#if INPUTSYSTEM_SUPPORT && UX_NAVIGATION
using System;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.Controls;

namespace UnityEngine.UI
{
    internal sealed class UXInputModeService : MonoBehaviour
    {
        private static UXInputModeService _instance;

        private InputAction _pointerAction;
        private InputAction _gamepadAction;

        public static UXInputMode CurrentMode { get; private set; } = UXInputMode.Pointer;

        public static event Action<UXInputMode> OnModeChanged;

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterSceneLoad)]
        private static void Bootstrap()
        {
            EnsureInstance();
        }

        internal static UXInputModeService EnsureInstance()
        {
            if (_instance != null)
            {
                return _instance;
            }

            var go = new GameObject("[UXInputModeService]");
            go.hideFlags = HideFlags.HideAndDontSave;
            DontDestroyOnLoad(go);
            _instance = go.AddComponent<UXInputModeService>();
            return _instance;
        }

        private void Awake()
        {
            if (_instance != null && _instance != this)
            {
                Destroy(gameObject);
                return;
            }

            _instance = this;
            DontDestroyOnLoad(gameObject);
            hideFlags = HideFlags.HideAndDontSave;
        }

        private void OnEnable()
        {
            CreateActions();
        }

        private void OnDisable()
        {
            DisposeActions();
        }

        private void OnDestroy()
        {
            DisposeActions();
            if (_instance == this)
            {
                _instance = null;
            }
        }

        private void CreateActions()
        {
            if (_pointerAction != null || _gamepadAction != null)
            {
                return;
            }

            _pointerAction = new InputAction("UXPointerInput", InputActionType.PassThrough);
            _pointerAction.AddBinding("<Keyboard>/anyKey");
            _pointerAction.AddBinding("<Mouse>/delta");
            _pointerAction.AddBinding("<Mouse>/scroll");
            _pointerAction.AddBinding("<Mouse>/leftButton");
            _pointerAction.AddBinding("<Mouse>/rightButton");
            _pointerAction.AddBinding("<Mouse>/middleButton");
            _pointerAction.performed += OnPointerInput;
            _pointerAction.Enable();

            _gamepadAction = new InputAction("UXGamepadInput", InputActionType.PassThrough);
            _gamepadAction.AddBinding("<Gamepad>/*");
            _gamepadAction.AddBinding("<Joystick>/*");
            _gamepadAction.performed += OnGamepadInput;
            _gamepadAction.Enable();
        }

        private void DisposeActions()
        {
            if (_pointerAction != null)
            {
                _pointerAction.performed -= OnPointerInput;
                _pointerAction.Disable();
                _pointerAction.Dispose();
                _pointerAction = null;
            }

            if (_gamepadAction != null)
            {
                _gamepadAction.performed -= OnGamepadInput;
                _gamepadAction.Disable();
                _gamepadAction.Dispose();
                _gamepadAction = null;
            }
        }

        private static void OnPointerInput(InputAction.CallbackContext context)
        {
            if (!IsInputMeaningful(context.control))
            {
                return;
            }

            SetMode(UXInputMode.Pointer);
        }

        private static void OnGamepadInput(InputAction.CallbackContext context)
        {
            if (!IsInputMeaningful(context.control))
            {
                return;
            }

            SetMode(UXInputMode.Gamepad);
        }

        private static bool IsInputMeaningful(InputControl control)
        {
            if (control == null || control.device == null || control.synthetic)
            {
                return false;
            }

            switch (control)
            {
                case ButtonControl button:
                    return button.IsPressed();
                case StickControl stick:
                    return stick.ReadValue().sqrMagnitude >= 0.04f;
                case Vector2Control vector2:
                    return vector2.ReadValue().sqrMagnitude >= 0.04f;
                case AxisControl axis:
                    return Mathf.Abs(axis.ReadValue()) >= 0.2f;
                default:
                    return !control.noisy;
            }
        }

        internal static void SetMode(UXInputMode mode)
        {
            EnsureInstance();
            if (CurrentMode == mode)
            {
                return;
            }

            CurrentMode = mode;
            OnModeChanged?.Invoke(mode);
        }
    }
}
#endif