using NEG.UI.UnityUi.Window;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.UI;

namespace NEG.UI.UnityUi
{
    public enum SelectionSource
    {
        Pointer,
        Direction
    }

    public class UiInputModule
    {
        public SelectionSource CurrentSelectionSource { get; protected set; }
    }

    public class DefaultInputModule : UiInputModule
    {
        public DefaultInputModule()
        {
            var defaultActions = new DefaultInputActions();
            InputActionReference.Create(defaultActions.UI.Navigate).action.performed +=
                ctx => OnSelectionChangeStarted();
            InputActionReference.Create(defaultActions.UI.Cancel).action.performed +=
                _ => UiManager.Instance.UseBack();
            defaultActions.Enable();

            if (Gamepad.current != null)
                SetDirectionInput();
            else
                SetPointerInput();

            //var keyboardAction = new InputAction(binding: "/<Keyboard>/*");
            //keyboardAction.performed += (context) => CurrentInputSource = EInputSource.Keyboard;
            //keyboardAction.Enable();
            //var gamepadAction = new InputAction(binding: "/<Gamepad>/*");
            //gamepadAction.performed += (context) => OnSelectionChangeStarted();
            //gamepadAction.Enable();

            var mouseAction = new InputAction(binding: "/<Mouse>/*");
            mouseAction.performed += context =>
            {
                if (CurrentSelectionSource == SelectionSource.Pointer)
                    return;
                SetPointerInput();
            };
            mouseAction.Enable();
        }

        private void OnSelectionChangeStarted()
        {
            if (CurrentSelectionSource == SelectionSource.Direction &&
                EventSystem.current.currentSelectedGameObject != null)
                return;
            SetDirectionInput();
        }

        private void SetDirectionInput()
        {
            if (EventSystem.current == null || MonoUiManager.Instance == null) return;
            CurrentSelectionSource = SelectionSource.Direction;
            Cursor.visible = false;
            if (EventSystem.current.currentSelectedGameObject == null &&
                MonoUiManager.Instance.CurrentMainWindow != null)
            {
                EventSystem.current.SetSelectedGameObject(((MonoWindow)MonoUiManager.Instance.CurrentMainWindow)
                    .DefaultSelectedItem);
                return;
            }

            var data = new PointerEventData(EventSystem.current);
            var currentSelected = EventSystem.current.currentSelectedGameObject;
            if (currentSelected != null)
                for (var current = EventSystem.current.currentSelectedGameObject.transform;
                     current != null;
                     current = current.parent)
                    ExecuteEvents.Execute(current.gameObject, data, ExecuteEvents.pointerExitHandler);

            EventSystem.current.SetSelectedGameObject(currentSelected);
        }

        private void SetPointerInput()
        {
            CurrentSelectionSource = SelectionSource.Pointer;
            Cursor.visible = true;

            if (EventSystem.current == null)
            {
                SetDirectionInput();
                return;
            }

            if (EventSystem.current.currentInputModule == null)
                return;

            EventSystem.current.SetSelectedGameObject(null);

            var module = (InputSystemUIInputModule)EventSystem.current.currentInputModule;
            var result = module.GetLastRaycastResult(0);
            if (result.gameObject == null)
                return;

            var data = new PointerEventData(EventSystem.current);
            for (var current = result.gameObject.transform;
                 current != null;
                 current = current.parent)
                ExecuteEvents.Execute(current.gameObject, data, ExecuteEvents.pointerEnterHandler);
        }
    }
}