using UnityEngine;
using DG.Tweening;
using System.Collections;

public class ClawMachineController : MonoBehaviour
{
    [Header("组件引用")]
    [SerializeField] private Transform topEdge; // 上边沿
    [SerializeField] private Transform leftClaw; // 左爪
    [SerializeField] private Transform rightClaw; // 右爪
    
    [Header("移动参数")]
    [SerializeField] private float moveSpeed = 5f;
    [SerializeField] private float scaleSpeed = 2f;
    [SerializeField] private float minScale = 0.8f; // 下降时的缩放比例
    
    [Header("抓取参数")]
    [SerializeField] private float grabOffset = 0.1f; // 抓取时的位置偏移
    [SerializeField] private float clawExtendSpeed = 2f; // 爪子伸缩速度

    [Header("测试")]
    public Transform target;
    
    private Vector3 initialPosition;
    private Vector3 initialScale;
    private Transform currentTarget;
    private bool isGrabbing;
    private bool isMoving;
    
    private void Start()
    {
        initialPosition = transform.position;
        initialScale = transform.localScale;
       
    }
    
    private void Update() {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            GrabTarget(target);
        }
    }
    
    public void GrabTarget(Transform target)
    {
        if (isGrabbing || isMoving) return;
        
        currentTarget = target;
        StartCoroutine(GrabSequence());
    }
    
    private IEnumerator GrabSequence()
    {
        isGrabbing = true;
        isMoving = true;
        
        // 1. 移动到目标上方
        Vector3 targetPos = currentTarget.position;
        targetPos.x = transform.position.x;
        yield return MoveToPosition(targetPos);
        
        // 2. 调整位置和抓钩
        yield return AdjustPositionAndClaws();
        
        // 3. 下降
        yield return Descend();
        
        // 4. 再次调整抓钩
        //yield return AdjustClawsForGrab();
        
        // 5. 抓取目标
        //currentTarget.SetParent(transform);
        
        // 6. 上升
        //yield return Ascend();
        
        // 7. 返回初始位置
        //yield return ReturnToInitialPosition();
        
        isGrabbing = false;
        isMoving = false;
    }
    
    private IEnumerator MoveToPosition(Vector3 targetPos)
    {
        float distance = Vector3.Distance(transform.position, targetPos);
        float duration = distance / moveSpeed;
        
        transform.DOMove(targetPos, duration).SetEase(Ease.Linear);
        yield return new WaitForSeconds(duration);
    }
    
    private IEnumerator AdjustPositionAndClaws()
    {
        if (currentTarget == null) yield break;
        
        SpriteRenderer targetSprite = currentTarget.GetComponent<SpriteRenderer>();
        if (targetSprite == null) yield break;
        
        // 计算目标上边沿位置
        float targetTop = targetSprite.bounds.max.y;
        float currentTop = topEdge.position.y;
        
        // 计算需要移动的距离
        float moveDistance = targetTop - currentTop + grabOffset;
        
        // 调整位置使上边沿接近目标上边沿
        Vector3 newPos = transform.position;
        newPos.y += moveDistance;
        yield return MoveToPosition(newPos);
        
        // 调整爪子位置
        float targetWidth = targetSprite.bounds.size.x;
        float currentWidth = Vector3.Distance(leftClaw.position, rightClaw.position);
        
        // 计算需要的爪子伸缩量
        float extendAmount = (targetWidth + grabOffset * 2) - currentWidth;
        yield return ExtendClaws(extendAmount);
    }
    
    private IEnumerator Descend()
    {
        Vector3 targetScale = initialScale * minScale;
        float duration = (initialScale.x - targetScale.x) / scaleSpeed;
        
        transform.DOScale(targetScale, duration).SetEase(Ease.Linear);
        yield return new WaitForSeconds(duration);
    }
    
    private IEnumerator AdjustClawsForGrab()
    {
        if (currentTarget == null) yield break;
        
        SpriteRenderer targetSprite = currentTarget.GetComponent<SpriteRenderer>();
        if (targetSprite == null) yield break;
        
        // 计算目标宽度
        float targetWidth = targetSprite.bounds.size.x;
        
        // 调整爪子位置以卡住边缘
        float extendAmount = targetWidth + grabOffset;
        yield return ExtendClaws(extendAmount);
    }
    
    private IEnumerator ExtendClaws(float amount)
    {
        Vector3 leftTarget = leftClaw.localPosition;
        Vector3 rightTarget = rightClaw.localPosition;
        
        leftTarget.x -= amount / 2;
        rightTarget.x += amount / 2;
        
        float duration = amount / clawExtendSpeed;
        
        leftClaw.DOLocalMove(leftTarget, duration).SetEase(Ease.Linear);
        rightClaw.DOLocalMove(rightTarget, duration).SetEase(Ease.Linear);
        
        yield return new WaitForSeconds(duration);
    }
    
    private IEnumerator Ascend()
    {
        float duration = (initialScale.x - transform.localScale.x) / scaleSpeed;
        
        transform.DOScale(initialScale, duration).SetEase(Ease.Linear);
        yield return new WaitForSeconds(duration);
    }
    
    private IEnumerator ReturnToInitialPosition()
    {
        // 先回到初始Y位置
        Vector3 targetPos = transform.position;
        targetPos.y = initialPosition.y;
        yield return MoveToPosition(targetPos);
        
        // 再回到初始X位置
        targetPos.x = initialPosition.x;
        yield return MoveToPosition(targetPos);
    }
}