wabbajack/Wabbajack.Common/StoreHandlers/EpicGameStoreHandler.cs

using System;
using System.Linq;
using Microsoft.Win32;

namespace Wabbajack.Common.StoreHandlers
{
    public class EpicGameStoreHandler : AStoreHandler
    {
        public override StoreType Type { get; internal set; }

        public string BaseRegKey = @"SOFTWARE\Epic Games\EOS";
        public override bool Init()
        {
            return true;
        }

        public override bool LoadAllGames()
        {
            try
            {
                using var eosKey = Registry.CurrentUser.OpenSubKey(BaseRegKey);
                if (eosKey == null)
                {
                    Utils.Log("Epic Game Store is not installed");
                    return false;
                }

                var name = eosKey.GetValue("ModSdkMetadataDir");
                if (name == null)
                {
                    Utils.Log("Registry key entry does not exist for Epic Game store");
                    return false;
                }

                var byID = GameRegistry.Games.SelectMany(g => g.Value.EpicGameStoreIDs
                        .Select(id => (id, g.Value.Game)))
                    .GroupBy(t => t.id)
                    .ToDictionary(t => t.Key, t => t.First().Game);

                foreach (var itm in ((AbsolutePath)(string)(name!)).EnumerateFiles(false, "*.item"))
                {
                    var item = itm.FromJson<EpicGameItem>();
                    Utils.Log($"Found Epic Game Store Game: {item.DisplayName} at {item.InstallLocation}");

                    if (byID.TryGetValue(item.CatalogItemId, out var game))
                    {
                        Games.Add(new EpicStoreGame(game, item));
                    }

                }
            }
            catch (NullReferenceException)
            {
                Utils.Log("Epic Game Store is does not appear to be installed");
                return false;
            }

            return true;
        }

        public class EpicStoreGame : AStoreGame
        {
            public EpicStoreGame(Game game, EpicGameItem item)
            {
                Type = StoreType.EpicGameStore;
                Game = game;
                Path = (AbsolutePath)item.InstallLocation;
                Name = game.MetaData().HumanFriendlyGameName;
                
            }

            public override Game Game { get; internal set; }
            public override StoreType Type { get; internal set; }
        }

        public class EpicGameItem
        {
            public string DisplayName { get; set; } = "";
            public string InstallationGuid { get; set; } = "";
            public string CatalogItemId { get; set; } = "";
            public string CatalogNamespace { get; set; } = "";
            public string InstallSessionId { get; set; } = "";
            public string InstallLocation { get; set; } = "";
        }
    }
}