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

namespace AibisDream
{
    public class ShapeDragger : MonoBehaviour, IBlockShapeDragger, IInteraction
    {
        #region 编辑器字段
        [SerializeField] private bool isDraggable = true;

        [SerializeField] private int sortingLayerId;
        [SerializeField] private int dragLayerOrder;
        [SerializeField] private int idleLayerOrder;
        [SerializeField] private int pressLayerOrder;
        
        [Header("长按设置")]
        [SerializeField] private float longPressDuration = 0.65f;
        [SerializeField] private float longPressScale = 1.1f;
        [SerializeField] private float shakeIntensity = 1f;

        [Header("拖拽跟随")]
        [SerializeField] private float dragFollowSpeed = 15f;
        #endregion

        // 拖拽状态
        private DragState _currentState = DragState.Placed;
        public DragState CurrentState
        {
            get => _currentState;
            set
            {
                if (value == _currentState) return;
                // 处理状态切换
                HandleStateChange(value);
                _currentState = value;
            }
        }
        private SnapResult _snapResult;
        
        // 长按相关状态
        private bool _isPressing;
        private bool _isLongPressTriggered;
        private bool _canEndDragOnClick; // 标记是否可以通过点击结束拖拽
        private Sequence _longPressSequence;
        private Vector3 _originalScale;
        private Vector3 _originalPosition;

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

        public bool IsDraggable { get => isDraggable; set => isDraggable = value; }
        public IBlockPuzzleGrid TargetGrid => BlockPuzzleSystem.Instance.grid;
        public IBlockShape BlockShape => _blockShape;

        // 事件
        public event Action<IBlockShape> OnDragStart;
        public event Action<IBlockShape> OnDragUpdate;
        public event Action<IBlockShape, bool> OnDragEnd;

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

            RegisterEvent();
        }

        private void OnDestroy()
        {
            _eventTrigger.UnRegister(EventTriggerType.PointerDown, OnPointerDown);
            _eventTrigger.UnRegister(EventTriggerType.PointerUp, OnPointerUp);
            _eventTrigger.UnRegister(EventTriggerType.PointerClick, OnPointerClick);
            
            // 清理 DOTween 动画
            _longPressSequence?.Kill();
        }

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

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

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

            // 如果当前正在拖拽中，标记可以通过点击结束
            if (CurrentState == DragState.Dragging)
            {
                _canEndDragOnClick = true;
            }
            // 只有在静止状态才能开始长按
            else if (CurrentState == DragState.Idle || CurrentState == DragState.Placed)
            {
                _isPressing = true;
                _isLongPressTriggered = false;
                _canEndDragOnClick = false; // 长按开始时不允许点击结束
                StartLongPressAnimation();
            }
        }
        
        private void OnPointerUp(BaseEventData eventData)
        {
            if (eventData is not PointerEventData { button: PointerEventData.InputButton.Left })
            {
                return;
            }

            // 如果还在长按过程中（未完成），则取消
            if (_isPressing && !_isLongPressTriggered)
            {
                CancelLongPress();
            }
        }
        
        private void OnPointerClick(BaseEventData eventData)
        {
            if (eventData is not PointerEventData { button: PointerEventData.InputButton.Left })
            {
                return;
            }

            // 只有在拖拽中且允许点击结束时才结束拖拽
            if (CurrentState == DragState.Dragging && _canEndDragOnClick)
            {
                EndDrag();
                _canEndDragOnClick = false; // 重置标记
            }
        }

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

            // 如果原本就在网格中，则先移除
            TargetGrid?.TryRemoveShapeFromGrid(_blockShape);
            TargetGrid?.ResetPreviewGrid();

            CurrentState = DragState.Dragging;

            OnDragStart?.Invoke(_blockShape);
        }

        public void EndDrag()
        {
            // 清理长按状态
            CancelLongPress();
            
            // 先吸附到回收槽
            var recycled = BlockPuzzleSystem.Instance.TrySnapToRecycleSlot(_blockShape);
            if (recycled)
            {
                CurrentState = DragState.Idle;
                _snapResult = SnapResult.RecycleResult;
                TargetGrid.ShowSnapPreview(_snapResult);
                OnDragEnd?.Invoke(_blockShape, CurrentState == DragState.Placed);
                return;
            }

            // 再吸附到网格
            TargetGrid?.ResetPreviewGrid();
            if (_snapResult.canSnap)
            {
                CurrentState = DragState.Placed;
                transform.localScale = Vector3.one;

                TargetGrid.TrySnapToGrid(_blockShape, _snapResult.RootCell);

                // 处理Cursor
                _eventTrigger.OnPointerUp(null);
                OnDragEnd?.Invoke(_blockShape, CurrentState == DragState.Placed);
            }
            else
            {
                // 都没吸附到，恢复原状态和缩放
                transform.localScale = Vector3.one;
            }

            TargetGrid.GridVisualizer.UpdateAllCellsVisual();
        }

        public void UpdateDrag()
        {
            // 检测右键点击进行旋转（仅在拖动中）
            if (Input.GetMouseButtonDown(1)) // 1 = 右键
            {
                _blockShape.RotateClockwise();
            }

            // 更新拖拽位置（带轻微滞后感）
            var targetPos = GetMouseWorldPosition() - _blockShape.GetCenterPosition();
            transform.position = Vector3.Lerp(transform.position, targetPos, Time.deltaTime * dragFollowSpeed);

            // 进行Snap检查
            _snapResult = TargetGrid.CheckSnapToGrid(_blockShape);
            // 在网格显示预览
            TargetGrid.ShowSnapPreview(_snapResult);

            OnDragUpdate?.Invoke(_blockShape);
        }

        private void HandleStateChange(DragState newState)
        {
            var sortingGroup = _blockShape?.SortingGroup;
            if (sortingGroup == null) return;

            sortingGroup.sortingLayerID = sortingLayerId;
            switch (newState)
            {
                case DragState.Idle:
                case DragState.Dragging:
                    sortingGroup.sortingOrder = dragLayerOrder;
                    break;
                case DragState.Placed:
                    sortingGroup.sortingOrder = idleLayerOrder;
                    break;
            }
        }

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

        private void StartLongPressAnimation()
        {
            _originalScale = transform.localScale;
            _originalPosition = transform.localPosition;
            
            // 杀掉之前的动画
            _longPressSequence?.Kill();
            
            // 创建 DOTween 序列
            _longPressSequence = DOTween.Sequence();
            
            // 放大效果（使用 EaseOutQuad）
            _longPressSequence.Append(
                transform.DOScale(_originalScale * longPressScale, longPressDuration)
                    .SetEase(Ease.OutQuad)
            );
            
            // 抖动效果（使用 DOShakePosition，与放大同时进行）
            _longPressSequence.Join(
                transform.DOShakePosition(
                    longPressDuration,
                    new Vector3(shakeIntensity, shakeIntensity, 0), // 只在 X 轴抖动
                    60, // 振动频率
                    90, // 随机性
                    false, // 不淡出
                    true // 使用局部坐标
                )
            );
            
            // 完成时的回调
            _longPressSequence.OnComplete(() =>
            {
                _isLongPressTriggered = true;
                StartDrag();
            });
            
            // 设置为不自动销毁
            _longPressSequence.SetAutoKill(true);
        }
        
        private void CancelLongPress()
        {
            // 杀掉 DOTween 动画
            if (_longPressSequence != null && _longPressSequence.IsActive())
            {
                _longPressSequence.Kill();
                _longPressSequence = null;
            }
            
            // 恢复原始状态
            if (_isPressing && !_isLongPressTriggered)
            {
                transform.DOKill(); // 确保所有动画都停止
                transform.localScale = _originalScale;
                transform.localPosition = _originalPosition;
            }
            
            _isPressing = false;
            _isLongPressTriggered = false;
            _canEndDragOnClick = false;
        }

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