//////////////////////////////////////////////////////////////////////////
// Mapper091  PC-HK-SF3                                                 //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using static VirtualNes.Core.CPU;
using INT = System.Int32;
using BYTE = System.Byte;
using System;
//using Codice.CM.Client.Differences;

namespace VirtualNes.Core
{
	public class Mapper091 : Mapper
	{
		BYTE irq_enable;
		BYTE irq_counter;
		public Mapper091(NES parent) : base(parent)
		{
		}

		public override void Reset()
		{
			SetPROM_32K_Bank(PROM_8K_SIZE - 2, PROM_8K_SIZE - 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);

			if (VROM_8K_SIZE != 0)
			{
				SetVROM_8K_Bank(0, 0, 0, 0, 0, 0, 0, 0);
			}

			irq_enable = 0;
			irq_counter = 0;

			nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
		}

		//void Mapper091::WriteLow(WORD addr, BYTE data)
		public override void WriteLow(ushort addr, byte data)
		{
			//DEBUGOUT( "$%04X:$%02X(%3d) L=%3d\n", addr, data, data, nes.GetScanline() );
			switch (addr & 0xF003)
			{
				case 0x6000:
				case 0x6001:
				case 0x6002:
				case 0x6003:
					SetVROM_2K_Bank((byte)((addr & 0x03) * 2), data);
					break;

				case 0x7000:
					SetPROM_8K_Bank(4, data);
					break;
				case 0x7001:
					SetPROM_8K_Bank(5, data);
					break;

				case 0x7002:
					irq_enable = 0;
					irq_counter = 0;
					nes.cpu.ClrIRQ(IRQ_MAPPER);
					break;
				case 0x7003:
					irq_enable = 1;
					break;
			}
		}

		//void Mapper091::HSync(INT scanline)
		public override void HSync(int scanline)
		{
			if ((scanline >= 0 && scanline < 240) && nes.ppu.IsDispON())
			{
				if (irq_enable != 0)
				{
					irq_counter++;
				}
				if (irq_counter >= 8)
				{
					//			nes.cpu.IRQ_NotPending();
					nes.cpu.SetIRQ(IRQ_MAPPER);
				}
			}
		}

		//void Mapper091::SaveState(LPBYTE p)
		public override void SaveState(byte[] p)
		{
			p[0] = irq_enable;
			p[1] = irq_counter;
		}

		//void Mapper091::LoadState(LPBYTE p)
		public override void LoadState(byte[] p)
		{
			irq_enable = p[0];
			irq_counter = p[1];
		}


		public override bool IsStateSave()
		{
			return true;
		}
	}
}