using System.Reflection;
using System.Reflection.PortableExecutable;
using Core;
using System.Threading.Tasks;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace Desktop
{
    public partial class Form1 : Form
    {
        private SmsMachine _machine = null!;
        private DebuggerForm _debugger;
        private Bitmap _screenBitmap = new Bitmap(256, 192, PixelFormat.Format32bppArgb);


        public bool IsRunning { get; private set; } = false;

        public ushort? Breakpoint
        {
            get => _machine?.Breakpoint;
            set { if (_machine != null) _machine.Breakpoint = value; }
        }

        public Form1()
        {
            InitializeComponent();
            _machine = new SmsMachine();
        }

        private void DrawScreen()
        {
            // Rapidly copy our VDP FrameBuffer into the Windows Bitmap
            var data = _screenBitmap.LockBits(new Rectangle(0, 0, 256, 192), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
            Marshal.Copy(_machine.VideoProcessor.FrameBuffer, 0, data.Scan0, _machine.VideoProcessor.FrameBuffer.Length);
            _screenBitmap.UnlockBits(data);

            // Update the PictureBox
            pbScreen.Image = _screenBitmap;
        }

        public void StartEmulator()
        {
            if (IsRunning) return;
            IsRunning = true;

            // Fire off a background task so we don't freeze the Windows UI!
            Task.Run(() =>
            {
                while (IsRunning)
                {
                    _machine.RunFrame();

                    Invoke((System.Windows.Forms.MethodInvoker)delegate { DrawScreen(); });

                    // Safety catch: If we hit a breakpoint while running, stop the loop!
                    if (_machine.Breakpoint.HasValue && _machine.Cpu.PC == _machine.Breakpoint.Value)
                    {
                        IsRunning = false;

                        // Optional: Force the debugger UI to update immediately so you see it!
                        Invoke((System.Windows.Forms.MethodInvoker)delegate { _debugger?.uiUpdateTimer_Tick(null, EventArgs.Empty); });
                    }
                    else
                    {
                        // Only throttle the speed if we are actively running
                        Thread.Sleep(16);
                    }
                }
            });
        }

        public void StopEmulator()
        {
            IsRunning = false;
        }


        public void StepEmulator()
        {
            _machine.StepMachine();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // 1. Load a commercial Master System ROM!
            
                byte[] rom = File.ReadAllBytes(@"C:\Parsons\Local Code Projects\ParsonsMasterSystem2026\Desktop\ROMS\Golden Axe Warrior.sms");

                // 2. Jam it into the Sega Mapper
                _machine.LoadCartridge(rom);

            // 3. Open the Debugger to look around
            if (_debugger == null || _debugger.IsDisposed)
                {
                    _debugger = new DebuggerForm(_machine.Cpu, _machine.MemoryBus, this);
                    _debugger.Show();
                }
            
        }
    }
}