using System.Drawing;
using OpenTK.Mathematics;
using OpenTK.Platform;
using TK = OpenTK.Platform.Toolkit;

namespace Dashboard.OpenTK.PAL2
{
    public class PhysicalWindow : IPhysicalWindow
    {
        public WindowHandle WindowHandle { get; }
        public IDeviceContext DeviceContext { get; }
        public bool DoubleBuffered => true; // Always true for OpenTK windows.

        public string Title
        {
            get => TK.Window.GetTitle(WindowHandle);
            set => TK.Window.SetTitle(WindowHandle, value);
        }

        public SizeF OuterSize
        {
            get
            {
                TK.Window.GetSize(WindowHandle, out Vector2i size);
                return new SizeF(size.X, size.Y);
            }
            set => TK.Window.SetSize(WindowHandle, new Vector2i((int)value.Width, (int)value.Height));
        }

        public SizeF ClientSize
        {
            get
            {
                TK.Window.GetClientSize(WindowHandle, out Vector2i size);
                return new SizeF(size.X, size.Y);
            }
            set => TK.Window.SetClientSize(WindowHandle, new Vector2i((int)value.Width, (int)value.Height));
        }

        public PhysicalWindow(WindowHandle window, IDeviceContext dc)
        {
            WindowHandle = window;
            DeviceContext = dc;
        }

        public PhysicalWindow(WindowHandle window, OpenGLContextHandle context, ISwapGroup? swapGroup = null)
        {
            WindowHandle = window;
            DeviceContext = new OpenGLDeviceContext(window, context, swapGroup);
        }

        public PhysicalWindow(GraphicsApiHints hints)
        {
            WindowHandle = TK.Window.Create(hints);
            DeviceContext = CreateDeviceContext(WindowHandle, hints);
        }

        private static IDeviceContext CreateDeviceContext(WindowHandle window, GraphicsApiHints hints)
        {
            switch (hints.Api)
            {
            case GraphicsApi.OpenGL:
            case GraphicsApi.OpenGLES:
                OpenGLContextHandle context = TK.OpenGL.CreateFromWindow(window);
                return new OpenGLDeviceContext(window, context);
            default:
                throw new Exception($"Unknown graphics API {hints.Api}.");
            }
        }

        private bool _isDisposed = false;
        public void Dispose()
        {
            if (_isDisposed) return;
            _isDisposed = true;

            (DeviceContext as IDisposable)?.Dispose();
            TK.Window.Destroy(WindowHandle);
        }
    }
}