using UnityEngine;
using UnityEngine.EventSystems; 
public class ControlMove : MonoBehaviour
{
    private float moveSpeed = 50f;                // 右键平移速度

    [Header("滚轮缩放速度系数")]
    public float zoomSpeed = 10f;                 // 滚轮缩放速度

    [Header("相机与水库中心的最大距离")]
    public float maxDistance = 600f;              // 最大缩放距离

    [Header("相机的最大高度限制")]
    public float maxHeight = 220f;                // 最大高度限制

    [Header("右键平移速度衰减系数")]
    public float rightClickPanSpeed = 100f;       // 右键平移速度除数

    private Vector3 inScript;                     // 引用焦点脚本，提供 core

    [Header("左键拖拽旋转灵敏度系数")]
    public float rotationSensitivity = 0.2f;      // 左键拖拽旋转灵敏度

    private Camera cam;                           // 主相机引用
    private bool isRotating = false;              // 是否正在旋转标志
    private Vector2 lastMousePos;                 // 上次鼠标位置（用于旋转计算）

    [Header("初始距离中心")]
    public Vector3 reservoirCenter;               // 水库中心坐标

    [Header("初始旋转中心")]
    public Vector3 startinScript;                 // 初始焦点位置

    private Rigidbody rb;                         // 刚体组件（如需要物理模拟）
    private bool isCameraCtrl = true;             // 相机是否可控制

    //相机操作有效性判断
    private bool isClickUI = false;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
        cam = Camera.main;
        if (inScript == Vector3.zero)
        {
            GetInScriptCore();
        }
    }

    void Update()
    {
        if (isCameraCtrl)
        {
            //操作有效性判断
            if (EventSystem.current != null)
            {
                if (Input.GetMouseButtonDown(0) || Input.GetMouseButtonDown(1) || Input.GetMouseButtonDown(2))
                {
                    isClickUI = EventSystem.current.IsPointerOverGameObject();
                }
                if (Input.GetMouseButtonUp(0) || Input.GetMouseButtonUp(1) || Input.GetMouseButtonUp(2))
                {
                    isClickUI = false;
                }
            }

            if (!isClickUI)
            {
                Vector3 core = inScript;
                // —— 右键平移 ——  
                if (Input.GetMouseButton(1))
                {
                    moveSpeed = Vector3.Distance(core, transform.position) / 2f;
                    float mx = Input.GetAxis("Mouse X");
                    float my = Input.GetAxis("Mouse Y");

                    // Vector3 desiredPosition = transform.position + (-transform.right * mx + -transform.up * my) * moveSpeed * Time.deltaTime;
                    Vector3 desiredPosition = transform.position + (-transform.right * mx + -transform.up * my) * moveSpeed / rightClickPanSpeed;

                    // 判断是否与障碍物发生碰撞
                    if (!WillCollideWithObstacle(desiredPosition))
                    {
                        //    transform.position = Vector3.Lerp(transform.position, desiredPosition, moveSpeed * Time.deltaTime);
                        transform.position = desiredPosition;
                    }
                }

                // —— 滚轮缩放 ——  
                float scroll = Input.GetAxis("Mouse ScrollWheel");
                if (Mathf.Abs(scroll) > 0.001f)
                {
                    Vector3 desiredPosition = transform.position + transform.forward * scroll * zoomSpeed;

                    // 判断是否与障碍物发生碰撞
                    if (!WillCollideWithObstacle(desiredPosition))
                    {
                        transform.position = desiredPosition;
                    }
                }

                // —— 左键开始/结束旋转 ——  
                if (Input.GetMouseButtonDown(0))
                {
                    isRotating = true;
                    lastMousePos = Input.mousePosition;
                }
                if (Input.GetMouseButtonUp(0))
                {
                    isRotating = false;
                }

                // —— 左键拖拽：RotateAround 实现 + 俯仰限制 ——  
                if (isRotating && Input.GetMouseButton(0))
                {
                    Vector2 curr = Input.mousePosition;
                    Vector2 delta = (curr - lastMousePos) * rotationSensitivity;
                    lastMousePos = curr;

                    /*

                    */
                    // 1. 水平绕世界 Y 轴旋转
                    //Vector3 desiredPosition = transform.position;
                    //transform.RotateAround(core, Vector3.up, delta.x);

                    Vector3 localPosHorizonal = transform.position - core;
                    Quaternion rotationHorizonal = Quaternion.AngleAxis(delta.x, Vector3.up);
                    Vector3 newLocalPosHorizonal = rotationHorizonal * localPosHorizonal;
                    Vector3 newPosHorizonal = core + newLocalPosHorizonal;


                    // 检查旋转后是否发生碰撞
                    if (!WillCollideWithObstacle(newPosHorizonal))
                    {
                        // 如果没有碰撞，执行旋转
                        transform.RotateAround(core, Vector3.up, delta.x);
                    }
                    else
                    {
                        // 如果碰撞了，撤销旋转，恢复到原来的位置

                    }

                    // 2. 俯仰旋转
                    Vector3 dir = (transform.position - core).normalized;
                    Vector3 flat = new Vector3(dir.x, 0f, dir.z).normalized;
                    float selfFlatX = transform.forward.x;
                    float selfFlatZ = transform.forward.z;
                    Vector3 selfFlat = new Vector3(selfFlatX, 0f, selfFlatZ).normalized;
                    float selfPitch = Vector3.SignedAngle(selfFlat, transform.forward, transform.right);



                    if (selfPitch <= 80f && selfPitch >= 0f)
                    {

                        float pitchDelta = delta.y * -1f;

                        Vector3 localPosVertical = transform.position - core;
                        Quaternion rotationVertical = Quaternion.AngleAxis(pitchDelta, transform.right);
                        Vector3 newPosVertical = core + rotationVertical * localPosVertical;


                        if (!WillCollideWithObstacle(newPosVertical))
                        {
                            transform.RotateAround(core, transform.right, pitchDelta);
                        }

                    }
                    else if (selfPitch > 80f)
                    {
                        float pitchDelta = delta.y * -1f;
                        if (pitchDelta < 0f)
                        {
                            transform.RotateAround(core, transform.right, pitchDelta);
                        }
                    }
                    else if (selfPitch < 0f)
                    {
                        float pitchDelta = delta.y * -1f;
                        if (pitchDelta > 0f)
                        {
                            transform.RotateAround(core, transform.right, pitchDelta);
                        }
                    }
                }
            }
        }
    }

    // 碰撞检测方法
    bool WillCollideWithObstacle(Vector3 targetPosition)
    {
        // 计算从当前位置到目标位置的方向和距离
        Vector3 moveDir = targetPosition - transform.position;
        float moveDist = moveDir.magnitude;

        // 使用 SphereCast 检查即将到达的位置是否会与障碍物发生碰撞
        RaycastHit hit;
        if (Physics.SphereCast(transform.position, 0.5f, moveDir.normalized, out hit, moveDist, LayerMask.GetMask("Default"), QueryTriggerInteraction.Collide))
        {
            // 如果检测到碰撞，返回 true
            // Debug.Log("collider");
            return true;
        }
        else if (Vector3.Distance(targetPosition, reservoirCenter) < maxDistance && targetPosition.y < maxHeight)
        {
            // 如果在范围内，返回 false
            return false;
        }
        else
            // Debug.Log("outRange");
            return true;

    }

    public void GetInScriptCore()
    {
        inScript = startinScript;
    }
    public void GetInScriptCore(Vector3 position)
    {
        inScript = position;
    }

    public void StartCameraControl()
    {
        isCameraCtrl = true;
        isClickUI = false;
    }

    //停止相机控制
    public void StopCameraControl()
    {
        isCameraCtrl = false;
    }
}