using System;

using OpenTK;
using OpenTK.Platform.Android;

using Android.Views;
using Android.Content;
using Android.Util;
using Android.Runtime;
using Noesis;
using System.IO;

namespace App1
{
    public class AndroidXamlProvider : XamlProvider
    {
        public override Stream LoadXaml(string filename)
        {
            var memory = new MemoryStream();
            using (var res = Android.App.Application.Context.Assets.Open(filename))
            {
                res.CopyTo(memory);
                memory.Position = 0;
            }
            return memory;
        }
    }

    public class AndroidFontProvider : FontProvider
    {
        public override void ScanFolder(string folder)
        {
            var strs = Android.App.Application.Context.Assets.List(folder);
            foreach(string s in strs)
            {
                RegisterFont(folder, s);
            }
        }

        public override Stream OpenFont(string folder, string id)
        {
            var memory = new MemoryStream();
            using (var res = Android.App.Application.Context.Assets.Open(folder + "/" + id))
            {
                res.CopyTo(memory); // ReadByte(); //Read(buf, 0, (int)res.Length);
                memory.Position = 0;
            }
            return memory;
        }
    }


    class GLView1 : AndroidGameView
    {
        static Noesis.View _view = null;
        static Noesis.Renderer _renderer = null;
        static bool _eventsAttached = false;
        bool inited = false;
        public GLView1(Context context) : base(context)
        {

            AutoSetContextOnRenderFrame = true;


            RenderOnUIThread = true;
        }


        protected override void OnLoad(System.EventArgs e)
        {
            base.OnLoad(e);


            Run();
        }

        public override bool OnTouchEvent(MotionEvent e)
        {
            base.OnTouchEvent(e);

            var e_x = (int)e.GetX();
            var e_y = (int)e.GetY();

            //this doesn't really work, but sometimes it does

            if (e.Action == MotionEventActions.Down)
                _view.TouchDown(e_x, e_y, 0); //I don't know what touch id is, sorry
            if (e.Action == MotionEventActions.Move)
                _view.TouchMove(e_x, e_y, 0);
            if (e.Action == MotionEventActions.Up)
                _view.TouchUp(e_x, e_y, 0);


            return true;
        }

        protected override void CreateFrameBuffer()
        {
            ContextRenderingApi = OpenTK.Graphics.GLVersion.ES2;

            // the default GraphicsMode that is set consists of (16, 16, 0, 0, 2, false)
            try
            {
                Android.Util.Log.Verbose("GLCube", "Loading with default settings");


                base.CreateFrameBuffer();
                return;
            }
            catch (Exception ex)
            {
                Android.Util.Log.Verbose("GLCube", $"{ex}");
            }


            try
            {
                Android.Util.Log.Verbose("GLCube", "Loading with custom Android settings (low mode)");
                GraphicsMode = new AndroidGraphicsMode(0, 0, 0, 0, 0, false);


                base.CreateFrameBuffer();
                return;
            }
            catch (Exception ex)
            {
                Android.Util.Log.Verbose("GLCube", $"{ex}");
            }
            throw new Exception("Can't load egl, aborting");
        }


        DateTime start = DateTime.Now;
        protected override void OnRenderFrame(FrameEventArgs e)
        {
            base.OnRenderFrame(e);

            if(!inited)
            {
                Noesis.GUI.Init();
                Noesis.GUI.SetResourceProvider(new Provider() { XamlProvider = new AndroidXamlProvider(), FontProvider = new AndroidFontProvider() });

                // Global theme
                {
                    var theme = (Noesis.ResourceDictionary)Noesis.GUI.LoadXaml("NoesisStyle.xaml");
                    Noesis.GUI.SetTheme(theme);
                }

                // Data loading
                {
                    var content = (Noesis.Grid)Noesis.GUI.LoadXaml("TextBox.xaml");
                    _view = Noesis.GUI.CreateView(content);

                    IWindowManager windowManager = Context.GetSystemService(Context.WindowService).JavaCast<IWindowManager>();
                    var device = windowManager.DefaultDisplay;
                    Android.Graphics.Point size = new Android.Graphics.Point();
                    device.GetSize(size);
                    _view.SetSize(size.X, size.Y);

                    _renderer = _view.Renderer;
                    _renderer.InitGL(new Noesis.VGOptions() { });
                }
                inited = true;
            }
            _view.Update((DateTime.Now - start).TotalSeconds);

            _renderer.UpdateRenderTree();

            if (_renderer.NeedsOffscreen())
            {
                _renderer.RenderOffscreen();
            }

            _renderer.Render();

            SwapBuffers();
        }

    }
}