using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using UnityExplorer.Inspectors;
using UnityExplorer.UI.Modules;
using System.IO;
using System.Reflection;
using UnityExplorer.Helpers;
using UnityExplorer.UI.Shared;
using UnityExplorer.Input;
#if CPP
using UnityExplorer.Unstrip;
#endif

namespace UnityExplorer.UI
{
    public static class UIManager
    {
        public static GameObject CanvasRoot { get; private set; }
        public static EventSystem EventSys { get; private set; }

        internal static Font ConsoleFont { get; private set; }

        internal static Sprite ResizeCursor { get; private set; }
        internal static Shader BackupShader { get; private set; }

        public static void Init()
        {
            LoadBundle();

            // Create core UI Canvas and Event System handler
            CreateRootCanvas();

            // Create submodules
            new MainMenu();
            MouseInspector.ConstructUI();
            PanelDragger.LoadCursorImage();

            // Force refresh of anchors
            Canvas.ForceUpdateCanvases();
        }

        public static void OnSceneChange()
        {
            SceneExplorer.Instance?.OnSceneChange();
            SearchPage.Instance?.OnSceneChange();
        }

        public static void Update()
        {
            MainMenu.Instance?.Update();

            if (EventSys)
            {
                if (EventSystem.current != EventSys)
                {
                    ForceUnlockCursor.SetEventSystem();
                }

#if CPP
                // Fix for games which override the InputModule pointer events (eg, VRChat)
                var evt = InputManager.InputPointerEvent;
                if (evt != null)
                {
                    if (!evt.eligibleForClick && evt.selectedObject)
                        evt.eligibleForClick = true;
                }
#endif
            }

            if (PanelDragger.Instance != null)
            {
                PanelDragger.Instance.Update();
            }

            for (int i = 0; i < SliderScrollbar.Instances.Count; i++)
            {
                var slider = SliderScrollbar.Instances[i];

                if (slider.CheckDestroyed())
                    i--;
                else
                    slider.Update();
            }

            for (int i = 0; i < InputFieldScroller.Instances.Count; i++)
            {
                var input = InputFieldScroller.Instances[i];

                if (input.sliderScroller.CheckDestroyed())
                    i--;
                else
                    input.Update();
            }
        }

        private static void LoadBundle()
        {
            var bundlePath = ExplorerCore.EXPLORER_FOLDER + @"\explorerui.bundle";
            if (File.Exists(bundlePath))
            {
                var bundle = AssetBundle.LoadFromFile(bundlePath);

                BackupShader = bundle.LoadAsset<Shader>("DefaultUI");

                // Fix for games which don't ship with 'UI/Default' shader.
                if (Graphic.defaultGraphicMaterial.shader?.name != "UI/Default")
                {
                    ExplorerCore.Log("This game does not ship with the 'UI/Default' shader, using manual Default Shader...");
                    Graphic.defaultGraphicMaterial.shader = BackupShader;
                }

                ResizeCursor = bundle.LoadAsset<Sprite>("cursor");

                ConsoleFont = bundle.LoadAsset<Font>("CONSOLA");

                ExplorerCore.Log("Loaded UI bundle");
            }
            else
            {
                ExplorerCore.LogWarning("Could not find the ExplorerUI Bundle! It should exist at '" + bundlePath + "'");
                return;
            }
        }

        private static GameObject CreateRootCanvas()
        {
            GameObject rootObj = new GameObject("ExplorerCanvas");
            UnityEngine.Object.DontDestroyOnLoad(rootObj);
            rootObj.layer = 5;

            CanvasRoot = rootObj;
            CanvasRoot.transform.position = new Vector3(0f, 0f, 1f);

            EventSys = rootObj.AddComponent<EventSystem>();
            InputManager.AddUIModule();

            Canvas canvas = rootObj.AddComponent<Canvas>();
            canvas.renderMode = RenderMode.ScreenSpaceCamera;
            canvas.referencePixelsPerUnit = 100;
            canvas.sortingOrder = 999;
            canvas.pixelPerfect = false;

            CanvasScaler scaler = rootObj.AddComponent<CanvasScaler>();
            scaler.referenceResolution = new Vector2(1920, 1080);
            scaler.screenMatchMode = CanvasScaler.ScreenMatchMode.Expand;

            rootObj.AddComponent<GraphicRaycaster>();

            return rootObj;
        }

        public static Sprite CreateSprite(Texture2D tex, Rect size = default)
        {
#if CPP
            Vector2 pivot = Vector2.zero;
            Vector4 border = Vector4.zero;

            if (size == default)
            {
                size = new Rect(0, 0, tex.width, tex.height);
            }

            return Sprite.CreateSprite_Injected(tex, ref size, ref pivot, 100f, 0u, SpriteMeshType.Tight, ref border, false);
#else
            return Sprite.Create(tex, size, Vector2.zero);
#endif
        }

        public static Texture2D MakeSolidTexture(Color color, int width, int height)
        {
            Color[] pixels = new Color[width * height];
            for (int i = 0; i < pixels.Length; i++)
            {
                pixels[i] = color;
            }

            Texture2D tex = new Texture2D(width, height);
            tex.SetPixels(pixels);
            tex.Apply();

            return tex;
        }
    }
}