using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections;
using System;
using AX.InputSystem;

//处理UI拖动的脚本,该脚本需要挂在可拖动的panel（该panel需要在canvas下）下的直属子物体上，
//鼠标托这个子物体时可拖动的panel会在canvas下拖动
[RequireComponent(typeof(CreateStaticObjID))]
[RequireComponent(typeof(BaseGameObjInfo))]
public class DragPanel : MonoBehaviour, IDragHandler, IEndDragHandler,IBeginDragHandler
{
    private Vector2 originalLocalPointerPosition;
    private Vector3 originalPanelLocalPosition;
    private RectTransform panelRectTransform;//要拖动的panel
    private RectTransform parentRectTransform;//可拖动的panel的拖动范围（这里是画布Canvas）

    void Start()
    {
        panelRectTransform = transform.parent as RectTransform;
        parentRectTransform = panelRectTransform.parent as RectTransform;
    }
    public void OnBeginDrag(PointerEventData eventData)
    {
        if (eventData.button != PointerEventData.InputButton.Left) return;//不是左键按下就不能拖拽
        var arg = new OnDragCmdArgs();
        arg.position = eventData.position;
        DragBegin(arg);
        InputManager.isDargUI = true;
    }
    public void DragBegin(OnDragCmdArgs args)
    {
        RegisterUIInputEvent.RegisterUIInputHistory(gameObject, this.GetType().Name, "DragBegin", args);
        originalPanelLocalPosition = panelRectTransform.localPosition;
        RectTransformUtility.ScreenPointToLocalPointInRectangle(parentRectTransform, args.position, null, out originalLocalPointerPosition);

    }
    public void OnDrag(PointerEventData data)
    {
        if (data.button != PointerEventData.InputButton.Left) return;//不是左键按下就不能拖拽
        var arg = new OnDragCmdArgs();
        arg.position = data.position;
        Drag(arg);
    }
    public void Drag(OnDragCmdArgs args)
    {
        RegisterUIInputEvent.RegisterUIInputHistory(gameObject, this.GetType().Name, "Drag", args);

        if (panelRectTransform == null || parentRectTransform == null)
            return;
        Vector2 localPointerPosition;
        if (RectTransformUtility.ScreenPointToLocalPointInRectangle(parentRectTransform, args.position, null, out localPointerPosition))
        {
            Vector3 offsetToOriginal = localPointerPosition - originalLocalPointerPosition;
            panelRectTransform.localPosition = originalPanelLocalPosition + offsetToOriginal;
        }
        ClampToWindow();
    }
    void ClampToWindow()
    {
        Vector3 pos = panelRectTransform.localPosition;

        Vector3 minPosition = parentRectTransform.rect.min - panelRectTransform.rect.min;
        Vector3 maxPosition = parentRectTransform.rect.max - panelRectTransform.rect.max;

        pos.x = Mathf.Clamp(panelRectTransform.localPosition.x, minPosition.x, maxPosition.x);
        pos.y = Mathf.Clamp(panelRectTransform.localPosition.y, minPosition.y, maxPosition.y);
        panelRectTransform.localPosition = pos;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        if (eventData.button != PointerEventData.InputButton.Left) return;//不是左键按下就不能拖拽
        var arg = new OnDragCmdArgs();
        arg.currentCursorPos = Input.mousePosition;
        RegisterUIInputEvent.RegisterUIInputHistory(gameObject, this.GetType().Name, "EndDrag", arg);
        EndDrag(arg);
    }
    public void EndDrag(CmdArgs args)
    {
        if (GameSettings.othersSettings.playState == PlayState.Playing)
        {
            CursorManager.GetInstance.SetClick(args);
        }
      InputManager.isDargUI = false;
    }

   
}