modules/project/Aki.Reflection/Utils/PatchConstants.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Comfort.Common;
using EFT;
using FilesChecker;

namespace Aki.Reflection.Utils
{
    public static class PatchConstants
    {
        public static BindingFlags PrivateFlags { get; private set; }
        public static BindingFlags PublicFlags { get; private set; }
        public static BindingFlags PublicDeclaredFlags { get; private set; }
        public static Type[] EftTypes { get; private set; }
        public static Type[] FilesCheckerTypes { get; private set; }
        public static Type LocalGameType { get; private set; }
        public static Type ExfilPointManagerType { get; private set; }
        public static Type SessionInterfaceType { get; private set; }
        public static Type BackendSessionInterfaceType { get; private set; }

        private static ISession _backEndSession;
        public static ISession BackEndSession
        {
            get
            {
                if (_backEndSession == null)
                {
                    _backEndSession = Singleton<ClientApplication<ISession>>.Instance.GetClientBackEndSession();
                }

                return _backEndSession;
            }
        }

        static PatchConstants()
        {
            _ = nameof(ISession.GetPhpSessionId);

            PrivateFlags = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly;
            PublicFlags = BindingFlags.Public | BindingFlags.Instance;
            PublicDeclaredFlags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly;
            EftTypes = typeof(AbstractGame).Assembly.GetTypes();
            FilesCheckerTypes = typeof(ICheckResult).Assembly.GetTypes();
            LocalGameType = EftTypes.SingleCustom(x => x.Name == "LocalGame");
            ExfilPointManagerType = EftTypes.SingleCustom(x => x.GetMethod("InitAllExfiltrationPoints") != null);
            SessionInterfaceType = EftTypes.SingleCustom(x => x.GetMethods().Select(y => y.Name).Contains("GetPhpSessionId") && x.IsInterface);
            BackendSessionInterfaceType = EftTypes.SingleCustom(x => x.GetMethods().Select(y => y.Name).Contains("ChangeProfileStatus") && x.IsInterface);
        }

        /// <summary>
        /// A custom LINQ .Single() implementation with improved logging for easier patch debugging
        /// </summary>
        /// <returns>A single member of the input sequence that matches the given search pattern</returns>
        /// <exception cref="ArgumentNullException"></exception>
        /// <exception cref="InvalidOperationException"></exception>
        public static T SingleCustom<T>(this IEnumerable<T> types, Func<T, bool> predicate) where T : MemberInfo
        {
            if (types == null)
            {
                throw new ArgumentNullException(nameof(types));
            }

            if (predicate == null)
            {
                throw new ArgumentNullException(nameof(predicate));
            }

            var matchingTypes = types.Where(predicate).ToArray();

            if (matchingTypes.Length > 1)
            {
                throw new InvalidOperationException($"More than one member matches the specified search pattern: {string.Join(", ", matchingTypes.Select(t => t.Name))}");
            }

            if (matchingTypes.Length == 0)
            {
                throw new InvalidOperationException("No members match the specified search pattern");
            }

            return matchingTypes[0];
        }
    }
}