aibis-dream/Assets/Scripts/MiniGame/BlockPuzzle/Class/ShapeDragger.cs

using System;
using AibisDream.Framework;
using UnityEngine;
using UnityEngine.EventSystems;

namespace AibisDream
{
    public class ShapeDragger : MonoBehaviour, IBlockShapeDragger, IInteraction
    {
        [Header("拖拽设置")]
        [SerializeField] private bool isDraggable = true;
        [SerializeField] private float snapDistance = 0.5f;
        [SerializeField] private BlockPuzzleGrid targetGrid;

        [Header("视觉反馈")]
        [SerializeField] private Color snapColor = new Color(0f, 1f, 0f, 0.7f);
        [SerializeField] private Color invalidColor = new Color(1f, 0f, 0f, 0.7f);
        [SerializeField] private Color normalColor = Color.white;
        [SerializeField] private float dragScale = 1.1f;

        // 拖拽状态
        private DragState _currentState = DragState.Idle;
        private Vector3 _dragOffset;
        private Vector3 _originalPosition;
        private Vector3 _originalScale;
        private int _originalSortingOrder;
        private SnapResult _snapResult;

        // 组件引用
        private BlockShape _blockShape;
        private SpriteRenderer _spriteRenderer;
        private EventTriggerEx _eventTrigger;

        public DragState CurrentState => _currentState;

        public bool IsDraggable { get => isDraggable; set => isDraggable = value; }
        public IBlockPuzzleGrid TargetGrid { get => targetGrid; set => targetGrid = value as BlockPuzzleGrid; }
        public float SnapDistance { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }

        // 事件
        public event Action<IBlockShape> OnDragStart;
        public event Action<IBlockShape, Vector3> OnDragUpdate;
        public event Action<IBlockShape, bool> OnDragEnd;
        public event Action<IBlockShape, Vector3, int, int> OnSnap;
        public event Action<IBlockShape> OnUnsnap;

        private void Awake()
        {
            _blockShape = GetComponent<BlockShape>();
            _spriteRenderer = GetComponent<SpriteRenderer>();
            _eventTrigger = GetComponent<EventTriggerEx>();

            RegisterEvent();
        }

        private void OnDestroy()
        {
            _eventTrigger.UnRegister(EventTriggerType.PointerClick, OnPointerClick);
        }

        private void RegisterEvent()
        {
            _eventTrigger.Register(EventTriggerType.PointerClick, OnPointerClick);
            // _eventTrigger.Register(EventTriggerType.PointerDown, OnPointerDown);
            // _eventTrigger.Register(EventTriggerType.PointerUp, OnPointerUp);
        }

        private void Update()
        {
            if (_currentState == DragState.Dragging)
            {
                UpdateDrag();
            }
        }

        private void OnPointerClick(BaseEventData eventData)
        {
            if (eventData is not PointerEventData { button: PointerEventData.InputButton.Left })
            {
                return;
            }

            Vector3 mouseWorldPos = GetMouseWorldPosition(eventData);
            // 如果当前物体不在拖拽中则进入拖拽逻辑
            if (_currentState == DragState.Idle || _currentState == DragState.Placed)
            {
                StartDrag(mouseWorldPos);
            }
            // 如果当前物体在拖拽中则取消拖拽
            else
            {
                EndDrag();
            }
        }

        public void StartDrag(Vector3 mouseWorldPos)
        {
            if (!isDraggable) return;

            _currentState = DragState.Dragging;
            _originalPosition = transform.position;

            // 计算拖拽偏移量
            _dragOffset = transform.position - mouseWorldPos;

            // 处理层级和缩放
            HandleDragStart();

            OnDragStart?.Invoke(_blockShape);
        }

        private void HandleDragStart()
        {
            // 调整缩放和层级
            transform.localScale = dragScale * Vector3.one;
        }

        public void CancelDrag()
        {
            throw new NotImplementedException();
        }

        public void EndDrag()
        {
            // 如果吸附到了就靠过去
            if (_snapResult.canSnap)
            {
                _currentState = DragState.Placed;
                transform.localScale = Vector3.one;
                TargetGrid.TrySnapToGrid(_blockShape, _snapResult.RootCell);
            }
            else
            {
                _currentState = DragState.Idle;
                transform.position = _originalPosition;
                transform.localScale = Vector3.one;
            }

            OnDragEnd?.Invoke(_blockShape, _currentState == DragState.Placed);
        }

        public void UpdateDrag()
        {
            // 更新拖拽位置
            transform.position = GetMouseWorldPosition() + _dragOffset;
            // 进行Snap检查
            _snapResult = TargetGrid.CheckSnapToGrid(_blockShape);
            // 在网格显示预览
            TargetGrid.ShowSnapPreview(_snapResult.gridPositions);
        }

        /// <summary>
        /// 获取鼠标世界坐标
        /// </summary>
        private Vector3 GetMouseWorldPosition(BaseEventData eventData)
        {
            Vector3 mouseWorldPos;
            if (eventData is not PointerEventData pointerEventData)
            {
                mouseWorldPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            }
            else
            {
                mouseWorldPos = Camera.main.ScreenToWorldPoint(pointerEventData.position);
            }
            return new Vector3(mouseWorldPos.x, mouseWorldPos.y, 0);
        }

        private Vector3 GetMouseWorldPosition()
        {
            var mouseWorldPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            return new Vector3(mouseWorldPos.x, mouseWorldPos.y, 0);
        }

        // 实现IInteraction接口
        public bool IsActive => true;
        public bool IsAvailable => true;
        public GameObject GetGameObject() => gameObject;
    }
}