using UnityEngine;
using UnityEngine.UI;
using LightGlue.Unity.Game;
using LightGlue.Unity.Networking;
using LightGlue.Unity.Roma;
using LightGlue.Unity.Config;

namespace LightGlue.Unity.UI
{
    /// <summary>
    /// 简单的相机位置标记器
    /// - 直接将相机坐标映射到屏幕坐标
    /// - 只需要一个Image图标，用RectTransform设置位置
    /// - 不需要考虑图片大小，直接用坐标定位
    /// </summary>
    public class SimpleCameraPositionMarker : MonoBehaviour
    {
        [Header("结果来源")]
        [Tooltip("必须指定 LightGlueManager，由其统一分发算法结果。禁止直接从 Bridge 获取结果。")]
        public LightGlueManager manager;

        [Tooltip("Roma 场景可选：若没有 LightGlueManager，则使用 RomaManager 获取算法结果。")]
        public RomaManager romaManager;

        [Header("UI图标")]
        [Tooltip("要移动的Image图标（在Canvas下的任意Image组件）")]
        public Image markerImage;

        [Header("参考图像尺寸（用于坐标映射）")]
        [Tooltip("参考图像的宽度（像素）")]
        public int referenceImageWidth = 640;

        [Tooltip("参考图像的高度（像素）")]
        public int referenceImageHeight = 480;

        [Header("屏幕显示区域")]
        [Tooltip("目标显示区域的宽度（像素，通常等于Canvas宽度或屏幕宽度）")]
        public float screenWidth = 1920f;

        [Tooltip("目标显示区域的高度（像素，通常等于Canvas高度或屏幕高度）")]
        public float screenHeight = 1080f;

        [Tooltip("是否自动使用Canvas尺寸（如果为true，会自动获取Canvas尺寸）")]
        public bool autoUseCanvasSize = true;

        [Header("坐标偏移（用于微调位置）")]
        [Tooltip("是否自动计算偏移量（如果坐标映射有整体偏移，可以自动修正）")]
        public bool autoCalculateOffset = true;

        [Tooltip("X轴偏移（像素，如果autoCalculateOffset=false则使用此值）")]
        public float offsetX = 0f;

        [Tooltip("Y轴偏移（像素，如果autoCalculateOffset=false则使用此值）")]
        public float offsetY = 0f;

        [Header("平滑参数来源（唯一来源，无本地参数）")]
        [Tooltip("留空则使用 LightGlueCursorSettings.Instance；所有平滑参数均由此引用读取，UI 修改后即时生效")]
        public LightGlueCursorSettings cursorSettings;

        private RectTransform _markerRect;
        private Canvas _canvas;
        private Vector2 _currentScreenPos;
        private bool _hasCurrentScreenPos;
        private Vector2 _smoothStartPos;
        private Vector2 _smoothTargetPos;
        private float _smoothProgress;

        // 由 LightGlueManager 分发的最新结果缓存
        private LightGlueResult _latestResult;
        private bool _hasLatestResult;

        private LightGlueCursorSettings GetCursorSettings()
        {
            if (cursorSettings != null) return cursorSettings;
            return LightGlueCursorSettings.Instance;
        }

        private void OnEnable()
        {
            ReferenceImageResizeService.EnsureInitialized();
            SetReferenceImageSize(ReferenceImageResizeService.Width, ReferenceImageResizeService.Height);
            ReferenceImageResizeService.OnResizeChanged -= SetReferenceImageSize;
            ReferenceImageResizeService.OnResizeChanged += SetReferenceImageSize;
        }

        private void OnDisable()
        {
            ReferenceImageResizeService.OnResizeChanged -= SetReferenceImageSize;
        }

        private void Start()
        {
            if (cursorSettings == null)
                cursorSettings = LightGlueCursorSettings.Instance;

            if (GetCursorSettings() == null)
                Debug.LogWarning("[SimpleCameraPositionMarker] 未找到 LightGlueCursorSettings，标记器平滑参数将不可用，请确保 GameManager 已生成设置预制。");

            // 结果来源：强制通过全局 LightGlueManager 获取
            if (manager == null)
            {
                manager = LightGlueManager.Instance;
            }

            if (manager != null)
            {
                manager.OnResultUpdated += OnResultUpdated;
                if (manager.HasLatestResult)
                    OnResultUpdated(manager.LatestResult);
            }
            else
            {
                // Roma：统一通过 RomaManager 获取（RomaManager 内部会自动桥接 RomaHardwareToPythonBridge）
                if (romaManager == null)
                    romaManager = RomaManager.Instance;
                if (romaManager != null)
                {
                    romaManager.OnResultUpdated += OnResultUpdated;
                    if (romaManager.HasLatestResult)
                        OnResultUpdated(romaManager.LatestResult);
                }
                else
                {
                    Debug.LogError("[SimpleCameraPositionMarker] 未找到 LightGlueManager 或 RomaManager，无法获取算法结果。");
                }
            }

            // 获取Image的RectTransform
            if (markerImage != null)
            {
                _markerRect = markerImage.GetComponent<RectTransform>();
                if (_markerRect == null)
                {
                    Debug.LogError("[SimpleCameraPositionMarker] Image组件必须附加在带有RectTransform的GameObject上");
                }
                else
                {
                    // 确保anchor和pivot设置正确（左下角anchor，中心pivot）
                    _markerRect.anchorMin = new Vector2(0, 0);
                    _markerRect.anchorMax = new Vector2(0, 0);
                    _markerRect.pivot = new Vector2(0.5f, 0.5f); // 中心pivot，这样图标会以中心点定位

                    // 输出当前设置用于调试
                    Debug.Log($"[SimpleCameraPositionMarker] RectTransform设置: " +
                             $"anchor=({_markerRect.anchorMin.x},{_markerRect.anchorMin.y}), " +
                             $"pivot=({_markerRect.pivot.x},{_markerRect.pivot.y}), " +
                             $"当前位置=({_markerRect.anchoredPosition.x},{_markerRect.anchoredPosition.y})");
                }
            }
            else
            {
                Debug.LogWarning("[SimpleCameraPositionMarker] 请指定要移动的Image图标");
            }

            // 自动获取Canvas尺寸
            if (autoUseCanvasSize)
            {
                if (markerImage != null)
                {
                    _canvas = markerImage.canvas;
                    if (_canvas != null)
                    {
                        RectTransform canvasRect = _canvas.GetComponent<RectTransform>();
                        if (canvasRect != null)
                        {
                            screenWidth = canvasRect.rect.width;
                            screenHeight = canvasRect.rect.height;
                            Debug.Log($"[SimpleCameraPositionMarker] 自动获取Canvas尺寸: {screenWidth}x{screenHeight}");
                        }
                    }
                }

                // 如果还是没找到Canvas，使用屏幕尺寸
                if (screenWidth <= 0 || screenHeight <= 0)
                {
                    screenWidth = Screen.width;
                    screenHeight = Screen.height;
                    Debug.Log($"[SimpleCameraPositionMarker] 使用屏幕尺寸: {screenWidth}x{screenHeight}");
                }
            }

            // 自动计算偏移量（如果需要）
            if (autoCalculateOffset)
            {
                // 如果anchor设置为左下角(0,0)但实际需要中心点偏移，自动计算
                // 通常这种情况是因为Canvas坐标系原点在中心而不是左下角
                // 偏移量 = -中心点坐标
                offsetX = -screenWidth * 0.5f;
                offsetY = -screenHeight * 0.5f;
                Debug.Log($"[SimpleCameraPositionMarker] 自动计算偏移量: offsetX={offsetX:F1}, offsetY={offsetY:F1} (Canvas中心点偏移)");
            }
        }

        private void Update()
        {
            if (manager == null && romaManager == null)
                return;

            if (!_hasLatestResult || !_latestResult.IsValid)
                return;

            LightGlueCursorSettings settings = GetCursorSettings();
            if (settings == null)
                return;

            var result = _latestResult;
            Vector2 targetScreenPos = result.GetMappedPosition(
                referenceWidth: referenceImageWidth,
                referenceHeight: referenceImageHeight,
                targetWidth: screenWidth,
                targetHeight: screenHeight,
                type: LightGlueResult.MappedCoordinateType.UIAnchored,
                offset: new Vector2(offsetX, offsetY));

            bool useSmooth = settings.markerEnableSmoothFollow;
            float lerpSpeed = settings.markerPositionLerpSpeed;
            float jitter = settings.markerJitterThresholdPixels;
            AnimationCurve curve = settings.markerSmoothCurve;

            if (!useSmooth || !_hasCurrentScreenPos)
            {
                _currentScreenPos = targetScreenPos;
                _hasCurrentScreenPos = true;
                _smoothStartPos = targetScreenPos;
                _smoothTargetPos = targetScreenPos;
                _smoothProgress = 1f;
            }
            else
            {
                if (jitter > 0f && Vector2.Distance(_currentScreenPos, targetScreenPos) < jitter)
                    targetScreenPos = _currentScreenPos;

                _smoothTargetPos = targetScreenPos;
                if (_smoothProgress >= 1f)
                {
                    _smoothStartPos = _currentScreenPos;
                    _smoothProgress = 0f;
                }
                _smoothProgress += Time.deltaTime * lerpSpeed;
                _smoothProgress = Mathf.Clamp01(_smoothProgress);
                float t = (curve != null && curve.keys.Length > 0) ? curve.Evaluate(_smoothProgress) : _smoothProgress;
                t = Mathf.Clamp01(t);
                _currentScreenPos = Vector2.Lerp(_smoothStartPos, _smoothTargetPos, t);
            }

            if (_markerRect != null)
            {
                _markerRect.anchoredPosition = _currentScreenPos;
            }

            // 调试输出（每30帧输出一次，避免日志过多）
            //if (Time.frameCount % 30 == 0)
            //{
            //    Debug.Log($"[SimpleCameraPositionMarker] 坐标映射: " +
            //             $"参考图({result.CameraPosition.x:F1},{result.CameraPosition.y:F1}) -> " +
            //             $"屏幕({targetScreenPos.x:F1},{targetScreenPos.y:F1}), " +
            //             $"Canvas尺寸={screenWidth}x{screenHeight}, " +
            //             $"参考图尺寸={referenceImageWidth}x{referenceImageHeight}");
            //}

            // 显示图标
            if (markerImage != null && !markerImage.gameObject.activeSelf)
            {
                markerImage.gameObject.SetActive(true);
            }
        }

        /// <summary>
        /// 设置参考图像尺寸（供外部调用）
        /// </summary>
        public void SetReferenceImageSize(int width, int height)
        {
            referenceImageWidth = width;
            referenceImageHeight = height;
        }

        /// <summary>
        /// 设置屏幕显示区域尺寸（供外部调用）
        /// </summary>
        public void SetScreenSize(float width, float height)
        {
            screenWidth = width;
            screenHeight = height;
        }

        /// <summary>
        /// 设置坐标偏移（供外部调用）
        /// </summary>
        public void SetOffset(float x, float y)
        {
            offsetX = x;
            offsetY = y;
        }

        /// <summary>
        /// 由 LightGlueManager 触发的结果更新回调，仅做结果缓存，坐标计算在 Update 每帧执行。
        /// </summary>
        private void OnResultUpdated(LightGlueResult result)
        {
            _latestResult = result;
            _hasLatestResult = true;
        }

        private void OnDestroy()
        {
            if (manager != null)
            {
                manager.OnResultUpdated -= OnResultUpdated;
            }
            if (romaManager != null)
            {
                romaManager.OnResultUpdated -= OnResultUpdated;
            }
        }
    }
}