Interactive Commands in Wolfringo

Wolfringo.Utilities.Interactive provides helper methods to easily await next message by user, in group, or custom conditions by providing own Func delegate.

Interactive Utilities function by listening to IWolfClient's events, and completing the Task when a received message matches criteria. This can be useful if for example user is using a command that has multiple steps.

Interactive Utilities by default can await a private message from user, a message from user in a specified group, or any message in a specified group. To do this, use AwaitNextPrivateByUserAsync, AwaitNextGroupByUserAsync and AwaitNextInGroupAsync, respectively.
You can also provide custom criteria - check Custom Criteria below for details.

private async void OnChatMessage(ChatMessage message)
{
    if (!message.IsPrivateMessage) 
        return;

    await _client.ReplyTextAsync(message, "Ready? Set? Go!");
    DateTime startTime = DateTime.UtcNow;
    ChatMessage response = await _client.AwaitNextPrivateByUserAsync(message.SenderID.Value);

    double userSpeed = (DateTime.UtcNow - startTime).TotalSeconds;
    await _client.ReplyTextAsync(response, $"Congrats, you replied within {userSpeed}!");
}

This feature was inspired by the same feature in DSharpPlus library for Discord.
This is a neat idea that I directly borrowed, so figured a credit is due. :)

Timeouts

You most likely do not want to keep waiting for user's response forever - this could cause memory leaks, groups being blocked, etc. For this reason, you can add a timeout to your interactive commands.

Interactive extension methods take TimeSpan as one of the parameters. If no received message matches criteria within that time, the interactive method will simply return null.

private async void OnChatMessage(ChatMessage message)
{
    // ...
    ChatMessage response = await _client.AwaitNextPrivateByUserAsync(message.SenderID.Value, TimeSpan.FromSeconds(30));

    if (response == null) // if response message is null, it timed out
        await _client.ReplyTextAsync(message, "Aww, too slow. :(");
    else
    {
        // proceed as normal
    }
}

Tip

Like most of async methods in Wolfringo, Interactive Utilities support CancellationToken - combined with CancellationTokenSource, you can implement custom timeouts if simple TimeSpan does not suit your needs.
Fun-fact: internally, that's exactly what Wolfringo does with the provided TimeSpan.

Custom Criteria

If the built-in simple criteria do not match your needs, you can use AwaitNextAsync<T> which takes Func<T, bool> as one of parameters. That delegate should return true if message matches your custom criteria, otherwise it should return false.

The example below will await next image sent by the same user that sent the first message - regardless if the message is sent in private, or any of the groups.

private async void OnChatMessage(ChatMessage message)
{
    // ...
    ChatMessage response = await _client.AwaitNextAsync<ChatMessage>((msg) =>
    {
        if (msg.SenderID.Value != message.SenderID.Value)
            return false;
        if (!msg.IsImage)
            return false;
        return true;
    });
    
    // proceed as normal
}

Tip

T in AwaitNextAsync<T> can be any IChatMessage. This enables usage of interactivity for other scenarios than just receiving a ChatMessage.