nadekobot/src/NadekoBot/Modules/Administration/Services/GameVoiceChannelService.cs

using NadekoBot.Common.Collections;
using NadekoBot.Extensions;
using NadekoBot.Db;

namespace NadekoBot.Modules.Administration.Services;

public class GameVoiceChannelService : INService
{
    public ConcurrentHashSet<ulong> GameVoiceChannels { get; } = new ConcurrentHashSet<ulong>();

    private readonly DbService _db;
    private readonly DiscordSocketClient _client;

    public GameVoiceChannelService(DiscordSocketClient client, DbService db, Bot bot)
    {
        _db = db;
        _client = client;

        GameVoiceChannels = new(
            bot.AllGuildConfigs.Where(gc => gc.GameVoiceChannel != null)
                .Select(gc => gc.GameVoiceChannel.Value));

        _client.UserVoiceStateUpdated += Client_UserVoiceStateUpdated;
        _client.GuildMemberUpdated += _client_GuildMemberUpdated;
    }

    private Task _client_GuildMemberUpdated(SocketGuildUser before, SocketGuildUser after)
    {
        var _ = Task.Run(async () =>
        {
            try
            {
                //if the user is in the voice channel and that voice channel is gvc
                var vc = after.VoiceChannel;
                if (vc is null || !GameVoiceChannels.Contains(vc.Id))
                    return;

                //if the activity has changed, and is a playing activity
                if (before.Activity != after.Activity
                    && after.Activity is { Type: Discord.ActivityType.Playing })
                {
                    //trigger gvc
                    await TriggerGvc(after, after.Activity.Name);
                }

            }
            catch (Exception ex)
            {
                Log.Warning(ex, "Error running GuildMemberUpdated in gvc");
            }
        });
        return Task.CompletedTask;
    }

    public ulong? ToggleGameVoiceChannel(ulong guildId, ulong vchId)
    {
        ulong? id;
        using (var uow = _db.GetDbContext())
        {
            var gc = uow.GuildConfigsForId(guildId, set => set);

            if (gc.GameVoiceChannel == vchId)
            {
                GameVoiceChannels.TryRemove(vchId);
                id = gc.GameVoiceChannel = null;
            }
            else
            {
                if (gc.GameVoiceChannel != null)
                    GameVoiceChannels.TryRemove(gc.GameVoiceChannel.Value);
                GameVoiceChannels.Add(vchId);
                id = gc.GameVoiceChannel = vchId;
            }

            uow.SaveChanges();
        }
        return id;
    }

    private Task Client_UserVoiceStateUpdated(SocketUser usr, SocketVoiceState oldState, SocketVoiceState newState)
    {
        var _ = Task.Run(async () =>
        {
            try
            {
                if (!(usr is SocketGuildUser gUser))
                    return;

                var game = gUser.Activity?.Name;

                if (oldState.VoiceChannel == newState.VoiceChannel ||
                    newState.VoiceChannel is null)
                    return;

                if (!GameVoiceChannels.Contains(newState.VoiceChannel.Id) ||
                    string.IsNullOrWhiteSpace(game))
                    return;

                await TriggerGvc(gUser, game);
            }
            catch (Exception ex)
            {
                Log.Warning(ex, "Error running VoiceStateUpdate in gvc");
            }
        });

        return Task.CompletedTask;
    }

    private async Task TriggerGvc(SocketGuildUser gUser, string game)
    {
        if (string.IsNullOrWhiteSpace(game))
            return;

        game = game.TrimTo(50).ToLowerInvariant();
        var vch = gUser.Guild.VoiceChannels
            .FirstOrDefault(x => x.Name.ToLowerInvariant() == game);

        if (vch is null)
            return;

        await Task.Delay(1000).ConfigureAwait(false);
        await gUser.ModifyAsync(gu => gu.Channel = vch).ConfigureAwait(false);
    }
}