using UnityEngine;

namespace LightGlue.Unity.Game
{
    /// <summary>
    /// 全局光标/跟随平滑设置（可挂在全局预制上，与 LightGlueManager 同节点或独立）。
    /// - 供 SimpleCameraPositionMarker、LightGlueCameraAimController 等读取，统一调节平滑参数。
    /// - 支持本地持久化（PlayerPrefs），启动时自动加载，修改后需调用 SaveToLocal() 保存。
    /// </summary>
    public class LightGlueCursorSettings : MonoBehaviour
    {
        public static LightGlueCursorSettings Instance { get; private set; }

        private const string KeyPrefix = "LightGlueCursor_";
        private const string KeyMarkerSmooth = KeyPrefix + "MarkerSmooth";
        private const string KeyMarkerLerp = KeyPrefix + "MarkerLerp";
        private const string KeyMarkerJitter = KeyPrefix + "MarkerJitter";
        private const string KeyCameraSmooth = KeyPrefix + "CameraSmooth";
        private const string KeyCameraLerp = KeyPrefix + "CameraLerp";
        private const string KeyCameraJitter = KeyPrefix + "CameraJitter";

        [Header("标记器跟随（SimpleCameraPositionMarker）")]
        [Tooltip("是否对 UI 标记位置做平滑插值")]
        public bool markerEnableSmoothFollow = true;

        [Tooltip("位置平滑插值速度，值越大响应越快")]
        public float markerPositionLerpSpeed = 100f;

        [Tooltip("抖动阈值（像素），小于该距离的位移将被忽略")]
        public float markerJitterThresholdPixels = 25f;

        [Tooltip("平滑曲线：横轴为进度 [0,1]，纵轴为插值系数。由快到慢用缓出")]
        public AnimationCurve markerSmoothCurve = new AnimationCurve(
            new Keyframe(0f, 0f, 0f, 2f),
            new Keyframe(1f, 1f, 2f, 0f));

        [Header("相机朝向跟随（LightGlueCameraAimController）")]
        [Tooltip("是否对 CameraToLook 的旋转做平滑插值")]
        public bool cameraAimEnableSmoothRotation = true;

        [Tooltip("旋转平滑插值速度，值越大响应越快")]
        public float cameraAimRotationLerpSpeed = 100f;

        [Tooltip("旋转抖动阈值（角度，度），小于该角度变化将被忽略")]
        public float cameraAimRotationJitterThresholdDeg = 0.5f;

        [Tooltip("旋转平滑曲线：横轴为进度 [0,1]，纵轴为插值系数")]
        public AnimationCurve cameraAimSmoothCurve = new AnimationCurve(
            new Keyframe(0f, 0f, 0f, 2f),
            new Keyframe(1f, 1f, 2f, 0f));

        /// <summary> 是否在 Awake 时从本地加载已保存的参数。 </summary>
        [Header("持久化")]
        [Tooltip("启动时是否从本地（PlayerPrefs）加载上次保存的参数")]
        public bool loadFromLocalOnAwake = true;

        [Header("显示控制")]
        [Tooltip("要控制显示/隐藏的 UI 根节点。不指定则使用本 GameObject")]
        public GameObject panelRoot;

        private void Awake()
        {
            if (Instance != null && Instance != this)
            {
                gameObject.SetActive(false);
                Destroy(gameObject);
                return;
            }
            Instance = this;

            if(panelRoot != null) panelRoot.SetActive(false);

            DontDestroyOnLoad(gameObject);

            if (loadFromLocalOnAwake)
                LoadFromLocal();
        }

        private void OnDestroy()
        {
            if (Instance == this)
                Instance = null;
        }

        /// <summary>
        /// 从本地（PlayerPrefs）加载已保存的参数；若无记录则保持当前 Inspector 默认值。
        /// </summary>
        public void LoadFromLocal()
        {
            if (PlayerPrefs.HasKey(KeyMarkerSmooth))
                markerEnableSmoothFollow = PlayerPrefs.GetInt(KeyMarkerSmooth) != 0;
            if (PlayerPrefs.HasKey(KeyMarkerLerp))
                markerPositionLerpSpeed = PlayerPrefs.GetFloat(KeyMarkerLerp);
            if (PlayerPrefs.HasKey(KeyMarkerJitter))
                markerJitterThresholdPixels = PlayerPrefs.GetFloat(KeyMarkerJitter);
            if (PlayerPrefs.HasKey(KeyCameraSmooth))
                cameraAimEnableSmoothRotation = PlayerPrefs.GetInt(KeyCameraSmooth) != 0;
            if (PlayerPrefs.HasKey(KeyCameraLerp))
                cameraAimRotationLerpSpeed = PlayerPrefs.GetFloat(KeyCameraLerp);
            if (PlayerPrefs.HasKey(KeyCameraJitter))
                cameraAimRotationJitterThresholdDeg = PlayerPrefs.GetFloat(KeyCameraJitter);
        }

        /// <summary>
        /// 将当前参数保存到本地（PlayerPrefs），下次启动将自动加载。
        /// </summary>
        public void SaveToLocal()
        {
            PlayerPrefs.SetInt(KeyMarkerSmooth, markerEnableSmoothFollow ? 1 : 0);
            PlayerPrefs.SetFloat(KeyMarkerLerp, markerPositionLerpSpeed);
            PlayerPrefs.SetFloat(KeyMarkerJitter, markerJitterThresholdPixels);
            PlayerPrefs.SetInt(KeyCameraSmooth, cameraAimEnableSmoothRotation ? 1 : 0);
            PlayerPrefs.SetFloat(KeyCameraLerp, cameraAimRotationLerpSpeed);
            PlayerPrefs.SetFloat(KeyCameraJitter, cameraAimRotationJitterThresholdDeg);
            PlayerPrefs.Save();
        }

        /// <summary>
        /// 恢复为代码默认值并保存到本地。
        /// </summary>
        public void ResetToDefaultAndSave()
        {
            markerEnableSmoothFollow = true;
            markerPositionLerpSpeed = 100f;
            markerJitterThresholdPixels = 25f;
            cameraAimEnableSmoothRotation = true;
            cameraAimRotationLerpSpeed = 100f;
            cameraAimRotationJitterThresholdDeg = 0.5f;
            SaveToLocal();
        }

        /// <summary> 获取实际控制显示隐藏的 GameObject（panelRoot 为空则为本物体）。 </summary>
        private GameObject GetPanelRoot()
        {
            return panelRoot != null ? panelRoot : gameObject;
        }

        /// <summary> 显示设置面板。 </summary>
        public void ShowPanel()
        {
            GetPanelRoot().SetActive(true);
        }

        /// <summary> 隐藏设置面板。 </summary>
        public void HidePanel()
        {
            GetPanelRoot().SetActive(false);
        }

        /// <summary> 切换设置面板显示状态。 </summary>
        public void TogglePanel()
        {
            GameObject root = GetPanelRoot();
            root.SetActive(!root.activeSelf);
        }

        /// <summary> 当前面板是否处于显示状态。 </summary>
        public bool IsPanelVisible()
        {
            return GetPanelRoot().activeSelf;
        }
    }
}