using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using System.Collections.Generic;
using CurvedUI;
using UnityEngine.Serialization;

#if CURVEDUI_UNITY_XR
using UnityEngine.XR;
//using UnityEngine.XR.Interaction.Toolkit;
#endif 
#if CURVEDUI_STEAMVR_LEGACY || CURVEDUI_STEAMVR_2
using Valve.VR;
#endif 

[assembly: CurvedUI.OptionalDependency("Valve.VR.InteractionSystem.Player", "CURVEDUI_STEAMVR_INT")]



[ExecuteInEditMode]
#if CURVEDUI_GOOGLEVR
public class CurvedUIInputModule : GvrPointerInputModule {
#else
public class CurvedUIInputModule : StandaloneInputModule {
#endif

    //SETTINGS-------------------------------------------------//
    #region SETTINGS
#pragma warning disable 414, 0649

    //Common
    [SerializeField]
    CUIControlMethod controlMethod;
    [SerializeField]
    string submitButtonName = "Fire1";
    [SerializeField]
    Camera mainEventCamera;
    [SerializeField] 
    LayerMask raycastLayerMask = 1 << 5;
    
    //Gaze
    [SerializeField]
    bool gazeUseTimedClick = false;
    [SerializeField]
    float gazeClickTimer = 2.0f;
    [SerializeField]
    float gazeClickTimerDelay = 1.0f;
    [SerializeField]
    Image gazeTimedClickProgressImage;

    //World Space Mouse
    [SerializeField]
    float worldSpaceMouseSensitivity = 1;

    //SteamVR and Oculus
    [SerializeField]
    Hand usedHand = Hand.Right;
    [FormerlySerializedAs("controllerTransformOverride")] [SerializeField]
    Transform pointerTransformOverride;

    //SteamVR 2.0 specific
#if CURVEDUI_STEAMVR_2
    [SerializeField]
    SteamVR_Action_Boolean m_steamVRClickAction;
#endif

    //hidden
    static bool disableOtherInputModulesOnStart = true; //default true

    #endregion
    //---------------------------------------------------------//





    //COMMON VARIABLES-----------------------------------------//
    #region VARIABLES


    //Support Variables - common
    static CurvedUIInputModule instance;
    GameObject currentDragging;
    GameObject currentPointedAt;


    //Support Variables - handheld controllers
    GameObject m_rightController;
    GameObject m_leftController;

    //Support Variables - gaze
    float gazeTimerProgress;

    //Support variables - custom ray
    Ray customControllerRay;

    //support variables - other
    float dragThreshold = 10.0f;
    bool pressedDown = false;
    bool pressedLastFrame = false;

    //support variables - world space mouse
    Vector3 lastMouseOnScreenPos = Vector2.zero;
    Vector2 worldSpaceMouseInCanvasSpace = Vector2.zero;
    Vector2 lastWorldSpaceMouseOnCanvas = Vector2.zero;
    Vector2 worldSpaceMouseOnCanvasDelta = Vector2.zero;
    //---------------------------------------------------------//





    //PLATFORM DEPENDANT VARIABLES AND SETTINGS----------------//

#if CURVEDUI_STEAMVR_LEGACY
    //Settings & References - SteamVR
    [SerializeField]
    SteamVR_ControllerManager steamVRControllerManager;

    //Support Variables - SteamVR
    private static SteamVR_ControllerManager controllerManager;
    private static CurvedUIViveController rightCont;
    private static CurvedUIViveController leftCont;
    private CurvedUIPointerEventData rightControllerData;
    private CurvedUIPointerEventData leftControllerData;
#endif

#if CURVEDUI_STEAMVR_2
    [SerializeField]
    SteamVR_PlayArea steamVRPlayArea;
#endif

#if CURVEDUI_OCULUSVR
    //Settings & References - Oculus SDK
    [SerializeField]
    Transform TouchControllerTransform;
    [SerializeField]
    OVRInput.Button InteractionButton = OVRInput.Button.PrimaryIndexTrigger;
    [SerializeField]
    OVRCameraRig oculusCameraRig;

    //Support variables - Touch
    private OVRInput.Controller activeCont;
#endif
    
#if CURVEDUI_UNITY_XR
    //[SerializeField] private XRController rightXRController; 
    //[SerializeField] private XRController leftXRController; 
#endif



#pragma warning restore 414, 0649
    #endregion
    //---------------------------------------------------------//



#if !CURVEDUI_GOOGLEVR 

    #region LIFECYCLE
    protected override void Awake()
    {
        forceModuleActive = true;
        
        if (!Application.isPlaying) return;

        Instance = this;
        base.Awake();

        //component setup
        EventCamera = mainEventCamera == null ? Camera.main : EventCamera;

        //Gaze setup
        if (gazeTimedClickProgressImage != null)
            gazeTimedClickProgressImage.fillAmount = 0;

        //SDK setup
#if CURVEDUI_STEAMVR_LEGACY
		if(ControlMethod == CUIControlMethod.STEAMVR_LEGACY) SetupViveControllers();
#elif CURVEDUI_STEAMVR_2
        if (ControlMethod == CUIControlMethod.STEAMVR_2) SetupSteamVR2Controllers();
#elif CURVEDUI_UNITY_XR
        if (ControlMethod == CUIControlMethod.UNITY_XR) SetupUnityXRControllers();
#endif
    }


    
    protected override void Start()
    {
        if (!Application.isPlaying) return;

        base.Start();
        
        //OculusVR setup
#if CURVEDUI_OCULUSVR
        if (oculusCameraRig == null)
        {
            //find the oculus rig - via manager or by findObjectOfType, if unavailable
            if (OVRManager.instance != null) oculusCameraRig = OVRManager.instance.GetComponent<OVRCameraRig>();
            if (oculusCameraRig == null)  oculusCameraRig = Object.FindObjectOfType<OVRCameraRig>();
            if (oculusCameraRig == null && ControlMethod == CUIControlMethod.OCULUSVR)Debug.LogError("CURVEDUI: OVRCameraRig prefab required. Import Oculus Utilities and drag OVRCameraRig prefab onto the scene.");           
        }
#endif
    }
    
    
    
    protected virtual void Update()
    {
        //find camera, if we lost it
        if (mainEventCamera == null && Application.isPlaying)
            EventCamera = Camera.main;

        if (Time.frameCount % 120 == 0)//do it only once every 120 frames
        {
            //check if we don't have extra eventSystem on the scene, as this may mess up interactions.
            if (EventSystem.current != null && EventSystem.current.gameObject != this.gameObject)
                Debug.LogError("CURVEDUI: Second EventSystem component detected. This can make UI unusable. Make sure there is only one EventSystem component on the scene. Click on this message to have the extra one selected.", EventSystem.current.gameObject);
        }
    }
    #endregion // LIFECYCLE

    

    #region EVENT PROCESSING - GENERAL
    /// <summary>
    /// Process() is called by UI system to process events 
    /// </summary>
    public override void Process()
    {
        switch (controlMethod)
        {
            case CUIControlMethod.MOUSE: base.Process(); break;
            case CUIControlMethod.GAZE: ProcessGaze(); break;
            case CUIControlMethod.STEAMVR_LEGACY: ProcessViveControllers(); break;
            case CUIControlMethod.STEAMVR_2: ProcessSteamVR2Controllers(); break;
            case CUIControlMethod.OCULUSVR: ProcessOculusVRController();break;
            case CUIControlMethod.CUSTOM_RAY:  ProcessCustomRayController(); break;
            case CUIControlMethod.UNITY_XR: ProcessUnityXRController(); break;
            case CUIControlMethod.WORLD_MOUSE:
            {
                //touch can also be used as a world space mouse,
                //although its probably not the best experience
                //Use standard mouse controller with touch.
                if (Input.touchCount > 0)
                    worldSpaceMouseOnCanvasDelta = Input.GetTouch(0).deltaPosition * worldSpaceMouseSensitivity;
                else {
                    worldSpaceMouseOnCanvasDelta = new Vector2((Input.mousePosition - lastMouseOnScreenPos).x, (Input.mousePosition - lastMouseOnScreenPos).y) * worldSpaceMouseSensitivity;
                    lastMouseOnScreenPos = Input.mousePosition;
                }
                lastWorldSpaceMouseOnCanvas = worldSpaceMouseInCanvasSpace;
                worldSpaceMouseInCanvasSpace += worldSpaceMouseOnCanvasDelta;

                base.Process();
                break;
            }
            default: goto case CUIControlMethod.MOUSE;
        }

        //save button pressed state for reference in next frame
        pressedLastFrame = pressedDown;
    }
    #endregion // EVENT PROCESSING - GENERAL



    #region EVENT PROCESSING - GAZE
    protected virtual void ProcessGaze()
    {
        bool usedEvent = SendUpdateEventToSelectedObject();

        if (eventSystem.sendNavigationEvents)
        {
            if (!usedEvent) usedEvent |= SendMoveEventToSelectedObject();

            if (!usedEvent) SendSubmitEventToSelectedObject();
        }
        ProcessMouseEvent();
    }
    #endregion // EVENT PROCESSING - GAZE



    #region EVENT PROCESSING - CUSTOM RAY
    protected virtual void ProcessCustomRayController() {

        this.ProcessMouseEvent();
    }

    protected override MouseState GetMousePointerEventData(int id)
    {
        MouseState ret = base.GetMousePointerEventData(id);

        if(ControlMethod != CUIControlMethod.MOUSE && ControlMethod != CUIControlMethod.WORLD_MOUSE)
            ret.SetButtonState(PointerEventData.InputButton.Left, CustomRayFramePressedState(), ret.GetButtonState(PointerEventData.InputButton.Left).eventData.buttonData);

        return ret;
    }

    PointerEventData.FramePressState CustomRayFramePressedState()
    {
        if (pressedDown && !pressedLastFrame)
            return PointerEventData.FramePressState.Pressed;
        else if (!pressedDown && pressedLastFrame)
            return PointerEventData.FramePressState.Released;
        else return PointerEventData.FramePressState.NotChanged;
    }
    #endregion // EVENT PROCESSING - CUSTOM RAY


    

    #region EVENT PROCESSING - STEAMVR LEGACY
    protected virtual void ProcessViveControllers()
    {
#if CURVEDUI_STEAMVR_LEGACY
        switch (usedHand)
        {
            case Hand.Right:
            {
                //in case only one controller is turned on, it will still be used to call events.
                if (controllerManager.right.activeInHierarchy)
                    ProcessController(controllerManager.right);
                else if (controllerManager.left.activeInHierarchy)
                    ProcessController(controllerManager.left);
                break;
            }
            case Hand.Left:
            {
                //in case only one controller is turned on, it will still be used to call events.
                if (controllerManager.left.activeInHierarchy)
                    ProcessController(controllerManager.left);
                else if (controllerManager.right.activeInHierarchy)
                    ProcessController(controllerManager.right);
                break;
            }
            case Hand.Both:
            {
                ProcessController(controllerManager.left);
                ProcessController(controllerManager.right);
                break;
            }
            default: goto case Hand.Right;
        }
    }


    /// <summary>
    /// Processes Events from given controller.
    /// </summary>
    /// <param name="myController"></param>
    void ProcessController(GameObject myController)
	{
        //do not process events from this controller if it's off or not visible by base stations.
        if (!myController.gameObject.activeInHierarchy) return;

        //get the assistant or add it if its missing.
        CurvedUIViveController myControllerAssitant = myController.AddComponentIfMissing<CurvedUIViveController>();

        // send update events if there is a selected object - this is important for InputField to receive keyboard events
        SendUpdateEventToSelectedObject();

        // see if there is a UI element that is currently being pointed at
        PointerEventData ControllerData;
        if (myControllerAssitant == Right)
            ControllerData = GetControllerPointerData(myControllerAssitant, ref rightControllerData);
        else
            ControllerData = GetControllerPointerData(myControllerAssitant, ref leftControllerData);


        currentPointedAt = ControllerData.pointerCurrentRaycast.gameObject;

        ProcessDownRelease(ControllerData, myControllerAssitant.IsTriggerDown, myControllerAssitant.IsTriggerUp);

        //Process move and drag if trigger is pressed
        if (!myControllerAssitant.IsTriggerUp)
        {
            ProcessMove(ControllerData);
            ProcessDrag(ControllerData);
        }

        if (!Mathf.Approximately(ControllerData.scrollDelta.sqrMagnitude, 0.0f))
        {
            var scrollHandler = ExecuteEvents.GetEventHandler<IScrollHandler>(ControllerData.pointerCurrentRaycast.gameObject);
            ExecuteEvents.ExecuteHierarchy(scrollHandler, ControllerData, ExecuteEvents.scrollHandler);
            // Debug.Log("executing scroll handler");
        }

    }

          /// <summary>
    /// Sends trigger down / trigger released events to gameobjects under the pointer.
    /// </summary>
    protected virtual void ProcessDownRelease(PointerEventData eventData, bool down, bool released)
    {
        var currentOverGo = eventData.pointerCurrentRaycast.gameObject;

        // PointerDown notification
        if (down)
        {
            eventData.eligibleForClick = true;
            eventData.delta = Vector2.zero;
            eventData.dragging = false;
            eventData.useDragThreshold = true;
            eventData.pressPosition = eventData.position;
            eventData.pointerPressRaycast = eventData.pointerCurrentRaycast;

            DeselectIfSelectionChanged(currentOverGo, eventData);

            if (eventData.pointerEnter != currentOverGo)
            {
                // send a pointer enter to the touched element if it isn't the one to select...
                HandlePointerExitAndEnter(eventData, currentOverGo);
                eventData.pointerEnter = currentOverGo;
            }

            // search for the control that will receive the press
            // if we can't find a press handler set the press
            // handler to be what would receive a click.
            var newPressed = ExecuteEvents.ExecuteHierarchy(currentOverGo, eventData, ExecuteEvents.pointerDownHandler);

            // didnt find a press handler... search for a click handler
            if (newPressed == null)
                newPressed = ExecuteEvents.GetEventHandler<IPointerClickHandler>(currentOverGo);


            float time = Time.unscaledTime;

            if (newPressed == eventData.lastPress)
            {
                var diffTime = time - eventData.clickTime;
                if (diffTime < 0.3f)
                    ++eventData.clickCount;
                else
                    eventData.clickCount = 1;

                eventData.clickTime = time;
            }
            else
            {
                eventData.clickCount = 1;
            }

            eventData.pointerPress = newPressed;
            eventData.rawPointerPress = currentOverGo;

            eventData.clickTime = time;

            // Save the drag handler as well
            eventData.pointerDrag = ExecuteEvents.GetEventHandler<IDragHandler>(currentOverGo);

            if (eventData.pointerDrag != null)
                ExecuteEvents.Execute(eventData.pointerDrag, eventData, ExecuteEvents.initializePotentialDrag);
        }

        // PointerUp notification
        if (released)
        {
            ExecuteEvents.Execute(eventData.pointerPress, eventData, ExecuteEvents.pointerUpHandler);

            // see if we mouse up on the same element that we clicked on...
            var pointerUpHandler = ExecuteEvents.GetEventHandler<IPointerClickHandler>(currentOverGo);

            // PointerClick and Drop events
            if (eventData.pointerPress == pointerUpHandler && eventData.eligibleForClick)
            {
                ExecuteEvents.Execute(eventData.pointerPress, eventData, ExecuteEvents.pointerClickHandler);
                //Debug.Log("click");
            }
            else if (eventData.pointerDrag != null && eventData.dragging)
            {
                ExecuteEvents.ExecuteHierarchy(currentOverGo, eventData, ExecuteEvents.dropHandler);
                //Debug.Log("drop");
            }

            eventData.eligibleForClick = false;
            eventData.pointerPress = null;
            eventData.rawPointerPress = null;

            if (eventData.pointerDrag != null && eventData.dragging)
            {
                ExecuteEvents.Execute(eventData.pointerDrag, eventData, ExecuteEvents.endDragHandler);
                //Debug.Log("end drag");
            }

            eventData.dragging = false;
            eventData.pointerDrag = null;

            // send exit events as we need to simulate this on touch up on touch device
            ExecuteEvents.ExecuteHierarchy(eventData.pointerEnter, eventData, ExecuteEvents.pointerExitHandler);
            eventData.pointerEnter = null;
        }
    }

    /// <summary>
    /// Create a pointerEventData that stores all the data associated with Vive controller.
    /// </summary>
    private CurvedUIPointerEventData GetControllerPointerData(CurvedUIViveController controller, ref CurvedUIPointerEventData ControllerData)
    {

        if (ControllerData == null)
            ControllerData = new CurvedUIPointerEventData(eventSystem);

        ControllerData.Reset();
        ControllerData.delta = Vector2.one; // to trick into moving
        ControllerData.position = Vector2.zero; // this will be overriden by raycaster
        ControllerData.Controller = controller.gameObject; // raycaster will use this object to override pointer position on screen. Keep it safe.
        ControllerData.scrollDelta = controller.TouchPadAxis - ControllerData.TouchPadAxis; // calcualte scroll delta
        ControllerData.TouchPadAxis = controller.TouchPadAxis; // assign finger position on touchpad

        eventSystem.RaycastAll(ControllerData, m_RaycastResultCache); //Raycast all the things!. Position will be overridden here by CurvedUIRaycaster

        //Get a current raycast to find if we're pointing at GUI object. 
        ControllerData.pointerCurrentRaycast = FindFirstRaycast(m_RaycastResultCache);
        m_RaycastResultCache.Clear();

        return ControllerData;
    }


    private bool ShouldStartDrag(Vector2 pressPos, Vector2 currentPos, float threshold, bool useDragThreshold)
    {
        if (!useDragThreshold)
            return true;

        //this always returns false if override pointereventdata in curveduiraycster.cs is set to false. There is no past pointereventdata to compare with then.
        return (pressPos - currentPos).sqrMagnitude >= threshold * threshold;
    }

    /// <summary>
    /// Force selection of a gameobject.
    /// </summary>
    private void Select(GameObject go)
    {
        ClearSelection();
        if (ExecuteEvents.GetEventHandler<ISelectHandler>(go))
        {
            eventSystem.SetSelectedGameObject(go);
        }
    }

    /// <summary>
    /// Adds necessary components to Vive controller gameobjects. These will let us know what inputs are used on them.
    /// </summary>
    private void SetupViveControllers()
    {
        //find controller reference
        if (controllerManager == null)
                controllerManager = steamVRControllerManager;

        //Find Controller manager on the scene.
        if (controllerManager == null)
        {
            SteamVR_ControllerManager[] potentialManagers = Object.FindObjectsOfType<SteamVR_ControllerManager>();
            controllerManager = null;

            //ignore external camera created by externalcamera.cfg for mixed reality videos
            if (potentialManagers.GetLength(0) > 0)
            {
                for (int i = 0; i < potentialManagers.GetLength(0); i++)
                {
                    if (potentialManagers[i].gameObject.name != "External Camera")
                        controllerManager = potentialManagers[i];
                }
            }

            if (controllerManager == null)
                Debug.LogError("Can't find SteamVR_ControllerManager on scene. It is required to use VIVE control method. Make sure all SteamVR prefabs are present.");
        }
#endif
    }

    #endregion



    #region EVENT PROCESSING - OCULUS TOUCH
    protected virtual void ProcessOculusVRController()
    {
#if CURVEDUI_OCULUSVR

        activeCont = OVRInput.GetActiveController();


        //Find the currently used HandAnchor----------------------//
        //and set direction ray using its transform
        switch (activeCont)
        {
            //Oculus Touch
            case OVRInput.Controller.RTouch: CustomControllerRay = new Ray(oculusCameraRig.rightHandAnchor.position, oculusCameraRig.rightHandAnchor.forward); break;
            case OVRInput.Controller.LTouch: CustomControllerRay = new Ray(oculusCameraRig.leftHandAnchor.position, oculusCameraRig.leftHandAnchor.forward); break;
            //Oculus Go controller
            case OVRInput.Controller.RHand: goto case OVRInput.Controller.RTouch;
            case OVRInput.Controller.LHand: goto case OVRInput.Controller.LTouch;
            //edge cases
            default: CustomControllerRay = new Ray(OculusTouchUsedControllerTransform.position, OculusTouchUsedControllerTransform.forward); break;
        }


        //Check if interaction button is pressed ---------------//

        //find if we're using Rift with touch. If yes, we'll have to check if the interaction button is pressed on the proper hand.
        bool touchControllersUsed = (activeCont == OVRInput.Controller.Touch || activeCont == OVRInput.Controller.LTouch || activeCont == OVRInput.Controller.RTouch);

        if (usedHand == Hand.Both || !touchControllersUsed) 
        {
            //check if this button is pressed on any controller. Handles GearVR controller and Oculus Go controller.
            CustomControllerButtonState = OVRInput.Get(InteractionButton);
        }
        else if (usedHand == Hand.Right) // Right Oculus Touch
        {
            CustomControllerButtonState = OVRInput.Get(InteractionButton, OVRInput.Controller.RTouch);
        }
        else if (usedHand == Hand.Left)  // Left Oculus Touch
        {
            CustomControllerButtonState = OVRInput.Get(InteractionButton, OVRInput.Controller.LTouch);
        }

        //process all events based on this data--------------//
        ProcessCustomRayController();
#endif // EVENT PROCESSING - CURVEDUI_OCULUSVR
    }
    #endregion



    #region EVENT PROCESSING - STEAMVR_2
    void ProcessSteamVR2Controllers()
#if CURVEDUI_STEAMVR_2
    {
        if(m_steamVRClickAction != null)
        {
            CustomControllerButtonState = m_steamVRClickAction.GetState(SteamVRInputSource);
            CustomControllerRay = new Ray(ControllerTransform.transform.position, ControllerTransform.transform.forward);

            ProcessCustomRayController();
        }
        else
        {
            Debug.LogError("CURVEDUI: Choose which SteamVR_Action will be used for a Click on CurvedUISettings component.");
        }
    }

    void SetupSteamVR2Controllers()
    {
        if (steamVRPlayArea == null)
            steamVRPlayArea = FindObjectOfType<SteamVR_PlayArea>();

        if (steamVRPlayArea != null)
        {
            foreach (SteamVR_Behaviour_Pose poseComp in steamVRPlayArea.GetComponentsInChildren<SteamVR_Behaviour_Pose>(true))
            {
                if (poseComp.inputSource == SteamVR_Input_Sources.RightHand)
                    m_rightController = poseComp.gameObject;
                else if (poseComp.inputSource == SteamVR_Input_Sources.LeftHand)
                    m_leftController = poseComp.gameObject;
            }
        }
        else
        {
#if CURVEDUI_STEAMVR_INT
            //Optional - SteamVR Interaction System
            Valve.VR.InteractionSystem.Player PlayerComponent = FindObjectOfType<Valve.VR.InteractionSystem.Player>();

            if(PlayerComponent != null)
            {
                m_rightController = PlayerComponent.rightHand.gameObject;
                m_leftController = PlayerComponent.leftHand.gameObject;
            }
            else
#endif
                Debug.LogError("CURVEDUI: Can't find SteamVR_PlayArea component or InteractionSystem.Player component on the scene. One of these is required. Add a reference to it manually to CurvedUIInputModule on EventSystem gameobject.", this.gameObject);
        }

        if (m_steamVRClickAction == null)
            Debug.LogError("CURVEDUI: No SteamVR action to use for button interactions. Choose the action you want to use to click the buttons on CurvedUISettings component.");
    }

#else
    { }
#endif //end of CURVEDUI_STEAMVR_2

#endregion // end of EVENT PROCESSING - STEAMVR_2
    
    
    
#region EVENT PROCESSING - UNITY XR

    protected virtual void ProcessUnityXRController()
#if CURVEDUI_UNITY_XR
    {
        //bool pressed;
        //switch (usedHand)
        //{
        //    case Hand.Right:  rightXRController.inputDevice.IsPressed(rightXRController.uiPressUsage,
        //            out pressed, rightXRController.axisToPressThreshold);
        //        break;
        //    case Hand.Left: leftXRController.inputDevice.IsPressed(leftXRController.uiPressUsage, 
        //            out pressed, leftXRController.axisToPressThreshold);
        //        break;
        //    default: goto case Hand.Right;
        //}
        //CustomControllerButtonState = pressed;
        //CustomControllerRay = new Ray(ControllerTransform.transform.position, ControllerTransform.transform.forward);
        
        //ProcessCustomRayController();
        
        //Debug.Log("XR Button: " + rightXRController.uiPressUsage.ToString() + " on " + usedHand.ToString() +" - " + CustomControllerButtonState ); 
    }
    
    private void SetupUnityXRControllers()
    {
        //if (rightXRController != null && leftXRController != null) return; 
        //foreach (var controller in GameObject.FindObjectsOfType<XRController>())
        //{
        //    if (rightXRController == null && controller.controllerNode == XRNode.RightHand)
        //        rightXRController = controller;
        //    if (leftXRController == null && controller.controllerNode == XRNode.LeftHand)
        //        leftXRController = controller;
        //}
    }
#else
    { }
#endif //end of CURVEDUI_UNITY_XR if
    #endregion 



#endif // END OF CURVEDUI_GOOGLEVR IF - GOOGLEVR INPUT MODULE OVERRIDES









    #region HELPER FUNCTIONS
    static T EnableInputModule<T>() where T : BaseInputModule
    {
        bool moduleMissing = true;
        EventSystem eventGO = GameObject.FindObjectOfType<EventSystem>();

        if (eventGO == null)
        {
            Debug.LogError("CurvedUI: Your EventSystem component is missing from the scene! Unity Canvas will not track interactions without it.");
            return null as T;
        }

        foreach (BaseInputModule module in eventGO.GetComponents<BaseInputModule>())
        {
            if (module is T) {
                moduleMissing = false;
                module.enabled = true;
            } else if (disableOtherInputModulesOnStart) {
                module.enabled = false;

#if CURVEDUI_GOOGLEVR //on GVR, we have to completely destroy the module because the code looks for first instance, even if it's disabled
				if(module is GvrPointerInputModule){
					if(Application.isPlaying){
						Destroy(module);
						Debug.LogError("CurvedUI: Fixed bad Input Module. Restart Play mode to continue.");
					} else {
						DestroyImmediate(module);
					}
				}
#endif
            }
        }

        if (moduleMissing)
            eventGO.gameObject.AddComponent<T>();

        return eventGO.GetComponent<T>();
    }
    #endregion  // HELPER FUNCTIONS










    #region SETTERS AND GETTERS - GENERAL
    public static CurvedUIInputModule Instance
    {
        get {
            if (instance == null) instance = EnableInputModule<CurvedUIInputModule>();
            return instance;
        }
        private set { instance = value; }
    }


    /// <summary>
    /// Current controller mode. Decides how user can interact with the canvas. 
    /// </summary>
    public static CUIControlMethod ControlMethod
    {
        get { return Instance.controlMethod; }
        set
        {
            if (Instance.controlMethod != value)
            {
                Instance.controlMethod = value;
#if CURVEDUI_STEAMVR_LEGACY
                if(value == CUIControlMethod.STEAMVR_LEGACY)
                    Instance.SetupViveControllers();
#endif 
            }
        }
    }

    /// <summary>
    /// Layermask used by Raycaster classes to perform a Physics.Raycast() in order to find
    /// where user is pointing at the canvas.
    /// </summary>
    public LayerMask RaycastLayerMask
    {
        get { return raycastLayerMask; }
        set { raycastLayerMask = value; }
    }

    /// <summary>
    /// Which hand can be used to interact with canvas. Left, Right or Both. Default Right.
    /// Used in control methods that differentiate hands (STEAMVR, OCULUSVR)
    /// </summary>
    public Hand UsedHand
    {
        get { return usedHand; }
        set { usedHand = value; }
    }

    /// <summary>
    /// Gameobject of the handheld controller used for interactions - Oculus Touch, GearVR remote etc. 
    /// If ControllerTransformOverride is set, that transform will be returned instead.
    /// Used in STEAMVR, STEAMVR_LEGACY, OCULUSVR and GOOGLEVR control methods.
    /// </summary>
    public Transform ControllerTransform {
        get
        {
          //use override, if available.
          if (PointerTransformOverride != null) return PointerTransformOverride;

#if CURVEDUI_OCULUSVR
          return UsedHand == Hand.Left ? oculusCameraRig.leftHandAnchor : oculusCameraRig.rightHandAnchor; 
#elif CURVEDUI_STEAMVR_LEGACY
          return UsedHand == Hand.Left ? leftCont.transform : rightCont.transform; 
#elif CURVEDUI_STEAMVR_2
            return UsedHand == Hand.Left ? m_leftController.transform : m_rightController.transform;
#elif CURVEDUI_GOOGLEVR
          return Pointer.PointerTransform;
#elif CURVEDUI_UNITY_XR
            //return UsedHand == Hand.Left ? leftXRController.transform : rightXRController.transform; 
            return null;
#else
          Debug.LogWarning("CURVEDUI: CurvedUIInputModule.ActiveController will only return proper gameobject in  STEAMVR, STEAMVR_LEGACY, OCULUSVR, UNITY_XR or GOOGLEVR control methods.");
          return null;
#endif
        }
    }

    /// <summary>
    /// Direction where the handheld controller points. Forward (blue) direction of the controller transform.
    /// If ControllerTransformOverride is set, its forward direction will be returned instead.
    /// Used in STEAMVR, STEAMVR_LEGACY, OCULUSVR and GOOGLEVR control methods.
    /// </summary>
    public Vector3 ControllerPointingDirection {
        get
        {
#if  CURVEDUI_STEAMVR_LEGACY || CURVEDUI_STEAMVR_2 || CURVEDUI_GOOGLEVR || CURVEDUI_OCULUSVR || CURVEDUI_UNITY_XR
            return ControllerTransform.forward;
#else
            Debug.LogWarning("CURVEDUI: CurvedUIInputModule.PointingDirection will only return proper direction in  STEAMVR, STEAMVR_LEGACY, OCULUSVR, UNITY_XR or GOOGLEVR control methods.");
            return Vector3.forward;
#endif
        }
    }


    /// <summary>
    /// World Space position where the pointing ray starts. Usually the location of controller transform.
    /// If ControllerTransformOverride is set, its position will be returned instead.
    /// Used in STEAMVR, STEAMVR_LEGACY, OCULUSVR and GOOGLEVR control methods.
    /// </summary>
    public Vector3 ControllerPointingOrigin {
        get
        {
#if  CURVEDUI_STEAMVR_LEGACY || CURVEDUI_STEAMVR_2 || CURVEDUI_GOOGLEVR || CURVEDUI_OCULUSVR || CURVEDUI_UNITY_XR
            return ControllerTransform.position;
#else
            Debug.LogWarning("CURVEDUI: CurvedUIInputModule.PointingOrigin will only return proper position in  STEAMVR, STEAMVR_LEGACY, OCULUSVR, UNITY_XR or GOOGLEVR control methods.");
            return Vector3.zero;
#endif
        }
    }

    /// <summary>
    /// If not null, this transform will be used as the Pointer.
    /// Its position will be used as PointingOrigin and its forward (blue) direction as PointingDirection.
    /// </summary>
    public Transform PointerTransformOverride {
        get { return instance.pointerTransformOverride; }
        set { instance.pointerTransformOverride = value; }
    }

    /// <summary>
    /// Gameobject we're currently pointing at.
    /// Updated every frame.
    /// </summary>
    public GameObject CurrentPointedAt {
        get { return currentPointedAt; }
    }

    public Camera EventCamera {
        get { return mainEventCamera; }
        set
        {
            mainEventCamera = value;

            //add physics raycaster to event camera, so we can click on 3d objects
            if (mainEventCamera != null) mainEventCamera.AddComponentIfMissing<CurvedUIPhysicsRaycaster>();
        }
    }

    /// <summary>
    ///Get a ray to raycast with. Depends in EventCamera and current Control Method
    /// </summary>
    /// <returns></returns>
    public Ray GetEventRay(Camera eventCam = null) {

        if (eventCam == null) eventCam = mainEventCamera;

        switch (ControlMethod)
        {
            case CUIControlMethod.MOUSE:
            {
                // Get a ray from the camera through the point on the screen - used for mouse input
                return eventCam.ScreenPointToRay(Input.mousePosition);
            }
            case CUIControlMethod.GAZE:
            {
                //get a ray from the center of world camera. used for gaze input
                return new Ray(eventCam.transform.position, eventCam.transform.forward);
            }
            //case CUIControlMethod.WORLD_MOUSE: //processed in CurvedUIRaycaster instead
            case CUIControlMethod.GOOGLEVR:
            {
                if(pointerTransformOverride)
                    return new Ray(pointerTransformOverride.position, pointerTransformOverride.forward);
                
                return new Ray(ControllerPointingOrigin, ControllerPointingDirection);
            }
            case CUIControlMethod.CUSTOM_RAY:
            {
                if(pointerTransformOverride)
                    return new Ray(pointerTransformOverride.position, pointerTransformOverride.forward);
                
                return CustomControllerRay;
            }
            case CUIControlMethod.STEAMVR_LEGACY: goto case CUIControlMethod.GOOGLEVR;
            case CUIControlMethod.STEAMVR_2: goto case CUIControlMethod.CUSTOM_RAY;
            case CUIControlMethod.OCULUSVR: goto case CUIControlMethod.CUSTOM_RAY;
            case CUIControlMethod.UNITY_XR: goto case CUIControlMethod.CUSTOM_RAY;
            default: goto case CUIControlMethod.CUSTOM_RAY;
        }

    }
    #endregion






    #region SETTERS AND GETTERS - CUSTOM RAY
    /// <summary>
    /// When in CUSTOM_RAY controller mode, Canvas Raycaster will use this worldspace Ray to determine which Canvas objects are being selected.
    /// </summary>
    public static Ray CustomControllerRay
    {
        get { return Instance.customControllerRay; }
        set { Instance.customControllerRay = value; }
    }

    /// <summary>
    /// Tell CurvedUI if controller button is pressed when in CUSTOM_RAY controller mode. Input module will use this to interact with canvas.
    /// </summary>
    public static bool CustomControllerButtonState
    {
        get { return Instance.pressedDown; }
        set { Instance.pressedDown = value; }
    }

    [System.Obsolete("Use CustomControllerButtonState instead.")]
    public static bool CustomControllerButtonDown
    {
        get { return Instance.pressedDown; }
        set { Instance.pressedDown = value; }
    }

    #endregion






    #region SETTERS AND GETTERS - WORLD SPACE MOUSE
    /// <summary>
    /// Returns the position of the world space pointer in Canvas' local space. 
    /// You can use it to position an image on world space mouse pointer's position.
    /// </summary>
    public Vector2 WorldSpaceMouseInCanvasSpace
    {
        get { return worldSpaceMouseInCanvasSpace; }
        set
        {
            worldSpaceMouseInCanvasSpace = value;
            lastWorldSpaceMouseOnCanvas = value;
        }
    }

    /// <summary>
    /// The change in position of the world space mouse in canvas' units.
    /// Counted since the last frame.
    /// </summary>
    public Vector2 WorldSpaceMouseInCanvasSpaceDelta
    {
        get { return worldSpaceMouseInCanvasSpace - lastWorldSpaceMouseOnCanvas; }
    }

    /// <summary>
    /// How many units in Canvas space equals one unit in screen space.
    /// </summary>
    public float WorldSpaceMouseSensitivity
    {
        get { return worldSpaceMouseSensitivity; }
        set { worldSpaceMouseSensitivity = value; }
    }
    #endregion // SETTERS AND GETTERS - WORLD SPACE MOUSE





    #region SETTERS AND GETTERS - GAZE
    /// <summary>
    /// Gaze Control Method. Should execute OnClick events on button after user points at them?
    /// </summary>
    public bool GazeUseTimedClick
    {
        get { return gazeUseTimedClick; }
        set { gazeUseTimedClick = value; }
    }

    /// <summary>
    /// Gaze Control Method. How long after user points on a button should we click it? Default 2 seconds.
    /// </summary>
    public float GazeClickTimer
    {
        get { return gazeClickTimer; }
        set { gazeClickTimer = Mathf.Max(value, 0); }
    }

    /// <summary>
    /// Gaze Control Method. How long after user looks at a button should we start the timer? Default 1 second.
    /// </summary>
    public float GazeClickTimerDelay
    {
        get { return gazeClickTimerDelay; }
        set { gazeClickTimerDelay = Mathf.Max(value, 0); }
    }

    /// <summary>
    /// Gaze Control Method. How long till Click method is executed on Buttons under gaze? Goes 0-1.
    /// </summary>
    public float GazeTimerProgress
    {
        get { return gazeTimerProgress; }
    }

    /// <summary>
    /// Gaze Control Method. This Images's fill will be animated 0-1 when OnClick events are about
    /// to be executed on buttons under the gaze.
    /// </summary>
    public Image GazeTimedClickProgressImage
    {
        get { return gazeTimedClickProgressImage; }
        set { gazeTimedClickProgressImage = value; }
    }
    #endregion // SETTERS AND GETTERS - GAZE






    #region SETTERS AND GETTERS - STEAMVR_LEGACY
#if CURVEDUI_STEAMVR_LEGACY
    /// <summary>
    /// Scene's controller manager. Used to get references for Vive controllers.
    /// </summary>
    public SteamVR_ControllerManager SteamVRControllerManager {
            get { return steamVRControllerManager; }
            set {
                if (steamVRControllerManager != value)  {
                    steamVRControllerManager = value;
                }
            }
        }

        /// <summary>
        /// Get or Set controller manager used by this input module.
        /// </summary>
        public SteamVR_ControllerManager ControllerManager {
            get { return controllerManager; }
            set {
                controllerManager = value;
                SetupViveControllers();
            }
        }
   
        /// <summary>
        /// Returns Right SteamVR Controller. Ask this component for any button states.;
        /// </summary>
        public static CurvedUIViveController Right {
            get {
                if (!rightCont) rightCont = controllerManager.right.AddComponentIfMissing<CurvedUIViveController>();
                return rightCont ; 
            }
        }

        /// <summary>
        /// Returns Left SteamVR Controller. Ask this component for any button states.;
        /// </summary>
        public static CurvedUIViveController Left {
            get {
                if (!leftCont) leftCont = controllerManager.left.AddComponentIfMissing<CurvedUIViveController>();
                return leftCont; 
            }
        }  
#endif // CURVEDUI_STEAMVR_LEGACY
    #endregion // end of SETTERS AND GETTERS - STEAMVR_LEGACY






    #region SETTERS AND GETTERS - STEAMVR_2
#if CURVEDUI_STEAMVR_2
    public SteamVR_PlayArea SteamVRPlayArea {
        get { return steamVRPlayArea; }
        set { steamVRPlayArea = value; }
    }

    /// <summary>
    /// Currently used SteamVR Input Source, based on used Hand.
    /// </summary>
    public SteamVR_Input_Sources SteamVRInputSource {
        get {  return (UsedHand == Hand.Left ? Valve.VR.SteamVR_Input_Sources.LeftHand : Valve.VR.SteamVR_Input_Sources.RightHand); }
    }

    /// <summary>
    /// SteamVR 2.0 Action that should be used to click on UI elements.
    /// </summary>
    public SteamVR_Action_Boolean SteamVRClickAction {
        get { return m_steamVRClickAction;  }
        set { m_steamVRClickAction = value; }
    }
#endif // end of STEAMVR2
    #endregion // SETTERS AND GETTERS - STEAMVR_2





    #region SETTERS AND GETTERS - OCULUSVR
#if CURVEDUI_OCULUSVR
    public OVRCameraRig OculusCameraRig {
        get { return oculusCameraRig; }
        set {  oculusCameraRig = value;  }
    }

    public OVRInput.Button OculusTouchInteractionButton {
        get { return InteractionButton; }
        set  {  InteractionButton = value;  }
    }

    public Transform OculusTouchUsedControllerTransform {
        get { return UsedHand == Hand.Left ? oculusCameraRig.leftHandAnchor : oculusCameraRig.rightHandAnchor; }
    }
#endif // end of CURVEDUI_OCULUSVR
    #endregion // SETTERS AND GETTERS - OCULUSVR
    
    


    #region SETTERS AND GETTERS - UNITY_XR
#if CURVEDUI_UNITY_XR
    //public XRController RightXRController {
    //    get => rightXRController;
    //    set => rightXRController = value;
    //}

    //public XRController LeftXRController {
    //    get => leftXRController;
    //    set => leftXRController = value;
    //}
#endif // end of CURVEDUI_UNITY_XR
    #endregion // SETTERS AND GETTERS - UNITY_XR
    
    


    #region ENUMS
    public enum CUIControlMethod
    {
	    MOUSE = 0,
	    GAZE = 1,
	    WORLD_MOUSE = 2,
	    CUSTOM_RAY = 3,
	    STEAMVR_LEGACY = 4, //SDK version 1.2.3 or earlier
	    OCULUSVR = 5,
	    //DAYDREAM = 6,//deprecated, GoogleVR is now used for daydream.
	    GOOGLEVR = 7,
        STEAMVR_2 = 8, //SDK version 2.0 or later
        UNITY_XR = 9,
    }

    public enum Hand
    {
	    Both = 0,
	    Right = 1,
	    Left = 2,
    }
    #endregion // ENUMS

}