using System;
using UnityEngine;

namespace LightGlue.Unity.Config
{
    /// <summary>
    /// 统一管理「参考图像 resize（w,h）」的唯一来源：
    /// - C# 映射：referenceImageWidth/referenceImageHeight
    /// - Unity GameView 截图：referenceCaptureWidth/referenceCaptureHeight
    /// - Python 启动参数：--resize {w} {h}（由 NetworkConfig 占位符替换）
    /// </summary>
    public static class ReferenceImageResizeService
    {
        private const int MinSize = 1;
        private const int MaxSize = 8192;

        private static bool _initialized;
        private static int _width = 320;
        private static int _height = 240;

        public static int Width
        {
            get { EnsureInitialized(); return _width; }
        }

        public static int Height
        {
            get { EnsureInitialized(); return _height; }
        }

        public static event Action<int, int> OnResizeChanged;

        /// <summary>
        /// 确保从 NetworkConfig 初始化一次。
        /// </summary>
        public static void EnsureInitialized()
        {
            if (_initialized) return;
            _initialized = true;

            try
            {
                var cfg = NetworkConfigManager.GetCachedConfig();
                if (cfg != null)
                {
                    int w = cfg.referenceResizeWidth;
                    int h = cfg.referenceResizeHeight;
                    if (IsValid(w, h))
                    {
                        _width = w;
                        _height = h;
                    }
                }
            }
            catch
            {
                // ignore：保持默认 320x240
            }
        }

        /// <summary>
        /// 设置 resize；可选写入 NetworkConfig 并持久化到 JSON。
        /// </summary>
        public static void Set(int width, int height, bool persistToNetworkConfig = true)
        {
            EnsureInitialized();

            width = Mathf.Clamp(width, MinSize, MaxSize);
            height = Mathf.Clamp(height, MinSize, MaxSize);

            if (_width == width && _height == height) return;

            _width = width;
            _height = height;

            if (persistToNetworkConfig)
            {
                try
                {
                    var cfg = NetworkConfigManager.LoadConfig();
                    if (cfg != null)
                    {
                        cfg.referenceResizeWidth = _width;
                        cfg.referenceResizeHeight = _height;
                        NetworkConfigManager.SaveConfig(cfg);
                    }
                }
                catch (Exception ex)
                {
                    Debug.LogWarning($"[Resize] 保存到 NetworkConfig 失败：{ex.Message}");
                }
            }

            try
            {
                OnResizeChanged?.Invoke(_width, _height);
            }
            catch (Exception ex)
            {
                Debug.LogWarning($"[Resize] OnResizeChanged 回调异常：{ex.Message}");
            }
        }

        public static bool IsValid(int width, int height)
        {
            return width >= MinSize && height >= MinSize && width <= MaxSize && height <= MaxSize;
        }
    }
}