using System;
using System.IO;
using System.Linq;
using System.Reflection;
using UnityEngine;

namespace TH1_Logic.Hotfix
{
    public static class HotfixBootstrap
    {
        private static bool _initialized;

        public static bool IsLoaded { get; private set; }
        public static string LoadedAssemblyFullName { get; private set; }

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
        private static void AutoInitialize()
        {
            InitializeFromStreamingAssets(false);
        }

        public static bool InitializeFromStreamingAssets(bool requireHotfix)
        {
            if (_initialized) return IsLoaded;

            try
            {
                var root = Path.Combine(Application.streamingAssetsPath, HotfixManifest.RootFolderName);
                LoadAotMetadata(root);

                var hotfixPath = Path.Combine(root, HotfixManifest.HotfixDllFolderName, HotfixManifest.HotfixAssemblyFileName);
                if (!File.Exists(hotfixPath))
                {
                    if (requireHotfix)
                    {
                        Debug.LogWarning($"[TH1.Hotfix] Hotfix dll missing: {hotfixPath}");
                    }

                    return false;
                }

                var assembly = Assembly.Load(File.ReadAllBytes(hotfixPath));
                LoadedAssemblyFullName = assembly.FullName;
                InvokeHotfixEntry(assembly);
                _initialized = true;
                IsLoaded = true;
                Debug.Log($"[TH1.Hotfix] Loaded {LoadedAssemblyFullName}");
                return true;
            }
            catch (Exception e)
            {
                Debug.LogError($"[TH1.Hotfix] Initialize failed: {e}");
                return false;
            }
        }

        private static void LoadAotMetadata(string root)
        {
            var runtimeApiType = FindType("HybridCLR.RuntimeApi");
            var modeType = FindType("HybridCLR.HomologousImageMode");
            if (runtimeApiType == null || modeType == null)
            {
                return;
            }

            var method = runtimeApiType.GetMethod(
                "LoadMetadataForAOTAssembly",
                BindingFlags.Public | BindingFlags.Static,
                null,
                new[] { typeof(byte[]), modeType },
                null);
            if (method == null)
            {
                Debug.LogWarning("[TH1.Hotfix] HybridCLR RuntimeApi.LoadMetadataForAOTAssembly not found.");
                return;
            }

            var mode = Enum.Parse(modeType, "SuperSet");
            var aotDir = Path.Combine(root, HotfixManifest.AotMetadataFolderName);

            foreach (var fileName in HotfixManifest.AotMetadataAssemblyFileNames)
            {
                var path = Path.Combine(aotDir, fileName);
                if (!File.Exists(path)) continue;

                var result = method.Invoke(null, new object[] { File.ReadAllBytes(path), mode });
                Debug.Log($"[TH1.Hotfix] Load AOT metadata {fileName}: {result}");
            }
        }

        private static void InvokeHotfixEntry(Assembly assembly)
        {
            var entryType = assembly.GetType(HotfixManifest.EntryTypeName);
            if (entryType == null)
            {
                Debug.LogWarning($"[TH1.Hotfix] Entry type not found: {HotfixManifest.EntryTypeName}");
                return;
            }

            var method = entryType.GetMethod(HotfixManifest.EntryMethodName, BindingFlags.Public | BindingFlags.Static);
            if (method == null)
            {
                Debug.LogWarning($"[TH1.Hotfix] Entry method not found: {HotfixManifest.EntryMethodName}");
                return;
            }

            method.Invoke(null, null);
        }

        private static Type FindType(string fullName)
        {
            return AppDomain.CurrentDomain.GetAssemblies()
                .Select(assembly => assembly.GetType(fullName, false))
                .FirstOrDefault(type => type != null);
        }
    }
}