using System;
using BizHawk.Emulation.Common;

namespace BizHawk.Emulation.Cores.Nintendo.SubNESHawk
{
	public partial class SubNESHawk : IEmulator
	{
		public IEmulatorServiceProvider ServiceProvider { get; }

		public ControllerDefinition ControllerDefinition => _nesCore.ControllerDefinition;

		public bool FrameAdvance(IController controller, bool render, bool renderSound)
		{
			//Console.WriteLine("-----------------------FRAME-----------------------");
			if (_tracer.Enabled)
			{
				_nesCore.cpu.TraceCallback = s => _tracer.Put(s);
			}
			else
			{
				_nesCore.cpu.TraceCallback = null;
			}

			_frame++;

			if (controller.IsPressed("Power"))
			{
				HardReset();
			}

			reset_frame = false;
			if (controller.IsPressed("Reset"))
			{
				reset_frame = true;
			}

			reset_cycle = controller.AxisValue("Reset Cycle");
			reset_cycle_int = (int)Math.Floor(reset_cycle);

			_isLag = true;
			_nesCore.alt_lag = true;

			InputCallbacks.Call();

			DoFrame(controller);

			bool ret = pass_a_frame;

			if (pass_a_frame)
			{
				_nesCore.videoProvider.FillFrameBuffer();
				current_cycle = 0;
				_nesCore.cpu.ext_ppu_cycle = current_cycle;
			}
			
			_isLag = _nesCore.alt_lag;

			if (_isLag)
			{
				_lagCount++;
				VBL_CNT++;
			}

			reset_frame = false;
			return ret;
		}

		private bool stop_cur_frame;
		private bool pass_new_input;
		private bool pass_a_frame;
		private bool reset_frame;
		private int current_cycle;
		private float reset_cycle;
		private int reset_cycle_int;

		private void DoFrame(IController controller)
		{
			stop_cur_frame = false;
			while (!stop_cur_frame)
			{
				if (reset_frame && (current_cycle == reset_cycle_int))
				{
					SoftReset();
					reset_frame = false;
				}
				_nesCore.do_single_step(controller, out pass_new_input, out pass_a_frame);
				current_cycle++;
				_nesCore.cpu.ext_ppu_cycle = current_cycle;
				stop_cur_frame |= pass_a_frame;
				stop_cur_frame |= pass_new_input;
			}
		}

		public int Frame => _frame;

		public string SystemId => "NES";

		public bool DeterministicEmulation => _nesCore.DeterministicEmulation;

		public void ResetCounters()
		{
			_frame = 0;
			_lagCount = 0;
			_isLag = false;
		}

		public void Dispose() => _nesCore.Dispose();
	}
}