PluralKit/PluralKit.Bot/Interactive/YesNoPrompt.cs

using System;
using System.Threading;
using System.Threading.Tasks;

using Myriad.Gateway;
using Myriad.Rest.Types;
using Myriad.Types;

using PluralKit.Core;

using Autofac;

namespace PluralKit.Bot.Interactive
{
    public class YesNoPrompt: BaseInteractive
    {
        public bool? Result { get; private set; }
        public ulong? User { get; set; }
        public string Message { get; set; } = "Are you sure?";

        public string AcceptLabel { get; set; } = "OK";
        public ButtonStyle AcceptStyle { get; set; } = ButtonStyle.Primary;

        public string CancelLabel { get; set; } = "Cancel";
        public ButtonStyle CancelStyle { get; set; } = ButtonStyle.Secondary;

        public override async Task Start()
        {
            AddButton(ctx => OnButtonClick(ctx, true), AcceptLabel, AcceptStyle);
            AddButton(ctx => OnButtonClick(ctx, false), CancelLabel, CancelStyle);

            AllowedMentions mentions = null;

            if (User != _ctx.Author.Id)
                mentions = new AllowedMentions { Users = new[] { User!.Value } };

            await Send(Message, mentions: mentions);
        }

        private async Task OnButtonClick(InteractionContext ctx, bool result)
        {
            if (ctx.User.Id != User)
            {
                await Update(ctx);
                return;
            }

            Result = result;
            await Finish(ctx);
        }

        private bool MessagePredicate(MessageCreateEvent e)
        {
            if (e.ChannelId != _ctx.Channel.Id) return false;
            if (e.Author.Id != User) return false;

            var response = e.Content.ToLowerInvariant();

            if (response == "y" || response == "yes")
            {
                Result = true;
                return true;
            }

            if (response == "n" || response == "no")
            {
                Result = false;
                return true;
            }

            return false;
        }

        public new async Task Run()
        {
            // todo: can we split this up somehow so it doesn't need to be *completely* copied from BaseInteractive?

            var cts = new CancellationTokenSource(Timeout.ToTimeSpan());

            if (_running)
                throw new InvalidOperationException("Action is already running");
            _running = true;

            var queue = _ctx.Services.Resolve<HandlerQueue<MessageCreateEvent>>();

            var messageDispatch = queue.WaitFor(MessagePredicate, Timeout, cts.Token);

            await Start();

            cts.Token.Register(() => _tcs.TrySetException(new TimeoutException("Action timed out")));

            try
            {
                var doneTask = await Task.WhenAny(_tcs.Task, messageDispatch);
                if (doneTask == messageDispatch)
                    await Finish();
            }
            finally
            {
                Cleanup();
            }
        }

        public YesNoPrompt(Context ctx) : base(ctx)
        {
            User = ctx.Author.Id;
        }
    }
}