using System;
using System.Collections.Generic;
using System.Reflection.Emit;
using BepInEx.Configuration;
using HarmonyLib;
using UnityEngine;
using UXAssist.Common;

namespace UXAssist;

public static class GamePatch
{
    private const string GameWindowClass = "UnityWndClass";
    private const string GameWindowTitle = "Dyson Sphere Program";

    public static ConfigEntry<bool> EnableWindowResizeEnabled;
    public static ConfigEntry<bool> LoadLastWindowRectEnabled;
    public static ConfigEntry<bool> ConvertSavesFromPeaceEnabled;
    public static ConfigEntry<Vector4> LastWindowRect;
    private static Harmony _gamePatch;

    public static void Init()
    {
        EnableWindowResizeEnabled.SettingChanged += (_, _) => EnableWindowResize.Enable(EnableWindowResizeEnabled.Value);
        LoadLastWindowRectEnabled.SettingChanged += (_, _) => LoadLastWindowRect.Enable(LoadLastWindowRectEnabled.Value);
        ConvertSavesFromPeaceEnabled.SettingChanged += (_, _) => ConvertSavesFromPeace.Enable(ConvertSavesFromPeaceEnabled.Value);
        EnableWindowResize.Enable(EnableWindowResizeEnabled.Value);
        LoadLastWindowRect.Enable(LoadLastWindowRectEnabled.Value);
        ConvertSavesFromPeace.Enable(ConvertSavesFromPeaceEnabled.Value);
        _gamePatch ??= Harmony.CreateAndPatchAll(typeof(GamePatch));
    }
    
    public static void Uninit()
    {
        LoadLastWindowRect.Enable(false);
        EnableWindowResize.Enable(false);
        ConvertSavesFromPeace.Enable(false);
        _gamePatch?.UnpatchSelf();
        _gamePatch = null;
    }

    [HarmonyPrefix, HarmonyPatch(typeof(GameMain), nameof(GameMain.HandleApplicationQuit))]
    private static void GameMain_HandleApplicationQuit_Prefix()
    {
        var wnd = WinApi.FindWindow(GameWindowClass, GameWindowTitle);
        if (wnd == IntPtr.Zero) return;
        WinApi.GetWindowRect(wnd, out var rect);
        LastWindowRect.Value = new Vector4(rect.Left, rect.Top, Screen.width, Screen.height);
    }

    private static class EnableWindowResize
    {
        public static void Enable(bool on)
        {
            var wnd = WinApi.FindWindow(GameWindowClass, GameWindowTitle);
            if (wnd == IntPtr.Zero) return;
            if (on)
                WinApi.SetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE,
                    WinApi.GetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE) | (int)WindowStyles.WS_THICKFRAME | (int)WindowStyles.WS_MAXIMIZEBOX);
            else
                WinApi.SetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE,
                    WinApi.GetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE) & ~((int)WindowStyles.WS_THICKFRAME | (int)WindowStyles.WS_MAXIMIZEBOX));
        }
    }

    private static class LoadLastWindowRect
    {
        private static Harmony _patch;
        private static bool _loaded;
        public static void Enable(bool on)
        {
            if (on)
            {
                _patch ??= Harmony.CreateAndPatchAll(typeof(LoadLastWindowRect));
                if (Screen.fullScreenMode is not (FullScreenMode.ExclusiveFullScreen or FullScreenMode.FullScreenWindow or FullScreenMode.MaximizedWindow))
                {
                    var rect = LastWindowRect.Value;
                    var x = Mathf.RoundToInt(rect.x);
                    var y = Mathf.RoundToInt(rect.y);
                    var w = Mathf.RoundToInt(rect.z);
                    var h = Mathf.RoundToInt(rect.w);
                    var needFix = false;
                    if (w < 100)
                    {
                        w = 1280;
                        needFix = true;
                    }
                    if (h < 100)
                    {
                        h = 720;
                        needFix = true;
                    }
                    var sw = Screen.currentResolution.width;
                    var sh = Screen.currentResolution.height;
                    if (x + w > sw)
                    {
                        x = sw - w;
                        needFix = true;
                    }
                    if (y + h > sh)
                    {
                        y = sh - h;
                        needFix = true;
                    }
                    if (x < 0)
                    {
                        x = 0;
                        needFix = true;
                    }
                    if (y < 0)
                    {
                        y = 0;
                        needFix = true;
                    }
                    if (needFix)
                    {
                        LastWindowRect.Value = new Vector4(x, y, w, h);
                    }
                }
                MoveWindowPosition();
                return;
            }
            _patch?.UnpatchSelf();
            _patch = null;
        }

        private static void MoveWindowPosition()
        {
            if (Screen.fullScreenMode is FullScreenMode.ExclusiveFullScreen or FullScreenMode.FullScreenWindow or FullScreenMode.MaximizedWindow || GameMain.isRunning) return;
            var wnd = WinApi.FindWindow(GameWindowClass, GameWindowTitle);
            if (wnd == IntPtr.Zero) return;
            var rect = LastWindowRect.Value;
            if (rect.z == 0f && rect.w == 0f) return;
            var x = Mathf.RoundToInt(rect.x);
            var y = Mathf.RoundToInt(rect.y);
            WinApi.SetWindowPos(wnd, IntPtr.Zero, x, y, 0, 0, 0x0235);
        }

        [HarmonyPrefix]
        [HarmonyPatch(typeof(Screen), nameof(Screen.SetResolution), typeof(int), typeof(int), typeof(FullScreenMode), typeof(int))]
        private static void Screen_SetResolution_Prefix(ref int width, ref int height, FullScreenMode fullscreenMode)
        {
            if (fullscreenMode is FullScreenMode.ExclusiveFullScreen or FullScreenMode.FullScreenWindow or FullScreenMode.MaximizedWindow || GameMain.isRunning) return;
            var rect = LastWindowRect.Value;
            if (rect.z == 0f && rect.w == 0f) return;
            var w = Mathf.RoundToInt(rect.z);
            var h = Mathf.RoundToInt(rect.w);
            width = w;
            height = h;
        }
        
        [HarmonyPostfix]
        [HarmonyPatch(typeof(Screen), nameof(Screen.SetResolution), typeof(int), typeof(int), typeof(FullScreenMode), typeof(int))]
        private static void Screen_SetResolution_Postfix(FullScreenMode fullscreenMode)
        {
            MoveWindowPosition();
        }

        [HarmonyPostfix]
        [HarmonyPatch(typeof(VFPreload), "InvokeOnLoadWorkEnded")]
        private static void VFPreload_InvokeOnLoadWorkEnded_Postfix()
        {
            if (_loaded || Screen.fullScreenMode is FullScreenMode.ExclusiveFullScreen or FullScreenMode.FullScreenWindow or FullScreenMode.MaximizedWindow) return;
            _loaded = true;
            var wnd = WinApi.FindWindow(GameWindowClass, GameWindowTitle);
            if (wnd == IntPtr.Zero) return;
            var rect = LastWindowRect.Value;
            if (rect.z == 0f && rect.w == 0f) return;
            var x = Mathf.RoundToInt(rect.x);
            var y = Mathf.RoundToInt(rect.y);
            var w = Mathf.RoundToInt(rect.z);
            var h = Mathf.RoundToInt(rect.w);
            Screen.SetResolution(w, h, false);
            WinApi.SetWindowPos(wnd, IntPtr.Zero, x, y, 0, 0, 0x0235);
            if (EnableWindowResizeEnabled.Value)
                WinApi.SetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE,
                    WinApi.GetWindowLong(wnd, (int)WindowLongFlags.GWL_STYLE) | (int)WindowStyles.WS_THICKFRAME | (int)WindowStyles.WS_MAXIMIZEBOX);
        }
    }

    private static class ConvertSavesFromPeace
    {
        private static Harmony _patch;
        private static bool _needConvert;
        public static void Enable(bool on)
        {
            if (on)
            {
                _patch ??= Harmony.CreateAndPatchAll(typeof(ConvertSavesFromPeace));
                return;
            }
            _patch?.UnpatchSelf();
            _patch = null;
        }
        
        [HarmonyPostfix]
        [HarmonyPatch(typeof(GameDesc), nameof(GameDesc.Import))]
        private static void GameDesc_Import_Postfix(GameDesc __instance)
        {
            if (DSPGame.IsMenuDemo || !__instance.isPeaceMode) return;
            __instance.combatSettings = UIRoot.instance.galaxySelect.uiCombat.combatSettings;
            __instance.isPeaceMode = false;
            _needConvert = true;
        }
        
        [HarmonyTranspiler]
        [HarmonyPatch(typeof(GameData), nameof(GameData.Import))]
        private static IEnumerable<CodeInstruction> GameData_Import_Transpiler(IEnumerable<CodeInstruction> instructions, ILGenerator generator)
        {
            var matcher = new CodeMatcher(instructions, generator);
            matcher.Start().MatchForward(false,
                new CodeMatch(instr => (instr.opcode == OpCodes.Ldc_I4 || instr.opcode == OpCodes.Ldc_I4_S) && instr.OperandIs(0x1B)),
                new CodeMatch(OpCodes.Call, AccessTools.Method(typeof(PerformanceMonitor), nameof(PerformanceMonitor.EndData)))
            );
            matcher.Advance(2).Opcode = OpCodes.Brfalse;
            matcher.Insert(
                new CodeInstruction(OpCodes.Ldsfld, AccessTools.Field(typeof(ConvertSavesFromPeace), nameof(ConvertSavesFromPeace._needConvert)))
            );
            return matcher.InstructionEnumeration();
        }

        [HarmonyPostfix]
        [HarmonyPatch(typeof(GameData), nameof(GameData.Import))]
        private static void GameData_Import_Postfix()
        {
            _needConvert = false;
        }
    }
}