using System;
using UnityEngine;
using UnityEngine.EventSystems;
using System.Collections.Generic;

namespace vnxbqy.UI
{
    [DisallowMultipleComponent]
    public class DragSelectComponentEx : MonoBehaviour
    {
        [SerializeField] float m_Sensitive = 10f;
        [SerializeField] GameObject m_TargetObject;

        public event Action<int> onDragComplete;

        private bool m_StartDrag = false;

        Vector3 start_position = Vector3.zero;
        bool isArea = false;

        private void LateUpdate()
        {
            if (Input.touchCount > 1)
            {
                m_StartDrag = false;
                return;
            }
            if (Input.GetMouseButtonDown(0))
            {
                m_StartDrag = true;
                start_position = Input.mousePosition;
                isArea = RectTransformUtility.RectangleContainsScreenPoint(this.transform as RectTransform, start_position, CameraManager.uiCamera);
                if (!IsOverTarget())
                {
                    m_StartDrag = false;
                    return;
                }
            }
            else if (Input.GetMouseButtonUp(0) && m_StartDrag)
            {
                var delta = Input.mousePosition - start_position;
                m_StartDrag = false;

                // 判断滑动方向
                if (Mathf.Abs(delta.x) >= m_Sensitive || Mathf.Abs(delta.y) >= m_Sensitive)
                {
                    int direction = 0;

                    // 水平方向优先
                    if (Mathf.Abs(delta.x) > Mathf.Abs(delta.y))
                    {
                        direction = delta.x > 0 ? 1 : -1; // 1 表示向右滑动，-1 表示向左滑动
                    }
                    // 垂直方向优先
                    else
                    {
                        direction = delta.y > 0 ? 2 : -2; // 2 表示向上滑动，-2 表示向下滑动
                    }

                    // 新增目标对象检测条件
                    if (onDragComplete != null && isArea)
                    {
                        onDragComplete(direction);
                    }
                }
            }
        }

        // 新增目标检测方法
        private bool IsOverTarget()
        {
            if (m_TargetObject == null) return true;

            PointerEventData eventData = new PointerEventData(EventSystem.current)
            {
                position = Input.mousePosition
            };

            List<RaycastResult> results = new List<RaycastResult>();
            EventSystem.current.RaycastAll(eventData, results);

            if (results.Count > 0)
            {
                RaycastResult result = results[0];
                if (result.gameObject == m_TargetObject)
                {
                    return true;
                }
                if (result.gameObject.transform.parent.gameObject == m_TargetObject)
                {
                    return true;
                }
            }
            return false;
        }

        private void OnDisable()
        {
            m_StartDrag = false;
        }
    }
}