//////////////////////////////////////////////////////////////////////////
// Mapper067  SunSoft Mapper 3                                          //
//////////////////////////////////////////////////////////////////////////
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 Mapper067 : Mapper
	{
		BYTE irq_enable;
		BYTE irq_occur;
		BYTE irq_toggle;
		INT irq_counter;
		public Mapper067(NES parent) : base(parent)
		{
		}

		public override void Reset()

		{
			irq_enable = 0;
			irq_toggle = 0;
			irq_counter = 0;
			irq_occur = 0;

			SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);

			SetVROM_4K_Bank(0, 0);
			SetVROM_4K_Bank(4, VROM_4K_SIZE - 1);

			uint crc = nes.rom.GetPROM_CRC();

			if (crc == 0x7f2a04bf)
			{   // For Fantasy Zone 2(J)
				nes.SetRenderMethod(EnumRenderMethod.PRE_ALL_RENDER);
			}
		}

		//void Mapper067::Write(WORD addr, BYTE data)
		public override void Write(ushort addr, byte data)
		{
			switch (addr & 0xF800)
			{
				case 0x8800:
					SetVROM_2K_Bank(0, data);
					break;
				case 0x9800:
					SetVROM_2K_Bank(2, data);
					break;
				case 0xA800:
					SetVROM_2K_Bank(4, data);
					break;
				case 0xB800:
					SetVROM_2K_Bank(6, data);
					break;

				case 0xC800:
					if (irq_toggle == 0)
					{
						irq_counter = (irq_counter & 0x00FF) | ((INT)data << 8);
					}
					else
					{
						irq_counter = (irq_counter & 0xFF00) | ((INT)data & 0xFF);
					}
					irq_toggle ^= 1;
					irq_occur = 0;
					nes.cpu.ClrIRQ(IRQ_MAPPER);
					break;
				case 0xD800:
					irq_enable = (byte)(data & 0x10);
					irq_toggle = 0;
					irq_occur = 0;
					nes.cpu.ClrIRQ(IRQ_MAPPER);
					break;

				case 0xE800:
					data &= 0x03;
					if (data == 0) SetVRAM_Mirror(VRAM_VMIRROR);
					else if (data == 1) SetVRAM_Mirror(VRAM_HMIRROR);
					else if (data == 2) SetVRAM_Mirror(VRAM_MIRROR4L);
					else SetVRAM_Mirror(VRAM_MIRROR4H);
					break;

				case 0xF800:
					SetPROM_16K_Bank(4, data);
					break;
			}
		}

		//void Mapper067::Clock(INT cycles)
		public override void Clock(int cycles)
		{
			if (irq_enable != 0)
			{
				if ((irq_counter -= cycles) <= 0)
				{
					irq_enable = 0;
					irq_occur = 0xFF;
					irq_counter = 0xFFFF;
					nes.cpu.SetIRQ(IRQ_MAPPER);
				}
			}

			//	if( irq_occur ) {
			//		nes.cpu.IRQ_NotPending();
			//	}
		}

		//void Mapper067::SaveState(LPBYTE p)
		public override void SaveState(byte[] p)
		{
			//p[0] = irq_enable;
			//p[1] = irq_occur;
			//p[2] = irq_toggle;
			//*((INT*)&p[3]) = irq_counter;
		}

		//void Mapper067::LoadState(LPBYTE p)
		public override void LoadState(byte[] p)
		{
			//irq_enable = p[0];
			//irq_occur = p[1];
			//irq_toggle = p[2];
			//irq_counter = *((INT*)&p[3]);
		}


		public override bool IsStateSave()
		{
			return true;
		}

	}
}