Impostor/src/Impostor.Server/Net/Manager/GameManager.cs

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using Impostor.Api;
using Impostor.Api.Config;
using Impostor.Api.Events.Managers;
using Impostor.Api.Games;
using Impostor.Api.Games.Managers;
using Impostor.Api.Innersloth;
using Impostor.Api.Innersloth.GameOptions;
using Impostor.Api.Net;
using Impostor.Api.Net.Manager;
using Impostor.Server.Events;
using Impostor.Server.Net.State;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Impostor.Server.Net.Manager
{
    internal class GameManager : IGameManager
    {
        private readonly ILogger<GameManager> _logger;
        private readonly IPEndPoint _publicIp;
        private readonly ConcurrentDictionary<int, Game> _games;
        private readonly CompatibilityConfig _compatibilityConfig;
        private readonly IServiceProvider _serviceProvider;
        private readonly IEventManager _eventManager;
        private readonly IGameCodeFactory _gameCodeFactory;
        private readonly ICompatibilityManager _compatibilityManager;
        private readonly ConcurrentDictionary<IClient, Game?> _gamesCreatedBy;

        public GameManager(
            ILogger<GameManager> logger,
            IOptions<ServerConfig> config,
            IServiceProvider serviceProvider,
            IEventManager eventManager,
            IGameCodeFactory gameCodeFactory,
            IOptions<CompatibilityConfig> compatibilityConfig,
            ICompatibilityManager compatibilityManager)
        {
            _logger = logger;
            _serviceProvider = serviceProvider;
            _eventManager = eventManager;
            _gameCodeFactory = gameCodeFactory;
            _publicIp = new IPEndPoint(IPAddress.Parse(config.Value.ResolvePublicIp()), config.Value.PublicPort);
            _games = new ConcurrentDictionary<int, Game>();
            _compatibilityConfig = compatibilityConfig.Value;
            _compatibilityManager = compatibilityManager;
            _gamesCreatedBy = new ConcurrentDictionary<IClient, Game?>();
        }

        IEnumerable<IGame> IGameManager.Games => _games.Select(kv => kv.Value);

        IGame? IGameManager.Find(GameCode code) => Find(code);

        public Game? Find(GameCode code)
        {
            _games.TryGetValue(code, out var game);
            return game;
        }

        public async ValueTask RemoveAsync(GameCode gameCode)
        {
            if (_games.TryGetValue(gameCode, out var game) && game.PlayerCount > 0)
            {
                foreach (var player in game.Players)
                {
                    await player.KickAsync();
                }

                return;
            }

            if (!_games.TryRemove(gameCode, out game))
            {
                return;
            }

            _logger.LogDebug("Remove game with code {0} ({1}).", GameCodeParser.IntToGameName(gameCode), gameCode);

            await _eventManager.CallAsync(new GameDestroyedEvent(game));
        }

        public async ValueTask<IGame?> CreateAsync(IClient? owner, IGameOptions options, GameFilterOptions filterOptions)
        {
            if (owner != null && !_gamesCreatedBy.TryAdd(owner, null))
            {
                _logger.LogWarning("Connection {Name}({ClientId}) has tried to create a second game, blocked", owner.Name, owner.Id);
                return null;
            }

            var @event = new GameCreationEvent(this, owner);
            await _eventManager.CallAsync(@event);

            if (@event.IsCancelled)
            {
                return null;
            }

            var (success, game) = await TryCreateAsync(options, filterOptions, owner, @event.GameCode);

            for (var i = 0; i < 10 && !success; i++)
            {
                (success, game) = await TryCreateAsync(options, filterOptions, owner);
            }

            if (owner != null)
            {
                _gamesCreatedBy[owner] = game;
            }

            if (!success || game == null)
            {
                throw new ImpostorException("Could not create new game"); // TODO: Fix generic exception.
            }

            return game;
        }

        public ValueTask<IGame?> CreateAsync(IGameOptions options, GameFilterOptions filterOptions)
        {
            return CreateAsync(null, options, filterOptions);
        }

        private async ValueTask<(bool Success, Game? Game)> TryCreateAsync(IGameOptions options, GameFilterOptions filterOptions, IClient? owner, GameCode? desiredGameCode = null)
        {
            var gameCode = desiredGameCode ?? _gameCodeFactory.Create();
            var game = ActivatorUtilities.CreateInstance<Game>(_serviceProvider, _publicIp, gameCode, options, filterOptions);

            if (!_games.TryAdd(gameCode, game))
            {
                return (false, null);
            }

            _logger.LogDebug("Created game with code {0}.", game.Code);

            await _eventManager.CallAsync(new GameCreatedEvent(game, owner));

            return (true, game);
        }
    }
}