using System;
using System.Collections;
using System.Threading;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.XR.Interaction.Toolkit;
using UnityEngine.XR.Interaction.Toolkit.Interactables;
using UnityEngine.XR.Interaction.Toolkit.Interactors;

public interface IInteractionView
{

}

public enum HandSide { Left, Right }

public class InteractionView : MonoBehaviour, IInteractionView
{
    public event Action<Vector3, Quaternion> OnRobotGrabbed;
    public event Action<RobotData> OnRobotReleased;
    public event Action<int, Vector3> OnPointClicked;
    public event Action<int> OnPointDragStart;
    public event Action<int, Vector3, Quaternion> OnPointDragUpdate;
    public event Action<int> OnPointDragEnd;

    [SerializeField]private NearFarInteractor nearFarInteractor;
    public HandSide handSide;
    private XRBaseInteractor baseInteractor;
    private IXRRayProvider rayProvider;

    [SerializeField]
    [Tooltip("µå·¡±× ½Ã À§Ä¡¸¦ Ç¥½ÃÇÒ ¹ÝÅõ¸í ·Îº¿ ¸ðµ¨")]
    private GameObject ghostRobot;
    [SerializeField]
    [Tooltip("µå·¡±×¿ë ¸¶¿ì½º À̹ÌÁö")]
    private GameObject dragArrow;
    [SerializeField] private float clickTimeThreshold = 0.5f;
    [SerializeField] private float dragMovementThreshold = 0.05f;
    private Coroutine clickOrDragCoroutine = null;
    private Vector3 startGrabPosition;

    private bool isInitialized = false;
    private bool isGrabbingPoint = false;
    private int currentGrabbedPointIndex = -1;

    Vector3 currentTargetPosition = Vector3.zero;
    Quaternion currentTargetRotation = Quaternion.identity;

    public bool isGrabbingRobot = false;

    //void Start()
    //{
    //    nearFarInteractor = GetComponentInChildren<NearFarInteractor>();

    //    if (nearFarInteractor == null)
    //    {
    //        Debug.LogError("InteractionView: 'nearFarInteractor'°¡ ÇÒ´çµÇÁö ¾Ê¾Ò½À´Ï´Ù", this);
    //        return;
    //    }

    //    baseInteractor = nearFarInteractor as XRBaseInteractor;
    //    rayProvider = nearFarInteractor as IXRRayProvider;

    //    if (baseInteractor == null)
    //    {
    //        Debug.LogError("NearFarInteractor¸¦ XRBaseInteractor·Î º¯È¯ÇÒ ¼ö ¾ø½À´Ï´Ù.", this);
    //        return;
    //    }

    //    InitializeInteraction();
    //}

    void Update()
    {
        if (!isInitialized || rayProvider == null)
        {
            if (nearFarInteractor == null)
            {
                nearFarInteractor = GetComponentInChildren<NearFarInteractor>(true);
                baseInteractor = nearFarInteractor as XRBaseInteractor;
                rayProvider = nearFarInteractor as IXRRayProvider;
            }
            if (nearFarInteractor != null)
            {
                InitializeInteraction();
            }
        }
        else
        {
            currentTargetPosition = rayProvider.rayEndPoint;
            currentTargetRotation = baseInteractor.attachTransform.rotation;

            if (isGrabbingRobot)
            {
                OnRobotGrabbed?.Invoke(currentTargetPosition, currentTargetRotation);
                return;
            }

            if (isGrabbingPoint)
            {
                OnPointDragUpdate?.Invoke(currentGrabbedPointIndex, currentTargetPosition, currentTargetRotation);
            }
            else if (clickOrDragCoroutine != null)
            {
                float distance = Vector3.Distance(startGrabPosition, currentTargetPosition);

                if (distance > dragMovementThreshold)
                {
                    StartDragMode();
                }
            }
        }
    }

    private void InitializeInteraction()
    {
        // XRI À̺¥Æ® ±¸µ¶
        baseInteractor.selectEntered.AddListener(HandleGrabStart);
        baseInteractor.selectExited.AddListener(HandleGrabEnd);

        isInitialized = true;
        AppManager.Instance.RegisterView(this);
    }

    private void OnDestroy()
    {
        if (baseInteractor != null)
        {
            baseInteractor.selectEntered.RemoveListener(HandleGrabStart);
            baseInteractor.selectExited.RemoveListener(HandleGrabEnd);
        }
    }

    // --- XRI À̺¥Æ® Çڵ鷯 ---

    private void HandleGrabStart(SelectEnterEventArgs args)
    {
        GameObject grabbedGO = args.interactableObject.transform.gameObject;

        RobotPoint point = grabbedGO.GetComponent<RobotPoint>();
        if (point != null)
        {
            isGrabbingPoint = true;
            isGrabbingRobot = false;
            currentGrabbedPointIndex = point.pointIndex;

            // ŸÀÌ¸Ó ½ÃÀÛ
            startGrabPosition = rayProvider.rayEndPoint;
            if (clickOrDragCoroutine != null) 
                StopCoroutine(clickOrDragCoroutine);
            clickOrDragCoroutine = StartCoroutine(ClickOrDragTimer());

            //OnPointDragStart?.Invoke(currentGrabbedPointIndex);
        }
        else if (grabbedGO.CompareTag("RobotArm"))
        {
            isGrabbingPoint = false;
            isGrabbingRobot = true;
            currentGrabbedPointIndex = -1;

            OnPointDragStart?.Invoke(currentGrabbedPointIndex);
        }
    }

    private void HandleGrabEnd(SelectExitEventArgs args)
    {
        if (isGrabbingRobot)
        {
            OnRobotReleased?.Invoke(new RobotData());
        }
        else
        {
            if (clickOrDragCoroutine != null)
            {
                StopCoroutine(clickOrDragCoroutine);
                clickOrDragCoroutine = null;

                OnPointClicked?.Invoke(currentGrabbedPointIndex, currentTargetPosition);
            }
            else if (isGrabbingPoint)
            {
                OnPointDragEnd?.Invoke(currentGrabbedPointIndex);
            }
        }

        // »óÅ ÃʱâÈ­
        clickOrDragCoroutine = null;
        isGrabbingPoint = false;
        isGrabbingRobot = false;
        currentGrabbedPointIndex = -1;
    }

    // Ŭ¸¯/µå·¡±× ±¸ºÐÇϴ ŸÀÌ¸Ó ÄÚ·çƾ
    private IEnumerator ClickOrDragTimer()
    {
        yield return new WaitForSeconds(clickTimeThreshold);

        if (clickOrDragCoroutine != null)
        {
            Debug.Log("½Ã°£ ÃÊ°ú·Î µå·¡±× ½ÃÀÛ (OnPointDragStart)");
            StartDragMode();
        }
    }

    // ŸÀÌ¸Ó ÁßÁöÇÏ°í µå·¡±× ¸ðµå·Î Àüȯ
    private void StartDragMode()
    {
        if (clickOrDragCoroutine != null)
        {
            StopCoroutine(clickOrDragCoroutine);
            clickOrDragCoroutine = null;
        }

        isGrabbingPoint = true;
        OnPointDragStart?.Invoke(currentGrabbedPointIndex);
    }

    // ·Îº¿ ÁÂÇ¥°è(mm)¸¦ Unity ¿ùµå ÁÂÇ¥°è(m)·Î º¯È¯
    private Vector3 ConvertRobotDataToVector3(RobotData pose)
    {
        float x = Convert.ToSingle(pose.x / -1000.0);
        float y = Convert.ToSingle(pose.z / 1000.0);
        float z = Convert.ToSingle(pose.y / -1000.0);
        return new Vector3(x, y, z);
    }

    // ·Îº¿ ¿ÀÀÏ·¯ °¢(rx,ry,rz)À» Unity ÄõÅʹϾðÀ¸·Î º¯È¯
    private Quaternion ConvertRobotDataToQuaternion(RobotData pose)
    {
        return Quaternion.Euler(pose.rx, pose.ry, pose.rz);
    }

    // °í½ºÆ® ·Îº¿ÀÇ À§Ä¡/ȸÀü ¼³Á¤
    public void ShowGhostRobot()
    {
        if (ghostRobot == null)
        {
            Debug.LogWarning("Ghost RobotÀÌ Inspector¿¡ ÇÒ´çµÇÁö ¾Ê¾Ò½À´Ï´Ù.");
            return;
        }

        ghostRobot.SetActive(true);
    }

    // °í½ºÆ® ·Îº¿ ºñÈ°¼ºÈ­
    public void HideGhostRobot()
    {
        if (ghostRobot != null)
        {
            ghostRobot.SetActive(false);
        }
    }

    // µå·¡±× È­»ìÇ¥ È°¼ºÈ­ ¹× À§Ä¡ ¼³Á¤
    public void ShowDragArrow(Vector3 position)
    {
        if (dragArrow == null)
        {
            Debug.LogWarning("Drag Arrow°¡ Inspector¿¡ ÇÒ´çµÇÁö ¾Ê¾Ò½À´Ï´Ù.");
            return;
        }

        dragArrow.SetActive(true);
        dragArrow.transform.position = position;
    }

    // µå·¡±× È­»ìÇ¥ ºñÈ°¼ºÈ­
    public void HideDragArrow()
    {
        if (dragArrow != null)
        {
            dragArrow.SetActive(false);
        }
    }

    // ±¤¼± ³¡ À§Ä¡ ¹Ýȯ
    public Vector3 GetCurrentRayPosition()
    {
        if (rayProvider != null)
        {
            return rayProvider.rayEndPoint;
        }

        if (baseInteractor != null)
        {
            return baseInteractor.attachTransform.position;
        }

        return transform.position;
    }
}