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

public class JoystickController : MonoBehaviour, IDragHandler, IEndDragHandler
{
    public bool isDrag = false;
    public RectTransform joystickBackground; // 摇杆背景
    public RectTransform joystick;           // 摇杆
    public Camera playerCamera;              // 摄像机
    public float rotationSpeed = 0.5f;         // 摄像机旋转速度

    // 旋转角度限制
    public float horizontalMinRotation = -75f;  // 水平旋转最小值
    public float horizontalMaxRotation = 75f;   // 水平旋转最大值
    public float verticalMinRotation = -75f;     // 垂直旋转最小值
    public float verticalMaxRotation = 75f;      // 垂直旋转最大值

    private Vector2 joystickInput = Vector2.zero;

    private float currentXRotation = 0f;     // 当前的水平旋转角度
    private float currentYRotation = 0f;     // 当前的垂直旋转角度

    private float targetXRotation = 0f;      // 目标水平旋转角度
    private float targetYRotation = 0f;      // 目标垂直旋转角度

    void Start()
    {
        // 初始化摇杆的位置
        joystick.anchoredPosition = Vector2.zero;

        // 初始化摄像机的旋转角度
        targetXRotation = playerCamera.transform.eulerAngles.y;
        targetYRotation = playerCamera.transform.eulerAngles.x;
    }

    // 每帧更新摇杆的输入
    void Update()
    {
        if (joystickInput.magnitude > 0)
        {
            // 根据摇杆的输入控制摄像机旋转
            targetXRotation += joystickInput.x * rotationSpeed * Time.deltaTime;
            targetYRotation -= joystickInput.y * rotationSpeed * Time.deltaTime;

            // 限制水平旋转范围，防止摄像机旋转过头
            targetXRotation = Mathf.Clamp(targetXRotation, horizontalMinRotation, horizontalMaxRotation);

            // 限制垂直旋转范围，防止摄像机翻转
            targetYRotation = Mathf.Clamp(targetYRotation, verticalMinRotation, verticalMaxRotation);

            // 使用 Quaternion 来平滑过渡到目标旋转角度
            playerCamera.transform.localRotation = Quaternion.Euler(targetYRotation, targetXRotation, 0f);
        }
    }

    // 摇杆拖动时更新摇杆位置和输入
    public void OnDrag(PointerEventData eventData)
    {
        Vector2 localPoint;

        // 将触摸位置从屏幕坐标转换为UI本地坐标
        RectTransformUtility.ScreenPointToLocalPointInRectangle(joystickBackground, eventData.position, eventData.pressEventCamera, out localPoint);

        // 计算摇杆的输入方向
        joystickInput = localPoint.normalized;

        // 限制摇杆的移动范围，确保它不会超出背景的边界
        if (localPoint.magnitude > joystickBackground.sizeDelta.x / 2)
        {
            joystickInput = localPoint.normalized * (joystickBackground.sizeDelta.x / 2);
        }

        // 更新摇杆的位置
        joystick.anchoredPosition = joystickInput;
    }

    // 摇杆松开时重置摇杆位置
    public void OnEndDrag(PointerEventData eventData)
    {
        isDrag = false;

        // 摇杆松开后重置位置
        joystick.anchoredPosition = Vector2.zero;
        joystickInput = Vector2.zero;
    }
}