using Microsoft.AspNetCore.SignalR;
using Hi.Geom;
using Hi.Native;
using System.IO.Compression;
using Hi.Webapi.Services;

namespace Hi.Webapi.Hubs
{
	/// <summary>
	/// SignalR Hub for Rendering.
	/// </summary>
	public class RenderingHub : Hub
	{
		public RenderingService RenderingService { get; }
		public ILogger<RenderingHub> Logger { get; }
		Dictionary<string, Mat4d> SketchViewCache { get; } = [];

		public RenderingHub(RenderingService renderingService, ILogger<RenderingHub> logger)
		{
			RenderingService = renderingService;
			Logger = logger;
		}

		/// <summary>
		/// 客戶端連接時初始化渲染引擎
		/// </summary>
		public async Task InitializeCanvas(int width, int height)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"InitializeCanvas called - ConnectionId: {connectionId}, Width: {width}, Height: {height}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			Logger.LogInformation($"Engine created/retrieved - ConnectionId: {connectionId}");

			engine.Start(width, height);
			Logger.LogInformation($"Engine started with size {width}x{height} - ConnectionId: {connectionId}");

			// 捕獲必要的參數，避免閉包問題
			var logger = Logger;
			var frameCount = 0;
			var renderingService = RenderingService;

			// 設置渲染回調
			unsafe
			{
				engine.ImageRequestAfterBufferSwapped += (byte* bgra, int w, int h) =>
				{
					if (bgra == null)
						return;

					frameCount++;
					if (frameCount <= 5) // 只記錄前5幀
						logger.LogInformation($"Frame {frameCount} rendered - Size: {w}x{h}, ConnectionId: {connectionId}");

					if (w <= 0 || h <= 0)
					{
						logger.LogWarning($"Invalid image size: {w}x{h} - ConnectionId: {connectionId}");
						return;
					}

					try
					{
						int wh = w * h;
						byte[] rgba = new byte[wh * 4];
						for (int i = 0; i < wh; i++)
						{
							rgba[i * 4] = bgra[i * 4 + 2];
							rgba[i * 4 + 1] = bgra[i * 4 + 1];
							rgba[i * 4 + 2] = bgra[i * 4];
							rgba[i * 4 + 3] = bgra[i * 4 + 3];
						}

						if (frameCount <= 5)
							logger.LogInformation($"Frame {frameCount} sending - Size: {w}x{h}, Data: {rgba.Length} bytes");

						using MemoryStream dstMemoryStream = new MemoryStream();
						using GZipStream gZipStream = new GZipStream(dstMemoryStream, CompressionMode.Compress);
						using MemoryStream srcMemoryStream = new MemoryStream(rgba);
						srcMemoryStream.CopyTo(gZipStream);
						gZipStream.Close();
						byte[] compressedRgbaArray = dstMemoryStream.ToArray();

						if (compressedRgbaArray == null)
							return;

						var compressionRatio = (float)compressedRgbaArray.Length / rgba.Length * 100;

						if (frameCount <= 5)
							logger.LogInformation($"Compressed: {compressedRgbaArray.Length} bytes ({compressionRatio:F1}% of original)");

						// 使用 RenderingService 的線程安全方法發送數據
						_ = renderingService.SendImageToClient(
							connectionId,
							compressedRgbaArray,
							rgba.Length,
							w,
							h)
							.ContinueWith(t =>
							{
								if (t.IsFaulted)
								{
									logger.LogError($"Failed to send frame: {t.Exception?.GetBaseException().Message} - ConnectionId: {connectionId}");
								}
							});
					}
					catch (Exception ex)
					{
						logger.LogError(ex, $"渲染回調錯誤 - ConnectionId: {connectionId}");
					}
				};
			}

			// 設置初始視圖
			if (SketchViewCache.TryGetValue(connectionId, out var cachedView))
			{
				engine.SketchView = cachedView;
			}
			else
			{
				engine.SetViewToHomeView();
				SketchViewCache[connectionId] = engine.SketchView;
			}
			Logger.LogInformation($"View initialized - ConnectionId: {connectionId}");

			// 確保引擎可見並開始渲染
			engine.IsVisible = true;
			Logger.LogInformation($"Engine visibility set to true - ConnectionId: {connectionId}");

			await Clients.Caller.SendAsync("CanvasInitialized", connectionId);
			Logger.LogInformation($"Canvas initialized for session: {connectionId}");
		}

		/// <summary>
		/// 處理鼠標移動事件
		/// </summary>
		public Task HandleMouseMove(double x, double y, int buttonMask)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogDebug($"HandleMouseMove - ConnectionId: {connectionId}, X: {x}, Y: {y}, ButtonMask: {buttonMask}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			var p = new Vec2i((int)x, (int)y);

			// 移動鼠標
			engine.MouseMove(p.x, p.y);

			// 如果有按鈕按下，處理拖曳
			if (buttonMask > 0)
			{
				engine.MouseDragTransform(p.x, p.y,
					new mouse_button_table__transform_view_by_mouse_drag_t()
					{
						LEFT_BUTTON = 0,
						RIGHT_BUTTON = 2
					});
				SketchViewCache[connectionId] = engine.SketchView;
			}

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理鼠標按下事件
		/// </summary>
		public Task HandleMouseDown(double x, double y, int button)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleMouseDown - ConnectionId: {connectionId}, X: {x}, Y: {y}, Button: {button}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.MouseButtonDown(button);
			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理鼠標釋放事件
		/// </summary>
		public Task HandleMouseUp(double x, double y, int button)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleMouseUp - ConnectionId: {connectionId}, X: {x}, Y: {y}, Button: {button}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.MouseButtonUp(button);
			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理鼠標滾輪事件
		/// </summary>
		public Task HandleMouseWheel(double x, double y, double deltaX, double deltaY, string browserBrand = "chrome")
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleMouseWheel - ConnectionId: {connectionId}, X: {x}, Y: {y}, DeltaX: {deltaX}, DeltaY: {deltaY}, Browser: {browserBrand}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);

			// 根據瀏覽器類型獲取縮放比例
			double scale = GetWheelScaling(browserBrand);

			engine.MouseWheel((int)(deltaX * scale), -(int)(deltaY * scale));

			// 使用 MouseWheelTransform 進行視圖變換
			engine.MouseWheelTransform(
				(int)(deltaX * scale * 1000), -(int)(deltaY * scale * 1000), 0.1 / 1000);

			SketchViewCache[connectionId] = engine.SketchView;

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理窗口大小變化
		/// </summary>
		public Task HandleResize(int width, int height)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleResize - ConnectionId: {connectionId}, Width: {width}, Height: {height}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			//since the resize from js is floating value,
			//the resize event may raise with the same integer size.
			//the canvas will be blank after resize event.
			//ClearCache to trigger the rendering process.
			engine.ClearCache();
			engine.Resize(width, height);

			Logger.LogInformation($"Resize completed - ConnectionId: {connectionId}");
			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理可見性變化
		/// </summary>
		public Task HandleVisibilityChange(string visibilityState)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleVisibilityChange - ConnectionId: {connectionId}, State: {visibilityState}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.IsVisible = visibilityState == "visible";

			return Task.CompletedTask;
		}

		/// <summary>
		/// 設置視圖
		/// </summary>
		public Task SetView(string viewType)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"SetView called - ConnectionId: {connectionId}, ViewType: {viewType}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);

			switch (viewType.ToLower())
			{
				case "front":
					engine.SetViewToFrontView();
					break;
				case "back":
					engine.SetViewToFrontView();
					engine.TurnBackView();
					break;
				case "left":
					engine.SetViewToRightView();
					engine.TurnBackView();
					break;
				case "right":
					engine.SetViewToRightView();
					break;
				case "top":
					engine.SetViewToTopView();
					break;
				case "bottom":
					engine.SetViewToTopView();
					engine.TurnBackView();
					break;
				case "isometric":
					engine.SetViewToIsometricView();
					break;
				case "home":
					engine.SetViewToHomeView();
					break;
				default:
					Logger.LogWarning($"Unknown view type: {viewType} - ConnectionId: {connectionId}");
					break;
			}

			SketchViewCache[connectionId] = engine.SketchView;

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理鍵盤按下事件
		/// </summary>
		public Task HandleKeyDown(string key, string code, bool ctrlKey, bool shiftKey, bool altKey)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleKeyDown - ConnectionId: {connectionId}, Key: {key}, Code: {code}, Ctrl: {ctrlKey}, Shift: {shiftKey}, Alt: {altKey}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);

			// 使用 key 的 HashCode（與 Blazor 版本一致）
			long keyCode = key.ToLower().GetHashCode();
			engine.KeyDown(keyCode);

			// 使用 KeyDownTransform 進行視圖變換
			engine.KeyDownTransform(keyCode, new key_table__transform_view_by_key_pressing_t()
			{
				HOME = "home".ToLower().GetHashCode(),
				PAGE_UP = "pageup".ToLower().GetHashCode(),
				PAGE_DOWN = "pagedown".ToLower().GetHashCode(),
				F1 = "f1".ToLower().GetHashCode(),
				F2 = "f2".ToLower().GetHashCode(),
				F3 = "f3".ToLower().GetHashCode(),
				F4 = "f4".ToLower().GetHashCode(),
				SHIFT = "shift".ToLower().GetHashCode(),
				ARROW_LEFT = "arrowleft".ToLower().GetHashCode(),
				ARROW_RIGHT = "arrowright".ToLower().GetHashCode(),
				ARROW_DOWN = "arrowdown".ToLower().GetHashCode(),
				ARROW_UP = "arrowup".ToLower().GetHashCode()
			});

			SketchViewCache[connectionId] = engine.SketchView;

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理鍵盤釋放事件
		/// </summary>
		public Task HandleKeyUp(string key, string code, bool ctrlKey, bool shiftKey, bool altKey)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleKeyUp - ConnectionId: {connectionId}, Key: {key}, Code: {code}, Ctrl: {ctrlKey}, Shift: {shiftKey}, Alt: {altKey}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);

			long keyCode = key.ToLower().GetHashCode();
			engine.KeyUp(keyCode);

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理觸摸按下事件
		/// </summary>
		public Task HandleTouchDown(int pointerId, double x, double y)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleTouchDown - ConnectionId: {connectionId}, PointerId: {pointerId}, X: {x}, Y: {y}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.TouchDown(pointerId, (int)x, (int)y);

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理觸摸移動事件
		/// </summary>
		public Task HandleTouchMove(int pointerId, double x, double y)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogDebug($"HandleTouchMove - ConnectionId: {connectionId}, PointerId: {pointerId}, X: {x}, Y: {y}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.TouchMove(pointerId, (int)x, (int)y);

			return Task.CompletedTask;
		}

		/// <summary>
		/// 處理觸摸釋放事件
		/// </summary>
		public Task HandleTouchUp(int pointerId)
		{
			var connectionId = Context.ConnectionId;
			Logger.LogInformation($"HandleTouchUp - ConnectionId: {connectionId}, PointerId: {pointerId}");

			var engine = RenderingService.GetOrCreateEngine(connectionId);
			engine.TouchUp(pointerId);

			return Task.CompletedTask;
		}

		/// <summary>
		/// 獲取瀏覽器滾輪縮放比例
		/// </summary>
		private double GetWheelScaling(string browserBrand)
		{
			switch (browserBrand.ToLower())
			{
				case "firefox":
					return 1.0;
				case "chrome":
				case "edge":
				case "safari":
				default:
					return 0.01;
			}
		}

		/// <summary>
		/// 客戶端斷開連接時清理資源
		/// </summary>
		public override async Task OnDisconnectedAsync(Exception exception)
		{
			var connectionId = Context.ConnectionId;

			SketchViewCache.Remove(connectionId);

			RenderingService.RemoveEngine(connectionId);
			Logger.LogInformation($"Client disconnected: {connectionId}");
			await base.OnDisconnectedAsync(exception);
		}
	}
}