feature request here.

[stevefan1999-personal]

This looks quite close to what I wanted to do

Console.OutputEncoding = Encoding.UTF8;

var cla = new CommandLineApplication<AppOptions>();
cla.Conventions
    .UseDefaultConventions();
var app = cla.Parse(args).SelectedCommand;

var textInfo = new CultureInfo("en-US", false).TextInfo;
var builder = Host.CreateApplicationBuilder();
builder.Configuration.AddInMemoryCollection(app
    .GetOptions()
    .ToDictionary(x => textInfo.ToTitleCase(x.LongName), x => x.Values)
    .SelectMany(kvp => kvp.Value.Count switch
    {
        1 => Enumerable.Repeat(KeyValuePair.Create(kvp.Key, kvp.Value[0]), 1),
        > 1 => kvp.Value.Select((value, idx) => KeyValuePair.Create($"{kvp.Key}:{idx}", value)),
        _ => null
    } ?? Array.Empty<KeyValuePair<string, string?>>()));
builder.Services.AddOptions<AppOptions>().BindConfiguration("");
builder.Services.AddSingleton(provider =>
{
    var options = provider.GetRequiredService<IOptions<AppOptions>>().Value;
    return new MaimaiConvertOption
    {
        ExtractImage = options.ExtractImage,
        BitRate = options.BitRate
    };
});
builder.Services.AddSingleton(provider =>
{
    var option = provider.GetRequiredService<MaimaiConvertOption>();
    return new MaimaiConverter(new WindowsPath(@"C:\maimai_universe"), option);
});

builder.Services.AddHostedService<AppService>();
using var host = builder.Build();
host.Run();

record AppOptions
{
    [Option("--extract-image")]
    public bool ExtractImage { get; init; }

    [Option("-b|--bit-rate")]
    public int? BitRate { get; init; }

    [Option("-P|--parallelism")]
    public int Parallelism { get; init; } = 1;
    [Option("-v|--verbose", CommandOptionType.MultipleValue)]
    public bool[]? Verbose { get; init; }
}

record AppService(MaimaiConverter Converter, IOptions<AppOptions> Options, ILogger<AppService> Logger) : IHostedService
{
    public Task StartAsync(CancellationToken cancellationToken)
    {
        var taskQueue = new List<Action>();

        foreach (var x in Converter.AvailableSongs?.Take(100) ?? ImmutableList<MusicData>.Empty)
        {
            async void Run()
            {
                Logger.LogInformation($"Processing {x.CueName.Id} - {x.CueName.Str}");
                var path = new WindowsPath("./output").Join($"{x.CueName.Id} - {x.CueName.Str}.mp3".ToValidFileName());
                {
                    await using var memStream = new MemoryStream();
                    await Converter.ExtractMusicTrackWithJacketByMusicData(x, memStream);

                    await using var file = path.Open(FileMode.Create);
                    memStream.WriteTo(file);
                }

                GC.Collect();

                Logger.LogInformation($"Processed {x.CueName.Str}");
            }

            taskQueue.Add(Run);
        }

        Parallel.Invoke(new() { MaxDegreeOfParallelism = Options.Value.Parallelism }, taskQueue.ToArray());
        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        return Task.CompletedTask;
    }
}

[github-actions]

This issue has been automatically marked as stale because it has no recent activity. It will be closed if no further activity occurs. Please comment if you believe this should remain open, otherwise it will be closed in 14 days. Thank you for your contributions to this project.

[stevefan1999-personal]

/remove-stale

[github-actions]

This issue has been automatically marked as stale because it has no recent activity. It will be closed if no further activity occurs. Please comment if you believe this should remain open, otherwise it will be closed in 14 days. Thank you for your contributions to this project.

[stevefan1999-personal]

/remove-stale

[github-actions]

This issue has been automatically marked as stale because it has no recent activity. It will be closed if no further activity occurs. Please comment if you believe this should remain open, otherwise it will be closed in 14 days. Thank you for your contributions to this project.

[stevefan1999-personal]

/remove-stale