using System;
using UnityEngine;

namespace CharacterPreview
{
    public class ModelMove : MonoBehaviour
    {
        // 摄像机属性
        private Camera _camera;

        public Camera CurrentCamera
        {
            get
            {
                if (!_camera)
                {
                    _camera = Camera.main;
                    if (!_camera)
                    {
                        _camera = FindObjectOfType<Camera>();
                    }
                }

                return _camera;
            }
        }

        public Vector2 horizontalMoveRange = new Vector2(-1f, 2f); // X轴范围
        public Vector2 verticalMoveRange = new Vector2(-2f, 2f); // Y轴范围
        public Vector2 depthMoveRange = new Vector2(-1, 10f); // Z轴范围 (深度)

        public Vector2 scaleRange = new Vector2(0.5f, 3f); // 缩放范围 (x=min, y=max)

        // 初始状态变量
        private Vector3 _initialScale = Vector3.one;

        private Quaternion _initialRotation = Quaternion.identity;

        // 模型相对于摄像机的初始局部位置偏移量
        private Vector3 _initialCameraLocalOffset;

        // 用于Input输入的控制器对象
        private GameObject _controlModelMoveGameObject;

        public bool CanFix => ModBehaviour.config.data.canEdit;

        // 模型在摄像机局部空间中的默认位置偏移量 (用于Reset)
        public static readonly Vector3 DefaultCameraLocalOffset = new Vector3(0.38f, -0.92f, 2.00f);

        private void Awake()
        {
            EnsureControlModelMoveGameObject();
        }

        private void Start()
        {
            if (ModBehaviour.config.data.use)
            {
                ApplyConfig();
            }
            else
            {
                RefreshPosition();
            }
        }

        private void Update()
        {
            // // 调试功能，按下 "-" 打印模型相对于摄像机的局部位置
            // if (Input.GetKeyDown(KeyCode.Minus))
            // {
            //     if (CurrentCamera)
            //     {
            //         var localPositionRelativeToCamera =
            //             CurrentCamera.transform.InverseTransformPoint(transform.position);
            //         Debug.Log($"模型相对于摄像机的局部位置: {localPositionRelativeToCamera}");
            //     }
            //     else
            //     {
            //         Debug.LogWarning("找不到摄像机，无法计算局部位置。模型的全局位置为: " + transform.position);
            //     }
            // }
        }

        private void OnDestroy()
        {
            // 销毁时清理生成的控制器GameObject
            if (_controlModelMoveGameObject)
            {
                Destroy(_controlModelMoveGameObject);
                _controlModelMoveGameObject = null;
            }
        }

    
        /// <summary>
        /// 确保ControlModelMove GameObject存在并绑定脚本。
        /// </summary>
        private void EnsureControlModelMoveGameObject()
        {
            if (_controlModelMoveGameObject == null)
            {
                // 尝试查找场景中已有的ControlModelMove
                _controlModelMoveGameObject = GameObject.Find("ControlModelMove");
                if (_controlModelMoveGameObject == null)
                {
                    // 如果没有，则创建新的
                    _controlModelMoveGameObject = new GameObject("ControlModelMove");
                }

                // 确保ControlModelMove组件已添加
                if (_controlModelMoveGameObject.GetComponent<ControlModelMove>() == null)
                {
                    _controlModelMoveGameObject.AddComponent<ControlModelMove>();
                }
            }
        }

        /// <summary>
        /// 将模型朝向当前摄像机。
        /// </summary>
        public void LookAtCamera()
        {
            if(!CanFix)
                return;
            if (CurrentCamera)
            {
                transform.LookAt(CurrentCamera.transform);
            }
            else
            {
                Debug.LogWarning("ModelMove.LookAtCamera: 找不到摄像机，无法使模型朝向摄像机。");
            }
            SaveDataToConfig();
            
        }

        /// <summary>
        /// 重置模型的位置、旋转和缩放
        /// </summary>
        public void RefreshPosition()
        {
            if(!CanFix)
                return;
            // 重置缩放和旋转到初始状态
            transform.localScale = _initialScale;
            transform.rotation = _initialRotation;

            if (CurrentCamera)
            {
                // 计算模型在世界空间中相对于摄像机的默认位置
                var worldPos = CameraLocalToWorld(CurrentCamera, DefaultCameraLocalOffset);
                transform.position = worldPos;

                // 使模型朝向摄像机
                LookAtCamera();

                // 记录模型重置后的相对于摄像机的局部偏移量，作为后续移动的基准
                _initialCameraLocalOffset = CurrentCamera.transform.InverseTransformPoint(transform.position);
            }
            else
            {
                Debug.LogWarning("ModelMove.RefreshPosition: 找不到摄像机。模型将保持其当前世界位置，且相机相对移动功能将无法正常工作。");
                _initialCameraLocalOffset = transform.position;
                transform.position = new Vector3(8, 8, -16);
            }
            SaveDataToConfig();
            
        }

        /// <summary>
        /// 移动模型
        /// </summary>
        /// <param name="shift">相对于当前总偏移量的位移增量（在摄像机局部坐标系下）</param>
        public void Move(Vector3 shift)
        {
            if(!CanFix)
                return;
            if (!CurrentCamera)
            {
                Debug.LogWarning("ModelMove.Move: 找不到摄像机，无法执行相机相对移动。");
                return;
            }

   
            var currentLocalPos = CurrentCamera.transform.InverseTransformPoint(transform.position);
            var currentOffsetFromInitial = currentLocalPos - _initialCameraLocalOffset;
            var targetOffsetFromInitial = currentOffsetFromInitial + shift;
            targetOffsetFromInitial.x = Mathf.Clamp(targetOffsetFromInitial.x, horizontalMoveRange.x, horizontalMoveRange.y);
            targetOffsetFromInitial.y = Mathf.Clamp(targetOffsetFromInitial.y, verticalMoveRange.x, verticalMoveRange.y);
            targetOffsetFromInitial.z = Mathf.Clamp(targetOffsetFromInitial.z, depthMoveRange.x, depthMoveRange.y);
            
            var newLocalPos = _initialCameraLocalOffset + targetOffsetFromInitial;
            
            transform.position = CurrentCamera.transform.TransformPoint(newLocalPos);
            
            SaveDataToConfig();
        }


        /// <summary>
        /// 等比例缩放模型
        /// </summary>
        /// <param name="increment">缩放增量，通常来自鼠标滚轮或UI滑块</param>
        public void Scale(float increment)
        {
            if(!CanFix)
                return;
            // 假设是等比例缩放，所以只取x轴的值来计算
            var currentScale = transform.localScale.x;
            var newScale = currentScale + increment;

            // 将新的缩放值限制在预设范围内
            newScale = Mathf.Clamp(newScale, scaleRange.x, scaleRange.y);

            // 应用新的等比例缩放值
            SaveDataToConfig();
            transform.localScale = new Vector3(newScale, newScale, newScale);
        }

        /// <summary>
        /// 旋转模型
        /// </summary>
        /// <param name="rotationAmount">旋转量，通常来自鼠标拖拽的偏移量(delta)</param>
        public void Rotate(Vector2 rotationAmount)
        {
            if(!CanFix)
                return;
            // 左右拖拽（rotationAmount.x）时，围绕世界坐标的Y轴旋转，使模型保持直立
            transform.Rotate(Vector3.up, -rotationAmount.x * Time.deltaTime, Space.World);

            if (CurrentCamera)
            {
                // 上下拖拽（rotationAmount.y）时，围绕摄像机的右方向轴旋转，感觉更自然
                transform.Rotate(CurrentCamera.transform.right, rotationAmount.y * Time.deltaTime, Space.World);
            }
            else
            {
                // 如果找不到相机，则退而求其次，围绕世界坐标的X轴旋转
                Debug.LogWarning("ModelMove.Rotate: 找不到摄像机，上下旋转将使用世界X轴。");
                transform.Rotate(Vector3.right, rotationAmount.y * Time.deltaTime, Space.World);
            }
            SaveDataToConfig();
            
        }

        /// <summary>
        /// 沿摄像机的Z轴（朝向）旋转模型，实现“滚动”或“倾斜”效果。
        /// </summary>
        /// <param name="angle">要旋转的角度。正值通常为顺时针，负值为逆时针。</param>
        public void RotateAroundCameraZ(float angle)
        {
            if(!CanFix)
                return;
            if (CurrentCamera == null)
            {
                Debug.LogWarning("ModelMove.RotateAroundCameraZ: 无法执行围绕相机Z轴的旋转，因为找不到相机。");
                return;
            }

            var rotationAxis = CurrentCamera.transform.forward;
            transform.Rotate(rotationAxis, angle, Space.World);
            SaveDataToConfig();
        }

        public void SaveDataToConfig()
        {
            var configData = ModBehaviour.config.data;
            configData.modelPosition = CurrentCamera.transform.InverseTransformPoint(transform.position);
            configData.modelRotation = transform.eulerAngles;
            configData.modelScale = CurrentCamera.transform.localScale.x;
        }

        public void ApplyConfig()
        {
            var configData = ModBehaviour.config.data;
            transform.position = CameraLocalToWorld(CurrentCamera, configData.modelPosition);
            transform.eulerAngles = configData.modelRotation;
            transform.localScale = new Vector3(configData.modelScale, configData.modelScale, configData.modelScale);
        }

        /// <summary>
        /// 将摄像机局部空间中的点转换为世界空间中的点。
        /// </summary>
        /// <param name="camera">参考摄像机。</param>
        /// <param name="localPoint">摄像机局部空间中的点。</param>
        /// <returns>世界空间中的点。</returns>
        public static Vector3 CameraLocalToWorld(Camera camera, Vector3 localPoint)
        {
            if (camera == null)
                throw new ArgumentNullException(nameof(camera),
                    "Camera cannot be null for CameraLocalToWorld conversion.");

            var camTransform = camera.transform;
            return camTransform.position + camTransform.rotation * localPoint;
        }
    }
}