using UnityEngine;

public class ObjectDrag : MonoBehaviour
{
    [SerializeField]
    private Camera camMain;
    [SerializeField]
    private Transform trfDragWrapper;

    private float fClickTimeMax = 0.3f;

    private Vector3 v3Init = Vector3.zero;
    private Vector3 v3Offset = Vector3.zero;
    private float fTotalTime = 0f;
    private bool bTouch = false;
    private bool bDrag = false;



    private void Update()
    {
#if UNITY_EDITOR || UNITY_STANDALONE_WIN

        if (Input.GetMouseButtonDown(0))
        {
            OnTouchBegin();
        }
        else if (Input.GetMouseButtonUp(0))
        {
            OnTouchFinish();
        }
        else if (Input.GetMouseButton(0))
        {
            OnTouchContinue();
        }

#else
        if (Input.touchCount == 0)
            return;

        if (Input.GetTouch(0).phase == TouchPhase.Began)
        {
            OnTouchBegin();
        }
        else if (Input.GetTouch(0).phase == TouchPhase.Ended || Input.GetTouch(0).phase == TouchPhase.Canceled)
        {
            OnTouchFinish();
        }
        else if (Input.GetTouch(0).phase == TouchPhase.Moved)
        {
            OnTouchContinue();
        }
#endif
    }

    // 터치 취소.
    public void TouchCancel()
    {
        if (!bTouch)
            return;

        // 터치 이전 위치로 되돌림.
        trfDragWrapper.position = v3Init;

        v3Offset = Vector3.zero;
        bDrag = false;
        fTotalTime = 0f;
    }

    // 터치 시작.
    private void OnTouchBegin()
    {
        if (bTouch)
            return;

        Vector3 v3pos;
        if (Input.touchCount > 0)
            v3pos = Input.GetTouch(0).position;
        else
            v3pos = Input.mousePosition;
        Ray ray = camMain.ScreenPointToRay(v3pos);
        RaycastHit hit;
        if (!Physics.Raycast(ray, out hit))
        {
            return;
        }

        Vector3 v3worldpos = camMain.ScreenToWorldPoint(v3pos);
        v3Init = trfDragWrapper.position;
        v3Offset = trfDragWrapper.position - v3worldpos;
        v3worldpos += v3Offset;
        v3worldpos = ClampWorldPos(v3worldpos);
        v3worldpos.z = -1f;

        trfDragWrapper.position = v3worldpos;

        fTotalTime = 0f;
        bTouch = true;
        bDrag = false;
    }

    // 터치 지속.
    private void OnTouchContinue()
    {
        if (!bTouch)
            return;

        Vector3 v3pos;
        if (Input.touchCount > 0)
            v3pos = Input.GetTouch(0).position;
        else
            v3pos = Input.mousePosition;
        Vector3 v3worldpos = camMain.ScreenToWorldPoint(v3pos);
        v3worldpos += v3Offset;
        v3worldpos = ClampWorldPos(v3worldpos);
        v3worldpos.z = -1f;

        trfDragWrapper.position = v3worldpos;

        if (!bDrag)
        {
            fTotalTime += Time.unscaledDeltaTime;
            if (fTotalTime >= fClickTimeMax)
            {
                bDrag = true;
            }
        }
    }

    // 터치 종료.
    private void OnTouchFinish()
    {
        if (!bTouch)
            return;
        bTouch = false;

        Vector3 v3pos;
        if (Input.touchCount > 0)
            v3pos = Input.GetTouch(0).position;
        else
            v3pos = Input.mousePosition;
        Vector3 v3worldpos = camMain.ScreenToWorldPoint(v3pos);
        v3worldpos += v3Offset;
        v3worldpos = ClampWorldPos(v3worldpos);

        trfDragWrapper.position = v3worldpos;
        //if (!PveManager.Instance.UpdateCharPosition(v3worldpos))
        //    // 터치 이전 위치로 되돌림.
        //    trfDragWrapper.position = v3Init;

        v3Offset = Vector3.zero;
        bDrag = false;
        fTotalTime = 0f;
    }

    // 범위 제한.
    public static Vector3 ClampWorldPos(Vector3 v3worldpos)
    {
        v3worldpos.x = Mathf.Clamp(v3worldpos.x, -5.1f, 2.1f);
        v3worldpos.y = Mathf.Clamp(v3worldpos.y, 14.2f, 18.2f);
        v3worldpos.z = (v3worldpos.y - 16.5f) / 100f;
        return v3worldpos;
    }

    // 랜덤 위치.
    public static Vector3 RandomWorldPos()
    {
        Vector3 v3worldpos = new Vector3();
        v3worldpos.x = Random.Range(-5.1f, 2.1f);
        v3worldpos.y = Random.Range(14.2f, 18.2f);
        v3worldpos.z = (v3worldpos.y - 16.5f) / 100f;
        return v3worldpos;
    }
}