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

namespace SK.Framework
{
    /// <summary>
    /// 自由相机控制器
    /// WASD 移动，鼠标旋转，Q/E 上升下降，Shift 加速
    /// </summary>
    [DisallowMultipleComponent]
    public class FreeCameraController : MonoBehaviour
    {
        #region Inspector 参数

        [Header("控制总开关")]
        [Tooltip("是否启用相机控制")]
        public bool enableControl = true;

        [Tooltip("按住该鼠标键时才能旋转视角（0=左键，1=右键）")]
        public int lookMouseButton = 1;

        [Tooltip("旋转时是否锁定鼠标")]
        public bool lockCursor = true;

        [Header("移动参数（WASD）")]
        public float moveSpeed = 5f;
        public float moveDamping = 10f;

        [Header("Shift 加速")]
        [Tooltip("按住 Shift 时速度倍率")]
        public float shiftMultiplier = 2f;

        [Header("垂直移动（Q / E）")]
        [Tooltip("是否允许 Q/E 垂直移动")]
        public bool enableVerticalMove = true;

        public float verticalSpeed = 3f;
        public float minHeight = -10f;
        public float maxHeight = 50f;

        [Header("视角旋转")]
        public float mouseSensitivityX = 120f;
        public float mouseSensitivityY = 80f;

        [Tooltip("俯仰角最小值")]
        public float minPitch = -80f;

        [Tooltip("俯仰角最大值")]
        public float maxPitch = 80f;

        public float rotationDamping = 12f;

        #endregion

        #region 运行时状态

        // 目标旋转角
        private float yaw;
        private float pitch;

        // 平滑旋转角
        private float smoothYaw;
        private float smoothPitch;

        // 目标移动速度
        private Vector3 targetVelocity;
        private Vector3 smoothVelocity;

        #endregion

        #region Unity 生命周期

        void Start()
        {
            // 初始化角度
            Vector3 angles = transform.eulerAngles;
            yaw = angles.y;
            pitch = angles.x;

            smoothYaw = yaw;
            smoothPitch = pitch;
        }

        void Update()
        {
            if (!enableControl)
                return;

            HandleRotation();
            HandleMovement();
        }

        #endregion

        #region 视角旋转

        /// <summary>
        /// 鼠标控制相机旋转
        /// </summary>
        void HandleRotation()
        {
            if (!Input.GetMouseButton(lookMouseButton))
            {
                // 松开鼠标时恢复光标
                Cursor.lockState = CursorLockMode.None;
                Cursor.visible = true;
                return;
            }

            if (lockCursor)
            {
                Cursor.lockState = CursorLockMode.Locked;
                Cursor.visible = false;
            }

            yaw += Input.GetAxis("Mouse X") * mouseSensitivityX * Time.deltaTime;
            pitch -= Input.GetAxis("Mouse Y") * mouseSensitivityY * Time.deltaTime;
            pitch = Mathf.Clamp(pitch, minPitch, maxPitch);

            // 阻尼平滑
            smoothYaw = Mathf.LerpAngle(smoothYaw, yaw, Time.deltaTime * rotationDamping);
            smoothPitch = Mathf.Lerp(smoothPitch, pitch, Time.deltaTime * rotationDamping);

            transform.rotation = Quaternion.Euler(smoothPitch, smoothYaw, 0f);
        }

        #endregion

        #region 移动控制

        /// <summary>
        /// WASD + Q/E + Shift 移动
        /// </summary>
        void HandleMovement()
        {
            Vector3 inputDir = Vector3.zero;

            // WASD 平移
            float h = Input.GetAxis("Horizontal");
            float v = Input.GetAxis("Vertical");   
            inputDir += transform.forward * v;
            inputDir += transform.right * h;

            // Q / E 垂直移动（可开关）
            if (enableVerticalMove)
            {
                if (Input.GetKey(KeyCode.E))
                    inputDir += Vector3.up;

                if (Input.GetKey(KeyCode.Q))
                    inputDir += Vector3.down;
            }

            inputDir = inputDir.normalized;

            // 基础速度
            float currentSpeed = moveSpeed;

            // Shift 加速
            if (Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift))
            {
                currentSpeed *= shiftMultiplier;
            }

            // 目标速度
            targetVelocity = inputDir * currentSpeed;

            // 阻尼平滑
            smoothVelocity = Vector3.Lerp(
                smoothVelocity,
                targetVelocity,
                Time.deltaTime * moveDamping
            );

            Vector3 nextPos = transform.position + smoothVelocity * Time.deltaTime;

            // 高度限制
            nextPos.y = Mathf.Clamp(nextPos.y, minHeight, maxHeight);

            transform.position = nextPos;
        }

        #endregion
    }
}